muscle structure Flashcards
what is a tendon?
connects bone to skeletal muscle
what is a ligament?
connect bones to bones
what is a cartilage?
between bones ‘shock absorbers’
what is a muscle?
bundles of fibres, different structures
what is a cardiac muscle?
present in the heart, acts involuntarily (myogenic)
what are skeletal muscles?
attached to bones, vast majority of muscles, discontinuous contraction, controlled voluntarily
what are smooth muscles?
involuntary muscle, found in the gut, blood vessel walls and in the iris of the eye, slow and weak contraction
what is the function of skeletal muscle?
receiving a nerve impulse and working in antagonistic pairs to pull bones
what are antagonistic pairs?
you cannot stimulate the contraction of two antagonistic muscles at the same time, prime mover contracts and antagonist relaxes e.g. bicep and tricep in flexion/extension at the elbow
describe the structure of a skeletal muscle
made up of large bundles of long cells called muscle fibres, the cell membrane is called the sarcolemma, bits of the sarcolemma fold inwards and stick to the sarcoplasm, called T (transverse) tubules which help spread electrical impulses throughout the sarcoplasm to reach all parts of the muscle fibre, internal membranes called the sarcoplasmic reticulum run through sarcoplasm which stores and releases calcium ions, contain lots of mitochondria, they are multinucleate, lots of long cylindrical organelles called myofibrils made up of proteins
how are muscle fibres grouped into fast or slow twitch?
resistance to fatigue, speed of contraction
what is the speed of contraction in fast twitch muscle fibres?
fast
what is the speed of contraction in slow twitch muscle fibres?
slow
what is the power of contraction in fast twitch muscle fibres?
strong
what is the power of contraction in slow twitch muscle fibres?
weaker
what is the type of activity in fast twitch muscle fibres?
sprinting
what is the type of activity in slow twitch muscle fibres?
long distance running
what is the type of respiration in fast twitch muscle fibres?
anaerobic
what is the type of respiration in slow twitch muscle fibres?
aerobic
what is an example of a fast twitch muscle?
quad, biceps
what is an example of a slow twitch muscle?
core