Human Physiology – Advanced University‑Level Study Notes
Prepared for DNB CET – Biology (Human Physiology)
Audience: Medical students, doctoral candidates, and interdisciplinary researchers.
Prerequisites: Basic cell biology, biochemistry, and introductory physiology.
Goal: Provide a rigorous, first‑principles treatment of human physiology, integrating mathematical formalism, mechanistic reasoning, and clinical edge cases.
Table of Contents
- Foundations of Physiology
- Cellular Physiology
- 2.1 Membrane Potentials & Ion Transport
- 2.2 Excitable Cells: Action Potentials
- 2.3 Synaptic Transmission
- Neurophysiology
- 3.1 Neuron Structure & Function
- 3.2 Neurotransmitters & Receptor Dynamics
- 3.3 Central vs. Peripheral Nervous System
- Cardiovascular Physiology
- 4.1 Cardiac Electrophysiology
- 4.2 Hemodynamics & Flow Mechanics
- 4.3 Baroreflex & Autoregulation
- Respiratory Physiology
- 5.1 Mechanics of Breathing
- 5.2 Gas Exchange & Pulmonary Blood Flow
- 5.3 Oxygen Dissociation Curve & Bohr Effect
- Renal Physiology
- 6.1 Glomerular Filtration
- 6.2 Tubular Transport & Hormonal Regulation
- 6.3 Urine Concentration & Electrolyte Balance
- Endocrine Physiology
- 7.1 Hormone Signaling Pathways
- 7.2 Feedback Loops & Homeostatic Control
- 7.3 Axis Dysregulation & Clinical Correlates
- Immune Physiology
- 8.1 Innate Immunity – Pattern Recognition
- 8.2 Adaptive Immunity – Antigen Presentation
- 8.3 Cytokine Networks & Inflammation
- Integration & Homeostasis
- 9.1 Feedback Systems
- 9.2 Cross‑Organ Coordination
- Advanced Topics & Mathematical Models
- 10.1 Cardiac Action Potential Models
- 10.2 Hemodynamic Modeling (Poiseuille, Turbulence)
- 10.3 Renin–Angiotensin–Aldosterone System (RAAS) Dynamics
- Edge Cases & Clinical Correlates
- Challenging Problem
1. Foundations of Physiology
| Concept | Definition | Key Equations |
|---|---|---|
| Homeostasis | Maintenance of internal stability | ΔState = Control – Perturbation |
| Control System | Sensor → Comparator → Actuator | ( \Delta y = K_p \Delta e + K_i \int e , dt + K_d \frac{de}{dt} ) |
| Membrane Potential | Difference in electrical potential across a cell membrane | ( E = \frac{RT}{zF}\ln\frac{[X]{out}}{[X]{in}} ) (Nernst) |
First Principle: Every physiological process can be reduced to interactions among molecules obeying chemical thermodynamics, diffusion, and electrostatic forces.
2. Cellular Physiology
2.1 Membrane Potentials & Ion Transport
-
Resting Potential: Arises from selective permeability of the plasma membrane to K⁺, Na⁺, Cl⁻, and impermeant anions.
- Goldman–Hodgkin–Katz (GHK) Equation:
[ V_m = \frac{RT}{F}\ln\left(\frac{P_{K}[K^+]{out}+P{Na}[Na^+]{out}+P{Cl}[Cl^-]{in}}{P{K}[K^+]{in}+P{Na}[Na^+]{in}+P{Cl}[Cl^-]_{out}}\right) ] where (P_i) are permeabilities.
- Goldman–Hodgkin–Katz (GHK) Equation:
-
Ion Pumps:
- Na⁺/K⁺‑ATPase: 3 Na⁺ out, 2 K⁺ in