Chapter 5: Muscle contraction + neuromuscular junctions Flashcards
Name the three types of muscle
Involuntary/smooth, cardiac, voluntary/skeletal
Give three features of the structure of smooth muscle
-Under control of ANS
-Muscle cells - spindle shaped and contain single bundles of actin and myosin
-Contraction is slow but muscle tires slowly
What are the three types of cardiac muscle?
Atrial, ventricular, specialised excitory + conductive muscle fibres
Give three features of the structure of cardiac muscle
Myogenic - contracts without impulse
Neurones from ANS co-ordinate contractions
Cells are connected in rows and intercalated discs -between them - allow free diffusion of ions
Give three features of skeletal muscle structure
Multiple tubules (t-tubules) which go into fibre
Sarcoplasmic reticulum = specialised ER
Fatigues quickly as it contracts quickly + powerfully
In skeletal muscle, what is the cell membrane and cytoplasm referred to as?
Cell membrane = sarcolemma
Cytoplasm = sarcoplasm
Name two places that smooth muscle can be found
Walls of intestine,
Walls of arterioles + arteries
Does cardiac muscle fatigue?
No
Where are voluntary/striated/skeletal muscles found?
Muscles eg. biceps, triceps
Define myofibrils
Bundles of interconnected protein filaments of striated muscles
Outline 2 of the 4 protein molecules in myofibrils
Actin: Thin, twisted filaments made up of two strands
Myosin - Thick filaments made up of rods that project to the side
What is muscle contraction stimulated by?
Nerve impulse
What’s the neuromuscular junction?
A special synapse between the membrane of the axon on the motor neurone and the membrane of the muscle fibre
What’s a motor end plate?
Where the motor neurone axon divides into several branches forming a motor end plate
What’s the duration of time for the supply of ATP in the muscle fibre when contracting?
1-2 seconds
