Myology Flashcards
(87 cards)
All types of muscle tissue share these 4 characteristics:
1) Electrical Excitability
2) Contractility
3) Extensibility
4) Elasticity
Another word for striated muscle
Skeletal muscle
Alternating light and dark bands that are characteristic of this Skeletal muscle
Striations
If a muscle is a pack of spaghetti, these are like individual servings.
Fascicle
If a muscle is a pack of spaghetti, these are like single piece of spaghetti.
Muscle fibres (cells)
the cell (plasma) membrane of the muscle cell
sarcolemma
tiny invaginations tunnel in from the sarcolemma towards the centre of the muscle fibre
transverse tubules
the cytoplasm of the muscle fibres – contains lots of glycogen
sarcoplasm
a protein that binds oxygen that has diffused into the muscle fibre and delivers it to the mitochondria
myoglobin
specialized contractile organelles of the muscle cell
myofibrils
fluid filled tubes and sacs running along and surrounding each myofibril– they store and release calcium into the cell (when it’s needed)
sarcoplasmic reticulum
the functional unit of a myofibril (of contraction)
sarcomeres
makes up the thin filaments of a sarcomere
actin
the thick filaments of a sarcomere
myosin
What gives gives skeletal muscle its striated
appearance?
Thick and thin myofilaments overlapping during contraction.
What do skeletal muscle cells need to generate tension?
Stimulated by a nerve signal from a motor neuron
What is the name for the junction between the axon terminal of a motor neuron and the sarcolemma of muscle cells?
Neuromuscular junction (NMJ)
What is the name for the gap between an axon terminal and a motor neuron?
A synaptic cleft
Which neurotransmitter is released
across the synaptic cleft when the signal reaches the NMJ?
acetylcholine (ACh)
True or false: muscles can create their own action potentials.
False: they must come from the nervous system
When the signal crosses the synaptic cleft it stimulates the _____________
Sarcolemma
The ability to respond to certain stimuli by producing electrical signals is called _____________
Electrical excitability
When an action potential travels down the transverse tubules and stimulates the sarcoplasmic reticulum, it releases ___________
Calcium
What is the effect of the release of calcium within a muscle fibre?
It allows the myosin (of the thick filament) to connect with the actin (of the thin filament)