Muscle

Question 1

Muscle classification (3 types)

Answer 1

Striated – voluntary
Cardiac – involuntary
Smooth – in voluntary

Question 2

Properties of muscular tissue

Answer 2

Excitability – action potentials via innovation of muscle triggered by auto rhythmic nature of heart and chemical, stimulate via neurotransmitters
Contractility - generation of force as an output from an action potential
Extensibility – stretch without being damaged
Elasticity - ability to return to original shape and confirmation following contraction of muscle

Question 3

Hypertrophy and atrophy

Answer 3

H- Increase in fibre size
A- reduction in fibre size

Question 4

Skeletal muscle tissue

Answer 4

Sarcolemma – plasma membrane of muscle cell
T. Tubules - imagination of the sarcolemma, involved in Action potential progression
Sarcoplasm – cytoplasm of muscle fibre
Myofibrils – contractile machinery of muscle, compromise of actin and myosin
Sarcoplasmic reticulum – network of endoplasmic reticulum, specialised for skeletal muscle in ca2+ handling

Question 5

The sarcomere

Answer 5

Compromise of thick filament myosin and thin, filament actin
Contractile proteins – generate force during contraction
Regulatory proteins – help switch contraction process on/off
Structural, proteins – maintain structural integrity of sarcomere

Question 6

Muscle contraction

Answer 6

Location of neural stimulation
Action potential (electrical signal) travels along nerve, axon, ends at synaptic terminal, releases neurotransmitter into the synaptic cleft

Question 7

Muscle contraction steps

Answer 7

CA2+ ions fine to troponin which weekends tropin in which forms troppo – myosin, complexes and actin
With the actin active site exposed, myosin heads bind, forming cross bridges
After Crossbridge formation, ATP present is used to change angle of myosin, ADP + pi released when ATP used
When another ATP molecule attaches to myosin, Crossbridge is broke and freeze up, head to make another bridge and complete contraction
Myosin splits the ATP into ADP, plus pi and uses energy to change back angle of myosin head

Question 8

Twitch contraction

Answer 8

Latent period – propagation of the AP across the sarcolemma and CO2 plus is released
Contraction period – Ca2+ binds troponin-tropomysin, cross bridges, formed, reach, peak tension/force
Relaxation period – CA2 plus reuptake into SR, myosin binding sites reset
Refractory period – loss of excitability, post contraction