Neuro Block 1
Disclaimer: Notes not included for pretty much everything. Use Sylvius, and slides. The best way to learn neuroanatomy is a brain atlas.
9/1/2010
Q: What are three ways to organize the nervous system?
A: Location — Central vs. Peripheral
Direction — Afferent vs. Efferent
Function — Somatic vs. Autonomic for Efferent. Somatic vs. Visceral for Afferent
Q: What are the three autonomic efferents (GVE)?
A: Cardiac Muscle, Smooth Muscle, Glands, Adipose
Q: Are all somatic functions voluntary?
A: NO!! Knee jerk reflex and pain withdrawal reflex are somatic but involuntary.
SPINAL CORD DEVELOPMENT
Q: What closes on Day 24-25?
A:
Q: How does the brain differentiate?
A: Pro –> Tel + Di
Mes –> Mes
Rhomb –> Met + Mye
Q: What are the neural tube developmental defects?
A:
Spina bifida occulta — least severe. vertebrae do not completely enclose spinal cord. tuft of hair.
Meningocele — spinal cord embedded in vertebrae but exposed to outside. Usually have fluid filled subarachnoid space around spinal cord.
Meningomyelocele — spinal cord not embedded in vertebrae and exposed to outside. Usually have fluid filled subarachnoid space around spinal cord. Most severe.
Rachischisis — incomplete closure of neural tube.
Q: What do the neuroepithelial cells become?
A: ALL MACROGLIA (non-neural cells in CNS) AND CNS NEURONS
Q: Neurons vs. Neural:
A: Neural = related to neurons + glia
Q: What zones are there in a developing spinal cord?
A: Ventricular Zone
Mantle Zone –> Alar and Basal
Marginal Zone –> White Matter
Q: Is Breathing an autonomic function?
A: No! Because diaphragm is SKELETAL MUSCLE, and skeletal muscle is ALWAYS SOMATIC!
9/2/2010
Q: What does neural crest become?
A: Ganglia (part of PNS)
Q: Neural Tube –>?
A: CNS
Q: How much of your neurons are multipolar?
A: 99%
Q: Denticulate ligament does what?
A: anchors spinal chord.
Q: Limbs, and all your plexuses innervated by what?
A: ventral rami
Q: White vs. Gray ramus of sympathetic nerves.
A: White ramus = preganglionic
Gray ramus = post ganglionic
Anterior spinal arteries supply 2/3 of spnial cord.
Q: What level is the end of spinal cord?
A: L1
Q: What level is end of dural sac?
A: S2
Q: What level is attachment of filum terminale?
A: Cox
Q: What are the two enlargements of the spinal cord?
A: Cervical enlargement and lumbosacral enlargement
Q: What are the horns of the spinal cord cross-section?
A: Dorsal, Lateral, Ventral horns
Q: What exactly are in the horns? And what is in the matter (white/gray matter)?
A: Horns — nerve cell bodies
Matter — nerve fiber tracts
Q: What are the funiculi of the spinal cord cross-section?
A: Dorsal (tracts go north), Lateral and Ventral funiculus (both tracts go both directions)
Q: What are the septi of the spinal cord cross-section?
A: Posterior median septum, posterior intermediate septum (PIMS), posterolateral sulcus, anterolateral sulcus, anterior median fissure.
Q: PIMS is a great landmark to distinguish between what?
A: PIMS is in T6 or above. No PIMS = T7 or below.
Q: Where do the ventral roots come out of the spinal cord?
A: at the anterolateral sulcus
Q: where do the dorsal roots go into the spinal cord?
A: at the posterolateral sulcus
Q: Median vs. Medial?
A: Median — on the midline
Medial — towards the midline
Q: What are the general regions fo the spinal cord cross-section?
A: Dorsal horn has General Somatic Afferent (GSA), General Visceral Afferent (GVA)
Ventral horn has General Somatic Efferent (GSE)
Lateral horn has General Visceral Efferent (GVE)
Q: Which of Rexed’s Laminae are in the dorsal horn?
A: Lam I — “Posteromarginal nucleus” — receives somatic senses (touch, temperature, etc.)
Lam II — “Substantia gelatinosa” — receives somatic senses
Lam III and IV — “Proper Sensory Nucleus” — processes sensory info
Lam V and VI — only at the enlargements — processes sensory info
Q: Which of Rexed’s Laminae are in intermediate zone?
A: Lam VII
Q: Lam VII has two special regions… what are they?
Dorsal Nucleus of Clark — relays muscle afferents (C8-L2)
Intermediolateral Nucleus — aka Lateral horn — has preganglionic sympathetic (T1-L2/3) and preganglionic parasympathetic (S2-4), which is in the nucleus, but doesn’t appear as lateral horn.
Q: Which of Rexed’s Laminae are in the ventral horn?
A: Lam VIII — get neurons from higher centers, then send to Lam IX.
Lam IX — receives motor neurons from Lam XI.
Q: All the motor neurons are in which Lamina?
A: Lam IX!!!!
Q: What are the two types of motor neurons?
A: Alpha — innervates skeletal muscles (big)
Gamma — innervates muscle spindles (small)
Q: What about Lam X?
A: It is around the central canal of the spinal cord cross-section, but it’s not that important.
Q: What is the Zone of Lissauer?
A: Also called “posterolateral tract.” It is a tract at the posterior of the spinal cord (by Lam I) that is gray and carries pain and temperature neurons (afferent).
Q: What are the neurotransmitters of the dorsal horn?
A: Substance P — P stands for Pain
Enkephalin — regulates pain
Gaba — inhibitory
Q: What are the neurotransmitters of the ventral horn?
A: Gaba and Glycine, ACh
Q: Glycine is used in what kinda inhibition?
A: Recurrent inhibition — inhibition from the muscle to the brain rather than from brain to muscle.
Q: How do you distinguish between cervical, thoracic, lumbar, and sacral levels of the spinal cord just by looking at the cross-section?
A: Cervical — flat shape
Thoracic — round shape, thin dorsal horn, lateral horn
Lumbar — round shape, thick ventral horn
Sacral — low white:gray ratio
Q: Which level has the most white matter?
A: Cervical. Because more and more afferent tracts accumulate to go to brain as you go up the spinal cord.
Q: Which dermatome is at the shoulders?
A: C5
Q: Which dermatome is at the umbilicus?
A: T10
Q: Which dermatome is at the groin?
A: L1
Q: How many levels of spinal nerves do you have to knock out for you to feel the numbness on your skin?
A: 3, because dermatomes overlap each other by 50%.
Q: Afferent or Efferent? Dorsal vs. Ventral root?
A: Dorsal Root — Afferent
Ventral Root — Efferent — in Lam IX.
9/3/2010
Q: What marks the border between brain and spinal cord?
A: Foramen magnum
Q: What line is in the middle of the front of the medulla?
A: Ventral median sulcus
Q: What ridges lie on either side of the ventral median sulcus?
A: Pyramids
Q: What is the function of the pyramids?
A: contain main motor descending pathways (from brain go to Lamina IX)
Q: What lump lies at the bottom of the ventral medulla between the pyramids?
A: Pyramidal decussation, where crossing-over happens. left controls right, right controls left.
Q: What lies behind the pyramid?
A: Olive — associated with cerebellum.
Q: What sulci lie on each side of the olive?
A: Pre- and Post-olivary sulcus
Q: What cranial nerve comes out of the postolivary sulcus?
A: CN 9, 10, 11
Q: What cranial nerv
e comes out of the preolivary sulcus?
A: CN 12
Q: What sulcus forms the border between the pons and medulla?
A: inferior pontine sulcus
Q: What cranial nerves come out of the pontocerebellar medullary fovea?
A: CN 6, 7, 8, 9, 10, 11
Q: Which cranial nerves are associated with the midbrain?
A: CN 3,4
Q: Which cranial nerves are associated with the pons?
A: CN 5, 6, 7, 8
Q: Which cranial nerves are associated with the medulla?
A: 6, 7, 8, 9, 10, 11, 12
Q: The Cerebral Peduncle contains what three parts?
A: Midbrain tegmentum, Substantia nigra, and Crus Cerebri.
Q: What do the Peduncles do?
A: They are the stalk that hold up the mushroom (the cerebellum or cerebrum).
Q: Substantia Nigra is associated with what disease?
A: Parkinson’s Disease
9/6/2010 Morning
DORSAL BRAINSTEM
Q: What is the sulcus in the middle of the dorsal medulla called?
A: Median Dorsal Sulcus.
Q: Name the ridge, groove, ridge, groove, and ridge lateral to the Median Dorsal Sulcus?
A: Median Dorsal Sulcus –> Tuberculum Gracilis –> PIMS –> Tuberculum Cuneatus –> Posterolateral Sulcus –> Tuberculum Cinereum.
Q: What are the ridges on either side called?
A: Tuberculum gracilis
Q: What are the grooves lateral to the tuberculum gracilis?
A: PIMS!
Q: What’s the ridge lateral to tuberculum gracilis?
A: Tuberculum Cuneatus?
Q: What is the line that connects the superior and inferior fovea?
A: Sulcus limitans.
Q: What is the sulcus limitans?
A: Separates medial motor things and sensory things on the side
Q: What structure is below the medial sulcus? above?
A: below = vagal trigone — vagal nucleus under here
above = hypoglossal trigone — hypoglossal nucleus under here
Q:What’s lateral to the sulcus limitans?
A: The vestibular trigone — CN VIII
Q: What makes up the tuberculum gracilis?
A: Nucleus gracilis and the fasciculus gracilis
Q: What nucleus is under the Tuberculum cinereum?
A: Spinal Nucleus of CN V and Spinal Tract of CN V — from pons and synapse here.
Q: Where is the medial lemniscus derived from?
A: nucleus cuneatus and nucleus gracilis
Q: What do the superior and inferior colliculli do?
A: Superior = vision
Inferior = hearing
Q: What do the superior and inferior colliculli connect to via the brachium?
A: Superior colliculli connect to the lateral geniculate body
Inferior colliculli connect to the medial geniculate body
9/6/2010 Afternoon
Q: How many lobes do each hemisphere of the cerebrum have?
A: 5 — Frontal Parietal, Occipital, Temporal, and Insular
Q: The cells of the precentral gyrus reach down to form what?
A: The pyramids, pontine stuff, Lamina IX, etc.
Q:
Heschl – primary auditory cortex – hearing unlike most sensitive is BILATERAL!!!!! So they both cross and go straight up, so if you damage left Heschl, you’ll have diminished hearing, but it won’t be localized.
9/7/2010
CNIV — only CN on dorsal aspect
9/8/2010
Q: What’s under the uncus?
A: Amygdala — emotion
Q: When are the ventricles bigger than normal?
A: Hydrocephaly
Q: What do the basal ganglia do?
A: modifiers of motor activity
Q: What part of the brain lights up with heroine and cocaine addictions?
A: Accumbens
9/10/2010
Q: What cranial nerve comes out of hte interpeduncular fossa?
A: CN III comes out of interpeduncular fossa
Q: Can you peel pia mater off the brain?
A: NO!
Q: How many layer of dura do you have in your brain? spine?
A: Brain has two layers of dura — periosteal dura and meningeal dura, which folds onto itself to become the falx cerebri
Q: What’s the most common cause of subarachnoid hematoma?
A: ANEURYSM
Q: What’s the worst headache of my life?
A: Subarachnoid hematoma
Q: Which hematoma won’t have symptoms until weeks or months after injury?
A: Subdural hematoma
Q: Where does the sigmoidal sinus drain?
A: Internal Jugular
Q: Why is the cavernous sinus a dangerous place?
A: because we have an artery and cranial nerves traveling through a vein. so you could die from picking a pimple.
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