Physiology of Muscle Flashcards
What are the physiological functions of skeletal muscle?
- maintenance of posture
- purposeful movement
- respiratory movements
- heat production
- whole body metabolism
What are the 3 types of muscle?
skeletal, cardiac and smooth
What type of muscles are skeletal and cardiac muscles?
striated
What type of muscles are smooth muscles?
unstriated
What forms the darks bands of striation?
thick myosin filaments
What forms the light bands of striation?
thin actin filaments
What muscles innervated by somatic control?
skeletal muscles
What muscles are under voluntary control?
skeletal muscles
What muscles are innervated by autonomic control?
cardiac and smooth muscles
What muscles are under involuntary control?
cardiac and smooth muscles
What is the neurotransmitter at the neuromuscular junction?
acetylcholine
What is the motor unit?
a single alpha motor neurone and all the skeletal muscle fibres it innervates
Do precise movements require more or less muscle fibres in the motor unit?
less
precision>power=less and power>precision=more
What usually attaches skeletal muscles to bones?
tendons
What do muscles fibres (cells) contain?
many myofibrils (specialised contractile intracellular structures
What are sarcomeres?
actin and myocin are arranged into these (functional units of the muscle
What is the functional unit of any organ?
the smallest component capable of performing all the functions of the organ
What are the Z lines?
the boundaries of the sarcomere, connects the thin filaments of 2 adjoining sarcomeres
What is the A band?
thick filaments and the. areas of thin filaments that overlap the thick filaments
What is the H zone?
area of thick filaments that the thin filaments don’t reach
What is the I band?
remaining thin filaments that don’t contribute to the A band
What is the M line?
extends through the middle of the A band and H zone
What produces muscle tension?
sliding of actin filaments on myosin filaments
What is ATP required for?
contraction and relaxation
