Semester Test 2 – Comprehensive Revision Bullets

Endocrine System

• General scope

  • Covers Learning Unit $5$.

  • Know all hormones, sources, functions, inter-relations, diagrams, spellings (no abbreviations accepted).

• Hypothalamus – Pituitary Axis

  • Hypothalamic hormones (write in full; $6$ items, $12$ marks if matched with pituitary partners):

  • Gonadotropin-releasing hormone ➜ stimulates Follicle-stimulating hormone & Luteinizing hormone.

  • Thyrotropin-releasing hormone ➜ stimulates Thyroid-stimulating hormone.

  • Corticotropin-releasing hormone ➜ stimulates Adrenocorticotropic hormone.

  • Growth hormone-releasing hormone ➜ stimulates Growth hormone.

  • Prolactin-inhibiting hormone ➜ inhibits Prolactin.

  • Somatostatin ➜ inhibits Growth hormone.

  • Posterior pituitary (neurohypophysis; neural connection, not vascular):

  • Oxytocin.

  • Antidiuretic hormone.

  • Anterior pituitary (true endocrine, vascular portal link): $6$ major hormones—Follicle-stimulating, Luteinizing, Thyroid-stimulating, Adrenocorticotropic, Prolactin, Growth hormone.

  • Labelling diagrams: emphasise portal vessels, primary/secondary capillaries, hypothalamo-hypophyseal tract, nuclei, hormones.

• Thyroid & Parathyroid

  • Thyroid hormone (increases metabolic rate).

  • Calcitonin (released by parafollicular C-cells; lowers blood calcium).

  • Parathyroid hormone (raises blood calcium; antagonistic to Calcitonin).

  • $3$ hormones × functions ≈ $6$ marks.

• Adrenal gland

  • Two main layers: Adrenal cortex & Adrenal medulla.

  • Cortex sub-layers, hormones, functions (mind-map):

  • Zona glomerulosa → Mineralocorticoids (e.g.
    Aldosterone) → Na$^+$ retention, K$^+$ excretion, blood-pressure regulation.

  • Zona fasciculata → Glucocorticoids (e.g.
    Cortisol) → fat & protein catabolism, gluconeogenesis, stress adaptation.

  • Zona reticularis → Sex steroids (e.g.
    Estradiol, Androgens) → supplemental sex hormones, post-menopausal oestrogen source.

  • Medulla (neuro-endocrine, sympathetic): Catecholamines (≈ $75\%$ Adrenaline, $25\%$ Noradrenaline, trace Dopamine) → fight-or-flight, alertness.

  • Potential $14$–$15$-mark breakdown when layer + hormone + function required.

• Pancreas – Islets of Langerhans

  • $5$ cell types, hormones, principal actions:

  • Alpha cells → Glucagon → ↑ blood glucose.

  • Beta cells → Insulin → ↓ blood glucose.

  • Delta cells → Somatostatin (Growth-hormone-inhibiting hormone) → modulates digestion, enzyme secretion.

  • PP cells → Pancreatic polypeptide → inhibits gall-bladder contraction.

  • G cells → Gastrin → stimulates gastric acid, motility, emptying.

  • $10$–$15$ marks depending on whether functions are asked.

Cardiovascular System

• Functions of the circulatory system

  • Transport (O2$, CO$2, nutrients, wastes, hormones).

  • Protection (immune cell distribution, clotting).

  • Regulation (fluid balance, pH, temperature).

  • Question weight: $3$–$6$ marks.

• Formed elements (total $10$ marks)

  • Erythrocytes.

  • Platelets.

  • Leukocytes ➜ subdivide:

  • Granulocytes: Neutrophils, Eosinophils, Basophils.

  • Agranulocytes: Lymphocytes, Monocytes.

• ABO & Rh blood typing

  • Blood types $=4$ (A, B, AB, O).

  • Determined by presence/absence of antigens (agglutinogens) on RBC membranes.

  • Antibody logic: cannot form antibody against own antigen.

  • Quick chart:

  • Type A: A antigen, anti-B antibody.

  • Type B: B antigen, anti-A antibody.

  • Type AB: both antigens, no antibodies (universal recipient).

  • Type O: no antigens, both antibodies (universal donor).

  • Rh factor: antigen presence = Rh positive; absence = Rh negative.

• Hemostasis ("blood-stoppage")

  • $3$ sequential phases (≈ $3$–$6$ marks):

  1. Vascular spasm – vasoconstriction via prostaglandins, bradykinin.

  2. Platelet plug formation – platelet adhesion to exposed collagen.

  3. Coagulation – fibrin network stabilises clot; later clot removal.

• Cardiac conduction pathway (exact naming, $5$ marks)

  1. Sinoatrial node fires.

  2. Excitation spreads through atrial myocardium.

  3. Atrioventricular node fires.

  4. Signal travels via Atrioventricular bundle (Bundle of His).

  5. Purkinje fibres distribute excitation through ventricular myocardium.

• Electrocardiogram (ECG) drawing

  • Label: P, Q, R, S, T waves.

  • Intervals: PR, QRS, QT.

  • Segments: PQ, ST.

  • $10$ marks total (½ mark wave position, ½ mark name).

  • Interpretations:

  • P wave = atrial depolarisation/ contraction.

  • QRS complex = ventricular depolarisation & atrial repolarisation.

  • T wave = ventricular repolarisation.

Lymphatic System & Immunity

• Core functions (each $1$ mark)

  • Fluid recovery.

  • Immunity.

  • Lipid absorption.

• Four structural components

  1. Lymph (recovered fluid).

  2. Lymphatic vessels.

  3. Lymphatic tissue (diffuse cell aggregations).

  4. Lymphatic organs (encapsulated masses).

• Primary vs Secondary lymphatic organs

  • Primary: Red bone marrow (matures B cells), Thymus (matures T cells).

  • Secondary: Lymph nodes, Tonsils, Spleen.

  • $5$ marks (list & categorise).

• Lymphatic cells (name + role)

  • Natural killer cells – destroy bacteria, infected cells, cancer.

  • T lymphocytes – cell-mediated (intracellular) immunity.

  • B lymphocytes – humoral (antibody) immunity; differentiate to plasma cells.

  • Macrophages – large phagocytes clearing debris & pathogens.

  • Dendritic cells – mobile antigen-presenting "alarms".

  • Reticular cells – stationary APCs forming stroma of lymph organs.

• Inflammation ("itis") – five-word narrative

  1. Chemicals released from damaged cells (histamine, cytokines).

  2. Margination – vascular permeability ↑, WBCs cling to endothelium.

  3. Diapedesis – leukocytes squeeze through vessel wall.

  4. Chemotaxis – WBCs migrate toward chemical gradient.

  5. Phagocytosis – debris & microbes engulfed; repair initiated.

  • Cardinal signs produced: redness, heat, swelling, pain.

• Fever (Pyrexia)

  • Definition: abnormal body-temperature elevation.

  • Triggers: infection, trauma, drugs, tumours.

  • Benefits: promotes interferon, raises metabolic rate, inhibits microbe replication.

• Adaptive immunity dichotomy

  • Cellular (T-cell) immunity – attacks intracellular pathogens; effector = Cytotoxic T cells.

  • Humoral (B-cell) immunity – targets extracellular agents via antibodies; effector = Plasma cells.

  • Four contrast points often examined: disease agents, effector cells, MHC restriction, secreted products.

Respiratory System

• Functions (expect $4$–$5$ to list)

  • O$<em>2$/CO$</em>2$ exchange.

  • Speech & vocalisation.

  • Olfaction.

  • pH regulation (via CO$_2$).

  • Synthesis of Angiotensin II.

  • Thoracic pump aiding venous/lymph flow.

  • Breath-holding for abdominal expulsion.

• Mechanics of ventilation

  • Inhalation (Inspiration) – active:

  • Ribs swing up & out; diaphragm flattens.

  • Thoracic volume ↑ ➜ intrapulmonary pressure ↓ ($\downarrow P$).

  • Air flows from high (atmosphere) to low (lungs).

  • Exhalation (Expiration) – passive (quiet):

  • Elastic recoil compresses lungs.

  • Volume ↓ ➜ pressure ↑ ($\uparrow P$).

  • Air flows out along pressure gradient.

  • Forced expiration recruits internal intercostals, rectus abdominis, obliques.

• Four gas laws (verbatim definitions required)

  • Boyle: At constant temperature, the pressure of a given quantity of gas is inversely proportional to its volume.

  • Charles: The volume of a given quantity of gas is directly proportional to its absolute temperature, assuming constant pressure.

  • Dalton: Total pressure of a gas mixture equals the sum of the partial pressures of its individual gases.

  • Henry: At an air-water interface, the amount of gas that dissolves in water is proportional to its partial pressure in the air and its solubility, at constant temperature.

  • Exam = $8$ marks (name + explanation).

• Spirogram (drawing $10$ marks)

  • Label areas correctly:

  • Tidal Volume.

  • Inspiratory Reserve Volume.

  • Expiratory Reserve Volume.

  • Residual Volume.

  • Inspiratory Capacity, Functional Residual Capacity, Vital Capacity, Total Lung Capacity.

• Gas transport & exchange

  • In Lungs (alveoli):

  • O$_2$ loading: $98.5\%$ binds haemoglobin, $1.5\%$ dissolved in plasma.

  • CO$_2$ unloading: $70\%$ as bicarbonate, $23\%$ carbamino-Hb, $7\%$ dissolved.

  • In Tissues (reverse):

  • O$<em>2$ unloads to cells; CO$</em>2$ loads into blood via same three fractions.

  • Question weight: $5$–$7$ marks (fractions $+$ explanation of loading vs unloading).

Examination Logistics & Mark Guidance

• Semester Test $2$ covers Learning Units $5$–$8$ (Endocrine, Cardiovascular, Lymphatic/Immunity, Respiratory).

• Semester Test $3$ & sick-test = whole-year theory—begin early preparation.

• Typical question allocations (approx.):

  • Hormone lists $\approx14$ marks.

  • Adrenal gland $\approx14$–$15$.

  • Pancreatic islet $10$–$15$.

  • Cardiac formed elements $10$.

  • ECG $10$.

  • Inflammation $5$.

  • Gas laws $8$.

  • Spirogram $10$.

  • Overall paper $85$–$95$ marks, $2$-hour duration.

Study & Exam-Writing Tips

• No abbreviations: spell every hormone & structure completely (e.g.
  "Follicle-stimulating hormone", not "FSH").

• Practice handwriting: repeatedly write hormone names until automatic.

• Use diagrams: redraw pituitary links, adrenal layers, ECG, spirogram.

• Mind-maps help memorise layer → hormone → function chains.

• Five-keyword sentence trick for inflammation.

• Feel the physiology: physically mimic breathing mechanics while learning laws.

• Allocate time: $\approx1$ mark = $1$ minute; leave $5$–$10$ min to review spelling of hormones.

• • Alpha cells → Glucagon → ↑ blood glucose.

  • Beta cells → Insulin → ↓ blood glucose.

  • Delta cells → Somatostatin (Growth-hormone-inhibiting hormone) → modulates digestion, enzyme secretion.

  • PP cells → Pancreatic polypeptide → inhibits gall-bladder contraction.

  • G cells → Gastrin → stimulates gastric acid, motility, emptying.

  • $10$–$15$ marks depending on whether functions are asked.

• No abbreviations: spell every hormone & structure completely (e.g.
  "Follicle-stimulating hormone", not "FSH").

• Practice handwriting: repeatedly write hormone names until automatic.

• Use diagrams: redraw pituitary links, adrenal layers, ECG, spirogram.

• Mind-maps help memorise layer → hormone → function chains.

• Five-keyword sentence trick for inflammation.

• Feel the physiology: physically mimic breathing mechanics while learning laws.

• Allocate time: $\approx1$ mark = $1$ minute; leave $5$–$10$ min to review spelling of hormones.