unit 8 test review
Which number most closely approximates the number of skeletal muscles in the human body? -about a 1,000 -206 -650 -several thousand
650
used to help myosin heads release from actin
ATP
what substance must bind to myosin heads in order for the heads to detach from the thin filaments
ATP
Which of the following statements is NOT true of skeletal muscle activity? -All muscles have at least two attachments. -During contraction, the muscle origin moves towards the insertion. -The bulk of the muscle lies proximal to the joint crossed. -Typically, muscles cross at least one joint.
During contraction, the muscle origin moves towards the insertion
Which of the following statements is NOT true? -A strong contraction results when all motor units are stimulated -How forcefully a muscle contracts depends on how many cells are stimulated -Graded muscle contractions may be produced by changing the frequency of muscle stimulation. -The all-or-none law states that muscles may contract completely, partially, or not at all when stimulated
The all-or-none law states that muscles may contract completely, partially, or not at all when stimulated
Which of the following statements is NOT true? -Contractility refers to the muscles ability to shorten -Isotonic contractions result in sliding myofilaments and muscle movement -When a muscle relaxes, it pushes on the insertion -Muscles can only pull
When a muscle relaxes, it pushes on the insertion
neurotransmitter released from vesicles in the motor neuron, changes the permeability of the sarcolemma
acetylcholine
A single nerve impulse produces only one contraction because
acetylcholine is broken down by acetylcholinesterase during the action potential
The sliding filament theory involves the sliding of the ___________ during skeletal muscle contraction as each cross-bridge attaches and detaches several times.
actin filaments
acetychlorine is released from the neuron's membrane in the response to
action potential
the reversal of charges along the sarcolemma
action potential
Which of the following is NOT matched correctly? -atrophy - condition of sore muscles -muscle tone - continuous partial contractions -flaccid - soft and flabby muscles -muscle soreness - result of lactic acid build-up
atrophy - condition of sore muscles
muscles need more blood than organs. which of the statements isn't true -blood needs to carry away large amounts of carbon dioxide -blood brings large amounts of ATP -blood brings large amounts of oxygen -blood carries away large amounts of latic acid -blood brings large amounts of glucose
blood brings a large amounts of ATP
Which of the following is NOT involved in supplying energy for muscle contraction? -aerobic respiration/cellular respiration -creatine phosphate -breakdown of lactic acid -lactic acid fermentation
breakdown of lactic acid
Which of the following is NOT a result of aerobic exercise on muscles? -bulging muscles -more flexible muscles -stronger muscles -greater resistance to fatigue
bulging muscles
Serves as the actual "go" signal for the muscle contraction once released from the sarcoplasmic reticulum
calcium ions
The heads of the myosin filaments are called ___________ when they link the thick and thin filaments together during skeletal muscle contraction.
crossbridges
which activity would be most dependent on creative phosphate
diving
the connective tissue sheath that covers each individual muscle fiber is ______
endomysium
The connective tissue covering that surrounds an entire muscle is
epimysium
sarco
flesh/muscle
Which of the following is NOT a function of the muscular system? -production of movement -generation of heat -hematopoiesis -stabilization of joints
hematopoiesis
which of the following is not a function of skeletal muscle -generate heat -convert chemical energy to mechanical energy -move fluids (blood, food, etc) through the body -protect internal organs
move fluids (blood, food, etc) through the body
myo or mys
muscle
a long chain of sarcomeres _____
myofibrals
Which of the following lists the structures in order from smallest to largest? -muscle fiber, fascicle, myofibril, muscle -myofilament, myofibril, fascicle, muscle fiber -myofibril, muscle fiber, muscle, fascicle -myofilament, myofibril, muscle fiber, fascicle
myofilament, myofibril, muscle fiber, fascicle
which of the following is not a component of the thin filament
myosin
acetychlorine is a ________
neurotransmitter
t-tubes are on extension of the ________
sarcolemma
which of the following is a philospholipid bilayer w/ embedded proteins
sarcolemma
when a muscle cell is at rest, most of the intracellar calcium is found stored in the _________
sarcoplasmic reticulum
how is cardiac muscle
skeletal muscle voluntary
restores resting potential
sodium potassium pump
what is the name _____
synapse
The gap between the motor neuron and the muscle fiber it supplies at the neuromuscular junction is called the _____________.
synaptic cleft
Which of the following statements about muscle tissue is NOT correct? -an individual muscle cell is called a muscle fiber -in muscle cells, the cytoplasm is called the sarcoplasm -in muscle cells, the cytoplasm is called the sarcoplasm -the sarcomere is the space between the thick and thin filaments
the sarcomere is the space between the thick and thin filaments
in a resting muscle cell the myosin binding sites are blocked by ______
tropomyosin
calcium ions bind to _________ when present to in the sarcoplasm
troponin
