Lecture 6 - Medulla

name and view

dorsal brainstem

above line is pons

below is medulla

rhomboid fossa

name and view

ventral brainstem

showing the rostral - red boundary of the medulla —>posterior pontine protuberance to fourth ventricle

showing the caudal - green boundary of hte medulla —> 1 mm caudal to the motor dec

name and whats there

tegmentum

more dorsal

general sensory and reticular formation

name 1 and what travels there

pyramids

more ventral — motor

corticospinal and corticobulbars

name what is separated by what line

name and view

ventral brainstem

whats this cut thru

motor dec

whats this a cut of

motor decussation in medulla

1. diagonal opening on bottom - bc fibers cross

whats 2 cutting thru

sensory dec

1. cut thru bumps that house nuc gracilis

2. JUST BELOW OLIVES

3. still see pyramids

whats this a cut thru (ignore arrow)

sensory dec in closed medulla

what is indicated by the blue arrow

pyramids w corticospinals (Upper extremities, trunk, lower extremities —> medial to lateral)

closed medulla so no 4th ventricle

NOT THE LATERAL CORTICOSPINALS BC WE HAVENT CROSSED YET!!

no corticobulbars bc they have already come off

name cut of 3

inferior olives

we are in the 4th ventricle — we are in rhomboid fossa

pyramids are present

whats this a cut thru

inferior olives

name all arrows

1. if we see olives we are in open medulla

2. still no more cortical bulbars

name 4 cut

highest medulla

pyramids still prseent

name the cut

highest medulla (open medulla)

name all arrows

dotted line means its something you would see on gross brain - pyramid

visualize the order from rostral to caudal of medulla cuts

describe the corticospinals

1. anywhere above the crossing is corticospinals

2. after motor dec they are lateral corticospinal

whats the dark blue dotted line

gracile tubercule - can see on gross brainstem

sensory dec

whats a

nucleus gracilis

sensory dec

dotted blue line over b

cuneate tubercle

sensory dec

b

nucleus cuneatus

dotted hot pink

internal arcuates

d

sensory dec

purple arrow

spinothalamic

if we see olives we are at _______ medulla

open

name

medial lemniscus

inferior olives

purple

ventral and lateral spinothalamics

inferior olives

name pink and purple and view

pink - medial lemniscus

purple = ventral and lateral spinothalamic

highest open medulla

• note that the spot is basically the same as inferior olives cut

name

spinothalamics

name light pink dots

inferior olive

• olivary complex (nucleus)

inferior olives

name pink arrows

main olive

medial accessory olive

dorsal accessory olive

name green arrow and its purpose

sulcus limitans in medulla

separates motor (medial) from sensory (lateral)CN nuclei

name 1 and what it contains

hypoglossal trigone

contains hypoglossal (CN 12) nuc

2 adn what it contains

vagal trigone

dorsal efferent nuc

3

lateral recess

a and pink triangle

vestibular area (vestibular nuclei)

acoustic tubercle

orange square

nucleus prepositus hypoglossi

star

inferior cerebellar peduncle

a

fourth ventricle

floor of rhomboid fossa

inferior olives cut

b

hypoglossal nuc

inferior olives cut

c and its type of autonomic fiber and whats it associated w

dorsal efferent nuc

associated w CN 10

parasympathetic preganglionic

inferior olives cut

d

vestibular nuc — lateral bc sensory

inferior olives cut

pink arrow

inferior vestibular nucleus

d is our vestibular nuclei — and we are lower in medulla as far as its parts go

inferior olives cut

e

inferior cerebellar peduncle

green

tectospinal

motor reflex

inferior olives cut

yellow

medial longitudinal fasciculus

• how CN communicate

donut shape

looks like an egg and you have one egg for breakfast - nucleus and tract of solitarius

nucleus = light and tract = dark and inside

pink and crescent

1. nucleus and tract of 5

2. light = pink = nucleus

3. tract = white = dark

dotted pink circle and what it contains

nucleus ambiguous

• CN 9, 10, 11

name yellow triangle shape and what it contains

reticular formation

contains descending autonomics

whats all a part of the reticular formation

everything left over

• descending autonomics

• nuc ambiguus

• vomiting center

red dots

obex

red line and what its responsible for

area postrema

vomiting center

orange arrow

nuc prepositus hypoglossi

high medulla cut

what are the pink nuclei

tells you we are in high medulla

name yellow dotted area and yellow arrows

fxn of nucleus prepositus hypoglossi

gaze holding center (neural integrator) for lateral gaze

name neuron

CN 12 (LMN)

CNS bc in brainstem

lesion of hypoglossal nuc/ CN 12

paralysis is contralateral — corticospinal

tongue deviates towards sign of lesion

dark line is the CN

where do taste (7,9,10) synapse

VPM

VPL nucleus

sensory nucleus for BODY

VPM is sensory nuclei for

HEAD

name and where its seen

Raphe nuclei

seen more in high medulla than low pons