Anatomy

Question 1

What do the arachnoid granulations do?

Answer 1

Fluid passes through SAH into superior sagital sinus

Question 2

What produces CSF?

Answer 2

Choroid plexuses in the lateral, 3rd & 4th ventricles

Question 3

Why do you get papilloedema in raised ICP?

Answer 3

Extension of SAH space around optic nerve

Question 4

What is the venous drainage of the brain?

Answer 4

Superior & inferior sagittal sinuses run backwards
Join the straight sinus to form
Drain into sigmoid sinuses
Drain into internal jugular vein

Question 5

What structures run in the cavernous sinus?

Answer 5

Oculomotor nerve
Trochlear nerve
Opthalmic branch
Maxillary branch
Internal carotid artery
Abducens nerve
(Mnemonic O Tom Cat)

Question 6

What’s autoregulation?

Answer 6

Brain maintains constant cerebral blood flow despite changes to systemic BP
Above/below limits this is lost and cerebral blood flow becomes dependent on MAP

Question 7

How does CO2 act on the brain?

Answer 7

Dilatation of vessels
Rise in pressure
Inc cerebral blood flow

Question 8

What is the middle cerebral artery a continuation of?

Answer 8

Internal carotid

Question 9

What are the branches of the middle cerebral artery?

Answer 9

Opthalmic artery
Anterior cerebral artery

Question 10

What marks the posterior border of the frontal lobe?

Answer 10

Central sulcus

Question 11

What is the pre-central gyrus important for?

Answer 11

Motor cortex

Question 12

What is the post-central gyrus important for?

Answer 12

Sensory cortex

Question 13

What is Broca’s Area responsible for?

Answer 13

Speech production (motor)

Question 14

What is Wernicke’s area responsible for?

Answer 14

Comprehension

Question 15

What’s most of the internal area of the brain supplied by?

Answer 15

Anterior cerebral artery

Question 16

Where does the middle cerebral artery supply?

Answer 16

Largest area- lateral parts of the brain (temporal, parietal, part of frontal lobe)

Question 17

What does the posterior cerebral artery supply?

Answer 17

Cerebellum
Brainstem
Occipital lobe

Question 18

What is the function of the lenticulostriate branches?

Answer 18

Blood supply to internal capsule
Infarct to this area = lacunar infarct

Question 19

What Sx would be seen in an anterior cerebral artery stroke?

Answer 19

Contralateral leg paresis
Disinhibition

Question 20

What Sx would be seen in an middle cerebral artery stroke of the dominant hemisphere?

Answer 20

Most left hemisphere dominant (opposite to favoured limb)
Face & upper limb hemiparesis
Sensory loss
Homonymous hemianopia
Dysarthria
Receptive aphasia

Question 21

What Sx would be seen in an anterior cerebral artery stroke of the non-dominant hemisphere?

Answer 21

Face & upper limb hemiparesis
Sensory loss
Neglect
Homonymous hemianopia
Dyspraxia (e.g combing hair)

Question 22

What Sx would be seen in a lacunar stroke?

Answer 22

Purely motor/sensory defects

Question 23

What is the function of the internal capsule?

Answer 23

Transmits motor fibres from pre-central gyrus to brainstem

Question 24

What Sx would be seen in a posterior cerebral artery stroke?

Answer 24

Homonymous hemianopia
Memory impairment
Thalamic syndrome

Question 25

What Sx would be seen in a brain-stem stroke?

Answer 25

Ipsilateral CN palsy
Contralateral motor & sensory defect below lesion
Cerebellar features: N&V, ataxia, nystagmus
Impaired consciousness
Can have bilateral defects

Question 26

What is the route of a motor function from the brain to axon?

Answer 26

1) Pre-frontal gyrus
2) Internal capsule
3) Pons
4) Decussation of pyramids
5) Corticospinal tract
6) Anterior horn
7) alpha motor neuron axon
8) Peripheral nerve

Question 27

What is the Dura made up of?

Answer 27

OUTER: Periosteal layer
INNER: Meningeal layer

Question 28

What are the 4 infolding of the dura?

Answer 28

-Falx cerebri: Inf to TC, separates hemispheres
- Tentorium Cerebelli: Seperates cerebellum and cerebrum
-Falx Cerebelli: Seperates cerebellar hemispheres
-Diaphragma sellae: Envelopes pituitary gland in sella turcica

Question 29

What happens between the layers of the Dura?

Answer 29

Venous sinuses - venous blood from brain drains before draining into jugular veins

Question 30

What are the 3 spaces related to the meninges?

Answer 30

• Extradural: Potential space between skull & dura
• Subdural: Potential space between dura & arachnoid
  -Subarachnoid: Between Pia & arachnoid, contains CSF

Question 31

What is the role of CSF?

Answer 31

• Buoyancy & cushioning
• Maintenance: pH, glucose, electrolytes
  -Buffering: Changes in ICP

Question 32

Describe the lateral ventricles

Answer 32

• C shaped cavities
• Separated by septum pallucidum
  -Has 3 horns - ant/post/inf

Question 33

Where are the 3 horns of the lateral ventricles located?

Answer 33

• Ant = frontal lobes
• Post = Known as occipital horns
• Inf = largest, temporal lobes

Question 34

Where is the 3rd ventricle located?

Answer 34

Between thalami & hypothalamus

Question 35

Where is the 4th ventricle located?

Answer 35

Between pons and medulla and cerebellum

Question 36

What is the route of flow of CSF?

Answer 36

• Lateral ventricles
• Foramen of Monro
• 3rd ventricle
• Aqueduct of Sylvius
• 4th Ventricle
• ## Subarachnoid space via foramen of Magendie and foramen of Lusaka

Question 37

What is the function of the cerebellum?

Answer 37

Control of pre-programmed:
Motor tasks
Co-ordination of motor functions
Memory
Language processing
Logical reasoning