S5: Internal and External Anatomy of the Medulla Flashcards
Fasciculus cuneatus
function: carries ipsilateral epicritic sesnory from the UPPER HALF of the body
pathology: loss of epicritic below lesion on the SAME SIDE
fasciulus gracilis
carries ipislateral epicritic sensory from LOWER HALF of the body
pathology: loss of epicritic sensation below the lesion ON THE SAME SIDE
Nucleus gracilis
function: epicritc sensory, 2 point position, vibration, tactile for movement requiring fast sensory feedback
pathology: “dorsal column signs” loss of epicritic sensory for trunk and limb
inaccurate movements
Nucleas Cuneatus
function: epicritic somatosensory for upper trunk and limb on the SAME SIDE
pathology: in medulla: loss of 2 point vibration, position, tactile form sense, inaccurate movements
spinal nucleus of 5
function: somatosenoy for head and neck
pathology: loss of pain and temeprature senses on the same side of the head
Rubrospinal tract
function: distal motor control
pathology: ipsilateral loss of distal motor control below the X
Extrapyramidal tracts: vesitbulospinal reticulospinal, and tectospinal
function: proximal motor contorl
pathology: loss of proximal motor control below the lesion if damaged bilaterally along with the anterior corticospinal tract
Decussation of the pyramids
dorsal spinocerebellar tract
function: carries proproreceptive info. dstined for the cerebellum from the LOWER HALF OF THE BODY
pathology: controls ipsilateral muscle coordination but not obvious sx result from pathology
hypothalamoreticulospinal tract
function: carries rpegang symps to the intermediolateral cell column
pathology: ipsilateral horners syndrome
dorsal nucleus of vagus nerve
function: parasymps for heart, lungs, GI
pathology: inc in HR, subtle effects
Hypoglossal
pathology: tongue points to side of the lesion
medullary pyramids
corticospinal axons (before they crossed in decussations!)
yellow
decussation of pyramids
corticospinal tract crossing over here
what cranial nerves are around here?
what nuclei does it have?
olive
CN - hypoglossal exits between olive and the pyramids
the vestibulocochlear its between depression of the pons and the olive
nuclei - inferior olive n. which receives information from most areas of cerebral cortex, the red nucleus, and from the spinal cord and sends it to the cerebellum via the inferior peduncle
what does the inferior olive do? where is it?
inferior olive is in the olive complex in the medulla
sends axons from the cortex, red nucleus, and spinal cord to cross the midline and go to the inferior cerebellar peduncle
4’
input?
what does damage to this cause?
inferior cerebellar peduncle
receives input from opposite infeiror olive nulcei in medulla
often seen with PCA stroke. damage causes
- ataxia
- intention tremor to the ipsilateral side of the body
- lean towards side of the lesion
- clumsiness of ipsilateral hand
10
cuneate tubercle
carry somatosensory and proprioceptive information
gracile tubercle
have gracile nucleus
carry somatosensory and proprioceptive information
cuneate nucleus
reticular formation
nucleus ambiugous
Function:
Motor innervation of IPSI. muscles of the soft palate, pharynx, larynx and upper esophagus.
Deficits:
Lesion of nucleus ambiguus results in atrophy (lower motor neuron) and paralysis of innervated muscles, producing nasal speech, dysphagia, dysphonia, and deviation of the uvula toward the CONTRA
gracile nucleus
