Physiology Lecture: Action Potential And Neuromuscular Transmission

Question 1

Peripheral nervous system

Answer 1

All nerves and ganglia outside CNS
Autonomic: parasympathetic, sympathetic
Somatic: efferent motor nerve, afferent sensory nerve
Cranial nerves except II
Myelinated, thinly myelinated, unmyelinated

Question 2

Motor unit

Answer 2

Anterior horn cell
Motor nerve axon
all the muscle fibers it innovates
Size of motor unit varies depending on requirement

Question 3

Cell membrane

Answer 3

Bi-layer of phospholipids
Largely importable to water soluble composes and ions - large & charged
Selectively permeable to various ions and compounds -

Question 4

Membrane potential

Answer 4

Big difference in electoral potential within and outside Te cell
Ionic concentrations
K ions more in cell then outside
Na ions - more outside than inside cell

Question 5

Resting membrane potential

Answer 5

Cell membrane is relatively permeable to potassium ions,
Membrane is relatives impermeable to Na ions
the resting membrane potential is predominantly a potassi um diffusion potential

Question 6

The NERNST equation
Hodgkin equation
Goldman

Answer 6

Need to know they exist
Help figure potential differences

Question 7

Equilibrium and resting potential

Answer 7

The system is not in equilibrium
There is a permeability to na, cl, ca
Eventually mo system would ‘run down’
Active energy requiring processes maintains a steady state and regenerates the steady state
- sodium pump

Question 8

Sodium ATPase Pump Active transport

Answer 8

Na-K ATPase pump moves 2k+ molecules out for 3Na + ions in

Question 9

The action potential

Answer 9

The axon and muscle membrane not always move permeable
Cell starts at around -70mV
-55 milivolts is the magic threshold
Then sodium ions flood into cell making it positive to about 30
Potassium ions flood out of the cell

Question 10

All a none law

Question 11

Propagation of the action potential

Answer 11

Amplitude stays the same but more signals are sent

Question 12

Nerve conduction velocity

Answer 12

Schwann cell -
Myelin
Nodes of rangier - sodium channels one clustered at each
Saltatory conduction - responses jump to nodes

Question 13

Synapse & neuromuscular junction

Answer 13

50 m/s nerve speed due to myelin and conduction
-each nerve terminal has a muscle fiber
Acetal choline

Question 14

The synapse

Answer 14

The arriving ap

Question 15

Neuromuscular junction

Question 16

Boiled down principles