Histological structure of skin

Histological structure of skin

EPIDERMIS

Epidermis is the outer layer of skin. It is formed by stratified epithelium. Important feature of epidermis is that, it does not have blood vessels. Nutrition is provided to the epidermis by the capillaries of dermis.

Layers of Epidermis

Epidermis is formed by five layers:

1. Stratum corneum 2. Stratum lucidum 3. Stratum granulosum 4. Stratum spinosum 5. Stratum germinativum.

1. STRATUM CORNEUM: Stratum corneum is also known as horny layer. It is the outermost layer and consists of dead cells, which are called corneocytes. These cells lose their nucleus due to pressure and become dead cells. The cytoplasm is flattened with fibrous protein known as keratin. Apart from this, these cells also contain phospholipids and glycogen.

2. STRATUM LUCIDUM: Stratum lucidum is made up of flattened epithelial cells. Many cells have degenerated nucleus and in some cells, the nucleus is absent. As these cells exhibit shiny character, the layer looks like a homogeneous translucent zone. So, this layer is called stratum lucidum.

3. STRATUM GRANULOSUM: Stratum granulosum is a thin layer with two to five rows of flattened rhomboid cells. Cytoplasm contains granules of a protein called keratohyalin. Keratohyalin is the precursor of keratin.

4. STRATUM SPINOSUM: Stratum spinosum is also known as prickle cell layer because, the cells of this layer possess some spine like protoplasmic projections. By these projections, the cells are connected to one another. „

5. STRATUM GERMINATIVUM: Stratum germinativum is a thick layer made up of polygonal cells, superficially and columnar or cuboidal epithelial cells in the deeper parts. Here, new cells are constantly formed by mitotic division. The newly formed cells move continuously towards the stratum corneum. The stem cells, which give rise to new cells, are known as keratinocytes. Another type of cells called melanocytes are scattered between the keratinocytes. Melanocytes produce the pigment called melanin. The color of the skin depends upon melanin. From this layer, some projections called rete ridges extend down up to dermis. These projections provide anchoring and nutritional function.

DERMIS

Dermis is the inner layer of the skin. It is a connective tissue layer, made up of dense and stout collagen fibers, fibroblasts and histiocytes. Collagen fibers exhibit elastic property and are capable of storing or holding water. Collagen fibers contain the enzyme collagenase, which is responsible for wound healing.

Layers of Dermis

Dermis is made up of two layers:

1. Superficial papillary layer 2. Deeper reticular layer.

1. SUPERFICIAL PAPILLARY LAYER: Superficial papillary layer projects into the epidermis. It contains blood vessels, lymphatics and nerve fibers. This layer also has some pigmentcontaining

cells known as chromatophores. Dermal papillae are fingerlike projections, arising from the superficial papillary dermis. Each papilla contains a plexus of capillaries and lymphatics, which are oriented perpendicular to the skin surface. The papillae are surrounded by rete ridges, extending from the epidermis.

2.RETICULAR LAYER: Reticular layer is made up of reticular and elastic fibers. These fibers are found around the hair bulbs, sweat glands and sebaceous glands. The reticular layer also contains mast cells, nerve endings, lymphatics, epidermal appendages and fibroblasts. Immediately below the dermis, subcutaneous tissue is present. It is a loose connective tissue, which connects

the skin with the internal structures of the body. It serves as an insulator to protect the body from excessive heat and cold of the environment. Lot of smooth muscles called arrector pili are also found in skin around the hair follicles

Immune Players in the CNS: The Astrocyte

Immune Players in the CNS: The Astrocyte

Introduction:

In the finely balanced environment of the central nervous system astrocytes, the most numerous cell type, play a role in regulating almost every physiological system. First found to regulate extracellular ions and pH, they have since been shown to regulate neurotransmitter levels, cerebral blood flow and energy metabolism. There is also growing evidence for an essential role of astrocytes in central immunity, which is the topic of this review. In the healthy state, the central nervous system is potently anti-inflammatory but under threat astrocytes readily respond to pathogens and to both sterile and pathogen induced

cell damage. In response, astrocytes take on some of the roles of immune cells, releasing cyto- and chemokines to influence effector cells, modulating the blood–brain barrier and forming glial scars. To date, much of the data supporting a role

for astrocytes in immunity have been obtained from in vitro systems; however data from experimental models and clinical samples support the suggestion that astrocytes perform similar roles in more complex environments.

The blood brain barrier:

The innate immune system offers non-specific defence against foreign pathogens. The first role of astrocytes in innate immunity is their contribution to the blood brain barrier (BBB). The BBB prevents many large or polar molecules, such as antibody or complement, passing from the circulation into the brain parenchyma but at the same time allows access to small or hydrophobic molecules. While the principle components of the BBB are cerebral capillary endothelial cells, astrocytes contribute to the glia limitans which separates the perivascular space from the brain, supports the pericytes and endothelial cells around the capillaries and limits the entry of immune cells into the brain in the absence of inflammation. During inflammation, cells from the CNS release a range of pro-inflammatory cytokines, including interleukin (IL)-6, tumour necrosis factor (TNF)-α and IL-1β. Reactive astrocytes, respond to those signals in a range of ways including the release of the angiogenic factor VEGF-A which increases BBB permeability . That effect is combined with the expression of matrix metalloproteinase, some of which are astrocyte-specific and which break down the extracellular matrix to facilitate cell migration . Adhesive molecules such as VCAM-1 are expressed on astrocytes and endothelial cells, allowing T-cell migration into the CNS parenchyma. The relative permeability of the BBB affects the passage of hormones, cytokines and chemokines that modulate immune responses and also the entry of large molecules such as immunoglobulin and complement.

General functions of astrocytes:

Astrocytes are a heterogeneous population of cells. There have been several ways to categorise them but currently, the most frequently used classification is based on morphology, location and the developmental period in which they are observed. By maturity, two major classifications of astrocytes, protoplasmic and fibrous astrocytes, are dominant in mammals.

1.       Protoplasmic astrocytes are found through the grey matter where they envelop synapses and contact endothelial cells, usually having five to eight major branches that extend fine processes uniformly into the surrounding tissue.

2.       Fibrous  astrocytes are located in the white matter adjacent to axon bundles where they make contact with the nodes of Ranvier. Fibrous astrocytes have longer, thinner branches than protoplasmic astrocytes, smaller bodies and fewer organelles and both astrocyte types make intimate contact with blood vessels.

Astrocytes perform a range of activities during development and in the mature brain which contribute to the development and maintenance of a cohesive cognitive system.

Astrocytes support an inflammatory response:

The activation of astrocytes by inflammatory signals leads them to express a cascade of secondary signals that initiate and control the subsequent immune response (Fig. 1). The consequence may be the suppression of the immune response as evidenced by experiments in which T-cells co-cultured with astrocytes acquire characteristics of regulatory T-cells and have suppressed.

WHY SUGAR IS SO ADDICTIVE? – A NEUROLOGICAL ASPECT

WHY SUGAR IS SO ADDICTIVE?  – A NEUROLOGICAL ASPECT

        

Addiction is a kind of medical condition in which the person has unsustainable desire to consume a substance or engage in an activity, although knowing that it can cause various adverse effects. Taking that substance or engaging in that activity make the victim feel good. It case of sugar it is nearly the same. We Indians especially the Bengalis are very much addictive to sweets. The sweet item after a meal attracts maximum of us.

Sugar is used daily by most of the people. Modern food is very rich in sugar. This is one of the many cause behind the obesity epidemics.

Overconsumption of sugar can interact with different parts and substances of brain and changes their normal state and levels. Notably it affects the levels of Dopamine.

The most common form of sugar in our daily food is sucrose. When ingested this sugar is split in the digestive system into two constituents, glucose and fructose. Insulin and glucagon are two most important hormones that regulate the level of glucose in human body.

After ingestion and degradation of sugar, glucose molecules and absorbed and distributed to all organs and cells in our body. A group of proteins called GLUCs are responsible for transportation of glucose molecules to the brain. It mediates glucose uptake from ECF into astrocytes, oliogodendroglia and microglia but GLUT3 which has a much higher transport rate than GLUT1 facilitated neuronal glucose uptake. When glucose molecules reaches the destination cells, it not to go into the cell where it is consumed. There are different mechanisms behind thin. In some cells like RBCs use diffusion toget glucose from the blood plasma. Many other cell use active transport to transport glucose inside the cells. The main consumer of the total intake of the glucose is the brain. The human cortex along requires approx. 3x10²³ ATP/S/m³and energy expenditure to release one synaptic vesicle is roughly calculated to be 1.64x10⁵ molecules of ATP. The reason behind this that brain tissue or the neurons cannot store glucose thus it cannot use any glucose when the blood glucose level is low.

Neurological Aspect of Sugar Intake:

Figure 1: The neuronal network activated by sucrose intake. VII – facial nerve; IX –glossopharyngeal nerve; X – vagus nerve; Acb – nucleus accumbens; Amy – amygdala; ENP – enteric nervous plexus; LS – lateral septum; NTS – nucleus of the solitary tract; PB – parabrachial nucleus; PVT – paraventricular thalamic nucleus; T1R2/3 – sweet taste receptor subunits; VPM – ventral posteromedial nucleus of the thalamus; VTA – ventral tegmental area

Recent progress in molecular biology and genetics has revealed candidates for sweet perception, the members of T1Rfamily of receptors. More precisely, these studies showed that perception of sweetness in mammals depends on the expression of the receptor T1R3 that, at the apical membrane of the taste receptor cells, forms a complex with a related protein, T1R2. This T1R2-T1R3 heterodimer is a G-protein coupled receptor that binds with sugar and artificial sweeteners. Binding of sweet molecules to the T1R2-T1R3 receptor complex triggers a conformational change in the molecules of the complex. This change activates the G-protein, alpha-gustducin, which in turn activates adenylate cyclase and phospholipase C. Activation of these signaling molecules results in an increase in intracellular free calcium. The increase in calcium activates the transient receptor potential channel M5 (TRPM5), which causes release of the neurotransmitter and activation of the primary afferent neurons. Taste information ascends to the brain by the sensory fibers of the facial nerve (cranial nerve VII), which innervates the anterior tongue, and the glossopharyngeal nerve (cranial nerve IX) and the vagus nerve (cranial nerve X), which innervate the posterior tongue. Because the sweet taste buds are more concentrated at the anterior part of the tongue, the information about sweet taste enters the brain mostly by the facial nerve. Recent investigations suggest that the gastrointestinal tract may transfer to the brain information related to sweet molecules. The expression of all types’ ofT1Rs was found in the gastrointestinal tract, including the stomach, duodenum, jejunum, ileum, and colon. These taste receptors signal via the enteric nervous system to the brain.

 The enteric nervous system transfers guts sensory signals to the brain and can participate in forming long-term representations of gut sensations. These gut feelings, called ‘homeostatic emotions or even’ extended consciousness may affect our emotional state and underlie intuitive decision making. From the medullar NTS, the sensory information is directed to the parabrachial nucleus (PB; Figure 1) located in the pons. In addition to the main stream from the NTS to the PB, some NTS fibers run directly to the central amygdala, paraventricular thalamic (PVT), and paraventricular hypothalamic (PVH) nuclei. The brainstem gustatory centers may generate the mimetic response to the taste of sucrose in rats. The lesion of the PB impairs the increase in sucrose licking as a function of sucrose concentration seen in intact rats. Conversely, stimulation of the cannabinoid receptors CB1 in the PB selectively stimulates feeding of palatable foods in rats. From the PB, the gustatory pathway branches to densely innervate the medial hypothalamus, ventral tegmental area (VTA), and midline thalamic nuclei. From the parvocellular part of the ventral posterior thalamic nucleus (VPM), the gustatory information is directed to the primary gustatory insular cortex(Figure 1).

In the gustatory insular cortex, the neurons responsive to taste are located in the anterior, dysgranular region. Another thalamic gustatory related pathway travels from the PB to the PVT, and, after synapsing in the PVT, reaches the prefrontal cortex (Figure 1). The interconnecting loop formed by the prefrontal cortex, nucleus accumbens, lateral hypothalamus, and VTA is intimately related to the rewarding effects of sucrose. The taste of sucrose activates the dopaminergic neurons of the VTA and elevates dopamine levels in the nucleus accumbens. The dopamine levels increase in the accumbens in proportion to the sucrose concentration, and the neurons of the nucleus accumbens explicitly encode for the hedonic value of sucrose.

For us, Bengalis eating Rasgulla or Sandesh is one of the happiest moments of the life. And this phenomenon is totally normal. Sugar increases the release of neurotransmitter serotonin, which gives a person happy feeling. This also increases the release of insulin which eventually normalizes the blood sugar level, and when glucose is back to relatively low levels we will again strive to take sugar just to feel happy again. This leads to constantly eating sweets just to feel good. This results in overeating and possible addiction.

Another problem with sugar addiction is that the fact that human brain reacts differently to different trigger the impulses that tell us to stop eating. But for fructose this situation is rather different. Fructose amplifies the reward circuits much more than glucose, resulting affection of those foods containing fructose. Thus the human body needs much more fructose to suppress eating. Scientific studies have shown that glucose reduces the activity in hypothalamus, whereas fructose does not. The hypothalamus controls the hunger and thirst along with some metabolic functions.

Compared to glucose eating fructose also has been found to produce a smaller increase in satiety hormones. In a study on rats it has also being found that when fructose is delivered directly to brain the rats begins to eat, whereas glucose ingestion in the same way reduces their eating.

Recent studies show that after taking glucose those healthy non obese subjects show lower activity in the hypothalamus and the reward system and motivation. But fructose ingestion causes just the opposite, it also activates the nucleus accumbens which is a part of brain reward circuit resulting increased hunger and motivation compared to glucose.

The modern foods and drinks contain much more fructose and as the fructose is addictive this causes attraction of those foods and drinks. This proves the statistics that overweight and obese people globally increased from 857 million in 1980 to 2.1 billion in 2013 which is 1/3^rd of the world’s population.

CALCUTTA UNIVERSITY QUESTION PAPERS OF PHYSIOLOGY HONORS 3rd YEAR

Fifth paper

General endocrinology I

Year – 2016

a. “Hypothalamus is a neuro-endocrine organ” – Justify the statement. b. Discuss the mechanism of action of hormones that act on cytosolic or intracellular receptors. 4+6

                        OR

a. What do you mean by positive and negative feedback mechanism in the regulation of hormone secretion? b. How secretion of melatonin is regulated? c.  Discuss briefly the functions of melatonin. 3+2+5

Year – 2015

1.a.What are hypophysiotropic hormones/ Hypothalamic releasing factor. b. Mention their functions on anterior pituitary. c. How the secretion of hypothalamic releasing factors are regulated? 2+4+4

            OR

a. How the synthesized posterior pituitary hormones are transported from their site of synthesis to hypothalamus to their site of release at posterior pituitary? b. How the secretions of posterior pituitary hormones are regulated? c. Discuss the functions of posterior pituitary hormones as

i. Milk ejection in lactating mothers.

ii. Osmolarity in blood.

Year – 2014

a. What do you mean by positive and negative feedback mechanism? b. How GnRH regulates the gonadotropins secretion from anterior pituitary?

            OR

a. State briefly the chemical nature and biosynthesis of melatonin. b. How the secretion of melatonin is regulated? (2+4)+4

Year – 2013

a. “Hypothalamus is a neuroendocrine organ justify” – justify. b. Discuss the physiological role of oxytosin in the control of milk release in humans. 6+4

            OR

a. Describe the physiological functions of growth hormone. b. What are somatomedins? 8+2

Year – 2012

a. Discuss the role of DAG and IP₃ as second messenger in hormone action. 10

            OR

a. Discuss the role of hypothalamus in the regulation of secretion of hormones from anterior pituitary. 10

Year – 2011

a. Mention the names of cells of anterior pituitary and their secretary products. b. Describe the source, chemistry and functions of growth hormone. c. Why the action of growth hormone on growth is inhibited after attainment of a particular age. 1+2+10+3

Year – 2010

1. Discuss with examples the positive feedback and negative feedback in the regulation of hormone secretion. 10

2. State the functions of pineal hormones. 5

3. MSH 5

Year – 2009

1. Discuss the role of hypothalamus in the regulation of secretion of hormones from anterior pituitary. 10

OR

1. Discuss the role of G proteins in mediating hormone action. 10

Year – 2008

1. Discuss the role of DAG and IP₃ as second messenger of hormonal action. 10

            OR

2.a. Give the structures of posterior pituitary hormones mentioning their site of synthesis. b. Discuss the role of posterior pituitary hormones in the maintenance of body fluid osmolarity, milk ejection and parturition. c. Why uterine contractions remain inhibited during pregnancy?

General endocrinology II

Year – 2016

a. How the secretion of thyroid gland is regulated? b. Discuss the effects of thyroid hormones on growth and metabolism. 2+(4+4)

                                    OR

a. Describe with suitable diagram the histological structure of thymus gland. b. Discuss the chemical nature and functions of thymic hormones. 4+(3+3)

Year-2015

a. What is the normal blood calcium level? b. Name the hormones that are concerned with the regulation of normal blood calcium level. c. Discuss their actions on on the maintenance of calcium homeostasis. 1+3+6

            OR

a.  Name the source and chemistry of PTH. B. Discuss the functions of PTH. C. How the secretion of PTH is regulated? 2+5+3

Year-2014

a. Discuss the functions of thyroid hormones on growth and metabolism. B. What is reverse t₃ (nT₃)? C. How TSH regulates the secretions of thyroid hormones? (2+4)+1+3

            OR

a. What is wolf-chaikoff effect? B. Discuss the mode of action and fuctions of thymic hormones. C. What are functions of thyro-calcitonin? 2+(3+3)+2

Year- 2013

a. Describe the histological structure of thyroid gland with  the help of suitable diagram. b. How does the thyroid gland accumulate iodide required for hormone bio-synthesis? C. Describe in brief the clinical manifestations of thyrotoxicosis/ Grave’s disease  4+3+3

            OR

a. describe with a suitable diagram the histological structure of thymus. B. What are thymosins? C. How does parathormone affect plasma calcium levels ?  4+2+4

Year 2012

a. State the source, chemistry and synthesis of calcitriol. Discuss briefly the functions of this hormone. 1+1+3+4

            OR

a. Describe with neat diagram the histological structures of thyroid gland in normal, hypoactive and hyperactive conditions. B.  Why tyrosine is converted to  triiodothyrosine in peripheral tissues? C. Discuss the functions of thyroid hormone on growth and metabolism. D. How the secretion of thyroid gland is regulated? 6+2+8+4

Year- 2010

a. Discuss the role of parathormone and calcitonin in the maintenance of Ca²⁺ and phosphorus homeostasis in normal physiological condition. B. Thyroxine is administered orally but insulin is administered intra-muscular injection- Explain. 8+4

General Endocrinology- III

Year – 2016

a. Describe with suitable diagram the histological structure of adrenal cortex. b. Discuss the role of glucocorticoids on metabolism, inflammation and immunological processes. 3+(4+3)

                                    OR

a. “Heart is an endocrine organ” – justify. b. What are prostaglandins? c. Discuss the functions of prostaglandins in health and disease. 3+2+5

Year- 2015

a. What are the chemical minarelocorticoids? B. Discuss the functions of minarelocorticoids. C. Mention the significance of Renin-Angiotensin system. 3+4+3

OR

a. Draw a diagram showing the histological structure of adrenal medulla with proper label. B. Mention the biochemical pathway for the synthesis of adrenal medullary hormones. C. Discuss the function of adrenal medullary hormones in the regulation of stress. 3+3+4

Year- 2014

a. Describe with a suitable diagram the histological structure of adrenal cortex. B. State the mode of action of glucolocorticoids. C. Name the disease that occur in hypo functional condition of adrenal gland. 4+4+2

            OR

a. Discuss the functions of adrenal medullary hormones. B. How the secretions of adrenal medullary hormones are regulated? C. What are prostaglandins? 5+3+2

Year-2013

a. Discuss the following functions of glucocorticoids – i. Regulation of metabolism. ii. Regulation of inflammatory and immunologic process. B. Outline the physiological actions of ANF.  (4+3)+3

            OR

a. How is the secretion of aldosterol controlled? B. Discuss the biosynthesis and catabolism of catecolamines. 3+(4+3)

Year-2012

a. Discuss ANF. B. What is rennin –angiotensin system? Discuss the role of this system in physiological regulation. 5+(4+4)

Year- 2011

1a. Describe the histological structure of adrenal gland. b. Discuss the functions of glucocorticoids. c. what is pheochromocytoma?  6+12+2

2a. Discuss the biosynthesis and catabolism of adrenaline. 8+4 3. Prostaglandin

Year- 2010

1. QANF 5

Year- 2009

a. Describe the histological structure of adrenal gland. b. Describe the functions of gulcocorticoids. C. What is meant by adrenal virilism. D. Describe the synthesis and catabolism of adrenaline. Prostaglandin. 6+12+2+(6+4)+5

General Endocrinology- IV

Year – 2016

a. Discuss the role of different hormones in the regulation of blood sugar level. b. How the secretion of insulin is regulated? c. What is hyperinsulinism? 6+2+2

                                    OR

a. Discuss the chemical nature and function of ECF. b. State the functions of “Gastrin”. How the secretion of gastrin is regulated? (2+2)+3+3

Year- 2015

a. Draw a diagram showing the distribution of α,β and δ cells in pancreatic islets and name the hormones secreted from each type of cell. b. What are different types of diabetes? C. What are the causes for the occurrence of different types of diabetes? 3+2+5

OR

a. What are growth factors and why these are named so? b. Discuss the functions of QGF and IGF. c. How the secretion of these Growth factors are regulated? 3+5+2

Year - 2014

a. Name the hormones and hormone secreting cells of the pancreatic islets. B. Discuss the role of pancreatic hormones in the regulation of normoglycemia. c. Why ketosis develops in diabetes mellitus? 2+6+2

            OR

a. What are the origins and chemical nature of gastrin? b. Discuss the functions of gastrin. c. How the secretion of gastrin is regulated? d. What are the functions of EGF? 2+3+2+3

Year - 2013

a. Discuss the mechanism of actions of insulin on target organs. b. Mention the differences of Type I and Type II diabetes mellitus. 6+(2+2)

            OR

a. Mention the functions of PDGF and IGF. b. Discuss the functions of cholecystokinin. c. How the secretion of cholecystokinin regulated? (3+3)+2+2

Year - 2012

1a. Discuss the role of insulin in the maintenance normal blood sugar level. b. What are type I and type II diabetes mellitus?

2. EGF

Year - 2011

a. Discuss the functions of gastrin and secretin.

Year - 2010

a. Discuss the role of insulin and glucagon in the regulation of blood sugar level.  8+4

b. Growth factor 5

Year -2009

a. Describe the functions of gastrin, secretin and VIP. b. Diabetes insipidus 10+5

Year - 2008

1a. Mention the source and chemistry of insulin.

b. How insulin secretion is regulated? c. Discuss the role of insulin in the regulation of blood sugar level. (1+3)+6+10

2. CCK-PZ functions

Chronobiology

Year - 2016

a. What do you mean by ultradian, circadian and infradian rhythms? b Discuss the significance of hormonal biorhythms. (2+2+2)+4

OR

a. Discuss the different zeitgebers in relation with circadian clock. b. What is the role of suprachiasmatic nuclei on biological rhythm?       c. What is Jet-lag?

Year – 2015

a. What is the neurological basis of physiological rhythms? b. Discuss the role of pineal and prolactin in the regulation of biorhythms.

OR

a. Short note – i. Jet lag. ii. frame shift work. iii. Sleep wakefulness cycle. iv. Time keeping gene.

Year – 2014

a. What do you mean by ultradian and infradian rhythms? b. How zeitgebers are related with the circardian clock? c. What is the significance of adenocorticoical hormones in the maintenance of biorhythms? 3+3+3

OR

a. How suprachiasmatic nuclei regulate the biological clock? b. What is chronotherapy? 5+3

Year – 2013

a. What are circadian rhythms? Explain the neural basis of such rhythms. b. Write a short note on time-keeping genes. (2+4)+4

OR

a. Explain the physiological basis of sleep wakefulness cycle. b. Write a short note on Jet-lag. 6+4

Year – 2012

1a. Describe the biorhythms of adrenocortical hormones, pineal hormone and body temperature. b. What are zeitgebers? c. What is infradian rhythm ? How does shift work affect biorhythms? (3+3+3)+4+3+4

2. Reproductive biorethyms.

Year – 2011

1a. Describe the different types of physiological rhythms with example. b. Discuss the role of suprachiasmatic nucleus on the ‘biological clock’ 12+8

2. Time keeping gene. 5

Year – 2010

1a. What are zeitgebers? b. How are they related with circadian clock? Discuss the bio rhythms of adrenocorticoids, melatonin and prolactin mentioning their significance. 2+3+(5+5+5)

2. Jet lag. 3

Year – 2009

1a. Discuss the different types of physiological rhythms. b. Discuss the role of suprachiasmatic nucleus as the ‘biological clock’ 12+8

2. Time keeping gene. 5

Year – 2008

1a. What is zeitgebers? Mention its different types. b. Mention the sleep wakefulness cycle. c. Discuss the control of sleep-wakefulness cycle. (2+5)+5+10

2. Body temperature rhythm.

Reproductive physiology I

Year – 2016

a. Mention the changes associated with the onset of puberty in male. b. Discuss the role of Leydig cells and Sertoli cells in spermatogenesis. 4+6

OR

a. What are spontaeneous and induces ovulation? b. Describe the physiological mechanism of ovulation. 4+6

Year 2015

a. Name the accessory sex organs in male. b. What are the secondary sex characters of male? c. Discuss with diagram the different steps of spermatogenesis mentioning the mitotic and meiotic steps. How many spermatozoa are produced from a spermatogonia? 2+2+(5+1)

            OR

a. Describe with a suitable diagram the histological structure of an adult ovary. b. Discuss the role of hypothalamus in the. regulation of secretion ovarian hormones for endometrial changes during menstrual cycle. 6+4

Year - 2014

a. Describe with a suitable diagram the histological structure of testis. b. State briefly the hypothalamic control of testicular functions. 5+5

            OR

a. What is oogenesis? b. Discuss the mechanism of ovulation. c. How corpus luteum is formed? c. What if the function of corpus luteum. 2+4+2+2

Year 2013

a. Discuss with the help of suitable diagram the structure of a spermatozoon. b. Mention the functions of the different parts of spermatozoon. c. What is blood -testis barrier? 4+3+3

            OR

a. Describe the histological structure of ovary with a neat diagram. b. Discuss the physiology of puberty

Year 2012

1. Secondary sex characters.

2. Discuss with diagram the process of spermatogenesis. 10

3a. What is corpus luteum? Describe is formation and functions. b. What is blood testis barrier

Year 2011

a. What are the changes associated with puberty? 5

Year 2008

a. What is spermiation? b. Discuss the physiological mechanism of ovulation. c. State the functions of Corpus luteum. 2+10+4

Reproductive physiology II

Year – 2016

a. Describe the different phases of estrous cycle. b. Discuss the role of different hormones in the development of mammary gland in the different phases of life. 4+6

                                    OR

a. Describe the histological structure of placenta with a lebelled diagram. b. Discuss the physiological changes that take place in the body during pregnancy. 4+6

Year 2015

a. What is menopause? b. What are the postmenopausal physiological changes in female? c. State briefly the functions of placenta.

2+3+5

            OR

a. Discuss the role of hormones in maintenance of pregnancy. b. Elicits the neuroendocrine merchant that controls parturition

Year 2014

a. Describe the physiological change ovary and uterus during menstrual cycle. b. Discuss the role hormone in these processes.

            OR

a. Discuss with diagram the development of mammary gland at different parts of life. b. Mention the role of hormones in this process. c. What is the immunological basis of pregnancy tests. 5+3+2

Year 2013

a. Describe the physiological changes that occur at and after menopause. b. Write a note on foeto-placental unit.  6+4

            OR

a. Elucidate the neuroendocrine mechanisms that control parturition. b. Write a note on oestrosis cycle. 6+4

Year 2012

a. What is colostrum? Mention it's physiological importance. b. Why breast milk is better than cow’s milk for infants? c. Why milk secretion does not initiate during pregnancy? d. What is spontaneous and induced ovulation? (2+2)+2+2+(3+3)

Year 2011

1. Describe the role of different hormones in the different phases of development of mammary gland, milk production and milk ejection. 5+5+5

2a. Describe the changes in the ovary and the uterus in the different phases menstrual cycle.  b. Discuss the role of different hormones in this process. 10+10

3. Immunological pregnancy test

Year 2010

1.Describe the role of different hormones in the maintenance of pregnancy. 12

Year 2009

1.Pregnancy test

2. Describe the role of different hormones on the different phases of development of mammary gland, milk production and milk ejection. 5+5+5

3. Describe the changes in the ovary and the uterus in different phases of menstrual cycle emphasizing on the role of hormones in this process. 14

Year 2008

1. Describe the changes that take place in the ovary during different phases of female life. 14

Developmental biology

Year – 2016

a. Describe the development of alimentary system in human embryo with suitable diagram. 10

OR

a. Describe foetal circulation with a neat diagram. 10

Year 2015

a. What is stem cell? b. Write brief note on gastrulation and placentation.

            OR

a. Describe the embryonic development of human urino-genital system with suitable diagram. 10

Year 2014

1. Write notes

a. fertilization, b. Implantation . 5+5

            OR

a. Describe the embryonic human heart with diagram. 10

Year 2013

a. Mention two important characteristics of stem cells. Write an example to show the three importance stem cells in modern day implement. b.  What is the difference between adult stem cell and embryonic stem cell? c. Discuss the peculiarities of foetal circulation. (2+2)+1+5

            OR

a. Describe with the help of suitable diagram the embryonic development of urinary system on humans. 10

Year 2012

1a. Describe the development of the alimentary system. b. Discuss the changes in foetal circulation after birth. 15+5

2. Fertilization 5

Year 2011

1. IVF 5

2a. Describe with diagram the development of urino-genital system in human embryo. 20

Year 2010

a. Describe the foetal circulation with a neat diagram. b. Discuss the changes in foetal circulation after birth.

Nutrition and dietetics

Year – 2016

a. What is B.M.R? b. What are the factors that control B.M.R? c. How B.M.R can be determined? 2+4+4

OR

a. What is balanced diet? b. State briefly the principle of formulation of balanced diet for pregnant and lactating woman. c. What do you mean by protein efficiency ratio? 2+(3+3)+2

Year 2015

a. What are fundamental Foods? b. What do you mean by ACU? c. Figure the different methods that are commonly used for diet survey. 3+1+6

            OR

a. What is biological value of protein? b. What do you mean by positive and negative nitrogen balance? c. Discuss the physiology of obesity. 2+2+6

Year – 2014

a. Classify food and food groups. b. State the principle of formulation of balance diet.                c. Prepare the diet chart of a lactating mother of middle socioeconomic group. 3+3+4

            OR

a. State the factor that regulated BMR. b. Discuss a method of determination of BMR.        c. What is SDA? 4+4+2

Year - 2013

a. Describe the physiology of obesity.

Explain the following terms

        I.            Protein efficiency radio

      II.            Protein sparers 6+(2+2)

            OR

a. Outline the principles of diet survey. b. Write a note on specific dynamic action of food. 6+4

Year 2012

1a. Physiology of obesity. 5

2a. Prepare a diet chart of lactating mother.       b. What is supplementary value of proteins

c. What do you mean by the protein-sparing effect of glucose? d. State the significance of negative nitrogen balance. 8+2+3+2

Year – 2011

1. Dietary fibres. 5

2. SDA 5

3a. What is ACU? b. Discuss the principles of formulation of balanced diet. c Discuss the problem of obesity and outs possible remedial measures. 2+8+10

Year 2010

1a. Physiology of starvation. b. Proton efficiency ratio. 5+5

2a. What is BMR? b. Describe the methods of determining of BMR by Benedict Roth apparatus. Discuss briefly the different methods of diet survey. d. What is the biological value of protein. 2+8+8+2

Year 2009

1a. What is balanced diet? b. Discuss the principles of formulation of balanced diet.           c. Compare the balanced diet of woman and a lactating woman of same age group. 4+10+6

2.Dietary fibers  3. Biological value of proteins 5+5

Social physiology

Year -2016

a. What are the principles and methods of family planning ? b. What is PCM? c. Mention the causes and social implications of endemic goitre and xeropthalmia in the affected communities. 4+2+4

                                    OR

a. What are the social importance of immunization against diseases? b. Discuss the measures that could be taken for prevention of malaria and hepatitis.

Year 2015

a. Discuss the importance of assisted reproductive technologies. b. What the causes of marasmus, kwashiorkor and osteomalacia. c. Mention the implication of those nutritional disorders in the affects communities. 4+(1+1)+(1+2)

                        OR

a. Name the disease that can be controlled by immunization programmes. b. State the principles of immunization the prevention of these disease. c. Discuss the measure that could be taken for prevention or cholera and AIDS. 2+3+(2½+2½)

Year - 2014

a. State briefly the consequences of infertility

b. Mention the implication of those disorders in the affected communities. c. What are the causes of endemic goiter and xerophthalmia? 4+(2+2)+(1+1)

            OR

a. what is PCM? b. State end social importance of immunization the prevention of disease. c. What are the measures that could be taken for prevention of malaria and hepatitis? 2+2+(3+3)

Year 2013

a. Discuss the principles and methods that are used in family planning. b. What is marsmic kwashiorkor? Mention it's social implication. (3+4)+(1+2)

            OR

a. Mention the social importance of immunization  against disease. b. What are assisted reproductive technologies? c. What are the measures that could be taken for prevention of AIDS. 2+5+3

Year 2012

1. Protein calorie malnutrition. 5

2. Endemic goiter. 5

3. Distinguish marasmus and kwashiorkor.

4. Discuss the underlying causes symptoms and the social implications of a. Ricket b. Xerophthalmia. (6+6)

Year 2011

1a. Describe the principles and methods of family planning mentioning their advantages and disadvantages. 14

b. State end principles and social importance of immunization against infectious disease.

2a. AIDS

Year – 2010

1a. What do you mean by PCM? b. Distinguish between marasmus and kwashiorkor. c. Write the measures to be taken to prevent PCM. d. Describe the causes and symptoms of nutritional anaemias. 2+6+4+8

2. Hepatitis. 5

Year - 2009

1. AIDS.

2a. State the principles and social importance of immunization against infectious disease. 10

b. Discuss in brief the principles and methods of family planning. 10

Sixth paper

Work Physiology and Ergonomics

Year – 2016

a. Discuss the general application of ergonomics for improvement of industrial safety. b. Describe the general implications of anthropometry in ergonomics. 5+5

OR

a. Write a comparative note on Light, Moderate, Heavy work from the concept of physiological work. b. What do you mean by ergogenic aids? Give examples. 6+4

Year 2015

a. State the basic concept of ergonomics. B. Discuss the effect of ergonomics on the relation of occupational health hazards. 5+5

            OR

a. Define physical work. B. Discuss different reparatory changes occurred during heavy industrial work. C. What is the importance of rest pause during maximal physical work? 2+6+2

Year -2014

a. Discuss the effects of graded exercise on cardiovascular system. B. How can work load be classified? 6+4

            OR

a. What are positive and negative work? B. How can the energy cost of various  physical work be determined by indirect method? C. What is the significance of authropometic measurement? 4+4+2

Year -2013

a. What are isotonic, isometric works? B. Discuss the significance of work rest cycle in industrial work?  6+4

            OR

a. What is ergonomics? State the factors to be considered to improve industrial safety. B. Compare the advantages and disadvantages of Treadmill and Bicycle ergometer for evaluating human performance? 2+4+4

Year – 2012

1. Occupational health hazards? 5

2a. Define static and dynamic works. Give example. b. What is graded exercise? Describe the related cardiovascular changes due to graded exercise. (2+2+½+½)+(2+8)

3. How anthropometry is related with productivity? 4

4. Why anabolic steroid is considered as ergogenic aid? 3

Year – 2011

1a. Describe the basic principles involved in determination of energy cost of different physical activities. B. What is the significance of introduction of micropause in long term work. C. Describe the basic concept of ergonomics. 8+8

2. Industrial safety

Year- 2010

1. Occupational health hazards. 5

2. Source of energy for different types of physical activities. 5

3. Describe the effects of graded exercise on ventilation volumes. 8

4. Describe how physical work capacity can be assessed by Harvard step test. 8

5. What do you understand by isotonic work? 4

6. what are the application of anthropometic measurement in physiology. 10

Year -2009

1.  Discuss how proper application of ergonomic concept help in the fields of industry to increase productivity. 10

2. Describe and compare the application physiological aspects of static and dynamic work. 8

4. Discuss the significance of work rest cycle in long term industrial work. 8

Year- 2008

1. Significance of anthropometic measurement.

2. Heart rate may be a good parameter in assessing work capacity of an individual – Explain. 8

3. What is meant by ergonomic aids? 6

4.a Discuss the effects of graded exercise on cardiovascular and respiratory systems. 7+5

b. Show the limitations of different sources of energy on power of capacity of work of an individual. 8

4. What do you mean by positive, negative and isokinetic work? 9

Sports Physiology

Year – 2016

a. State the principles of physical training. b. Discuss its impact on performance level with reference to respiratory changes. c. What is detraining? 3+6+1

                                    OR

a. Describe briefly the factors that can affect the anaerobic power of an athlete. b. Describe a suitable method for measurement of maximal oxygen consumption of an healthy individual. 5+5

Year- 2015

a. What is physical fitness? B. Discuss the assessment of physical fitness by Harvert step test. C. What do you mean by warm and cool down? 2+4+(2+2)

            OR

a. Describe the basic concept and useful use of lactate threshold and lactate tolerance.5+5 B. Discuss the modern concept of muscle fatigue.

Year -2014

a. What is VO₂ max? How can VO₂ be measured? What are the normal values of VO₂ in sedentary adults? 2+4+1

b. What are overtraining and detraining? 3

                        OR
a. What is EPOC? What are components od EPOC? Discuss the significance of EPOC. B. What will be diet of an endurance athlete prior to competition? 2+4+2+2

Year -2013

a. What is physical fitness? How physical fitness can be assessed by Harvard step test? B. What do you mean by warm up? C. What is lactate threshold? 2+4+2+2

            OR

a. State the principles of physical training. Discuss the effect of physical training on cardiovascular system. B. What is pre-game meal? 4+4+2

Year -2012

a. Explain EPOC. How EPOC is determined? What is its significance? B. Describe the effects of long term physical training on skeletal muscle. c. Discuss the modern concept of muscle fatigue. 4+6+3+7+5

Year- 2011

a. What is maximal aerobic power? How can you determine it by a Treadmill? B. Discuss the physiological features responsible for differences in aerobic and anaerobic capacity of a trained person and for sedentary person. (4+6)+10

Year- 2010

a. What do you understand by O₂ debt? What is its relation with o₂ deficit? What is its significance in sports? 4+4+4

b. State the principle of physical training. 8

Skin and body Temperature regulation

Year – 2016

a. Describe the mechanism of sweat formation and secretion. b. State any four important featurs of cutaneous circulation. 6+4

                                    OR

a. Briefly write the neural process of body temperature regulation in homeotherms. b. Distinguish between hyperthermia and hypothermia. What is core temperature? 5+4+1

Year-2015

a. Describe the role of physical and physiological factors in body temperature regulation. B. What is hypoxia? How does it develop? 6+(2+2)

            OR

a. Describe with suitable diagram the histological structures of skin. B. What is sebum? C. What is Insensible perspiration? (3+4)+1+2

Year-2014

a. How does eccrine sweat gland differ from apocrine sweat gland? B. Discuss the mechanism of sweat formation? Mention the peculiarities of cutaneous circulation? 2+4+4

            OR

a. What are the physical process of body-temperature regulation? B. Discuss the causes of prevention of hypothermia? C. What is non shivering thermogenesis? 4+(2+2)+2

Year- 2013

a. Describe with suitable diagram the histological structure of skin. B. Discuss the neural regulation of sweat secretion. 5+5

            OR

a. Discuss the role of hypothalamus in the regulation of body temperature. B. What is insensible perspiration? C. What is core temperature? 6+2+2

Year – 2012

1. Hypothermia. 5

2.a. Mention the peculiarities of cutaneous circulation. B. How sweat secretion is regulated? C. Discuss the hormonal process involved in temperature regulation of homeotherms. D. What is non-shivering thermo genesis? E. Distinguish between eccrine and apocrine gland. 5+6+7+2+4

Year- 2011

a. Describe the process of temperature regulation in non-sweating glands. B. Describe with a suitable diagram the histological structure of skin. Discuss the physical aspects of body temperature regulation in homeotherms. 6+8+6

Year- 2010

a. Describe the histological structure of skin. B. Discuss the neural control of body temperature regulation. 8+12

Year- 2009

a. Discuss the physical and physiological process which are functioning in our body to maintain normal body temperature. B. Describe the mechanism of sweating. C. What is non-shivering thermogenesis? 9+8+3

Human and Environment I

Year – 2016

a. What do you understand by ‘external’ and ‘internal’ environment? b. Discuss the effects of hypobaric environment on human body. How they can be prevented? 2+(5+3)

                                    OR

a. Discuss the major physiological effects of cold environment on human body. b. Write in brief on acclimatization to cold. 6+4

Year- 2015

a. What is hyperbaric environment? Describe its effects on human. B. What is caisson disease? (2+6)+2

            OR

a. What is meant by heat stress and heat strain? B. Describe immediate and delayed respiratory changes due to acclimatisation to high altitude. (2+2)+(3+3)

Year-2014

a. Discuss the effects of exposure to extreme cold. How acclimatization to cold environment occurs? B. Discuss briefly the measures that could be taken for the prevention of hypobaric effects. 4+3+3

            OR

a. Discuss the changes in haematopoietic system in the process of acclimatization to high altitude. B. Discuss the preventive measures from different heat disorders. C. What is mountain sickness. 4+4+2

Year- 2013

A. Discuss physiological changes in the respiratory system in the process of acclimatization at high altitude. B. Discuss different heat disorders. 5+5

            OR

a. Discuss how O₂ toxicity occurs in human body in hyperbaric condition. Discuss briefly the preventive measures of hyperbaric effects. C. What is caisson diseases? 5+3+2

Year – 2012

a. Cold stress.

Year – 2011

1. Caisson disease. 5

2. Describe the different type of heat disorders. 8

3. Describe the process of acclimatization of human body to high altitude. 8

Year – 2008

1. Heat disorders. 5

2. Describe the physiological changes obserbed during ascend to high altitude in human body. 9

Human and Environment II

Year – 2016

a. Distinguish between ionizing and non-ionizing radiations with examples. b. Discuss the effects of G-force on human body.

                                    OR

a. Give at least one example of each of the followings: (i) Pesticide, (ii) Carcinogen, (iii) Mutagen, (iv) Neurotoxin. b. How can arsenic and cadmium influence human health? 4+6

Year – 2015

a. Give examples of any two air pollutants? How do they affect the human health. B. What is noise? Discuss briefly the non-auditory effects of noise on human body? (1+4)+(1+4)

                        OR
a. Name any two war gases. State their effects on human body. B. Describe the effects on non-ionizing radiation on human body. (1+4)+5

Year – 2014

a. Discuss the causes and prevention of water pollution. B. Discuss the hazards of insecticides and larvicides on humans. (3+3)+(2+2)

            OR

a. Describe the effects of positive and negative gravity on circulatory system of human. B. Discuss the green house effects on life. C. What are mutagens?

Year – 2013

a. Describe the effects on ionizing on human body. B. Mention the preventive measures against ionizing radiation. What is neurotoxins? 5+3+2

                                    OR

Describe the effects of noise pollution on auditory system. b. Describe the preventive measures of noise pollution. C. What are carcinogens? 4+4+2

Year – 2012

1. Impact of green house effects on life. 5

2a. Describe the effects of positive G force and negative G force on human body. B. Discuss the effects of air pollution on human body. C. How air pollution can be prevented? 4+4+8+4

3. Discuss the hazards of pesticides and mutagens on human body. 5+4

Year – 2011

1. Carcinogens. 5

2. Describe the effects of radiation on human body. How it can be prevented. 8+4

Year – 2010

1. Impacts of green house effects on life.

2a. What is meant by pollutants? Describe the effects and protective measures of air pollution. B. Describe the effects of radiation on human body.

3. Describe the hazards of pesticides and carcinogens. 5+5

Year – 2009

1. G force.

2a. Describe the harmful effects of gamma radiation with its protective measures. 10

b. Describe the cause and effects of sound pollution in the body. 4+6

Year – 2008

1. What are the sources of water pollution? Describe the effects of water pollution on human health. 3+8

Microbiology I

Year – 2016

a. In microbiology how do you define the term ‘sterile’? b. Describe the different phases of bacterial growth curve and state their significances. c. Why ager is used in synthetic media? d. Name the microscope specially used for identifying bacteria. 2+(4+2)+1+1

OR
a. What is plasmid? b. what do you understand by continuous growth culture and its utility? c. State the functions of pili. d. Name one beneficial and one harmful microorganisms in food. 2+(2+2)+2+2

Year – 2015

a. Discuss any four physical factors required for bacterial growth. B. Describe the LPS layer of gram negative bacterial structure. C. What do you mean by pasteurization. D. Why bacterial spores are heat resistant? 4+3+2+1

            OR

a. Discuss briefly the method of acid fast staining and state its importance. B. Write the major constituents of synthetic media for culture of bacteria. C. Discuss briefly the methods of prevention of food borne infection. D. State the function of flagella in bacteria. (3+1)+2+3+1

Year – 2014

a. discuss the different phases of bacterial growth curve with their significance. B. Describe the cell wall structure in Gram positive bacteria. C. State the function of pili in bacteria. 5+4+1

            OR

a. Difference between pasteurization and sterilization. State the function of plasmids. C. What is disinfection> name the methods of disinfection. 4+2+(2+2)

Year – 2013

a. Describe the chemical basis of Gram staining. B. Distinguish between pasteurization and flash pasteurization. State their utilities. C. Discuss the methods of prevention of food bourn infection. 4+(1+1)+4

OR
a. Can methylene blue be used as a counter stain in Gram staining procedure? Justify your answer. B. Why moist heat scores over dry heat in sterilization? C. Why agar is used in media? D. Describe spore structure. Why is it heat resistant? E. What is continuous growth culture? State its utility. (1+1)+1+1+(2+1)+(2+1)

Year – 2012

a. What is acid fastness? What structural peculiarity make bacterium acid fast? Sate the medical utility of acid fast staining? 2+3+1

Year- 2011

1. Describe with a suitable diagram bacterial growth with its major phases. 10

Year- 2009

1. Explain the different phase of bacterial growth with graphical representation. 6

2. Sterilization. 5

Microbiology II

Year – 2016

a. Describe the different steps of Entner-Doudorroff pathway and its significance. b. Describe briefly the process of bacterial conjugation. (3+2)+5

OR

a. What is prion? b. Briefly describe the lysogenic cycle of bacteriophage. c. What is the basic difference between ‘bacteriocidal’ and ‘bacteriostatic’ effects? d. Name one chemotherapeutic aagent used in humans

Year – 2015

a. Describe the glyoxalate cycle and state significance. B. What is fermentation? C. Define antibiotics. Why penicillin is safe antibiotics for human body. (4+1)+3+(1+1)

OR

a. Discuss the generalised transduction process in bacterium. B. Define virion. Classify viruses on nucleic acid composition and give examples. C. Name one homo-fermentative bacteria. 6+(1+2)+1

Year – 2014

a. Discuss different steps of Entner-Doudoroff pathway and significance of this cycle. B. Describe the lytic cycle of bacteriophage replication. (4+1)+5

                                    OR

a. Describe the process of bacterial fermentation. B What are chemotherapeutic agents? Give an example. C. Name a bacteriostatic antibiotic and state its mechanism of action. 5+2+(1+2)

Year - 2013

a. Discuss the different steps of Glyoxylate cycle and state its significance of that cycle. B. Define antibiotics. C. Define prions. Classify viruses based on nucleic acid composition and give examples. (4+2)+1+(1+2)

                                    OR

a. Describe the process of bacterial conjugation. B. Describe briefly the lysogenic phases of bacteriophage replication. 5+5

Year – 2012

a. Describe the transduction process of bacteria.

b. Describe the different steps of Entner-Doudoroff pathway. Mention its importance.

Year- 2011

a. Describe the Glyoxylate cycle and mention its significance.

b. What is fermentation?

Year – 2009

a. Describe the different steps of Entner-Doudoroff pathway. Mention its importance. 6+2

b. Describe the different steps of bacterial transformation. 6

Immunology

Year – 2016

a. Name primary organs involved in immune response. b. What  is adjuvant? Give example. c. Describe the structure of a typical IgG antibody. d. Name the antibody secreted during primary response. 2+(1+1)+5+1

                                    OR

a. What do you understand by natural killer cells? b. What do you mean by attrnute vaccine?. c. What is paratope? d. Give a brief note on Hybridoma technology. 2+2+1+5

Year – 2015

a. Define immunogen. State any four requirements of a molecule for being an immunogen. b. State the importance of variable region of an antibody molecule. c.Distinguish between affinity and avidity. d. Define tocoid. (1+4)+1+2+2

                                    OR

a. Describe the alternative pathway of complement activation. b. Write any two differences between structure of MHC class I and MHC class II molecules. c. Name any two cytokines produced by Th1 cells. d. What do you understand by allergens? 6+2+1+1

Year – 2014

a. Describe the structure of a typical IgG antibody. b. State the characteristics of the adoptive immune system. 6+4

                                    OR

a. What are haptens and adjuvants? b. Differentiate between active and passive immunity. c. Write briefly about antigen presentation during an immune response. 4+3+3

Year – 2013

a. Describe the process of class switching in antibody molecule. b. What are cytokines? How they are produces from T_H1 and T_H2 cells? c. Distinguish between affinity and avidity?  2+(2+4)+2

                                    OR

a. Why ‘complement’ is so called? Describe briefly the classical pathway of complement activation. b. Discuss briefly the process of hybridoma technology. (1+5)+4

Year - 2012

1. Haptens and adjuvants. 5

2a. What are 1^o and 2^o responses? b. What are adjuvant cells? c. What is complement system? Discuss its role in the body defence system.  d. Describe the formulation, maturation and activation of B cells. 2+2+(2+5)+6

Year – 2011

1. AIDS 5

2a. Describe the typical IGg antibody. b. Describe the interaction required for antigen antibody reaction. 10+10

3. Interferon immunity.

Year – 2009

1. Humoral immunity. 2a. Describe the structure of antibody with suitable diagram. b. How do the antigen presenting cells (APC), T_H Cells interact to induce humoral immunity? c. Distinguish between primary and secondary immune system. 8+8+4

Pharmacology

Year – 2016

a. Define drug. b. State the uses of ‘tubocucarine’ c. Describe the mechanism of action of an adrenoreceptor agonist and an antagonist.  2+2+(3+3)

                                    OR

a. What is meant by ED₅₀ od drug? b. What do you understand by desensitization of drug response? c. What do mean by drug accumulation? d. State the uses of benzodiazepine and nifedipine. 2+2+2+(2+2)

Year – 2015

a. What do you mean by osmotic and potassium

sparing diuretics? B. What is first pars effect? Define bioavailability of a drug. How first pas effect affects bioavailability? C. Describe briefly the mechanism of action of an anaestheti. D. What is drug toxicity? 2+(1+1+1)+3+2

                                    OR

a.State uses of succinyl choline and phenolamine. B. What is half life of a drug? C. What is drug biotransformation? (2+2+2)+2+2

Year – 2014

a. Define Drug, agonist and antagonist with examples.  B. State mechanism of action of  salbutamol. 6+4

                                    OR

a. What is dose response curve? State its characteristics? What are antianginal drugs? Give an example and state its mechanism of action.

(2+3)+(1+1+3)

Year – 2013

a. What is first pass effect? Define bioavailability of a drug. How first pass effect affects bioavailability. B. What is pro drug? Give an example. C. Define therapeutic index? What is its utility. D. Describe briefly the mechanism of drug distribution in human body. (1+1+1)+(1+1)+(1+1)+3

                                    OR

a. Discuss general mechanism of neuromuscular blocking agents. B. What are loop diuretics? What is half life drug. 6+(2+2)

Year – 2012

a. Describe the dose response relationship of drug along with its salient characteristics. B. What is drug biotransformation? C. Describe the pharmacological properties and mechanism of action of morphine. 7+5+(2+6)

Year – 2011

1. LD₅₀

2a. Describe the actions and therapeutic effects of propranolol in the body. B. Describe the general mechanis of absobtion and escretion of drugs. 10+10

3a. State the effects of diuretics on renal function. B. What is meant by bioavailability of drugs? 8+4

Year – 2010

1a. Describe the mechanism of action and pharmacological properties of morphine on human body. B. What is dose response curve? C. What is meant by drug toxicity? 10+6+4

2. LD₅₀

Year – 2009

1a. What is dose response curve? Discuss its characteristics. B. Describe the effects of diuretics on renal function and mechanism of action. C. What is meant by bioavailability of drug. 6+10+4

2a. State the mechanism of action of α₂ adrenoreceptor blocking agent. B. State the mechanism of action of antihistamic drug. C. Describe the effects of tubocurarine in our body. 6+10+4

Year – 2008

1. Short note – a. Diuretics b. LD₅₀ 5+5

2a. Describe the general mechanism of absobtion and exertion of drugs. B. Discuss the pharmacological properties and mechanism of action of morphine on human body. c. State the action of a neuromuscular blocking agent 8+12+4

Biostatistics

Year – 2016

a. What do you understand by distribution free test? Give an example. b. What is random sampling? c. What is Null Hypothesis? d. How can a bar diagram be drawn? (2+1)+2+3+2

                                    OR

a. write a short note on frequency polygon. b. What is error of inference? c. Distinguish between paired and unpaired “t” test. d. What is correlation co-efficient? 5+2+1+2

Year – 2015

a. What is histogram? b. State the advantages and disadvantages of using mean as a measure of central tendency over median and mode. C. How does correlation differ from regression? 2+(2+2)+4

OR

a. Describe the basic properties of normal distribution curve. B. What is meant by the level of significance. C. Define degrees of freedom and Z score.

Year – 2014

a. What is Null hypothesis? B. How can standard deviation and standard error of the mean be calculated? C. What is random sampling? 3+5+2

OR

Year – 2013

a. Define population. Distinguish between parameters and statistics. B. Differentiate between parametric and non-parametric test. Give one example of each. C. State one salient feature where normal distribution differs from ‘t’ distribution. D. What is Yate’s correction? Where is it used. E. Why standard deviation scores over mean deviation in the field of statistics. (1+1)+(2+½ +½)+1+(1+1)+2

                                    OR

a. Why an observed difference may be significant in one tailed ‘t’ test but not in two tailed ‘t’ test. B. Distinguish between paired and unpaired ‘t’ test. C. State the advantages and disadvantages of using mean as a measure of central tendency over median and mode. D. How mean, median and mode are mathematically related? 3+1+(2+2)+2

Year – 2012

1. Errors of inference.

2a. Define standard deviation. Describe the steps of computing standard deviation. B. What is null hypothesis? C. What is frequency distribution? Describe the method of construction of frequency distribution table with continuous data. (2+4)+4+(2+8)

3a. Describe the properties of normal distribution curve? B. What is meant by stratified random sampling? 4+4

Year – 2011

1. Standard error of mean.

2a. What is students t-distribution. How would you perform t-test for paired observations mentioning its limitations. B. What is meant by degrees of freedom?

Year – 2010

1. Frequency polygon.

2a. What is chi square test? How can you perform it? B. Explain what you understand by level of significance? C What is meant by degrees of freedom? (2+8)+5+5

Year – 2009

1. Frequency polygon.

2a. Describe Null hypothesis. B. Describe method for paired t-test. C. Describe the method of frequency distribution of a quantitative data. 4+4+8+8