Question 1

Complete failure of the neural tube to close in the region of the spinal cord is termed ________________.&#10;A)Spina bifida occulta&#10;B)Meningocele&#10;C)Cranioschisis&#10;D)Rachischisis&#10;E)Hydrocephalus

Accepted Answer

Rachischisis is the complete failure of the neural tube to close in the region of the spinal cord, resulting in an exposed spinal cord and open neural canal. Spina bifida occulta is a milder form of spinal dysraphism where the neural tube fails to close but the spinal cord remains intact and covered by skin. Meningocele is a type of spina bifida where the meninges (protective membranes around the spinal cord) protrude through a defect in the vertebrae. Cranioschisis is a severe form of neural tube defect where the skull fails to form properly, resulting in an open brain and exposed neural tissue. Hydrocephalus is a condition where there is an accumulation of cerebrospinal fluid in the brain, often due to a blockage or obstruction in the ventricular system. While hydrocephalus can be associated with spina bifida or other neural tube defects, it is not the term for the complete failure of the neural tube to close in the region of the spinal cord.

Question 2

The bulge in a myelomeningocele contains the ___________________.&#10;A)Spinal cord&#10;B)Arachnoid layer&#10;C)Subarachnoid space&#10;D)All of the above&#10;E)None of the above

Accepted Answer

A myelomeningocele is a type of spina bifida where the spinal cord and its protective covering, the meninges, protrude through an opening in the spine. This means the bulge can contain the spinal cord, arachnoid layer, and subarachnoid space, making "All of the above" the correct answer.

Question 3

?The alar plate is most closely associated with which function of the central nervous system?&#10;A)Motor&#10;B)Sympathetic&#10;C)Sensory&#10;D)Parasympathetic&#10;E)None of the above

Accepted Answer

The alar plate is most closely associated with sensory functions of the central nervous system. It gives rise to the dorsal horn of the spinal cord, which receives sensory input from the periphery and relays it to higher brain centers.

Question 4

The cell bodies of the motor neurons of a spinal nerve arise from the _____________.&#10;A)Basal plate&#10;B)Marginal zone&#10;C)Floor plate&#10;D)Roof plate&#10;E)Alar plate

Accepted Answer

The basal plate of the spinal cord gives rise to the cell bodies of motor neurons, which are responsible for controlling muscle movement.

Question 5

The floor plate of the spinal cord arises as the result of an induction by the ____________.&#10;A)Notochord&#10;B)Neural crest&#10;C)Dorsal aorta&#10;D)Dorsal part of somites&#10;E)Overlying ectoderm

Accepted Answer

The floor plate of the spinal cord arises due to an induction by the notochord, which is a structure that runs longitudinally along the developing embryo's midline.

Question 6

The cerebellum arises from the ________________.&#10;A)Prosencephalon&#10;B)Diencephalon&#10;C)Mesencephalon&#10;D)Metencephalon&#10;E)Myelencephalon

Accepted Answer

The cerebellum is part of the hindbrain, specifically the metencephalon, which also includes the pons.

Question 7

What molecule produced by the notochord is instrumental in inducing the floor plate of the neural tube?&#10;A)Hoxa-5&#10;B)Retinoic acid&#10;C)Acrosin&#10;D)Hyaluronic acid (haluronin)&#10;E)Sonic hedgehog

Accepted Answer

Sonic hedgehog is the molecule produced by the notochord that induces the floor plate of the neural tube. Sonic hedgehog plays a crucial role in the development of the nervous system, particularly in organizing the ventral-dorsal patterning of the neural tube.

Question 8

The cauda equina develops during the second and third trimesters of fetal development as a consequence of _______________.&#10;A)Slower growth of the spinal cord relative to the vertebral column&#10;B)Resorption of the tail that develops in a fetus during the first trimester&#10;C)Accelerated growth of the thoracic segments&#10;D)Formation of the lower limbs

Accepted Answer

The cauda equina is a bundle of nerve roots that extend from the lower end of the spinal cord. Its development is a consequence of slower growth of the spinal cord compared to the vertebral column, which pulls the lower nerve roots downward, resulting in their elongation and formation of the cauda equina.

Question 9

A growth cone would be most likely to respond specifically to _______________.&#10;A)Hoxb-4&#10;B)Sonic hedgehog&#10;C)Wnt-7a&#10;D)Semaphoring&#10;E)Bone morphogenetic protein-4

Accepted Answer

Semaphoring is a family of proteins that help guide axon growth and pathfinding during neural development. Growth cones are the specialized structures at the tip of growing axons that respond to guidance cues such as semaphorins.

Question 10

The cell bodies of sensory neurons arise from the ______________.&#10;A)Alar plate&#10;B)Basal plate&#10;C)Floor plate&#10;D)Roof plate&#10;E)Neural crest

Accepted Answer

The cell bodies of sensory neurons arise from the neural crest, which is a group of cells that develop from the embryonic ectoderm and give rise to various structures, including sensory neurons.

Question 11

A young patient with a tuft of hair over the lumbar region of the vertebral column is operated on for a congenital anomaly in that region.During surgery,it was found that the dura and arachnoid layers over the spinal cord were complete,but the neural arches of several vertebrae were missing.What condition did this patient have?

A)Meningocele
B)Meningomyelocele
C)Encephalocoele
D)Rachischisis
E)Spina bifida occulta

Accepted Answer

The answer of A young patient with a tuft of...

Question 12

The cranial nerve ganglia are associated with all of the following rhombomeres except ______________.&#10;A)r2&#10;B)r3&#10;C)r4&#10;D)r6&#10;E)r7

Accepted Answer

The answer of The cranial nerve ganglia are associated with...

Question 13

A molecule that repels the advance of a growth cone is called _______________.&#10;A)Netrin&#10;B)Acrosin&#10;C)Cadherin&#10;D)Semaphoring&#10;E)Laminin

Accepted Answer

The answer of A molecule that repels the advance of...

Question 14

The first rhombomere is characterized by the expression of _____________.&#10;A)Hoxa-1&#10;B)Hoxb-2&#10;C)Otx-2&#10;D)Sonic hedgehog&#10;E)None of the above

Accepted Answer

The answer of The first rhombomere is characterized by the...

Question 15

Growth cones adhere strongly to a substrate containing _______________.&#10;A)Acetylcholine&#10;B)Epinephrine&#10;C)Norepinephrine&#10;D)Laminin&#10;E)Sonic hedgehog

Accepted Answer

The answer of Growth cones adhere strongly to a substrate...

Deck 11: Nervous System