CNS & PNS Study Questions Flashcards
What portion of the spinal cord connects with nerves of the upper limbs?
The cervical enlargement connects with the sensory and motor nerves of the upper limbs.
What is the difference between a horn and a column in the spinal cord?
A horn is an area of gray matter and a column is an area of white matter.
Why does complete severing of the spinal cord at level C2 cause respiratory arrest?
Severing the spinal cord at level C2 causes respiratory arrest because it prevents descending nerve impulses from reaching the phrenic nerve, which stimulates contraction of the diaphragm, the main muscle needed for breathing.
What five important nerves arise from the brachial plexus?
The axillary, musculocutaneous, radial, median, and ulnar nerves are five important nerves that arise from the brachial plexus.
What initiates a nerve impulse in a sensory neuron?
A sensory receptor produces a generator potential, which triggers a nerve impulse if the generator potential reaches threshold. Reflex integrating centers are in the CNS.
Which branch of the nervous system includes all integrating centers for reflexes?
Reflex integrating centers are in the CNS.
What is reciprocal inhibition?
Reciprocal inhibition is a type of arrangement of a neural circuit involving simultaneous contraction of one muscle and relaxation of it antagonist.
Which is the largest part of the brain?
The cerebrum is the largest part of the brain.
What are the three layers of the cranial meninges from superficial to deep?
From superficial to deep the three cranial meninges are the dura mater, arachnoid, and pia mater.
Which brain region is anterior to the fourth ventricle? Which is posterior to it?
The brain stem is anterior to the fourth ventricle, and the cerebellum is posterior to it.
Where is cerebrospinal fluid reabsorbed?
The cerebrospinal fluid is reabsorbed by the arachnoid villi that project into the dural venous sinuses.
What does decussation mean?
Decussation means crossing to the opposite side.
What is the functional consequence of decussation of the pyramids?
The functional consequence of decussation of the pyramids is that each side of the cerebrum control muscles on the opposite side of the body.
Which tracts carry impulses between gyri of the same hemisphere?
Association tracts connect gyri of the same hemisphere
Which tracts carry impulses between gyri in opposite hemispheres?
Commissural tracts connect gyri in opposite hemispheres
Which tracts carry impulses from the cerebrum to the thalamus, brain stem, and spinal cord?
Projection tracts connect the cerebrum with the thalamus, brain stem, and spinal cord.
Where are the basal ganglia located relative to the thalamus?
The basal ganglia are lateral, superior, and inferior to the thalamus.
Where do axons in the olfactory tracts terminate?
Axons in the olfactory tracts terminate in the primary olfactory area in the temporal lobe of the cerebral cortex.
Where do the motor axons of the facial nerve originate?
Motor axons of the facial nerve originate in the pons.
What important motor functions does the hypoglossal nerve mediate?
Two important motor functions of the hypoglossal nerve are speech and swallowing.
How is a muscle spindle activated?
Muscle spindles are activated when the central areas of the intrafusal fivers are stretched.
What type of sensory deficits could be produced by damage to the right lateral spinothalamic tract?
Damage to the right lateral spinothalamic tract could result in loss of pain and thermal sensations on the left side of the body.
How do the somatosensory and motor representations compare for the hand, and what does this difference imply?
The hand has a larger representation in the motor area than in the somatosensory area, which implies greater precision in the hand’s movement control than fine ability in its sensation.
Which tracts carry information from proprioceptors in joints and muscles to the cerebellum?
The anterior and posterior spinocerebellar tracts carry information from proprioceptors in joints and muscles to the cerebellum.
Because they contain both sensory and motor axons, spinal nerves are considered to be ____________ nerves.
Mixed
The epidural space is located between the wall of the vertebral canal and the pia mater. True/False
False
Gray matter of the spinal cord contains somatic motor and sensory nuclei, autonomic motor and sensory nuclei, and functions to receive and integrate both incoming and outgoing information. True / False
True
Which of the following is a motor tract? (a) posterior spinocerebellar (b) lateral spinalthalamic (c) anterior spinocerebellar (d) lateral corticospinal (e) posterior column
D
The cerebral hemispheres are connected internally by a broad band of white matter know as the ____________________.
Corpus Callosum
List the five lobes of the cerebrum.
Frontal, Parietal, Temporal, Occipital, Insula
The brain stem consists of the medulla oblongata, pons and diencephalons. True/False
False
_____________ is the conscious or subconscious awareness of external or internal stimuli; _____________ is the conscious awareness and interpretation of sensory input.
Sensation and Perception
