Brain Stem External Features

Question 1

The longitudinal fibers which are considered an association tract is…..

Answer 1

Medial longitudinal bundle

Question 2

Mention non-cranial nuclei of brain stem

Answer 2

Olivary nuclei in medulla
Pontine nuclei in pons
Red nucleus in midbrain

Question 3

The olive is made by ….

Answer 3

Inferior olivary nucleus

Question 4

Describe attachment of last 4 cranial nerves

Answer 4

Attached to medulla
XII to anterooateral sulcus (between pyramid & olive)
IX,X,XI to posterolateral sulcus between olive & ICP

Question 5

The artery firming longitudinal sulcus on pons is….

Answer 5

Basilar artery

Question 6

Describe attachment of middle 4 CNs

Answer 6

V, junction of MCP with basis pontis, closer to upper border by 2 roots (sensory: large, lat & motor: small, med)
VI, lower border of pons just above olive
VII, to cerebello-pontine angle by 2 roots (motor: large, med & sensory nervus intermedius: small, lat)
VIII, to cerebello-pontine angle lateral to VII by 2 roots vestibular medially & cochlear laterally)

Question 7

Mention the structures winding around cerebral peduncle

Answer 7

1. Optic tract
2. Trochlear nerve
3. Basal vein
4. Posterior cerebella artery

Question 8

…….arises from medial side of cerebral peduncle

Answer 8

Oculomotor

Question 9

Interpeduncular fossa belongs to…..

Answer 9

Hypothalamus

Question 10

Describe cerebello-pontine angle tumour clinically

Answer 10

Lesion of VII, facial paralysis
Lesion of VIII, deafness & vertigo

Question 11

Describe boundaries of interpeduncular fossa

Answer 11

Ant: optic chiasma
Anterolateral: optic tract
Posterior: pons
Posterolateral: cerebral peduncles

Question 12

Mention contents of interpeduncular fossa

Answer 12

Tuber cinereum
Posterior perforated substance
Mammilary bodies
Oculomotor nerve

Question 13

……is connected with post lobe of pituitary by infundibulum

Answer 13

Tuber cinereum

Question 14

Posterior perforated substance is pierced by…., while ant perforated substance is pierced by…..

Answer 14

Posterior cerebellar art
Ant & middle cerebellar art

Question 15

Bund of open medulla

Answer 15

Triangular
Base: medullary stria
Apex: continuous with central canal
Floor: each side there is a V-shaped depression (inf fovea) separating 3 trigones.

Question 16

Mention trigones separated by inf fovea & their position

Answer 16

1. Hypoglossal trigone medial to fovea
2. Vagal trigone (over dorsal vagak nucleus) between limbs of fovea
3. Vestibular trigone lateral to fovea

Question 17

The medial eminence overlies……, its lower part is expanded to form ….which is fomed by…..

Answer 17

Abducent nucleus
Facial colliculus
The motor fibers of the facial nerve loop over the abducent nucleus

Question 18

Lateral to medial eminence is……, its upper part forms……that contains……,while its lower part forms…….,…….lies laterally to the latter.

Answer 18

Sulcus limitans
Locus cerulus
Norepinepherine
Superior fovea
Vestibular area

Question 19

Lower part of inferior fovea forms…..

Answer 19

Area postrema

Question 20

Describe connections of colliculi of midbrain

Answer 20

SC, connected to lateral geniculate body
IC, connected to medial geniculate body

Question 21

Describe roof of 4th ventricle

Answer 21

Superiorly: SCP, Superior medullary velum (layer of ependyma)
Inferiorly: inferior medullary velum has large median formaen called foramen of Magendie which connects interior to ventricle to subarachnoid space

Question 22

Describe lateral bounds of 4th ventricle

Answer 22

Sup: SCP
Inf: ICP
Lateral recess: a recess of the cavity of 4th ventricle extends laterally over surface of ICP. The lateral recess opens on each side into the subarachnoid space by foramen of Luschka.

Question 23

Describe reticular formation

Answer 23

Consists of nerve cells & nerve fibers scattered within the brain stem extending superiorly to hypothalamus & thalamus and inferiorly to spinal cord.
Neurons arranged inti 3 columns: median, medial & lateral