Question 1

In Fig. Img_003, a patient who has a stroke involving this region of the central nervous system has damage to her

Accepted Answer

B

Question 2

Major dense lines of a myelinated axon

Accepted Answer

Major dense lines of a myelinated axon represent the fused cytoplasmic surfaces of the Schwann cell membrane. These lines are formed by the tightly packed membrane layers of the myelin sheath wrapped around the axon. The major dense lines are where the cytoplasm of the Schwann cell is squeezed out, leaving only the fused membranes. The intraperiod line, located between the major dense lines, represents the extracellular space between the myelin layers. The node of Ranvier is the gap between the myelin sheaths where the axon membrane is exposed. Major dense lines are absent in myelin sheaths formed by oligodendroglia in the central nervous system.

Question 3

The nervous system has neurons as well as associated neuroglia. Which one of the following neuroglia is derived from cells of the bone marrow?

Accepted Answer

Microglia are the neuroglia derived from cells of the bone marrow.

Question 4

Identify the structure

Accepted Answer

The structure 11ea9939_c59f_055b_9f38_5383bc93d0be_TB3792_00 is identified as a nerve fiber.

Question 5

A patient presents with muscular rigidity, constant tremor, slow movement (bradykinesia), difficult voluntary movements, and rigid, mask-like features. Which neurotransmitter is lacking in this patient's brain?

Accepted Answer

The symptoms described are characteristic of Parkinson's disease, a condition caused by the degeneration of dopamine-producing neurons in the brain. Therefore, the neurotransmitter lacking in this patient's brain is dopamine.

Question 6

When an action potential reaches the presynaptic membrane, it causes the opening of certain voltage-gated ion channels that permit the influx of specific ions, which causes synaptic vesicles to fuse with the presynaptic membrane and release their neurotransmitter substances via exocytosis into the synaptic cleft. These voltage-gated ion channels permit the

Accepted Answer

Voltage-gated ion channels that permit the influx of specific ions are typically calcium channels, which allow the influx of Ca2+ ions. This influx of Ca2+ ions is what triggers synaptic vesicles to fuse with the presynaptic membrane and release their neurotransmitter substances into the synaptic cleft via exocytosis. Option A and B refer to the influx and outflow of sodium (Na+) and potassium (K+) ions, respectively, which are involved in generating the action potential but not in synaptic transmission. Option C refers to the influx of chloride (Cl-) ions, which can play a role in some inhibitory forms of synaptic transmission but is not necessary for all types of synaptic transmission. Option E refers to the outflow of chloride (Cl-) ions, which is also not necessary for synaptic transmission.

Question 7

Maintenance of the resting potential depends primarily on

Accepted Answer

The resting potential is maintained by the continuous leaking of K+ ions out of the cell through K+ leak channels. These channels are always open and allow K+ ions to passively diffuse out of the cell, maintaining the negative resting potential. The other options listed are involved in other cellular processes but are not primarily responsible for the maintenance of the resting potential.

Question 8

The region within the rectangle is the

Accepted Answer

The answer of The region within the rectangle is the...

Question 9

A patient presents in the emergency department with a knife wound to the arm. It is noted that some of the muscles of his arm are paralyzed. Which of the following will take place in the neurons whose axons were severed?

Accepted Answer

When the axons are severed, the neurons undergo changes, one of which is the displacement of their nucleus. This happens because the nucleus relies on transport signals from the axons to place it in the proper location in the cell. Without this signal, the nucleus moves to an abnormal position, which can affect the function of the neuron. The other choices are not supported by evidence and do not relate to the known effects of axon severing on neurons.

Question 10

Hospitalized patients can contract herpesvirus infections from each other because of

Accepted Answer

Retrograde transport refers to the movement of viruses or other pathogens from the axon terminals to the cell body. In the case of herpesvirus infections, this refers to the virus traveling from a previously infected patient's nerve endings back to the cell body and potentially infecting other hospitalized patients. This type of transmission can occur in hospitals where patients are in close proximity to one another, and therefore retrograde transport is the best choice as it accurately describes the mode of transmission.

Question 11

Identify the cell at the tip of the arrow

Accepted Answer

The answer of Identify the cell at the tip of...

Question 12

The neuron that is not present in a two-neuron reflex arc is known as a(n)

Accepted Answer

Interneurons are not part of the two-neuron reflex arc, which typically involves only a sensory neuron and a motor neuron. Interneurons are found in more complex neural pathways.

Question 13

An elderly patient is seen by his gerontologist and asks what the blood-brain barrier is and why certain drugs cannot enter the neural tissue. The physician explains that the principal anatomic structure that creates that barrier is the

Accepted Answer

The blood-brain barrier is primarily made up of specialized endothelial cells that have tight intercellular junctions which restrict the passage of certain drugs and molecules into the brain tissue.

Question 14

A patient with Hirschsprung disease has a developmental condition that involves

Accepted Answer

Hirschsprung disease is characterized by the absence of ganglion cells in the distal colon, which are parasympathetic postganglionic neurons, leading to a lack of peristalsis and bowel obstruction.

Question 15

During embryonic development, cells derived from neural crest migrate to form which of the following?

Accepted Answer

Neural crest cells migrate to form various structures, including neurons in Auerbach's plexus, which is part of the enteric nervous system.

Question 16

Identify the cell at the tip of the arrow

Accepted Answer

The answer of Identify the cell at the tip of...

Question 17

A 42-year-old patient presents with Huntington chorea. Which of the following neurotransmitter-producing cells is believed to be missing?

Accepted Answer

Huntington's disease is characterized by a deficiency of GABA (gamma-aminobutyric acid)-producing neurons in the brain, particularly in the basal ganglia, which play a crucial role in movement control.

Question 18

A patient is diagnosed with lockjaw. The tetanus toxin was transported from the periphery to the central nervous system by

Accepted Answer

The tetanus toxin is transported retrograde from the peripheral axons to the central nervous system. This occurs through the use of retrograde transport mechanisms, which involves the transportation of materials from the axon terminal to the cell body.

Question 19

The nervous system has neurons as well as associated neuroglia. Which one of the following neuroglia participates in the formation of the choroid plexus?

Accepted Answer

Ependymal cells are associated with the formation of the choroid plexus. They are specialized cells that line the ventricles of the brain and are responsible for producing cerebrospinal fluid (CSF). The choroid plexus is a network of capillaries located within the ventricles that is responsible for producing the CSF. Ependymal cells play a crucial role in this process by regulating the composition of the CSF and helping to maintain the proper balance of nutrients and electrolytes in the brain.

Question 20

The structure located in the rectangle is responsible for the

Accepted Answer

The structure located in the rectangle is the choroid plexus, which is responsible for the formation of cerebrospinal fluid.

Quiz 8: Nervous Tissue

In Fig. Img_003, a patient who has a stroke involving this region of the central nervous system has damage to her

Major dense lines of a myelinated axon

The nervous system has neurons as well as associated neuroglia. Which one of the following neuroglia is derived from cells of the bone marrow?

Identify the structure

A patient presents with muscular rigidity, constant tremor, slow movement (bradykinesia) , difficult voluntary movements, and rigid, mask-like features. Which neurotransmitter is lacking in this patient's brain?

Maintenance of the resting potential depends primarily on

The region within the rectangle is the

A patient presents in the emergency department with a knife wound to the arm. It is noted that some of the muscles of his arm are paralyzed. Which of the following will take place in the neurons whose axons were severed?

Hospitalized patients can contract herpesvirus infections from each other because of

Identify the cell at the tip of the arrow

The neuron that is not present in a two-neuron reflex arc is known as a(n)

An elderly patient is seen by his gerontologist and asks what the blood-brain barrier is and why certain drugs cannot enter the neural tissue. The physician explains that the principal anatomic structure that creates that barrier is the

A patient with Hirschsprung disease has a developmental condition that involves

During embryonic development, cells derived from neural crest migrate to form which of the following?

Identify the cell at the tip of the arrow

A 42-year-old patient presents with Huntington chorea. Which of the following neurotransmitter-producing cells is believed to be missing?

A patient is diagnosed with lockjaw. The tetanus toxin was transported from the periphery to the central nervous system by

The nervous system has neurons as well as associated neuroglia. Which one of the following neuroglia participates in the formation of the choroid plexus?

The structure located in the rectangle is responsible for the