N3: brainstem and blood supply

Question 1

functions of brainstem

Answer 1

• Conduit for tracts (sensory and motor)
• Consciousness, cardiovascular (CV) system, respiratory system, pain perception (reticular formation)

Question 2

structure of brainstem

Answer 2

• Midbrain
• Pons
• Medulla oblongata

Question 3

superior colliculi structure and function

Answer 3

bumpy top
part of visual pathway

Question 4

inferior colliculi structure and function

Answer 4

bumpy bottom
auditory pathway

Question 5

gracile tubercle structure and function

Answer 5

midline of brainstem
lower limb fibres

Question 6

cuneate tubercle structure and function

Answer 6

lateral brainstem
upper limb fibres

Question 7

where is the bulbo-pontine sulcus

Answer 7

between pons and medulla

Question 8

what lies in the bacilla sulcus

Answer 8

basilla artery

Question 9

where is the anterior median sulcus

Answer 9

between pyramids

Question 10

where are the olives

Answer 10

lateral to pyramids

Question 11

what is the decussation of pyrimidal tracts

Answer 11

where the tracts cross over

Question 12

in a horizontal section, what are the eyes and mouth of the pug

Answer 12

red nuclei = eyes
cerebral aquiduct = mouth

Question 13

cause and symptoms of parkinson’s disease

Answer 13

• Characterised by resting tremor, difficulty in initiating voluntary movement and jerking
• caused by depletion of dopamine in substantia nigra

Question 14

where do afferent neurones enter the spinal cord

Answer 14

dorsal horn

Question 15

where do efferent neurones exit the spinal cord

Answer 15

ventral horn

Question 16

function of white matter tracts

Answer 16

→ carry info to and from cerebrum

Question 17

what is the corticospinal tract

Answer 17

DESCENDING
- pyramidal tract
- voluntary control over skeletal muscles below the head and neck
- decussates at pyramids of medulla
- lateral and anteruir

Question 18

what is the corticobulbar tract

Answer 18

DESCENDING
- Voluntary (conscious) control over skeletal muscles of head and neck
- precentral gyrus -> internal capsule -> midbrain synapse -> brainstem synapse

Question 19

what is the dorsal column medial lemniscus tract?

Answer 19

ASCENDING
- relays sensory info from peripheral nerves to cerebral cortex
- proprioception, fine touch and vibration
- signals from gracile nucleus and cuneate nucleus

Question 20

where do signals from gracile nucleus come from?

Answer 20

lower limb
= medial part of dorsal column

Question 21

where do signals from cuneate nucleus come from?

Answer 21

from lower limb
lateral part of dorsal column

Question 22

what is the spinothalamic tract

Answer 22

• Sensory information from the peripheral nerves to the cerebral cortex
• pain, temperature, crude touch and pressure

Question 23

pathway of DCML

Answer 23

1st: dorsal root ganglion -> nucleus gracilis/cuneate
2nd: nucleus -> thalamus
3rd: thalamus -> post-central gyrus

Question 24

pathway of spinothalamic tract

Answer 24

1st: dorsal horn -> spinal cord
2nd: SC -> thalamus
3rd: thalamus -> post-central gyrus

Question 25

what are spinocerebellar tracts

Answer 25

- Unconscious proprioceptive information - Co-ordinate and refine motor movements - Signals from muscles to cerebellum

Question 26

what systems make up the cerebral arterial circle

Answer 26

- Internal carotid system - Vertebral-basilar system

Question 27

contents of cerebral arterial circle

Answer 27

- Two internal carotid arteries - Two vertebral arteries connect to form circle

Question 28

where do carotid arteries enter skull

Answer 28

through carotid canal

Question 29

where do vertebral arteries enter skull

Answer 29

through the foramen magnum

Question 30

what does internal carotid artery arise from

Answer 30

common carotid artery on arch of aorta

Question 31

where does vertebral artery originate

Answer 31

subclavian artery

Question 32

what artery supplies the lateral lobes

Answer 32

medial artery

Question 33

what artery supplies the anterior lobes

Answer 33

anterior artery

Question 34

what artery supplies the posterior lobes

Answer 34

posterior artery

Question 35

what is a Saccular (berry) Aneurysm

Answer 35

- most common type - occurs within the vessels that supply the cerebral arterial circle - rupture causes accumulation of blood in the subarachnoid space with a subsequent increase in intracranial pressure.

Question 36

major dural venous sinuses

Answer 36

- Superior sagittal sinus - Inferior sagittal sinus - Straight sinus - Transverse sinus - Confluence of sinuses - cavernous sinus - sigmoid sinus

Question 37

what vein do all venous sinuses drain into

Answer 37

internal jugular vein

Question 38

what are the motor pathways

Answer 38

= descending corticospinal tract corticobulbar

Question 39

what are the sensory pathways

Answer 39

= ascending spinothalamic tract dorsal column medial limniscus