Module 4 Flashcards
Skeletal muscle
Attach to and cover bony skeleton Longest muscle fibers Striated, voluntary Can contract rapidly; tires easily & must rest Strong, adaptable
Cardiac muscle
Only in heart Striated, involuntary Pacemaker sets rate of contraction; neural input can change rate
Smooth Muscle
Walls of hollow, visceral organs Nonstriated, involuntary Slow, sustained contractions
What is the function of muscles
1)Excitability: receive and respond to stimulus
2)Contractility: Ability to shorten forcibly when stimulated
3) Extensibility: Ability to be stretched.
4)Elasticity: resume strength after being stretched
What does syncytium mean
Single cell containing several nuclei.
What thin layer covers
surrounds the entier muscle
What covers the fascicle
Perimysium
What covers the muscle cell
endomysium
I-Band
Covers part from the myosin heads to the next myosin head in the next sacromere.
A-Band
Covers from the start of the myosin to the next end
H-Band
Covers only myosin stacks that have no arrows.
What is Z disk made of
Alpha Acticin
What is titin
Strong muscle muscle filaments with corkscrew-like elastic properties
What is the plasma membrane of a muscle cell
Sarcolemma
What is fasicle
bundle of muscle cells
What does rigor mortis tell you about the role of ATP in cross bridge detachment???
As ATP continues to be formed by anaerobic glycolysis, the muscles will remain rigid and will be unable to relax
When does relaxation occur?
relaxation occurs as SR reclaims Ca++
What are skeletal muscles stimulated by
motor neuron of the somatic NS
When does cross bridge cycling end?
Cross bridge cycling ends when sufficient calcium has been actively transported back into the sarcoplasmic reticulum to allow calcium to unbind from troponin
What is a muscle twitch
The response of a motor unit to a single action potential of its motor neuron
The calcium calmodulin system of contraction regulation is found in:
smooth muscle only.
What is excitation-contraction coupling?
events leading to the sliding of myofilaments
True or false skeletal muscles contain a mixture of fiber types
true
What does myglobons do
store oxygen in muscles cells
