06 - Muscle Flashcards
What are the 3 types of muscle tissue?
Skeletal
Smooth
Cardiac
What contractile proteins allow the muscle to contract?
Actin and myosin
What is the function of skeletal muscle?
to move the skeleton
What is an intercalated disc in cardiac muscle?
The place where cells are in close contact with each other at a junction
What do the intercalated discs do?
Allow nerve impulses to spread from cell to cell over the whole ‘sheet’ causing contraction
is smooth muscle striated?
No
What is smooth muscle controlled by?
the autonomic nervous system, hormones and local metabolites
What does the sarcoplasm in skeletal muscle contain large amounts of?
Glycogen
What are transverse tubules and what doe they do?
They are tiny invagination of the sarcolemma and action potentials travel along the T Tubules and spread out throughout the entire muscle fibre
What are myofibrils composed of?
Smaller filaments or myofilaments
What are the thin filaments composed of?
The protein actin
What are the thick filaments composed of?
The protein myosin
how many thin filaments for every thick?
2 for every 1
What are the 3 layers of CT that bind muscle tissue?
Endomysium
Perimysium
Epimysium
What do tendons attach?
muscle to bone
What are musculotendinous/ myotendinous junctions
Where the collagen fibres of tendons are attached to the muscle fibres
How does muscle contraction happen?
The myosin heads attach to and walk along the actin filaments at both ends of a sarcolemma, pulling the filaments closer to the M line
What os released from the sarcoplasmic reticulum following a nerve impulse received at the neuromuscular junction
Calcium
What does calcium bind to and what does it do?
It binds to troponin and triggers it to move the attached tropomyosin thereby freeing the myosin binding sites on actin
What does the myosin head do?
Hydrolysed ATP into ADP and a phosphate group, resulting in the energisation of the myosin head
What does the myosin head attach to and form?
It attatches to the myosin binding site and forms a cross bridge
What occurs after the cross-bridge has formed? And what does this cause
The power stroke. During the power stroke, the cross bridge rotates towards the centre of the sarcomere and generates a force, sliding the thin filament towards the thin filament past the thick filament towards the M line
What are the neurons that stimulate the muscle to contract called?
Somatic motor neurons
The neuromuscular junction is what between a the what and what?
The NMJ is a synapse between the motor neuron and the motor end plate of the muscle fibre
