Chapter 9 Flashcards
Skeletal muscle helps in what?
Muscle movement
Contracility
the ability of muscle to shorten forcefully or contract
Where is smooth muscle found
walls of hollow organs, blood vessels, eyes, glands, and skin
What do multinucleated cells generally develop from
myoblasts
What is the membrane that surrounds each fasiculus
the perimyseum
What does the endomyseum surround
the entire muscle
Actin (thin) filaments
two strands of fibrous actin form a double helix extending the length of the filament
is made up of globular G protein
The traponin is the _____ that has a ______ binding site
trigger calcium
ATPase is found where
the myosin (thick filament) heads
ATPase does what
breaks ATP into ADP+P+energy
The sarcolema is another name for what
cell membrane of a muscle
Charged battery has potential energy. Potential means the same as what
Polarized
Dead battery has no potential energy. No potential is the same as
depolarized
The prefix “Iso-“ means what
the same
A muscle cell is the same as what
muscle fiber
Other names for muscle cell membrane are
cell membrane
sarcolema
motor end plate
Where does a resting membrane potential exist
in a resting muscle fiber
Voltage gated channels
open & close in response to small voltage changes across the plasma membrane
Ligand gated channels
glycoprotein with a receptor site
Depolarization
inside of plasma membrane becomes less negative. If charge reaches threshold depolarization occurs
Repolarization
return of resting membrane potential
Threshold
value of the membrane potential at which an action potential is produced as a result of depolarization in response to a stimulus
What neurotransmitter is found at neuromuscular junction
acetylcholine
Acetylcholine is broken down by what
acettylcholinesterase
Tranverse (T) tubules
invagination of the sarcolema
What does the sarcoplasmic reticulum store
calcium
What is the order for excitation-contraction
- Sarcolema
- T tubules
- Sarcoplasmic reticulum
- Calcium ions
What is depolarization caused by
spontaneous diffusion of calcium and sodium
In excitation-contraction coupling myosin heads (“golf club”) bind to what
exposed active sites on actin
What is the power stroke
the myosin head moving, this shortens the sarcomere
What is required for the formation, movement, and release of cross bridges
1 ATP molecule
The contraction of of a muscle fiber is caused by what
a threshold stimulus
Whole muscles can respond in a graded fashion to a stimuli by what
varying the number of motor units recruited
Increased calcium concentration around myofibrils may explain what
multiple wave summation
Treppe does what?
improves muscle efficiency
may be drawn to an increase of calcium ions around myofibril
Common causes of muscle fatigue
acidosis & ATP depletion
Oxidative stress
Local inflammatory reactions
Whats the only cause of fatigue in the muscle FIBERS
ATP depletion
Psychological fatigue
the person believes they can’t keep going even tho the muscles are fine to keep going
Rigor Mortis
the stiffening of the body after death because of a loss of ATP from the bodies muscle
Which of the 3 muscle energy supplies for muscles is only produced during resting conditions
creatine phosphate
Whats the waste product of anaerobic respiration (without oxygen) called
lactic acid
Aerobic respiration (with oxygen) yields what
36 ATP’s per glucose molecule metabolized
Oxygen deficit
the amount of O2 that a cell needs to replenish ATP supplies after exercise
Slow twitch oxidative fibers are well adapted to what
anaerobic activity
Where is the protein tropomyosin found
along the groove of the of teh F-actin double helix
What acts as a blood reservoir forO2
myogoblin
What does aerobic exercise do
increase vascularity of muscle
develop fatigue resistant fast twitch fibers
increase the efficiency of slow twitch fibers
increase number of mitochondria in the cell
What does muscle hypertrophy result from
increased numbers of myobibrils and sarcomeres
Muscle Atrophy
decrease in muscle size
Body temp is almost always the result of what
muscle contraction
Shivering does what
raises body temp
ATPase is contained in what
myosin
Smooth muscles have no ______ and a ___-_____ complex initiate cross bridge formation
sarcomere
calcium-calmodulin
Smooth muscles depolarize when
both sodium and calcium diffuse into the cell (not just sodium)
Visceral smooth muscle occurs in sheets and exhibit what
numerous gap junctions
Where is multiunit smooth muscle located
in the wall of blood vessels
Smooth muscle is regulated by what
the autonomic nervous system
neurotransmitter
hormones
prostaglandins
Smooth muscle tone is is relatively what
constant tension maintained for a long period of time
Curare
a poison that blocks acetylcholine at the motor end plate (sarcolema)
Recovery from oxygen deficit involves what
conversion of lactic acid back to glucose
