Brainstem introduction Flashcards
what are the functions of the brainstem
motor coordination
reticular formation
cranial nerves
vital and non vital centres
describe the distribition of cranial nerves in the brainstem
4 from midbrain and above
4 from the pons
4 from the medulla
does a brainstem lesion cause ipsilateral or contralateral defects
ipsilateral usually
ambiguous nucleus
somatic motor
solitarius
visceral sensory
what structures are found superior to the brainstem
tentorium cerebelli and diencephalon
what is the superior cerebellar peduncle
connects the cerebellum and midbrain
what is the middle cerebellar peduncle
connects the pons and cerebellum
what connects the medulla and cerebellum
inferior cerebellar peduncle
where does conscious proprioception cross (ascends in the dorsal columns)
brainstem then ascends in the medial lemniscus
where does light touch cross
some crosses straight away
some crosses in the brainstem
what does unconscious proprioception ascend in
spinocerebellar tract
does not cross
what information is found in the corticospinal tract
descending motor
crosses in the brainstem
upper motor neurone synapses with a lower motor neuron in the spinal cord
in what lesion are fasciculations present
lower mn
tone and reflexes
increased in upper mn lesion
atrophy
only present in lower mn lesions
what is the sympathetic supply from the hypothalamus
facial sweating, eyelid elevation, vasomotor and pupil dilation
doesn’t usually cross
what is the general visceral autonomic output from the brainstem
eye, saliva, heart, lungs, gut
cn 3,7,9,10
what is the autonomic function of the facial nerve
chorda tympani to submandibular and sublingual glands
what are the components of special somatic afferent
hearing
balance
sight
cn 2 -sight
cn8- balance and hearing
corticobulbar tract
The muscles of the face, head and neck
UMN
corticospinal tract
Upper motor neurons for the body
may cross in the medulla or spinal cord
why will a brainstem lesion cause contralateral upper motor neurone signs
fibers cross in the brainstem below (start in the cortex)
what is the medial lemniscus a continuation of
the dorsal column
what is the function of the medial lemniscus
discriminatory touch and proprioception to the thalamus then cross over and ascends as medial lemniscus to sensory cortex
what is the spinal lemniscus
continuation of the spinothalamic tract
carries pain, temp, course touch to the thalamus and then to the post central gyrus
what is the function of the cuneocerebellar tract
continuation of the spinocerebellar tract
what is the function of the medial longitudinal fasciculus
carries information about the direction that the eyes should move
what is the diencephalon
posterior part of the forebrain, containing the epithalamus, thalamus, hypothalamus, and ventral thalamus and the third ventricle.
