EXAM 3 A&P
How many somatic motor neurons stimulate one muscle fiber?
1
53) This figure shows the three main functional classes of neurons.Which option below correctly matches the types of neuron to the numeric labels on the figure?
1-Afferent neuron, 2-Interneuron, 3-Efferent neuron
Aerobic respiration produces a net yield of approximately_________ ATPs per glucose.
32
6.1)What is contained within the structure at B?
Acetylcholine
Which neurotransmitter excites skeletal muscle and inhibits cardiac muscle?
Acetylcholine
41.1) What is labeled 1 on this figure?
Axon of presynaptic neuron
36.2) Which letter represents an A (dark) band?
B
40.3) Which structure binds ATP during contraction?
B
40.2) Between what two structures does a cross-bridge form?
B and C
Which statement about the nervous and endocrine systems is true?
Both systems are dedicated to maintaining stable internal conditions by detecting and responding to stimuli.
18.1) What is stored within the organelle at C?
Calcium ions
Which of the following has the largest mitochondria?
Cardiac muscle
40.1) Where do calcium ions bind during a muscle contraction?
D
30.4) Name the facial muscle labeled 4.
Masseter
Which of the following is most likey to cause a rapid depolarization?
Opening of sodium channels
30.1) Name the facial muscle labeled 1.
Orbicularis oculi
30.5) Name the facial muscle labeled 5.
Orbicularis oris
18.3) What is the structure at E primarily composed of?
Phospholipids
Which of the following is not a characteristic of a muscle cell?
Plasticity
18.2) What is the organelle at A primarily composed of?
Proteins
36.1) What is the term for the structure at C?
Sarcomere
6.3)What is contained in the space at E?
Sarcoplasm
20) What type of glial cell is shown here?
Schwann cell
Which glial cell is found wrapped around axons in the PNS?
Schwann cells
Which of the following is not a function of the muscular system?
Secretion
Which of the following is an accurate comparison of skeletal muscle to smooth muscle?
Smooth muscle contracts and relaxes more slowly.
6.2)When the structure at D opens, what does it let into the cell?
Sodium ions
In a whiplash injury, the neck undergoes forced hyperextension then hyperflexion, injuring multiple muscles in the neck. Which of the following muscles would be injured during the hyperextension phase of the injury?
Sternocleidomastoid
41.3) What is labeled 5 on this figure?
Synaptic cleft
41.2) What is labeled 2 on this figure?
Synaptic vesicle
29) The type of summation shown in this diagram is called _________ summation.
Temporal
Which of the following muscles of mastication would be responsible for mandibular elevation?
Temporalis
Why does one continue to breathe heavy after rigorous physical activity has stopped?
The body requires more oxygen to restore levels of ATP and creatine phosphate.
Which of the following best describes the resting membrane potential (RMP)?
The intracellular environment is negatively charged.
3.1)What is happening during the point on the graph labeled 1?
The local current arrives at the axon hillock.
3.2)Why is the membrane hyperpolarized at the point on the graph labeled 6?
The membrane is more temporarily more permeable to potassium than to sodium.
The axon terminal releases acetylcholine into the synaptic cleft, which is received by receptors on the motor end plate. Which structure does this describe?
The neuromuscular junction of a skeletal muscle
Which of the following is predominately made up of myosin?
The thick filament
An isometric contraction does not change muscle length.
True
3.3)Why does the voltage peak at the point on the graph labeled 4?
Voltage-gated sodium channels innactivate.
36.3) What is name of the structure in the middle of D?
Z disc
30.3) Name the facial muscle labeled 3.
Zygomaticus major
30.2) Name the facial muscle labeled 2.
Zygomaticus minor
A cholinergic synapse uses_________ as its neurotransmitter.
acetylcholine
The term "nerve fiber" refers to a(n)_________.
axon
The antagonist to the triceps brachii is the_________.
biceps brachii
The transfer of phosphate from CP to ADP is catalyzed by_________.
creatine kinase
All muscle types will respond to an electrical stimulus because all muscle cells are_________.
excitable
A dark band formed by parallel thick filaments that partly overlap the thin filaments is known as an H band.
false
A skeletal muscle fiber (cell) contains a single nucleus.
false
Oligodendrocytes serve the same purpose in the CNS that satellite cells do in the PNS.
false
A bundle of muscle fibers is known as a_________.
fascicle
Muscle fibers are arranged in bundles called_________.
fascicles
Resistance exercise will most likely cause muscle to __________.
hypertrophy
The training regimen of a competitive weight lifter is designed partly to_________.
increase the average number of myofibrils per muscle fiber
A myelin sheath is composed primarily of_________.
lipids and proteins
80% of the lactate produced by skeletal muscle is converted to pyruvate by the _________.
liver
Cross bridges form between binding sites on actin myofilaments and_________.
myosin heads
The rectus abdominis is a_________ muscle, while the rectus femoris is a_________ muscle.
parallel; bipennate
A skeletal muscle generates the greatest tension when it is_________.
partially stretched before being stimulated
The process of engaging more motor units to increase the strength of a muscle contraction is called_________.
recruitment
An action potential for a muscle cell is propagated along the_________.
sarcolemma
To stimulate muscle contraction, acetylcholine is released from the_________ into the synaptic cleft.
synaptic vesicles
Each T tubule is flanked by two_________.
terminal cisterns
During muscle contraction, binding sites for myosin are uncovered by the movement of_________.
tropomyosin
During muscle contraction, calcium ions bind to_________.
troponin
Ependymal cells line the inner cavities of the CNS.
true
In most neurons, action potentials occur in the axon.
true
Most neurons have multiple dendrites.
true
Unipolar neurons have only a single process leading away from the cell body.
true
The_________ division carries signals to the smooth muscle in the large intestine.
visceral motor
Skeletal muscle is called_________, because it is usually subject to conscious control.
voluntary