Brain Stem and Spinal Cord Flashcards
what type of neurons are found in the alar and basal plates
alar plates are sensory neurons (dorsall in spinal cord)
basal plates are motor neurons (ventral in spinal cord)
the sensory nuerons in the alar plate are divided into two divisions, what are they are where are they found
they are the somatic sensory and visceral sensory, the somatic sensory is more dorsal, the visceral sensory is more ventral (closer to the sulcus limitans)
what is the sulcus limitans
the division between the alar and basal plates
the motor neurons in the basal plate are divided into two divisons, what are they, and where are they found
they are the visceral motor, and somatci moter. the visceral motor is more dorsal (closer to the sulcus limitans) the somatic motor is more ventral
somatic is on the outside, visceral is on the inside
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What is the orientation of the alar and basal plates and their divisions in the brainstem (medulla and pons)
they are arranged (from medial to lateral)
(basal) somatic motor, visceral motor - sulcus limitans - (alar) visceral sensory, somatic sensory
they are all just ventral to the 4th ventricle
what is the branchial motor nuclei
it is specialized branchial arches forming the skeletal muscle in the head (they are motor nuclei that supply innervation to skeletal muscles that are only found in the brainstem)
where are the branchial motor nuclei found
ventral (away from 4th ventricle) to the visceral and somatic motor nuclei
what are the hearing and balance nuclei
sensory nuclei found only in the pons and medulla that help in hearing and balance
where are the hearing and balance nuclei found
dorsal (closer to the 4th ventricle) to the visceral and somatic sensory nuclei
what is the relation of sensory and motor neurons to the sulcus limitans in the pons and medulla
sensory nuclei are lateral to sulcus limitans and motor nuclei are medial to sulcus limitans
What are the cranial nerves that originate in the medulla oblongata
IX Glossopharyngeal
X Vagus
XI spinal accessory
XII Hypoglossal
what is the function of the IX glossopharnygeal nerve
sensation to the posterior third of the tongue and orophaynx
what is the function of the X vagus nerve
innervates heart, lungs, GI tract, palatal muscles, pharyngeal muscles, laryngeal muscles
what is the function of XI spinal accessory nerve
innervates the trapezius and sternocleidomastoid muscles
What is the function of the XII hypoglossal nerve
innervates tongue muscles
What are the four nuclei found in the medulla
hypoglossal nucleus (CN XII)
Dorsal motor nucleus (CN X)
Inferior salvatory nucleus (CN IX)
Nucleus Ambiguous (CN IX and X)
What are the nuclei found in the caudal pons
abducens nucleus (CN VI)
Superior salvatory nucleus
Facial Nucleus
what are the nuclei found in the mid pons
trigeminal motor nucleus
spinal trigeminal nucleus and tract
what are the nuclei found in the midbrain
oculomotor nucleus
edinger westphal nucleus
what are the external anatomical features of the medulla
pyramid
olive
CN IX, X, XI, XII
4th ventricle
what are the external anatomical features of the pons
pons proper middle cerebellar peduncle CN V, VI, VII, VIII fourth ventricle basilar artery
what are the external anatomical features of the midbrain
cerebral peduncles
superior and inferior colliculus
CN III, IV
cerebral aqueduct
what does the hypoglossal nucleus of the medulla control, how do you know if its damaged
CN XII it controls the muscle that prodtrudes the tongue if it is injured on one side when you stick your tongue out it will go to the side that is injured (lick your wounds)
what does the dorsal motor nucleus of the medulla control
it is CN X, and it controls the heart, trachea, bronchi, lungs, GI tract
what does the inferior salvatory nucleus of the medulla control
the parotid gland (visceral motor CN IX)
What does the nucleus ambiguus of the medulla control
laryngeal, palatal, and pharyngeal muscles (CN IX and X)
what level of the brainstem does the gag reflex test
the medulla (CNIX and CN X)
What are the cranial nerves that originate in the pons
CN V Trigeminal
CN VI Abducens
CN VII facial
CN VIII Vestibulocochlear
What are the functions of the trigeminal nerve
general sensory to the head (oral cavity and teeth) cornea, and muscles of mastication
what are the functions of the abducens nerve
lateral rectus of the eye
what are the functions of the facial nerve
muscles of facial expression, lacrimal gland, sublingual and submandibular salivary glands, taste of 2/3 anterior tongue
what are the functions of CNVIII vestibulococchlear nerve
hearing and balance
what does the abducens nucleus of the caudal pons innervate
lateral rectus of the eye (moves it laterally)
what does the superior salivatory nucleus of the caudal pons innervate
sublingual and submandibular salivary glands
what does the facial nucleus of the caudal pons innervate
muscles of facial expression
what does the trigeminal motor nucleus of the mid pons innervate
muscles of mastication
what does the spinal trigeminal nucleus and tract of the mid pons do
receives general sensory innervation from CN V face and head
what is involved in the corneal reflex
the trigeminal nucleus of mid pons (receives sensory information) and the facial nucleus of pons (blinks the eye)
what does the occulomotor nucleus of the midbrain (mesencephalon) do
moves the the eye up, medial, down. if its damaged the eye moves down and lateral
what does the edinger westphal nucleus of the midbrain (mesencephalon) do
innervate pupillary constrictor and ciliary muscles (eye dialates if damaged)
what does the caudal midbrain innervate
superior oblique muscle via the trochlear nucleus
What are the types and numbers of the vertebrae
cervical - 7 thoracic - 12 lumbar - 5 sacral - 5 (fused) coccygeal (3-4 fused)
what are the three meningeal layers, and where is CSF found
dura mater
arachnoid mater
pia mater
CSF if sound between arachnoid mater and pia mater
how many spinal cord levels in each section are there
8 cervical 12 thoracic 5 lumbar 5 sacral 1 coccygeal
how many spinal nerves in each section are there
8 cervical 12 thoracic 5 lumbar 5 sacral 1 coccygeal
where does the transition from naming spinal nerves change from being named for the vertebral pedicle below it, to the vertebral pedicle above it
at cervical vertebra 7 (C8 nerve goes under C7 vertebra)
in a fetus the vertebral levels and spinal cord levels are lined up, in an adult they aren’t
the vertebral column grows and becomes longer than the spinal cord, so the spinal cord levels become more and more superior than their corresponding vertebra level the further down the spinal cord you go
what does the alar plate become in the spinal cord
the dorsal horn (sensory)
what does the basal plate become in the spinal cord
the ventral horn (motor)
what is the white matter in the spinal cord
the myelinated axons (outside part)
how does the amount of white matter in the spinal cord change between levels of the spinal cord, and why
there is the most white matter in the cervical spinal cord, and it gets less and less as you go down the spinal cord with the least in the coccygeal spinal cord. this is because there are more axons in the cervical spinal cord
what are the ascending tracts of the spinal cord white matter
dorsal column - ascending sensory for fine touch, proprioception, and vibration
spinothalamic tract - ascending sensory for pain, temperature, and touch from contralateral side of body
what are the desceding tracts of the spinal cord
corticospinal tract - upper motor neurons from the cortex to the ventral horn gray matter
What are Rami, Trunks, and Roots
Roots - the two portions of nerves that directly connect to the spinal cord
Trunk - the place where the two rami meet, then turn into the two roots
Rami - the nerves that go out to the body
what are characteristis of nerve roots
one way streets
two roots
Dorsal (sensory, afferent, connects to dorsal horn)
Ventral (motor, Efferent, connects to ventral horn)
what are the characteristics of rami
two way streets (both motor and sensory axons)
two rami
Dorsal (muscles and skin in back)
Ventral (form plexuses)
dermatomes, what skin do they control C5 C6 C7 C8 T1 T4 T10 L1 L4
C5 - shoulder C6 - thumb C7 - pointer and middle finger C8 - pinkie and ring finger T1 - sub clavicle T4 - nipple line T10 - bellybutton L1 - inguinal L4 - knees
