ms - vocab test 2 Flashcards
contract to produce movement **unique
contractility
respond to stimuli
irritability
antagonistic relationship exists between muscle pairs, one contracts and the opposing muscle extends. (biceps & triceps)
extensibility
can return to their original shape when relaxed
elasticity
a. involuntary
b. found in the walls of organs
c. responsible for the movements that force food through the digestive tube
d. can remain contracted the longest
smooth muscle tissue
a. involuntary
b. some striations (stripes)
c. found only in the heart
d. does not fatigue (thank goodness! J )
e. contains intercalated discs
cardiac muscle tissue
a. has striations
b. voluntary: controlled consciously
c. attached to bones for movement of limbs
d. quickest response to stimuli
e. protective
f. quickest to fatigue
skeletal muscle tissue
move from one place to another, like walking
locomotion
connective tissue that covers and binds the muscle fiber (muscle cell)
endomysium
a covering of connective tissue that binds the muscle together in a big bundle
epimysium
connective tissue that covers and binds the fascicles
perimysium
bundles of muscle fibers
fascicles
separates muscles
tendons and fascia
muscle cell
muscle fiber =
1-2 microns in diameter these make up the striations or stripes; lie parallel to each other; extend the length of the fiber.
myofibrils
thin myofilament
actin (acTIN)
thick myofilament; actin and myosin overlap.
myosin
organized structures in muscle cells that contain the proteins actin and myosin
myofilaments
These myofilaments are arranged in repeated units called
sarcomere
When a muscle contracts, the myosin and actin slide over each other, actin is attached to the z lines; they slide inward pulling the z lines toward each other then the muscle fibers contract.
sliding filament theory
a. one muscle fiber is one muscle cell
b. it is the contractile unit of muscle
c. it is cylindrical and surrounded by a membrane called sarcolemma.
muscle fiber
the plasma membrane of the muscle cell
sarcolemma
contains many, many mitochondria and many myofibrils.
sarcoplasm
a. Producing body movements
b. Stabilizing body positions
c. Regulating organ volume
d. Moving substances within the body
e. Produce heat
functions of muscles
a system of channels and tubes that help in activating fiber contraction when nerves stimulate muscles to shorten.
sarcoplasmic reticulum
a. the neuromuscular Junction
b. neurotransmitters
c. motor unit
parts that make muscles work
the union between a motor neuron and a muscle fiber
the neuromuscular junction
chemicals that diffuse across the gap between a motor neuron and a muscle fiber bringing stimuli to muscle fiber, contraction then occurs.
neurotransmitters
all the muscle fibers associated with and stimulated by one motor neuron
motor unit
the smaller the number of muscle fibers in a motor unit, the finer the movements (eyes and fingers)
fine motor function
large number of muscle fibers in a motor unit produce strength or large movements, as in the leg
gross motor function
creatine phosphate (CP)
anaerobic cellular respiration (w/o oxygen)
aerobic cellular respiration (w/oxygen)
provides ATP (adenosine triphosphate) for muscle energy
break down carbohydrates for energy: build-up causes pain
lactic acid
rigidity of death: calcium ions leak out of the sarcoplasm causing stiffness of muscles. It begins 3-4 hours after death, lasts about 24 hours and disappears as enzymes digest.
rigor mortis
spasmodic, painful, involuntary muscle contractions, usually occur after exercise, during sleep. Painful because the muscle does not relax completely.
muscle cramps
sustained tension in muscles, muscles are firm but do not contract: muscles in the back and neck hold up your head, keep posture
muscle tone (tonus)
tightening, shortening, lengthening of muscles
muscle contraction
increase in size of skeletal muscle cells (ex. lifting weights)
muscle hypertrophy
decrease in size of skeletal muscle cells (ex. paralysis of limbs)
muscle atrophy
small structures in a cell that are found in the cytoplasm (fluid that surrounds the cell nucleus)
mitochondria
a series of wavelike muscle contractions that move food through the digestive tract
peristalsis
