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