Brainstem Cuts- Medulla

Question 1

What are the cuts of medulla

Answer 1

1- Thru decussion of pyramids

2- Passes thru sensory decussion

3- Mid olivary

4- Pases thru rostral end of olive/ cerebellar peduncles

Question 2

what cuts are part of the closed and open medulla

Answer 2

1+2- closed medulla

3+4- open medulla

Question 3

Notable contents of cut 1 (2)

Answer 3

Decussion of pyrmaids- 80% cross over here and other 20% @ every level (ant corticospinal tract)

Ambigous nucleus- origiun of spinal root of acessory n

Question 4

Notable contents of cut 2 (3)

Answer 4

• Pyramids (above decussasion)
• Sensory decussation- axons from gracilis and cutaneous cross and ascend to Ventral post lat thalmatic (bulbothalmatic)
• Ambigious nucleus- rostral part of accessory motor nucleus

Question 5

Notable contents of cut 3 (5)

Answer 5

Inf olivary nuclear complex- axons from red nucleus synapse here (rubrolivary fibres) then head to CL cerebellum (olivocerebellar fibres)

Medial lemniscus- ascending bulbothalmatic fibres from CL gracilis and cutaneous

Hypoglossal nuc

Middle part of ambeous nuc (for CN 10)

Dorsal vagal nucleus

Question 6

Notable contents of cut 4 (6)

Answer 6

medial lemniscus- ascending bulbothalmatic fibres from CL gracilis + cutaneous

base of inf cerebellar peduncle

vestibular area- has vestibular areas

ant and post cochlear nuclei (CN8)

ambigois nuc- (motor CN9)

Solitary nuc- carries taste for CN9