---

🏥 GNM 1st Year — Anatomy & Physiology

2nd Internal Exam: Most Important Questions & Answers

---

📋 SECTION A: LONG ANSWER QUESTIONS (High Probability)

---

❤️ 1. Describe the anatomy and physiology of the Heart

• Pericardium — double-walled sac
  • Fibrous pericardium (outer)
  • Serous pericardium (inner) — parietal and visceral layers (epicardium)
  • Pericardial cavity — contains 20–30 mL serous fluid (lubrication)

• Right Atrium — receives deoxygenated blood from superior/inferior vena cava
• Right Ventricle — pumps to lungs via pulmonary artery
• Left Atrium — receives oxygenated blood from 4 pulmonary veins
• Left Ventricle — pumps oxygenated blood to body via aorta (thickest wall)

• Systole (contraction) + Diastole (relaxation)
• Normal Heart Rate: 60–100 beats/min
• Cardiac Output: 5 L/min (HR × Stroke Volume)

• SA Node (Pacemaker) → AV Node → Bundle of His → Bundle Branches → Purkinje Fibers

---

🫁 2. Respiratory System

• Right lung — 3 lobes (upper, middle, lower)
• Left lung — 2 lobes (upper, lower) — has cardiac notch
• Covered by pleura (visceral and parietal)

• ~300 million alveoli
• Surfactant (produced by Type II pneumocytes) prevents collapse

• Inspiration: Diaphragm contracts (moves down) → thoracic volume increases → pressure falls → air enters
• Expiration: Diaphragm relaxes → passive process normally

---

🧠 3. Nervous System

Nervous System
├── Central Nervous System (CNS)
│   ├── Brain (cerebrum, cerebellum, brainstem)
│   └── Spinal Cord
└── Peripheral Nervous System (PNS)
    ├── Somatic (voluntary)
    └── Autonomic
        ├── Sympathetic ("fight or flight")
        └── Parasympathetic ("rest and digest")

1. Cell Body (Soma) — contains nucleus, Nissl bodies (ribosomes)
2. Dendrites — short, branched processes; receive impulses
3. Axon — single long process; carries impulse away from cell body
4. Myelin Sheath — formed by Schwann cells (PNS); speeds conduction
5. Nodes of Ranvier — gaps in myelin sheath; saltatory conduction
6. Axon terminal / Synaptic knob — releases neurotransmitters

• Sensory (afferent) — impulse to CNS
• Motor (efferent) — impulse from CNS
• Interneurons — connect sensory and motor

---

🫘 4. Urinary System / Kidney

• Bean-shaped; located retroperitoneally at T12–L3
• Right kidney is slightly lower (due to liver)
• Weight: ~150 g each
• Dimensions: 10–12 cm long, 5–6 cm wide, 3 cm thick

• Renal Cortex (outer) — contains glomeruli and convoluted tubules
• Renal Medulla (inner) — contains renal pyramids (loops of Henle, collecting ducts)
• Renal Pelvis → ureter → urinary bladder → urethra

1. Glomerular Filtration — ~180 L/day filtered
2. Tubular Reabsorption — ~178.5 L reabsorbed
3. Tubular Secretion — waste added → Final urine: ~1.5 L/day

---

🩸 5. Blood

• Total volume: ~5–6 L in adults
• Plasma (55%): Water (90%), proteins (albumin, globulin, fibrinogen), electrolytes, nutrients, hormones
• Formed Elements (45%):

  Cell	Normal Value	Function
  RBC (Erythrocytes)	4.5–5.5 million/mm³	O₂ transport via Hb
  WBC (Leukocytes)	4000–11000/mm³	Immunity, defence
  Platelets (Thrombocytes)	1.5–4 lakh/mm³	Clotting

---

📋 SECTION B: SHORT ANSWER QUESTIONS

---

Homeostasis is the tendency of the body to maintain a stable internal environment despite external changes. Examples: body temperature (37°C), blood pH (7.35–7.45), blood glucose (70–110 mg/dL).

• Planes: Sagittal, Coronal (Frontal), Transverse (Horizontal)
• Body Cavities: Dorsal (cranial + vertebral) and Ventral (thoracic + abdominal + pelvic)

A synapse is the junction between two neurons or between a neuron and an effector. Neurotransmitters: Acetylcholine, Noradrenaline (Norepinephrine), Dopamine, Serotonin, GABA.

CO = Heart Rate × Stroke Volume = 72 × 70 mL ≈ 5 L/min

Formation of RBCs. In adults, occurs in red bone marrow (sternum, vertebrae, ribs, proximal long bones). Stimulated by Erythropoietin (secreted by kidney).

Wave-like muscular contractions of the GI tract that propel food forward. Involves alternating contraction and relaxation of circular and longitudinal muscles.

A selective permeability barrier formed by tight junctions between brain capillary endothelial cells, astrocytic end-feet, and pericytes. Protects the brain from toxins and pathogens while allowing glucose, O₂, and CO₂ to pass.

---

🖼️ IMPORTANT DIAGRAMS (Exam Must-Know)

Diagram 1: Heart — Chambers, Valves & Blood Flow

---

Diagram 2: Nephron — Structure and Function

---

Diagram 3: Neuron — Structure

---

⭐ TOP 5 MOST LIKELY EXAM QUESTIONS

1. Describe the structure and function of the heart (with diagram) — almost always asked
2. Write a note on the Nephron (with labeled diagram)
3. Classify and describe the Nervous System / Structure of a Neuron
4. Composition and functions of Blood / Blood groups
5. Respiratory system — lungs and mechanism of breathing / lung volumes

---

📝 QUICK MEMORY AIDS

---