Physiology important "Q" for University by Gagre sir (part2) solution

 Sure, let's go through each topic one by one:

### Endocrine System

#### 1. Enumerate the hormones of the pituitary gland. Add a note on Growth Hormone.

**Hormones of the Pituitary Gland:**

- **Anterior Pituitary (Adenohypophysis):**

  1. Growth Hormone (GH)

  2. Thyroid-Stimulating Hormone (TSH)

  3. Adrenocorticotropic Hormone (ACTH)

  4. Follicle-Stimulating Hormone (FSH)

  5. Luteinizing Hormone (LH)

  6. Prolactin (PRL)

- **Posterior Pituitary (Neurohypophysis):**

  1. Oxytocin

  2. Antidiuretic Hormone (ADH) or Vasopressin

**Note on Growth Hormone (GH):**

Growth Hormone, also known as somatotropin, is a peptide hormone that stimulates growth, cell reproduction, and cell regeneration in humans and other animals. It is thus important for human development. GH also has significant effects on metabolism.

#### 2. Thyroid hormone – secretion, regulation & functions, and applied aspects

**Secretion:**

Thyroid hormones are primarily T3 (triiodothyronine) and T4 (thyroxine). They are produced by the thyroid gland, using iodine and tyrosine as precursors.

**Regulation:**

Thyroid hormone production is regulated by the hypothalamus and the pituitary gland through a feedback loop involving Thyrotropin-Releasing Hormone (TRH) and Thyroid-Stimulating Hormone (TSH).

**Functions:**

- Regulation of metabolic rate

- Heart rate and cardiac output

- Growth and development

- Body temperature regulation

- Brain development

**Applied Aspects:**

- Hypothyroidism (e.g., myxedema)

- Hyperthyroidism (e.g., Graves' disease)

- Thyroiditis

- Goiter

#### 3. Growth hormone - secretion, regulation, functions, and applied aspects

**Secretion:**

GH is secreted by the anterior pituitary gland. It is regulated by Growth Hormone-Releasing Hormone (GHRH) and Somatostatin (GHIH) from the hypothalamus.

**Regulation:**

GH secretion is pulsatile and influenced by factors such as sleep, stress, exercise, and nutritional status.

**Functions:**

- Stimulates growth of bones and muscles

- Promotes protein synthesis

- Increases fat utilization

- Influences carbohydrate metabolism

**Applied Aspects:**

- Gigantism (excess GH in children)

- Acromegaly (excess GH in adults)

- Growth hormone deficiency (leading to dwarfism)

#### 4. Adrenal cortex hormones - Secretion, and functions of glucocorticoids

**Secretion:**

Glucocorticoids, such as cortisol, are secreted by the adrenal cortex, specifically from the zona fasciculata. 

**Functions:**

- Metabolism regulation (proteins, fats, and carbohydrates)

- Anti-inflammatory effects

- Immunosuppressive actions

- Stress response

#### 5. Calcium metabolism: (PTH, calcitonin & Vitamin-D)

**Parathyroid Hormone (PTH) - Synthesis, secretion, and functions:**

- **Synthesis & Secretion:** PTH is produced by the parathyroid glands.

- **Functions:** Increases blood calcium levels by stimulating bone resorption, increasing calcium reabsorption in the kidneys, and activating vitamin D.

**Calcitonin:**

- Produced by the parafollicular cells (C cells) of the thyroid gland.

- Lowers blood calcium levels by inhibiting bone resorption.

**Vitamin D:**

- Synthesized in the skin upon exposure to sunlight, then activated in the liver and kidneys.

- Increases intestinal absorption of calcium and phosphate.

#### 6. Insulin: formation, regulation, and functions, and applied aspects

**Formation:**

- Insulin is synthesized in the beta cells of the islets of Langerhans in the pancreas.

**Regulation:**

- Blood glucose levels are the primary regulator of insulin secretion.

- Other factors include gastrointestinal hormones, amino acids, and autonomic nervous system inputs.

**Functions:**

- Lowers blood glucose levels by facilitating cellular uptake of glucose.

- Promotes glycogenesis and lipogenesis.

- Inhibits gluconeogenesis and glycogenolysis.

**Applied Aspects:**

- Diabetes Mellitus (Type 1 and Type 2)

- Hypoglycemia

- Insulin resistance

### Reproduction

#### Describe the hormonal regulation of the menstrual cycle. Add a note on LH surge.

**Hormonal Regulation of the Menstrual Cycle:**

1. **Follicular Phase:**

   - **FSH** stimulates follicle development.

   - Follicles produce **estrogen**, leading to the proliferation of the endometrium.

2. **Ovulation:**

   - Mid-cycle **LH surge** triggers ovulation (release of the egg).

3. **Luteal Phase:**

   - The ruptured follicle transforms into the corpus luteum, producing **progesterone** and **estrogen**.

   - Progesterone prepares the endometrium for potential implantation.

4. **Menstruation:**

   - If implantation does not occur, the corpus luteum degenerates, leading to a drop in progesterone and estrogen levels, resulting in menstruation.

**LH Surge:**

- The LH surge is a sharp increase in luteinizing hormone levels, typically occurring around day 14 of the menstrual cycle, triggering ovulation.

#### Short Notes

1. **Myxedema:**

   - Severe hypothyroidism in adults characterized by swelling of the skin and underlying tissues, giving a waxy consistency.

2. **Acromegaly:**

   - Excessive growth hormone in adults causing enlarged extremities and facial features.

3. **Tetany:**

   - Muscle cramps and spasms due to hypocalcemia, often associated with hypoparathyroidism.

4. **Diabetes Mellitus:**

   - A metabolic disorder characterized by chronic hyperglycemia due to defects in insulin secretion, action, or both.

5. **Gigantism:**

   - Excessive growth hormone in children leading to abnormal growth of bones and tissues.

6. **Cushing's Syndrome:**

   - Condition caused by prolonged exposure to high levels of cortisol, leading to weight gain, hypertension, and other symptoms.

### Gastrointestinal Tract

#### 1. Types of salivary glands. Describe secretion, regulation, and functions of saliva.

**Types of Salivary Glands:**

1. Parotid glands

2. Submandibular glands

3. Sublingual glands

**Secretion:**

- Saliva is produced by the salivary glands and contains water, electrolytes, mucus, enzymes (amylase, lipase), and antibacterial compounds.

**Regulation:**

- Autonomic nervous system controls saliva secretion. Parasympathetic stimulation increases secretion, while sympathetic stimulation modifies the composition.

**Functions:**

- Lubrication and binding of food

- Initiation of starch digestion by amylase

- Antimicrobial action

- Oral hygiene and taste facilitation

#### 2. Movements of GIT tracts.

- **Peristalsis:** Rhythmic contractions that move food through the digestive tract.

- **Segmentation:** Contractions that mix and break down food in the intestines.

- **Mass movements:** Large contractions in the colon that move feces towards the rectum.

#### 3. Gastric juice: Composition, secretion, regulation & function

**Composition:**

- Hydrochloric acid (HCl)

- Pepsinogen

- Mucus

- Intrinsic factor

**Secretion:**

- Produced by gastric glands in the stomach lining.

**Regulation:**

- Controlled by neural (vagus nerve), hormonal (gastrin), and paracrine (histamine) factors.

**Functions:**

- Digestion of proteins

- Activation of digestive enzymes

- Antimicrobial action

- Absorption of vitamin B12

#### 4. Pancreatic juice: Composition, secretion & functions

**Composition:**

- Enzymes (amylase, lipase, proteases)

- Bicarbonate ions

**Secretion:**

- Produced by the pancreas and regulated by hormones (secretin and cholecystokinin) and neural mechanisms.

**Functions:**

- Digestion of carbohydrates, fats, and proteins

- Neutralization of stomach acid

#### 5. Describe and discuss the structure and functions of liver and gall bladder.

**Liver:**

- **Structure:** Largest gland, divided into lobes, containing hepatocytes.

- **Functions:** Metabolism, detoxification, bile production, storage of vitamins and minerals, synthesis of plasma proteins.

**Gall Bladder:**

- **Structure:** Small, pear-shaped organ beneath the liver.

- **Functions:** Storage and concentration of bile, release bile into the small intestine during digestion.

### Short Notes

1. **Movements of small intestine:** Include peristalsis and segmentation, facilitating nutrient absorption and mixing of intestinal contents.

2. **Deglutition:** The process of swallowing, involving voluntary and involuntary muscle actions.

3. **Mechanism of HCl secretion in stomach & its function:** Parietal cells secrete HCl, which aids in protein digestion and provides an acidic environment for enzymes.

4. **Composition and functions of bile:** Bile contains bile salts, cholesterol, and bilirubin. It aids in the digestion and absorption of fats.

5. **GI hormones:**