Sliding Filament Theory

Question 0

Myofilaments

Answer 0

Myosin: (thick) cross bridges - attach to acting
Actin: (thin) troponin and tropmyosin

Question 1

Sarcomere

Answer 1

Contractile unit of a myofibril
Components:
Z line: both ends
I band: tight and only thin filaments, shortens
A band: dark area (thick and thin filaments overlap)
H zone: Middle of A band, only think filaments, shorten

Question 2

Sarcolemma

Answer 2

Cell membrane surrounding a muscle fibre and myofibrils

Question 3

Sarcoplasm

Answer 3

Inside the sarcolemma
Gelatin like substance
Surrounds actin and myosin
Contains mitochondria and myoglobin

Question 4

Transverse tubules

Answer 4

Small openings of the sarcolemma that carry neural impulses

Question 5

Sarcoplasmic reticulum

Answer 5

System of channels throughout the muscle fibre

Question 6

Motor unit

Answer 6

Motor neuron, plus the muscle fibres it stimulates

Ratio of muscle fibres innervated by a single motor nerve is determined by precision, accuracy, coordination of movement

Question 7

All or none law

Answer 7

Until impulses reaches a certain threshold level of intensity, it will not cause stimulation
Once threshold is reached, all muscle fibres of that motor unit contract at he same and it their maximum potential