Syllabus Breakdown

1. General Physiology - cell structure, sub-cellular units, cell membrane/transport, bioelectric potentials, body fluids/homeostasis
2. Blood - plasma proteins, bone marrow, erythrocytes, hemoglobin, anemia, jaundice, leucocytes, thrombocytes, hemostasis/coagulation, blood groups, lymph & immunity
3. Cardiovascular System - heart structure, ECG, cardiac cycle, heart sounds, blood pressure, circulation (coronary/cerebral/renal/pulmonary)
4. Respiratory System - mechanics of respiration, lung volumes, alveolar ventilation, pulmonary circulation, respiratory centers, hypoxia/high altitude physiology
5. Digestive System - saliva, stomach, pancreas, liver/bile, small & large intestine, GI hormones, GI movements, digestion/absorption

Quick Overview

Syllabus Breakdown

1. General Physiology - cell structure, sub-cellular units, cell membrane/transport, bioelectric potentials, body fluids/homeostasis
2. Blood - plasma proteins, bone marrow, erythrocytes, hemoglobin, anemia, jaundice, leucocytes, thrombocytes, hemostasis/coagulation, blood groups, lymph & immunity
3. Cardiovascular System - heart structure, ECG, cardiac cycle, heart sounds, blood pressure, circulation (coronary/cerebral/renal/pulmonary)
4. Respiratory System - mechanics of respiration, lung volumes, alveolar ventilation, pulmonary circulation, respiratory centers, hypoxia/high altitude physiology
5. Digestive System - saliva, stomach, pancreas, liver/bile, small & large intestine, GI hormones, GI movements, digestion/absorption

Quick Overview

Syllabus Breakdown

1. General Physiology - cell structure, sub-cellular units, cell membrane/transport, bioelectric potentials, body fluids/homeostasis
2. Blood - plasma proteins, bone marrow, erythrocytes, hemoglobin, anemia, jaundice, leucocytes, thrombocytes, hemostasis/coagulation, blood groups, lymph & immunity
3. Cardiovascular System - heart structure, ECG, cardiac cycle, heart sounds, blood pressure, circulation (coronary/cerebral/renal/pulmonary)
4. Respiratory System - mechanics of respiration, lung volumes, alveolar ventilation, pulmonary circulation, respiratory centers, hypoxia/high altitude physiology
5. Digestive System - saliva, stomach, pancreas, liver/bile, small & large intestine, GI hormones, GI movements, digestion/absorption

Quick Overview

Physiology Study Plan + Chapter 1 Detailed Notes

PART A: FULL STUDY PLAN (Week-by-Week)

PART B: DETAILED NOTES — UNIT I: GENERAL PHYSIOLOGY

1. Cell Structure & Sub-cellular Units

2. Cell Membrane and Its Properties

• Composition: phospholipids (amphipathic - hydrophilic heads face out/in, hydrophobic tails face each other), cholesterol (stabilizes fluidity), membrane proteins (integral/transmembrane and peripheral), carbohydrates (glycocalyx - cell recognition).
• Membrane proteins function as: ion channels, carrier/transport proteins, receptors, enzymes, cell-adhesion molecules.
• Per Guyton and Hall, several types of transport proteins are recruited to the membrane specifically to allow selective movement of substances that cannot cross the lipid bilayer directly (- Guyton and Hall Textbook of Medical Physiology).

3. Transport Mechanisms Across the Cell Membrane

• Simple diffusion - movement down concentration gradient (through lipid bilayer for lipid-soluble substances, or through channels for ions/water).
• Facilitated diffusion - carrier-mediated, down gradient, but saturable (e.g., GLUT transporters for glucose).
• Osmosis - diffusion of water across a semipermeable membrane from low to high solute concentration.

• Primary active transport - directly uses ATP (e.g., Na⁺-K⁺ ATPase pump - moves 3 Na⁺ out, 2 K⁺ in per ATP hydrolyzed; Ca²⁺ ATPase; H⁺ ATPase).
• Secondary active transport - uses the energy stored in an ion gradient (created by primary active transport) to move another substance:
  • Co-transport (symport): both substances move in the same direction (e.g., Na⁺-glucose cotransporter in intestine/kidney).
  • Counter-transport (antiport): substances move in opposite directions (e.g., Na⁺-Ca²⁺ exchanger, Na⁺-H⁺ exchanger).

• Isotonic solution: no change in cell volume.
• Hypotonic solution: water enters cell → swelling → hemolysis (in RBCs).
• Hypertonic solution: water leaves cell → shrinkage (crenation).

4. Bioelectric Potentials

• Defined as the potential difference across the cell membrane at rest, with the inside being negative relative to outside.
• Typical values: nerve fiber ≈ -70 mV; skeletal muscle ≈ -90 mV; cardiac muscle ≈ -90 mV.
• Cause: unequal distribution of ions (high intracellular K⁺, high extracellular Na⁺) maintained by the Na⁺-K⁺ ATPase pump, combined with differential membrane permeability - at rest the membrane is far more permeable to K⁺ than to Na⁺, so RMP lies close to the K⁺ equilibrium potential (Costanzo Physiology, 7th ed.).
• Nernst equation gives the equilibrium potential for a single ion: Ex = (61/z) × log₁₀([X]out/[X]in) at body temperature (z = valence of ion).
• Driving force on any ion = Em - Ex (the difference between actual membrane potential and that ion's own equilibrium potential). If driving force = 0, the ion is at electrochemical equilibrium and there's no net movement (Costanzo Physiology).
• Goldman-Hodgkin-Katz (GHK) equation is used when more than one ion contributes to membrane potential (accounts for relative permeabilities of Na⁺, K⁺, Cl⁻).

1. Resting stage - membrane polarized at RMP.
2. Depolarization - stimulus opens voltage-gated Na⁺ channels → rapid Na⁺ influx → membrane potential moves toward Na⁺ equilibrium potential (~+60 mV), overshoot beyond zero.
3. Repolarization - Na⁺ channels inactivate; voltage-gated K⁺ channels open → K⁺ efflux → membrane returns toward resting potential.
4. After-hyperpolarization (in some cells) - K⁺ channels remain open slightly longer, undershoot below RMP.

5. Body Fluids and Homeostasis

• Total body water (TBW) ≈ 60% of body weight, distributed into:
  • Intracellular fluid (ICF) ≈ 2/3 of TBW - rich in K⁺, Mg²⁺, phosphate, protein.
  • Extracellular fluid (ECF) ≈ 1/3 of TBW - subdivided into plasma (~1/4 of ECF) and interstitial fluid (~3/4 of ECF) - rich in Na⁺, Cl⁻, HCO₃⁻.
• Extracellular fluid contains large amounts of sodium but only small amounts of potassium, and large amounts of chloride, while the reverse is true intracellularly - this ionic asymmetry is fundamental to bioelectric phenomena described above (- Guyton and Hall Textbook of Medical Physiology).
• Homeostasis: the maintenance of a relatively constant internal environment despite external changes, achieved through negative feedback control systems (sensor → control center → effector), e.g., regulation of blood glucose, temperature, pH, blood pressure. A few systems (e.g., parturition, blood clotting) work via positive feedback - self-amplifying until a natural endpoint is reached.
• Fluid balance regulation involves ADH (water reabsorption), aldosterone (Na⁺ reabsorption), thirst mechanism, and atrial natriuretic peptide (ANP).

Quick Recall - Unit I Flow

1. Cell Membrane Structure

Shows the phospholipid bilayer (hydrophilic heads out, hydrophobic tails in), embedded integral/peripheral proteins, ion channels, carrier proteins, cholesterol, and surface glycoproteins/glycolipids (glycocalyx).

2. Resting Membrane Potential (RMP)

Shows the Na⁺/K⁺ concentration gradients across the membrane, the Na⁺-K⁺ ATPase pump (3 Na⁺ out : 2 K⁺ in), leak channels, and the resting voltage of about -70 mV inside relative to outside.

3. Action Potential

Shows the full voltage-time curve: resting stage → threshold → depolarization (Na⁺ influx) → overshoot → repolarization (K⁺ efflux) → after-hyperpolarization, with the absolute and relative refractory periods marked.

• Cell Membrane poster: label it blind from memory - test yourself on which transport mechanism (diffusion, facilitated diffusion, primary/secondary active transport) would move a given substance.
• RMP poster: be able to explain why the resting potential is close to the K⁺ equilibrium potential (membrane is more permeable to K⁺ at rest) - a favorite viva question.
• Action Potential poster: practice drawing this curve from scratch and annotating which channel (Na⁺ or K⁺, voltage-gated) is responsible for each phase, plus where each refractory period falls.

Syllabus Breakdown

1. General Physiology - cell structure, sub-cellular units, cell membrane/transport, bioelectric potentials, body fluids/homeostasis
2. Blood - plasma proteins, bone marrow, erythrocytes, hemoglobin, anemia, jaundice, leucocytes, thrombocytes, hemostasis/coagulation, blood groups, lymph & immunity
3. Cardiovascular System - heart structure, ECG, cardiac cycle, heart sounds, blood pressure, circulation (coronary/cerebral/renal/pulmonary)
4. Respiratory System - mechanics of respiration, lung volumes, alveolar ventilation, pulmonary circulation, respiratory centers, hypoxia/high altitude physiology
5. Digestive System - saliva, stomach, pancreas, liver/bile, small & large intestine, GI hormones, GI movements, digestion/absorption

Quick Overview

PART A: FULL STUDY PLAN (Week-by-Week)

PART B: DETAILED NOTES — UNIT I: GENERAL PHYSIOLOGY

1. Cell Structure & Sub-cellular Units

2. Cell Membrane and Its Properties

• Composition: phospholipids (amphipathic - hydrophilic heads face out/in, hydrophobic tails face each other), cholesterol (stabilizes fluidity), membrane proteins (integral/transmembrane and peripheral), carbohydrates (glycocalyx - cell recognition).
• Membrane proteins function as: ion channels, carrier/transport proteins, receptors, enzymes, cell-adhesion molecules.
• Per Guyton and Hall, several types of transport proteins are recruited to the membrane specifically to allow selective movement of substances that cannot cross the lipid bilayer directly (- Guyton and Hall Textbook of Medical Physiology).

3. Transport Mechanisms Across the Cell Membrane

• Simple diffusion - movement down concentration gradient (through lipid bilayer for lipid-soluble substances, or through channels for ions/water).
• Facilitated diffusion - carrier-mediated, down gradient, but saturable (e.g., GLUT transporters for glucose).
• Osmosis - diffusion of water across a semipermeable membrane from low to high solute concentration.

• Primary active transport - directly uses ATP (e.g., Na⁺-K⁺ ATPase pump - moves 3 Na⁺ out, 2 K⁺ in per ATP hydrolyzed; Ca²⁺ ATPase; H⁺ ATPase).
• Secondary active transport - uses the energy stored in an ion gradient (created by primary active transport) to move another substance:
  • Co-transport (symport): both substances move in the same direction (e.g., Na⁺-glucose cotransporter in intestine/kidney).
  • Counter-transport (antiport): substances move in opposite directions (e.g., Na⁺-Ca²⁺ exchanger, Na⁺-H⁺ exchanger).

• Isotonic solution: no change in cell volume.
• Hypotonic solution: water enters cell → swelling → hemolysis (in RBCs).
• Hypertonic solution: water leaves cell → shrinkage (crenation).

4. Bioelectric Potentials

• Defined as the potential difference across the cell membrane at rest, with the inside being negative relative to outside.
• Typical values: nerve fiber ≈ -70 mV; skeletal muscle ≈ -90 mV; cardiac muscle ≈ -90 mV.
• Cause: unequal distribution of ions (high intracellular K⁺, high extracellular Na⁺) maintained by the Na⁺-K⁺ ATPase pump, combined with differential membrane permeability - at rest the membrane is far more permeable to K⁺ than to Na⁺, so RMP lies close to the K⁺ equilibrium potential (Costanzo Physiology, 7th ed.).
• Nernst equation gives the equilibrium potential for a single ion: Ex = (61/z) × log₁₀([X]out/[X]in) at body temperature (z = valence of ion).
• Driving force on any ion = Em - Ex (the difference between actual membrane potential and that ion's own equilibrium potential). If driving force = 0, the ion is at electrochemical equilibrium and there's no net movement (Costanzo Physiology).
• Goldman-Hodgkin-Katz (GHK) equation is used when more than one ion contributes to membrane potential (accounts for relative permeabilities of Na⁺, K⁺, Cl⁻).

1. Resting stage - membrane polarized at RMP.
2. Depolarization - stimulus opens voltage-gated Na⁺ channels → rapid Na⁺ influx → membrane potential moves toward Na⁺ equilibrium potential (~+60 mV), overshoot beyond zero.
3. Repolarization - Na⁺ channels inactivate; voltage-gated K⁺ channels open → K⁺ efflux → membrane returns toward resting potential.
4. After-hyperpolarization (in some cells) - K⁺ channels remain open slightly longer, undershoot below RMP.

5. Body Fluids and Homeostasis

• Total body water (TBW) ≈ 60% of body weight, distributed into:
  • Intracellular fluid (ICF) ≈ 2/3 of TBW - rich in K⁺, Mg²⁺, phosphate, protein.
  • Extracellular fluid (ECF) ≈ 1/3 of TBW - subdivided into plasma (~1/4 of ECF) and interstitial fluid (~3/4 of ECF) - rich in Na⁺, Cl⁻, HCO₃⁻.
• Extracellular fluid contains large amounts of sodium but only small amounts of potassium, and large amounts of chloride, while the reverse is true intracellularly - this ionic asymmetry is fundamental to bioelectric phenomena described above (- Guyton and Hall Textbook of Medical Physiology).
• Homeostasis: the maintenance of a relatively constant internal environment despite external changes, achieved through negative feedback control systems (sensor → control center → effector), e.g., regulation of blood glucose, temperature, pH, blood pressure. A few systems (e.g., parturition, blood clotting) work via positive feedback - self-amplifying until a natural endpoint is reached.
• Fluid balance regulation involves ADH (water reabsorption), aldosterone (Na⁺ reabsorption), thirst mechanism, and atrial natriuretic peptide (ANP).

Quick Recall - Unit I Flow

1. Cell Membrane Structure

Shows the phospholipid bilayer (hydrophilic heads out, hydrophobic tails in), embedded integral/peripheral proteins, ion channels, carrier proteins, cholesterol, and surface glycoproteins/glycolipids (glycocalyx).

2. Resting Membrane Potential (RMP)

Shows the Na⁺/K⁺ concentration gradients across the membrane, the Na⁺-K⁺ ATPase pump (3 Na⁺ out : 2 K⁺ in), leak channels, and the resting voltage of about -70 mV inside relative to outside.

3. Action Potential

Shows the full voltage-time curve: resting stage → threshold → depolarization (Na⁺ influx) → overshoot → repolarization (K⁺ efflux) → after-hyperpolarization, with the absolute and relative refractory periods marked.

• Cell Membrane poster: label it blind from memory - test yourself on which transport mechanism (diffusion, facilitated diffusion, primary/secondary active transport) would move a given substance.
• RMP poster: be able to explain why the resting potential is close to the K⁺ equilibrium potential (membrane is more permeable to K⁺ at rest) - a favorite viva question.
• Action Potential poster: practice drawing this curve from scratch and annotating which channel (Na⁺ or K⁺, voltage-gated) is responsible for each phase, plus where each refractory period falls.