Human Anatomy and Physiology : Central Nervous System

Study concepts, example questions & explanations for Human Anatomy and Physiology

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Example Questions

Example Question #1 : Central Nervous System

The ventral horn in the spinal cord contains which of the following?

Possible Answers:

Motor neurons

Sensory nerves

Sensory neurons

Cerebrospinal fluid

Correct answer:

Motor neurons

Explanation:

The spinal cord has both ventral and dorsal horns. The dorsal horns contain afferent neurons that receive sensory input from the environment, while the ventral horns contain efferent motor neurons that send impulses to the effector.

Nerves are separate structures that branch out from the spinal cord and central nervous system into the periphery. Cerebrospinal fluid surrounds the components of the central nervous system and acts to protect the brain and spinal cord, as well as regulate the environment of the central nervous system.

Example Question #2 : Central Nervous System

What spinal tract carries sensory information about vibrations through the spinal cord before arriving at the post-central gyrus of the cerebral cortex?

Possible Answers:

Corticospinal pathway

Lateral spinothalamic pathway

Corticobulbar pathway

Dorsal column medial lemniscal pathway

Anterior spinothalamic pathway

Correct answer:

Dorsal column medial lemniscal pathway

Explanation:

The dorsal column medial lemniscal pathway is the sensory pathway of the neural system that transports vibration, proprioception, two-point discrimmination, and fine touch.

The lateral spinothalamic pathway is the sensory pathway that transports pain and temperature sensation.

The corticospinal pathway is the motor control pathway that travels from the brain—specifically the precentral gyrus—to the spinal cord.

The corticobulbar pathway is the motor control pathway that travels from the brain, to the brainstem and the cranial nerves.

The anterior spinothalamic pathway is sensory pathway for crude touch and pressure.

Example Question #3 : Central Nervous System

Cerebrospinal fluid (CSF) is made by the choroid plexus in the lateral ventricals of the telencephalon. The CSF is then reabsorbed in the arachnoid villi in the superior sagittal sinus.

Before cerebrospinal fluid (CSF) travels from the third ventricle into the fourth ventricle, what does it flow through?

Possible Answers:

Cerebral aqueduct of Sylvius

Foramen of Magendie

Central canal

Foramen of Monro

Foramen of Lushka

Correct answer:

Cerebral aqueduct of Sylvius

Explanation:

The correct order of CSF flow is as follows:

Lateral ventricals, foramen of Monro, third ventricle, cerebrel aqueduct of Sylvius, fourth ventricle, foramen of Magendie (medial) and foramen of Lushka (lateral), central canal and subarachnoid space, superior sagittal sinus

Example Question #4 : Central Nervous System

Which of the following neural tracts regulate activity of the extensor muscles of the lower extremities?

Possible Answers:

Lateral spinothalamic tract

Lateral vestibulospinal tract

Fasciculus gracilis

Tectospinal tract

Rubrospinal tract

Correct answer:

Lateral vestibulospinal tract

Explanation:

The lateral spinothalamic tract is a sensory tract that conveys pain and temperature information. Although the tectospinal tract is a motor tract, it coordinates reflexive head movements in response to visual stimuli. The rubrospinal tract is also a motor tract, but it regulates activity of the upper extremity flexors. The fasciculus gracilis is a sensory tract carries proprioception, vibration, and light touch information, from the lower extremities.

Example Question #5 : Central Nervous System

The thoracic spine gives rise to how many segments? 

Possible Answers:

 

Correct answer:

Explanation:

The spinal cord consists of 31 segments/pairs. The cervical contains 8, thoracic contains 12, lumbar contains 5, sacral contains 5, and coccygeal contains 1. 

Example Question #6 : Central Nervous System

The dorsal column tracts ascend in the fasciculus gracilis and fasiculus cuneatus and cross over in the __________

Possible Answers:

spinal cord 

thalamus 

hypothalamus 

medulla 

midbrain 

Correct answer:

medulla 

Explanation:

The dorsal column track is an ascending system conveying somatic sensory information to the brain. The dorsal column tracts ascend in the fasiculus gracilis and fasiculus cuneatus. They synapse in the medulla so that signals from the left side of the body are transmitted to the right side, and vice versa. 

Example Question #7 : Central Nervous System

Where do the nuclei of the parasympathetic nervous system originate? 

Possible Answers:

Thoracolumbar (T1-L3) and S2-S4

Craniosacral region (cranial nerves and S2-S4)

S2-S4 only

Thoracolumbar region (T1-L3)

Correct answer:

Craniosacral region (cranial nerves and S2-S4)

Explanation:

Preganglionic neurons of the parasympathetic nervous system originate in the nuclei of the craniosacral region (cranial nerves and in the spinal cord segments of S2-S4). Those of the sympathetic nervous system originate in the thoracolumbar region (spinal cord segments of T1-L3).   

Example Question #8 : Central Nervous System

What passes through the anterior roots of the spinal cord?

Possible Answers:

Cell bodies of neurons

Axons of the neurons

Outgoing instructions 

Incoming sensory information

Correct answer:

Outgoing instructions 

Explanation:

The anterior roots are where outgoing instructions leave the spinal cord. The posterior roots are where incoming sensory information enter the spinal cord. Grey matter contains the cell bodies of neurons, while the white matter contains the axons of nerves. 

Example Question #9 : Help With Spinal Physiology

Where do A delta fibers terminate in the Rexed laminae?

Possible Answers:

II and III

V only

II only

II, III, and V

I and II

Correct answer:

I and II

Explanation:

A delta fibers are responsible for signaling "new" sharp pain. The body sends this sensory information to Rexed Laminae I and II. *I and II are called the substantia gelatinosa.

Example Question #9 : Central Nervous System

Fasciculus gracilus carries primarily __________ information.

Possible Answers:

motor

proprioception/touch

taste

gustatory

pain and temperature

Correct answer:

proprioception/touch

Explanation:

Fasciculus gracilus is one of the component to the dorsal columns. Remember that anything that is dorsal of the spinal cord is associated with sensation. In addition, the dorsal columns control touch while the spinothalamic tract carries pain and temperature information.

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