Brainstem introduction

Question 1

what are the functions of the brainstem

Answer 1

motor coordination
reticular formation
cranial nerves
vital and non vital centres

Question 2

describe the distribition of cranial nerves in the brainstem

Answer 2

4 from midbrain and above

4 from the pons

4 from the medulla

Question 3

does a brainstem lesion cause ipsilateral or contralateral defects

Answer 3

ipsilateral usually

Question 4

ambiguous nucleus

Answer 4

somatic motor

Question 5

solitarius

Answer 5

visceral sensory

Question 6

what structures are found superior to the brainstem

Answer 6

tentorium cerebelli and diencephalon

Question 7

what is the superior cerebellar peduncle

Answer 7

connects the cerebellum and midbrain

Question 8

what is the middle cerebellar peduncle

Answer 8

connects the pons and cerebellum

Question 9

what connects the medulla and cerebellum

Answer 9

inferior cerebellar peduncle

Question 10

where does conscious proprioception cross (ascends in the dorsal columns)

Answer 10

brainstem then ascends in the medial lemniscus

Question 11

where does light touch cross

Answer 11

some crosses straight away

some crosses in the brainstem

Question 12

what does unconscious proprioception ascend in

Answer 12

spinocerebellar tract

does not cross

Question 13

what information is found in the corticospinal tract

Answer 13

descending motor
crosses in the brainstem

upper motor neurone synapses with a lower motor neuron in the spinal cord

Question 14

in what lesion are fasciculations present

Answer 14

lower mn

Question 15

tone and reflexes

Answer 15

increased in upper mn lesion

Question 16

atrophy

Answer 16

only present in lower mn lesions

Question 17

what is the sympathetic supply from the hypothalamus

Answer 17

facial sweating, eyelid elevation, vasomotor and pupil dilation

doesn’t usually cross

Question 18

what is the general visceral autonomic output from the brainstem

Answer 18

eye, saliva, heart, lungs, gut

cn 3,7,9,10

Question 19

what is the autonomic function of the facial nerve

Answer 19

chorda tympani to submandibular and sublingual glands

Question 20

what are the components of special somatic afferent

Answer 20

hearing
balance
sight

cn 2 -sight
cn8- balance and hearing

Question 21

corticobulbar tract

Answer 21

The muscles of the face, head and neck

UMN

Question 22

corticospinal tract

Answer 22

Upper motor neurons for the body

may cross in the medulla or spinal cord

Question 23

why will a brainstem lesion cause contralateral upper motor neurone signs

Answer 23

fibers cross in the brainstem below (start in the cortex)

Question 24

what is the medial lemniscus a continuation of

Answer 24

the dorsal column

Question 25

what is the function of the medial lemniscus

Answer 25

discriminatory touch and proprioception to the thalamus then cross over and ascends as medial lemniscus to sensory cortex

Question 26

what is the spinal lemniscus

Answer 26

continuation of the spinothalamic tract

carries pain, temp, course touch to the thalamus and then to the post central gyrus

Question 27

what is the function of the cuneocerebellar tract

Answer 27

continuation of the spinocerebellar tract

Question 28

what is the function of the medial longitudinal fasciculus

Answer 28

carries information about the direction that the eyes should move

Question 29

what is the diencephalon

Answer 29

posterior part of the forebrain, containing the epithalamus, thalamus, hypothalamus, and ventral thalamus and the third ventricle.