Muscular System

Arrange the following in the proper order in which they occur at the postsynaptic side of a neuromuscular junction. 1. Action potential is propagated over the muscle cell membrane 2. Depolarization of the post-synaptic membrane 3. Sodium ions move into muscle cell -1, 2, 3 -2, 1, 3 -2, 3, 1 -3, 2, 1 -3, 1, 2

-3, 2, 1

Place the events involved in muscle contraction in the correct order -A cyclic "attach, pivot, detach, return" event occurs. -A nerve impulse causes ACh release at a neuromuscular junction. -Myofilaments passively return to their original state. -Calcium ions are moved back into the sarcoplasmic reticulum by ATP-driven pumps. -Calcium ions bind to troponin, causing tropomyosin to move and expose active sites -ACh binds receptors on the motor end plate, initiating a muscle impulse -Myosin heads attach to actin and form crossbridges

-A nerve impulse causes ACh release at a neuromuscular junction. -ACh binds receptors on the motor end plate, initiating a muscle impulse -Calcium ions bind to troponin, causing tropomyosin to move and expose active sites -Myosin heads attach to actin and form crossbridges -A cyclic "attach, pivot, detach, return" event occurs. -Calcium ions are moved back into the sarcoplasmic reticulum by ATP-driven pumps. -Myofilaments passively return to their original state.

Check all that are proteins of thin filaments. -Myosin -Actin -Troponin -Titin -Tropomyosin

-Actin -Troponin -Tropomyosin

Check all that are a function of skeletal muscle tissue. -Regulation of blood pH -Body movement -Maintenance of posture -Heat production -Regulating elimination of materials -Protection and support

-Body movement -Maintenance of posture -Heat production -Regulating elimination of materials -Protection and support

Check all that are true statements regarding cardiac and smooth muscle. -Cardiac muscle cells can generate a muscle impulse without nervous stimulation. -Smooth muscle contraction is fast and fatigues easily. -Cardiac muscle cells are almost all aerobic. -Smooth muscle is not striated. -Smooth muscle contraction is almost always voluntary.

-Cardiac muscle cells can generate a muscle impulse without nervous stimulation -Cardiac muscle cells are almost all aerobic -Smooth muscle is not striated.

Place the organizational level of muscle tissue in order, beginning with muscle and ending with the smallest component. -Myofibril -Fascicle -Myofilament -Muscle -Muscle fiber

-Muscle -Fascicle -Muscle fiber -Myofibril -Myofilament

Match the connective tissue with the component of skeletal muscle tissue that it surrounds. 1. Surrounds each muscle fiber 2. Surrounds the fascicles 3. Surrounds the whole skeletal muscle

1. Endomysium:Surrounds the whole skeletal muscle 2. Perimysium:Surrounds the fascicles 3. Epimysium:Surrounds each muscle fiber

Match the type of muscle tissue with its brief description. 1. Unstriated, single nucleus 2. Striated, autorhythmic 3. Striated, multiple nuclei

1. Smooth:Unstriated, single nucleus 2. Cardiac: Striated, autorhythmic 3. SkeletalStriated, multiple nuclei

Match the five properties of muscle tissue with their descriptions. 1. Ability to pass an electrical change along a cell's plasma membrane 2. Active generation of force 3. Ability to extend in length 4. Ability to return to original length 5. Ability to respond to stimuli

1.Conductivity 2.Contraction 3.Extensibility 4.Elasticity 5 Excitability

Myosin heads directly use ______________ to transition to their _____________________ conformation, which enables them ready to bind to actin. -calcium; energized -calcium; non-energized -ATP; non-energized -ATP; energized

ATP; energized

Stand on both feet and bring one foot up to touch the heal of your foot to your buttocks. The hamstring muscles are acting as what? -Synergist -Agonist -Antagonist

Agonist

Your school wins the homecoming football game against its biggest rival. You watch as the smallest cheerleader tries to lift up the heaviest linebacker in her excitement. As she strains against his 300 lb. load and does not move him, what type of muscle contraction are her muscles experiencing? -Isotonic -Isometric -No contraction because she does not move him

Isometric

The area between the presynaptic nerve cell and the postsynaptic muscle cell is termed the synaptic cleft True or False

True

When a motor unit is sufficiently stimulated, all of the muscle fibers in that motor unit will contract. True or False

True

The primary neurotransmitter at the neuromuscular junction is -dopamine. -adrenaline. -acetylcholine. -histamine. -serotonin.

acetylcholine.

The brachialis muscle is the prime mover of elbow flexion, while biceps brachii assists. In other words, during elbow flexion brachialis is the ______ and biceps brachii serves as the ________. -agonist; synergist -agonist; antagonist -synergist; antagonist -fixator; agonist

agonist; synergist

After wearing a cast on your wrist for several weeks, you notice that your forearm muscles appear smaller and are weaker than before. This wasting of muscle tissue is termed muscle ______________.

atrophy

The ability of a muscle cell to lengthen in response to antagonistic muscles contracting is referred to as -extensibility. -contractility. -excitability. -elasticity. -conductivity

extensibility.

When a motor unit is sufficiently stimulated, all of the muscle fibers in that motor unit will contract. -lesser -greater -equal

greater

The specialized region of the sarcolemma that has folds and indentations to increase the membrane surface area covered by the synaptic knob is the -synaptic cleft. -synaptic vesicle. -motor end plate.

motor end plate.

A motor neuron transmits the effect of a nerve impulse to the muscle fiber at a ________ _________.

neuromuscular junction

Acetylcholine causes an end-plate potential by triggering the ______________________. -closing of calcium channels -opening of calcium channels -closing of sodium channels -opening of sodium channels -closing of chloride channels -opening of chloride channels

opening of sodium channels

Acetylcholine (ACh) is released from motor neurons and enters the __________________. -transverse tubules -axon terminal -sarcomere -synaptic cleft

synaptic cleft

At the ends of muscles, the connective tissues merge to form a __________, which attaches the muscle to other structures. -tendon -sheath -ligament -superficial fascia

tendon

The component of a muscle fiber that quickly transports a muscle impulse from the sarcolemma throughout the entire muscle fiber is called the -sarcoplasmic reticulum. -transverse tubule (T-tubule). -terminal cisternae. -titin.

transverse tubule (T-tubule).

Thin filaments connect to and extend from either side of a ___________. These thin filaments are composed largely of the myofilament ____________. -z disc; actin -M line; myosin -M line; actin -Z disc; myosin

z disc; actin