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Membrane Physiology
Dr. A. R. Joshi
Professor of Physiology,
Bharati Vidyapeeth Medical College,
Pune.
Structure of cell
Unit Membrane
(Fluid Mosaic Model)
•Ingredients: 1. Phospholipids & Cholesterol
2. Lipoproteins
3. Glycocalyx
Cell Membrane
Cell Membrane
Types of Channels
● Ligand gated channels
e.g. Na+ channels at N-M Junction
● Voltage gated channels
e.g. Ca++ channels on...
Functions of cell membrane
• Protection
• Electrical property
• Transports across membrane
(Semipermeable )
• Cell to cell...
Transports across cell membrane
Passive transports :
●Diffusion:
- Simple diffusion
- Facilitated diffusion
- Diffusion th...
Transports across cell membrane…
● Active transports
– Uniport
– Symport (co-transport)
– Antiport (counter-transport)
● E...
Simple diffusion
Facilitated diffusion
Diffusion thro’ channel
Osmosis
Summary of ionic transport
Active Transport - Glucose
Active Transport – Na-K pump
Endocytosis & Exocytosis
Ionic Concentration ECF ICF
Na+
142 mEq/l 10 mEq/l
K+
3 to 5 mEq/l 140 mEq/l
Cl-
103 mEq/l 4 mEq/l
HCO3-
28 mEq/l 10 mEq/l...
Resting Membrane Potential
• The difference in electric potential that
exists across the cell membrane when cell is
in res...
Measurement of RMP
Resting Membrane Potential
• Nernst’s equation:
RMP= +61 log ﴾Conc. of ions inside﴿
﴾Conc. of ions outside﴿
(Corrected by ...
Action potential
• Series of events occurring in RMP when
cell is stimulated with adequate stimulus
• Events 1. Applicatio...
Action Potential-Cardiac Muscle
Properties of action potential
• Propagation
(Impulse- self propagatory A.P.)
• All or none law
• Refractory period
(Short...
Auto-rhythmicity by S.A. Node
(Leaky sodium channels)
Cell to cell communication
• Mediators
– Neurotransmitter
– Local hormone
(either excitatory or inhibitory)
e.g. Neuromusc...
Neuromuscular junction
Drugs acting at Neuro-muscular Junction
● Cholinomimatic drugs- e.g. Pilocarpine
● Anti-cholinergic drugs-e.g.Atropine
● C...
For Assistance in Physiology
• Dr. A.R. Joshi
Professor of Physiology
(mobile : 9423523322)
email:
aniruddharj@hotmail.com
Membrane physiology
Membrane physiology
Membrane physiology
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Membrane physiology

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This PPT is uploaded by Prof.Dr.R.R.Deshpande.This is prepared by Prof.Dr.A.R.Joshi ,Physilogist on Membrane Physiology

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Membrane physiology

  1. 1. Membrane Physiology Dr. A. R. Joshi Professor of Physiology, Bharati Vidyapeeth Medical College, Pune.
  2. 2. Structure of cell
  3. 3. Unit Membrane (Fluid Mosaic Model) •Ingredients: 1. Phospholipids & Cholesterol 2. Lipoproteins 3. Glycocalyx
  4. 4. Cell Membrane
  5. 5. Cell Membrane
  6. 6. Types of Channels ● Ligand gated channels e.g. Na+ channels at N-M Junction ● Voltage gated channels e.g. Ca++ channels on nerve membrane
  7. 7. Functions of cell membrane • Protection • Electrical property • Transports across membrane (Semipermeable ) • Cell to cell communication • Movement and phagocytosis
  8. 8. Transports across cell membrane Passive transports : ●Diffusion: - Simple diffusion - Facilitated diffusion - Diffusion thro’ channels ●Osmosis
  9. 9. Transports across cell membrane… ● Active transports – Uniport – Symport (co-transport) – Antiport (counter-transport) ● Endocytosis & Exocytosis
  10. 10. Simple diffusion
  11. 11. Facilitated diffusion
  12. 12. Diffusion thro’ channel
  13. 13. Osmosis
  14. 14. Summary of ionic transport
  15. 15. Active Transport - Glucose
  16. 16. Active Transport – Na-K pump
  17. 17. Endocytosis & Exocytosis
  18. 18. Ionic Concentration ECF ICF Na+ 142 mEq/l 10 mEq/l K+ 3 to 5 mEq/l 140 mEq/l Cl- 103 mEq/l 4 mEq/l HCO3- 28 mEq/l 10 mEq/l Ca++ 2.4 mEq/l 0.0001 mEq/l Mg++ 1.2 mEq/l 58 mEq/l PO4--- 4 mEq/l 75 mEq/l SO4-- 1 mEq/l 2 mEq/l Proteins 2 gm/dl (5mEq/l ) 16gm/dl (40 mEq/l ) pH 7.4 7
  19. 19. Resting Membrane Potential • The difference in electric potential that exists across the cell membrane when cell is in resting state • Developed due to K ions (-94mV) Na ions (+ 8mV) Na-K pump (- 4mV)
  20. 20. Measurement of RMP
  21. 21. Resting Membrane Potential • Nernst’s equation: RMP= +61 log ﴾Conc. of ions inside﴿ ﴾Conc. of ions outside﴿ (Corrected by Goldman’s equation) • RMP -Skeletal muscle –90mV -Nerve fiber –90 mV -Heart SA node –55mV -Heart muscle fiber –90 mV -Hair cells in inner ear – 150mV
  22. 22. Action potential • Series of events occurring in RMP when cell is stimulated with adequate stimulus • Events 1. Application of adequate stimulus 2. Depolarization (Na+ influx) 3. Repolarization (K+ efflux) 4. Hyperpolarization 5. Na+-K+ pump
  23. 23. Action Potential-Cardiac Muscle
  24. 24. Properties of action potential • Propagation (Impulse- self propagatory A.P.) • All or none law • Refractory period (Short R.P. for skeletal muscle and nerve Long R.P. for cardiac muscle)
  25. 25. Auto-rhythmicity by S.A. Node (Leaky sodium channels)
  26. 26. Cell to cell communication • Mediators – Neurotransmitter – Local hormone (either excitatory or inhibitory) e.g. Neuromuscular transmission Synaptic transmission
  27. 27. Neuromuscular junction
  28. 28. Drugs acting at Neuro-muscular Junction ● Cholinomimatic drugs- e.g. Pilocarpine ● Anti-cholinergic drugs-e.g.Atropine ● Competitive inhibitors- e.g. Scholine ● Anticholinesterases -e.g.Neostigmine ● Drugs regenerating cholinesterase- e.g.PAM
  29. 29. For Assistance in Physiology • Dr. A.R. Joshi Professor of Physiology (mobile : 9423523322) email: aniruddharj@hotmail.com

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