Chapter 10 A&P HW Flashcards
What type of neurons initiate skeletal muscle contraction?
somatic motor neurons
What is the fuel for muscle contraction?
ATP
Where does glycolysis occur?
sarcoplasm
Where does aerobic respiration occur?
mitochondria
During muscle relaxation, what does tropomyosin block?
myosin binding sites on actin
What is the muscle cell’s contracting unit called?
sarcomere
What are binding sites on actin covered by?
tropomyosin
What is a group of muscle cells stimulated by a single motor neuron called?
a motor unit
What process does the motor neuron use to stimulate the muscle cell?
neurotransmitter is released into the synaptic cleft to cause an action potential in the muscle cell
What neurotransmitter is released by the motor neuron to cause muscle contraction?
acetylcholine
What protein does calcium bind to?
troponin
What is wave summation?
a second stimulus excites a partially relaxed muscle
How many ATP molecules can one glucose molecule produce in aerobic respiration?
30 or more
How long can energy provided from creatine phosphate sustain muscle contraction?
15 seconds
Which enzyme clears the action potential for muscle relaxation?
acetylcholinesterase
What does the endomysium do?
surrounds each individual muscle fiber and distributes capillaries to the fibers
Which type of muscle tissue is involuntary?
smooth and cardiac
Which layer of connective tissue surrounds a bundle of muscle fibers?
perimysium
What muscle tissue property allows it to return to its original size and shape after being stressed?
elasticity
What do intercalated discs do?
allow individual cells to be firmly attached to each other, provides mechanical strength during contraction, allows the action potential to spread rapidly so that contractions are smooth and coordinated
What is the energy generated during ATP hydrolysis used for?
to energize the myosin head during the sliding filament
What are the properties of muscle tissue?
electrical excitability, contractility, extensibility, elasticity
What is the difference between thick and thin filaments?
thin filaments are actin and thick filaments are myosin
How is the motor end plate different from the rest of the sarcolemma?
it contains large numbers of acetylcholine receptors
What do whole muscles that control precise movements consist of?
large numbers of small motor units
What increases muscle tension?
adjusting sarcomere length so that the actin and myosin partially overlap
What is motor unit recruitment?
force production requirements increase and the number of active motor units increases
