CNS 1 Flashcards
(40 cards)
4 Regions of the brain
- cerebrum,
- the diencephalon, the
- brainstem, and
- the cerebellum
single long fibers that conduct impulses to other parts of the nervous system.
Axons
Consists of aggregations of neuronal cell bodies. It rims the surfaces of the cerebral hemispheres, forming the cerebral cortex.
Gray mater
consists of neuronal axons that are coated with myelin. The myelin sheaths, which create the white color, allow nerve impulses to travel more rapidly.
White matter
which affect movement, and the thalamus and the hypothalamus structures in the diencephalon.
basal ganglia
processes sensory impulses and relays them to the cerebral cortex.
thalamus
maintains homeostasis and regulates temperature, heart rate, and blood pressure. It affects the endocrine system and governs emotional behaviors such as anger and sexual drive.
hypothalamus
is a white-matter structure where myelinated fibers converge from all parts of the cerebral cortex and descend into the brainstem.
internal capsule
which connects the upper part of the brain with the spinal cord, has three sections: the midbrain, the pons, and the medulla.
brainstem
which lies at the base of the brain, coordinates all movement and helps maintain the body upright in space.
cerebellum
Below the medulla, the CNS extends into the elongated ___, encased within the bony vertebral column and terminating at the first or second lumbar vertebra. It provides a series of segmental relays with the periphery, serving as a conduit for information flow to and from the brain. The motor and sensory nerve pathways relay neural signals that enter and exit the cord through posterior and anterior nerve roots and the spinal and peripheral nerves.
spinal cord
The spinal cord is divided into segments:
cervical from C1 to C8; thoracic, from T1 to T12; lumbar, from L1 to L5; sacral, from S1 to S5; and coccygeal
It is thickest in the cervical segment, which contains nerve tracts to and from both the upper and lower extremities.
spinal cord
consists of both CNs and peripheral nerves that project to the heart, visceral organs, skin, and limbs.
peripheral nervous system
which regulates muscle movements and response to the sensations of touch and pain
somatic nervous system
Connects to internal organs and generates autonomic reflex responses.
autonomic nervous system
mobilizes organs and their functions during times of stress and arousal
sympathetic nervous system
which conserves energy and resources during times of rest and relaxation.”
parasympathetic nervous system
Name the Cranial Nerves from I-XII functions
I - Olfactory - Sense of smell
II - Optic - Vision
III - Oculomotor - Pupillary constriction, opening the eye (lid elevation), and most extraocular movements
IV - Trochlear - Downward, internal rotation of the eye
V - Trigeminal - Motor—temporal and masseter muscles (jaw clenching), lateral pterygoids (lateral jaw movement)
Sensory—facial. The nerve has three divisions: (1)ophthalmic, (2) maxillary, and (3) mandibular.
VI - Abducens - Lateral deviation of the eye
VII - Facial - Motor—facial movements, including those of facial expression, closing the eye, and closing the mouth
Sensory—taste for salty, sweet, sour, and bitter substances on the anterior two thirds of the tongue and sensation from the ear
VIII - Acoustic - Hearing (cochlear division) and balance—(vestibular division)
IX - Glossopharyngeal - Motor—pharynx
Sensory—posterior portions of the eardrum and ear canal, the pharynx,
and the posterior tongue, including taste (salty, sweet, sour, bitter)
X- Vagus - Motor—palate, pharynx, and larynx
Sensory—pharynx and larynx
XI - Spinal accessory
- Motor—the sternocleidomastoid and upper portion of the trapezius
XII - Hypoglossal - Motor—tongue
Three kinds of motor pathways impinge on the anterior horn cells:
- the cortico-spinal tract,
- the basal ganglia system,
- the cerebellar system
Mediate voluntary movement and integrate skilled, complicated, or delicate movements by stimulating selected muscular actions and inhibiting others. They also carry impulses that inhibit muscle tone, the slight tension maintained by normal muscle even when it is relaxed.
corticospinal (pyramidal) tract
This exceedingly complex system includes motor pathways between the cerebral cortex, basal ganglia, brainstem, and spinal cord. It helps to maintain muscle tone and to control body movements, especially gross automatic movements such as walking.
basal ganglia system
The cerebellum receives both sensory and motor input and coordinates motor activity, maintains equilibrium, and helps to control posture.
cerebellar system
When upper motor neuron systems are damaged above their crossover in the medulla, motor impairment develops on the ____side. In damage below the crossover, motor
impairment occurs on the ___ side of the body.
- opposite or contralateral
- same or ipsilateral
