NB2

Question 1

How many cortexes are there in the brain

Answer 1

1. Motor cortex (in frontal lobe)
   - Somatic motor association area
2. Sensory cortex (in parietal lobe)
   - Somatic sensory association area
3. Visual cortex (in occipital lobe)
   - Primary visual cortex (posterior part of lobe) + Visual association area (anterior part of lobe)
4. Gustatory cortex
5. Olfactory cortex
   - connects smell with memory
6. Auditory cortex
   - Primary auditory cortex (superiorly) + Auditory association area (inferiorly)

Question 2

Efferent (motor) nerves is a 2 neurone pathway

Answer 2

• The two neurone pathway is upper motor neurone and lower motor neurone
• Upper motor neurone starts in the cerebral motor cortex (pre-central gyrus) to brainstem/spinal cord
• Lower motor neurone goes from brainstem cranial nerve motor nucleus or from cord to muscle

Question 3

Motor pathway definitions

Answer 3

1. Pyramidal system upper motor neurone starts in the cerebral cortex (pre-central gyrus). They pass through the pyramids of the medulla.
   - Conscious movement.
2. Extrapyramidal system upper motor neurone starts in other brain centre nuclei (basal ganglia). They do not pass through the pyramids of the medulla.
   - Fine tune movement

Question 4

What is the cerebellum responsible for

Answer 4

Balance, tone, posture & co-ordination and planning movement

Question 5

What is the basal ganglia

Answer 5

It is a diffuse set of nuclei responsible for allowing/stopping movements to happen
(nucleus accumbens, caudate, putamen, globus pallidus, subthalamic nucleus, substantia nigra)
Fine tune movement
Lentiform nucleus = Putamen + Globus pallidus

Question 6

What is the thalamus for

Answer 6

• Sensory relay station in the brain
• All general sensory information goes through the thalamus
• Located on either side of the third ventricle

Question 7

Major sensory pathways

Answer 7

Afferent nerves in cranial and spinal nerve
General senses: 3 neurones

2 sensation type :

1) Touch/Proprioception
- Dorsal columns
- Decussates in medulla

2) Pain & Temperature
- Spinothalamic tract
- Decussates immediately

Question 8

What is the limbic lobe and its function

Answer 8

(Cingulate gyrus, hippocampal formation and amyglada - deep in temporal lobe)

• Emotional aspects of behaviour and memory
• “Societal homeostasis” based on external inputs at a basic/survival level

Question 9

How many ventricles are there in the brain

Answer 9

4

2 Lateral; 1 Third Ventricle; 1 Fourth Ventricle

Question 10

What are the lateral ventricles for

Answer 10

Cavities of cerebral hemispheres filled with CSF

Question 11

Flow of CSF

Answer 11

CSF flows from lateral ventricle through interventricular foramen of Monro to third ventricle
-third ventricle is cavity of diencephalon
Third ventricle and fourth ventricle is joined together by cerebral aqueduct of Sylvius
CSF then flows to subarachnoid space through foramina of Lushka (laterally) and foramina of Magendie (posteriorly)

Question 12

Anatomy from 4th ventricle

Answer 12

Posteriorly - foramina of Magendie

Laterally - foramina of Lushka

Question 13

What is hydrocephalus

Answer 13

• Too much CSF will push the skull out
• Only occur in babies where bones are not fused yet
• In adults, there is an increase in intracranial pressure

Question 14

What is the term for the gaps before the bones are fused

Answer 14

Fontanelle

Question 15

Cranial nerve 1

Answer 15

Olfactory nerve

-smell

Question 16

Cranial nerve 2

Answer 16

Optic nerve

-vision

Question 17

Cranial nerve 3, 4, 6

Answer 17

3: Oculomotor nerve
4: Trochlear nerve
6: Abducens nerve
- eye movement

Question 18

Cranial nerve 5

Answer 18

Trigeminal nerve

-facial and scalp sensation, mandibular movements (chewing)

Question 19

Cranial nerve 7

Answer 19

Facial nerve

-facial expression

Question 20

Cranial nerve 8

Answer 20

Vestibulocochlear nerve

-hearing, balance

Question 21

Cranial nerve 9, 10

Answer 21

9: Glossopharyngeal nerve
10: Vagus nerve
- swallowing, phonation

Question 22

Cranial nerve 11

Answer 22

Accessory nerve

-neck and head movements

Question 23

Cranial nerve 12

Answer 23

Hypoglossal nerve

-tongue movement

Question 24

What is so special about the spinal cord

Answer 24

Dura and arachnoid mater is stuck together

There is no subdural space in the spinal cord

Question 25

What is Cauda Equina Syndrome (CES)

Answer 25

• bundle of nerves below the end of the spinal cord known as the cauda equina is damaged.
• spray of nerves that come off the bottom of the spinal cord and activates bladder, bowel, sexual organs and legs
• when nerves are compressed or damaged
• causes lower back pain (due to ruptured disc), pain that radiates down the leg, and loss of bowel or bladder control

Question 26

What causes CES

Answer 26

• back/spine problems such as slipped disc
• tumours near the spine
• injuries, trauma

Question 27

Warning signs of CES

Answer 27

“SPINE”
S: Saddle Anaesthesia
-Weakness, tingling or numbness in ‘saddle’ region (supplied by pudendal nerve - S2,3,4)

P: Pain
-Pain, weakness tingling or numbness in your lower back, backs of thighs, lower legs and feet

I: Incontinence
-Loss of control, urgency or finding it hard to pee or poo or any strange sensation when peeing or pooing

N: Numbness

• Numbness in your lower back, back of thighs, lower legs and feet
• Loss of feeling around groin during sex

E: Emergency