histology

Question 1

What is part of a neuromuscular junction

Answer 1

s\ynapse- rapid transmission of depolarising impulse

ach- binds to post synaptic achr

Question 2

types of muscle fibres

Answer 2

slow twitch- fatigue resistant
fast twitch- fatigue rapidly but generate a large peak of muscle tension
2a- glycolytic
2b- glycolytic - white

Question 3

sliding filament theory 5 steps

Answer 3

Myosin heads bind actin

Hydrolysis of ATP provides energy for a – -conformational change of the myosin head, pulling the actin

-Sarcomeric shortening due to sliding of the filaments NOT change in length of either actin or myosin

Initiated by increased cytosolic Ca2+

Accessory proteins
Troponin/tropomyosin – mediate Ca2+ regulation
Maintaining architecture of the filament – e.g. nebulin, titin
-

Question 4

requirements for energy

Answer 4

high energy from atp

creatine phosphate a short term energy release

CP replenished by creatine kinase (CK)

CK is released on muscle fibre damage

Question 5

function of dystrophin

Answer 5

confers stability to muscle cell membrane

Question 6

6 steps of neuromuscular junction

Answer 6

Nerve impulse results in the release of acetyl choline from synaptic vesicles
ACh binds to its receptor
Cation entry results in depolarisation, the end-plate potential
An action potential travels across the muscle cell membrane and into the T-tubule system
Calcium is released from the sarcoplasmic reticulum leading to activation of contraction
Dissociated ACh is hydrolysed by acetyl cholinesterase in the NMJ

Question 7

role of amygdala

Answer 7

Receives inputs (visual and auditory)
System for processing fearful and threatening stimuli
Modulation of autonomic nervous system
Learning (e.g. acquisition of conditioned fear)