Brainstem Flashcards
Somatic Afferent
-monitors external environment
Somatic Efferent
-reacts with external environment
Visceral Afferent
-monitors internal environement
Visceral Efferent
-controls internal environment
Sulcus limitans
-in the floor of the 4th ventricle; separates the cranial nerve motor nuclei from the sensory nuclei
Special Somatic Afferent
-afferent nerves that carry information from the special senses of vision, hearing and balance
General Somatic Afferent
- arise from cells in the spinal ganglia and are found in most the spinal nerves
- conduct impulses of pain, touch and temperature from the surface of the body through the posterior roots to the spinal cord and impulses of muscle sense, tendon sense and joint sense from the deeper structures
Special Visceral Afferent
-carry the special senses of smell (olfaction) and taste (gustation)
General Visceral Afferent
-conduct sensory impulses (usually pain or reflex sensations) from the viscera, glands, and blood vessels to the central nervous system
General Visceral Efferent
-refers to the efferent neurons of the autonomic nervous system that provide motor innervation to smooth muscle, cardiac muscle, and glands (contrast with SVE fibers)
Special Visceral Efferent
-efferent nerves that provide motor innervations to the muscles of pharyngeal arches in head and neck
Somatic Efferent
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4th Ventricle
- extends from the cerebral aqueduct to the obex
- filled with cerebrospinal fluid (CSF)
- located within the pons or in the upper part of the medulla
Abducens Nucleus
- originating nucleus from which the abducens nerve (VI) emerges - a cranial nerve nucleus
- nucleus is located beneath the fourth ventricle in the caudal portion of the pons, medial to the sulcus limitans
Basilar Pons
-anterior portion of the pons
Cerebral Aqueduct
- contains cerebrospinal fluid (CSF)
- within the mesencephalon (or midbrain)
- connects the third ventricle in the diencephalon to the fourth ventricle within the region of the mesencephalon and metencephalon
- located dorsal to the pons and ventral to the cerebellum
Cochlear Nucleus
- two heterogeneous collections of neurons in the mammalian brainstem that receive input from the cochlear nerve
- carries sound information from the cochleae
- outputs from the cochlear nuclei are received in higher regions of the auditory brainstem
Cuneate Tract
- carry proprioceptive and fine touch sensations
- carries sensations from upper half of our body
Dorsal Motor Nucleus of the Vagus
- cranial nerve nucleus for the vagus nerve in the medulla that lies under the floor of the fourth ventricle
- mostly serves parasympathetic vagal functions in the gastrointestinal tract, lungs, and other thoracic and abdominal vagal innervations
Facial Nucleus
- collection of neurons in the brainstem that belong to the facial nerve (cranial nerve VII)
- lower motor neurons innervate the muscles of facial expression and the stapedius
Gracilis Tract
- carry proprioceptive and fine touch sensations
- carries sensations from lower half of our body
Hypoglossal Nucleus
- a cranial nerve nucleus
- extends the length of the medulla, and being a motor nucleus, is close to the midline
- nucleus of hypoglossal nerve in the medulla oblongata
Inferior Colliculus
- principal midbrain nucleus of the auditory pathway
- receives input from several more peripheral brainstem nuclei in the auditory pathway, as well as inputs from the auditory cortex
Inferior Cerebellar Peduncle
- connects the spinal cord and medulla oblongata with the cerebellum
- comprises the juxtarestiform body and restiform body
Lateral Lemniscus
-tract of axons in the brainstem that carries information about sound from the cochlear nucleus to various brainstem nuclei and ultimately the contralateral inferior colliculus of the midbrain
Inferior Olive
- largest nucleus situated in the olivary body, part of the medulla oblongata
- control and coordination of movements
- sensory processing and cognitive tasks likely by encoding the timing of sensory input independently of attention or awareness
Middle Cerebellar Peduncle
- connect the cerebellum to the pons
- composed entirely of centripetal fibers, which arise from the cells of the nuclei pontis of the opposite side and end in the cerebellar cortex
Medial Lemniscus
-pathway in the brainstem that carries sensory information from the gracile and cuneate nuclei to the thalamus
Medial Longitudinal Fasciculus
- pair of crossed fiber tracts (group of axons), one on each side of the brainstem
- near the midline of the brainstem and are composed of both ascending and descending fibers
- carries information about the direction that the eyes should move
Nucleus Cuneatus
-carrying fine touch and proprioceptive information from the upper body
Nucleus Gracilis
-carrying fine touch and proprioceptive information from the lower body
Oculomotor Nuclear Complex
-give rise to the axons of the occulomotor nerve, both motor and parasympathetic fibers, situated at the midline at the level of the superior colliculus in the midbrain tegmentum
Pyramidal Tract
- pathway in central nervous system, originating in the sensorimotor areas of the cerebral cortex and generally descending through the brain stem to the spinal cord
- fibers transmit motor impulses that function in the control of voluntary movement
Periaqueductal Gray
- gray matter located around the cerebral aqueduct within the tegmentum of the midbrain
- role in the descending modulation of pain and in defensive behavior
Superior Colliculus
-visual reflex center
Superior Cerebellar Peduncle
- emerge from the upper and medial part of the white matter of the hemispheres
- under the upper part of the cerebellum
- all fibetrs carrying information from the spinal cord to the cerebellum (ventral spinocerebellar tract) pass through
Solitary Nucleus
-series of nuclei forming a vertical column of grey matter embedded in the medulla oblongata
Solitary Tract
- conveys afferent information from stretch receptors and chemoreceptors in the walls of the cardiovascular, respiratory, and intestinal tracts
- afferent fibers from cranial nerves 7, 9 and 10 convey taste (SVA) in its rostral portion
- general visceral sense (GVA) in its caudal part -taste buds in the mucosa of the tongue can generate impulses in the rostral regions of the tract -efferent fibers are distributed to the solitary tract nucleus
Trigeminal Mesencephalic Nucleus
- proprioception of the face, that is, the feeling of position of the muscles
- contains no chemical synapses but are electrically coupled
Trigeminal Motor Nucleus
- motor neurons that innervate muscles of the first branchial arch =the muscles of mastication, the tensor tympani, tensor veli palatini, mylohyoid, and anterior belly of the digastric
- mid pons
Trigeminal Mesencephalic Tract
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Trigeminal Nerve Root
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Trigeminal Principal Sensory Nucleus
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Trigeminal Spinal Nucleus
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Trigeminal Spinal Tract
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Vestibular Nuclear Complex
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