Last minute stuff

Question 1

assocaition, commiseral fibers
projection fibers
specific afferents
association and commerural afferents

Major types of cerebral cortex

Answer 1

• layer 3 (association - same side)
• layer 5
• layer 4
• layer 1-3

Homotypical()

agranular - primary motor cortex

granular - primary somatorsensory cortex, primary visual cotex, auditory cortex

Question 2

medial and lateral geniculate bodies

Answer 2

medial - auditory cortex

lateral - visual cortex

Question 3

Layers of the internal capusule

Answer 3

1. anterior limb
2. GENU
3. Posterior li,n
4. Retrolentticular (visual radiation) - come from lateral geniculate body
5. Sub-lenticular (auditory radiation) come from medial geniculate body

Question 4

Lamina 3 + 4
Lamina 5 + 6
Lamina 7
Lamina 8 + 9

Answer 4

-nucleous proprious - where get touch and pressure nerve fibers converging, then back to gracile fasiculus
-noxious viseral stimulli
-dorsal nucleus of clarck - spinocerebellar tract, unconscious proprioception (DSCT, VSCT) , rest of 7 - autonomic nervous system
8+9 - motor neurons - flexors at back

Question 5

Myotactic reflex (monosynaptic reflex)

Answer 5

Discriminative fibers will enter the dorsal root ganglion (these are myelinated and have free nerve endings are very fast)

• theses will go down into lamina 3+4 (noxiuos viseral stimuli) but also into lamina 8+9 - wher they will synapse onto lower motor neurons - flexor and extensors
• this will inform the lower motor neurons what is happening out in the periphery
• the lower motor neuron flexor and extensors can then work together to get a smooth movement

Question 6

Withdrawal reflex (polysynaptic reflex)

Answer 6

pain and temp neurons will be unmyelanated, slow, and will synapse onto lamina 1 and 2

• a second neuron will then fire down into the lamina 8+9 region and then will synapse here
• they will get flexors and extensors working to withdraw from painful stimuli
• (then this info also travels up towards the brain)
• this is slower because there is an extra neuron

Question 7

corpora quadagemina

Answer 7

superior calculus - orientates head towards visceral stimuli

Inferior - less precise, orientates towards auditory stimuli

Question 8

gracile and cuneate fasiculi positioning

Answer 8

gracile - medial, cuneate- lateral

Question 9

where does the dorsal column medial lemniscal pathway cross over - what is this called?

-where does it merge with spinothalamic tract?

Answer 9

internal arcuate fibers

-merges with medial lemiscal pathway in the pons

Question 10

Cranial nerves

Answer 10

Trigeminal - sensation in face, chewing - V1- opthalamic, V2 - maxillary, V3 - mandibular

Accessory = muscles in neck, help swallow and speak

Hypoglossal - throat and tongue muscles

Question 11

Which is D1 and which is D2 receptor - which neurons and excitatory or inhibitor

Answer 11

D1 - to substantria nigra excitatory

D2 - is to the globus palliuds inhibitory

Question 12

Loss of pain and temp around band of skin above umbilicus

Answer 12

• Ependymal cells = around the part of cross over in spinal cord - e.g tumour of these cells - ependymona
• if pushing down ehre, than will get both sides damage around body of pain and temp