Chapter 7 bio Muscular

cardiac muscle

heart muscle (myocardium) consisting of striated muscle cells that interlock

muscle fibers

aka muscle cell that are elongated

skeletal muscle

contractile tissue that comprises the muscles attached to the skeleton; aka voluntary muscle

smooth muscle

contractile tissue that comprises the muscles in the walls of internal organs; aka visceral muscle

striations

the alternate dark and light bands of a skeletal muscle fiber

tendon

tissue that connects muscle to bone

compartment syndrome

painful condition resulting from the expansion or overgrowth of a leg muscle within its connective tissue sheath, producing pressure that interferes with circulation and adversely affects the function and health of the muscle

A band

region in the center of a muscle sarcomere that contains overlapping thick and thin filaments

acetylcholine

neurotransmitter secreted at the ends of many neurons; responsible for the transmission of a nerve impulse across a synaptic cleft; (ACh)

actin

a globular protein found in thin filaments

anaerobic

not requiring oxygen

creatine phosphate

muscle biochemical that stores energy

H zone

in a sarcomere, the region in the center of an A band where only myosin filaments are found

I band

in a sarcomere, the region that is light colored and attached to the Z line; comprised of only thin filaments

motor unit

motor neuron and all the muscle fibers it innervates

myofibrils

contractile portion of muscle fibers

myofilaments

lengthy thick and thin protein molecules bundled together to make myofibrils

myoglobin

pigmented compound in muscle tissue that stores oxygen

myosin

the only protein found in thick filaments

neuromuscular junction

junction between a neuron and a muscle fiber

oxygen debt

amount of oxygen require after anaerobic exercise to replace that used during the exercise

power stroke

during muscle contraction, the action that pulls thin filaments to the center of the sarcomere

sarcomeres

structural and functional units of a myofibril

sliding filament theory

muscles contract when the thin (actin) and the thick (myosin) filaments move past each other, shortening the skeletal muscle cells

thick filaments

in the sarcomere, the filaments comprised of only myosin molecules; they appear wider in a photomicrograph

thin filaments

in the sarcomere, the filaments comprised of actin, troponin, and tropomyosin molecules; they appear narrower in a phtomicrograph

transverse tubules

in muscle, structures formed from the sarcolemma; they extend into the sarcoplasm and contact but do not touch the sarcoplasmic reticulum

tropomyosin

one of the three proteins that comprise the thin filaments in a sarcomere (with m)

troponin

one of the three proteins that comprise the thin filaments in a sarcomere

Z lines

vertical lines found in a sarcomere

botulism toxin

paralyzes muscle, including respiratory muscles, by blocking the release of acetylcholine from the motor neuron

all-or-none law

for muscle cells, property of muscle that states that a muscle cell contracts completely or not at all; for neurons, property states that neurons either conduct a nerve signal completely or not at all

muscle twitch

contraction of a whole muscle in response to a single stimulus

recruitment

increase in the number of motor units activated as intensity of stimulation increases

summation

in muscle contraction, increased contraction until maximal sustained contraction is achieved

tetanic contraction

sustained muscle contraction without relaxation

tetanus

acute infection caused by the toxin of the tetanus bacterium; results in a rigidly locked jaw

tone

continuous, partial contraction of muscle

amyotrophic lateral sclerosis (ALS)

disease caused by gradual death of motor neurons, which leads to loss of all movement, including swallowing and breathing

atrophy

wasting away or decrease in size of an organ or tissue

convulsions

an abnormal, violent, and involuntary contraction or series of contractions of the muscles

cramps

painful, involuntary muscle spasms

duchenne muscular dystrophy

progressive muscle weakness and atrophy caused by deficient dystrophin protein; affects only boys and is inherited through a flawed gene carried by the mother

fatigue

failure of a muscle fiber to continue to contract, due to exhaustion of ATP

fibromyalgia

chronic disorder characterized by widespread pain, tenderness, stiffness of muscles and associated connective tissue structures

hypertrophy

increase in the size of an organ, usually by an increase in the size of its cells

multiple sclerosis

disease in which the outer, myelin layer of nerve fiber insulation becomes scarred, interfering with normal conduction of nerve impulses

muscular dystrophy

progressive muscle weakness and atrophy caused by deficient dystrophin protein

myasthenia gravis

muscle weakness due to an inability to respond to the neurotransmitter acetylcholine

spasms

sudden involuntary contractions of a muscle or a group of muscles

sprain

joint injury in which some of the fibers of a supporting ligament are ruptured, but the continuity of the ligament remains intact

strain

an overstretching or overexertion of some muscles

tendinitis

inflammation of muscle tendons and their attachments

tetanus [disease]

disease the develops in people who have not been properly immunized against the toxin that causes this; bacteria shuts down brain areas that normally inhibit unnecessary muscle contractions, which results in excessive rain stimulation causes muscles to lock in a contraction

tics

local and habitual spasms of particular muscles, especially facial muscles

agonist

for muscle action, that muscle or group of muscles that carries out the primary action; aka prime mover

antagonists

muscle that acts in opposition to a prime mover

insertion

end of muscle that is attached to a movable part

origin

end of a muscle that is attached to a relatively immovable part

prime mover

for muscle action, that muscle or group of muscles that carry out the primary action; aka agonist

synergists

muscles that assist the action of the prime mover