Week 4 (Test 2) Flashcards
What’s the function of CN XII?
hypoglossal: motor innervation of all intrinsic and extrinsic skeletal muscles of tongue
What’s the function of the nucleus ambiguus?
this nucleus contains special “visceral” efferent neurons that innervate skeletal muscle of the larynx and pharynx as cranial nerves IX, X, and a small part of 11
What’s the function of the inferior salivatory nucleus?
contains preganglionic parasympathetic neurons that exit the brainstem as part of CN IX to innervate the parasympathetic neurons in the otic ganglion
What’s the function of the dorsal motor nucleus of Vagus nerve?
contains preganglionic parasympathetic neurons that send their long axons out of the brainstem with the vagus nerve to innervate the parasympathetic ganglia in the walls of the esophagus, trachea, bronchi, heart, and gastrointestinal tract down to the transverse colon
What’s the function of the nucleus of the solitary tract?
1) contains primary afferent axons of CN’s 9 and 10 that carry visceral sensation from carotid body to CN 9 and the pharynx, larynx, viscera in thorax and abdomen to CN 10 2) ALL TASTE AFFERENTS
What’s the function of the nucleus of the Spinal Trigeminal Tract?
this nucleus receives all somatic afferent info that comes from the face and also the oral and nasal cavities
Which artery is blocked in Wallenberg’s Syndrome?
PICA
What’s the function of the inferior olivary nucleus?
contains neurons whose axons (“climbing fibers”) enter the contralateral inferior cerebellar peduncle to travel to the cerebellum
What’s the function of the dorsal and ventral cochlear nuclei?
contain the secondary special sensory neurons for the special sense of hearing
What’s the function of pyramids?
contain cortical upper motor neurons, axons destined for the spinal cord, i.e., corticospinal fibers
What’s the function of the medial longitudinal fasciculus (MLF) tract?
they are composed of the axons of interneurons which interconnect the cranial nerve nuclei involved with movement of the eyes and balance. THEY ARE CLINICALLY IMPORTANT BECAUSE WHEN LESIONED, CONJUGATE EYE MOVEMENTS ARE LOST
What’s the function of the dorsal (posterior) longitudinal fasciculus (DLF) tract?
its axons carry signals from the hypothalamus to autonomic nuclei in the brainstem and spinal cord
When looking in the brainstem, what is the name commonly used for the spinothalamic tract?
Anterolateral system
What’s the function of the ventral spinocerebellar tract? (VSCT)?
it carries unconscious proprioceptive info from groups of muscles to the cerebellum
What’s the function of the dorsal spinocerebellar tract?
it carries unconscious proprioceptive info from single muscles to the cerebellum
What’s the function of the trigeminal thalamic tract?
it carries all somatic sensory modalities for the FACE and oral and nasal cavities
What’s the function of the spinal trigeminal tract?
carries primary somatic sensory axons from the trigeminal ganglion to the spinal trigeminal nucleus
What’s the function of the central tegmental tract?
contains ascending and descending fibers of the reticular formation and connects the inferior olivary nucleus of the medulla with the red nucleus of the midbrain
What do substantia nigra neurons produce?
dopamine
Which cranial nerves are found in the midbrain?
CN III and IV
Which cranial nerves are found in the pons?
CN 5, 6, 7, & 8
Which cranial nerves are found in the medulla?
CN 9, 10, 11, & 12
Which arteries supply the medulla?
vertebral arteries, PICA, anterior spinal artery, and posterior spinal artery
Which arteries supply the pons?
pontine arteries off of the basilar artery supply middle and AICA supplies lateral portion
Which arteries supply the midbrain?
posterior cerebral arteries
What does the upper part of the nucleus solitarius do?
taste
Why is the lower part of the nucleus solitarius important?
it contains cardio respiratory neurons; if these get damaged you can die
Which two muscles open the eye?
Mueller’s muscle and levator occuli
paralysis of one side of the body
hemiplegia
weakness of one side of the body
hemiparesis
pseudounipolar neurons =
general sensory
bipolar neurons =
special sensory
What is the function of the nucleus solitarius?
visceral sensory info (taste, baroreceptors, gut distention) [vagal nuclei]
What is the function of the nucleus ambiguus?
motor innervation of pharynx, larynx, and upper esophagus [vagal nuclei]
What is the function of the dorsal motor nucleus?
sends autonomic (parasympathetic) fibers to heart, lungs, and upper GI [vagal nuclei]
How would a lesion in cranial nerve 6 present clinically?
no lateral gaze of the eye on the same side as the lesion
How would a lesion in the nucleus of cranial nerve 6 present clinically?
no lateral gaze of the eye on the same side as the lesion and no conjugate contralateral medial gaze
Describe the pathway involved in the corneal reflex.
afferent signal is sent from V1 (trigeminal) to rostral spinal nucleus (trigeminal); efferent signal is then sent from facial motor nucleus to orbicular oculi muscle and you blink
Describe the pathway involved in the jaw jerk reflex.
afferent signal is sent to mesencephalic nucleus (trigeminal) and efferent signal is then sent from the motor nucleus (trigeminal) to masseter and temporal muscles
What are the common signs of a lesion to the trochlear nerve?
SIGNS: 1) Extorsion (Can’t Look Down & In) 2) Vertical Diplopia (Double Vision) when Reading or Walking Down Stairs 3) Head Tilt + Chin Down Contralat. to Affected SO
pin point pupil
miosis
dilated pupil
mydriasis
What do you see in Horner’s syndrome?
Sympathetics Lost: Partial Ptosis (Muller’s m.) Miosis (Pin Point Pupil) Anhydrosis
What do you see in a lesion of CN III?
Somatic Motor Lost: - Full Ptosis (Levator m.) –Eye closes all the way -Down and Out Parasympathetics Lost: - Mydriasis (Dilated Pupil)
What is the blood supply of brainstem nerves and nuclei for CN 1 & 2?
anterior cerebral artery
What is the blood supply of brainstem nerves and nuclei for CN 3 & 4?
posterior cerebral artery