Muscular System Flashcards
What are the functions of muscles
movement stability control of body openings and passages heat production glycemic control
movement
move from place to place; move body contents
stability
maintain posture
control of body openings and passages
mouth; internal sphincters
heat production
85% of body heat produced by skeletal muscles
glycemic control
regulation of blood glucose concentration within its normal range; skeletal muscles absorb, store, and use a large share of
one’s glucose, and play a highly significant role in stabilizing it’s blood concentration
what are the characteristics of muscles
responsiveness (excitability) conductivity contractility extensibility elasticity
responsiveness (excitability)
when stimulated by chemical signals, stretch, and other stimuli, muscle cells respond with electrical changes across the cell membrane
conductivity
stimulation of a muscle cell produces more than a local effect; the local electrical change triggers a wave of excitation that travels rapidly all the cell and initiates processes leading to contraction
contractility
muscle cells are unique in their ability to shorten substantially When stimulated; enables them to create movement
extensibility
ability to stretch again between contractions
elasticity
ability to stretch, release, and recoil to a shorter length
Epimysium
covers entire muscle; attachment to tendon
perimysium
surrounds fascicle or bundle of skeletal muscle
endomysium
surrounds individual skeletal muscle cell
parallel
fibers run parallel and can be arranged with or without body/gaster (biceps brachii – with body/gaster); (rectus abdominis – without body/gaster)
convergent
fibers meet at a common attachment site (mylohyoid)
pennate
fibers arranged at an angle;
unipennate
fibers on one side of tendon (extensor digitorum longus)
bipennate
fibers on both sides of tendon (rectus femoris)
multipennate
fibers branch within tendon (deltoid)
circular
fibers arranged in circular pattern (orbicularis oris or oculi); sphincters
tetanus (lock jaw)
caused by bacterium Clostridium tetani; toxins released cause the involuntary contraction of skeletal muscle; jaw muscles affected first
caused by a deep dirty wound
botulism (food poisoning)
caused by bacterium Clostridium botulinum; toxins released prevent the release of Ach (acetylcholine); causes paralysis of respiratory muscles
treated with oxygen, acetylcholine and pump the stomach