Week 1 - Wet Room

Question 1

What is the brainstem?

Answer 1

The brainstem is the part of the brain that lies just superior to the spinal cord. It is made up of 3 parts.
From superior to inferior they are:
-The midbrain
-The pons
-The medulla

Question 2

Which cranial cavity does the brainstem lie in?

Answer 2

Posterior cranial fossa

Question 3

Embryologically, which two vesicles of the neural tube give rise to the brainstem?

Answer 3

Metencephalon

Myelencephalon

Question 4

What are the cavities (of the ventricular system) that lie within the brainstem?

Answer 4

4th ventricle

Cerebral aqueduct

Question 5

Which cranial nerves can you see emerging from the pontomedullary junction?

Answer 5

VI, VII and VIII

Question 6

Which of the cranial nerves that emerge from the pontomedullary junction has the longest intracranial course?

Answer 6

Facial nerve (VII)

Question 7

Why is it clinically significant to know that the Facial nerve is so long?

Answer 7

Its long intracranial course makes this nerve very vulnerable to injury by increased intracranial pressure or other mechanical factors such as intracranial fractures or cerebral artery aneurysms.

Damage to this nerve will cause Bell’s palsy

Even though the actual pathology is increased intracranial pressure, the manifestation due to the nerve involved is far removed.
This can be a misleading clinical presentation and is hence called as a false localising sign.

Question 8

What produces the pyramids of the brainstem?

Answer 8

Descending fibres of ipsilateral cerebral cortex

Question 9

What produces the decussation of the pyramids?

Answer 9

75-90% of descending fibres cross over

Question 10

What produces the olive and what is its function?

Answer 10

Has connections primarily with the cerebellum

Involved in control of movement

Question 11

The medulla has an open and a closed part.

Which is superior and which is inferior?

Answer 11

Open = superior
Closed = inferior

Question 12

What structure does the “open” part of the medulla open onto?

Answer 12

IV ventricle posteriorly

Question 13

Through which foramen does the medulla pass to become the spinal cord?

Answer 13

Formen magnum

Question 14

What makes up the diencephalon?

Answer 14

Thalamus and hypothalamus

Question 15

How many part of the diencephalon can you see?

Answer 15

Most of the structures are deep and cannot be seen from the surface except for a small part of the hypothalamus

Question 16

What is the name given to the midline structure connecting the two cerebellar hemispheres?

Answer 16

Vermis

Question 17

What are the 3 lobes of each cerebellar hemisphere?

Answer 17

Anterior lobe
Posterior lobe
Flocculonodular lobe

Question 18

What parts of the brain is the cerebellum connected to anatomically be peduncles?

Answer 18

Medulla
Pons
Midbrain

Question 19

What is the name of the ventricular space that lies immediately anterior to the cerebellum?

Answer 19

4th Ventricle

Question 20

What cranial cavity if the cerebellum in contact with?

Answer 20

Posterior cranial fossa

Question 21

What foramen of the skull does the cerebellum sit above?

Answer 21

Foramen magnum

The part of the cerebellum that sits atop this foramen is called the cerebellar tonsils

Question 22

What may occur to the tonsils when there is a sudden drop in intracranial pressure?

Answer 22

The tonils may herniate through the foramen magnum

This is called cerebellar coning

Question 23

What is the overall structure of the cerebral hemispheres?

Answer 23

The cerebral hemispheres are paired (left and right) with a deep, but incomplete, fissure separating the two parts in the mid-sagittal line.

Question 24

What is the neame given to the large fissure separating the two cerebral hemispheres?

Answer 24

Median Longitudinal Fissure

Question 25

What structure connects the two hemishperes of the cerebrum?

Answer 25

Corpus callosum

Question 26

What nerve types are most likely to be carried in the corpus callosum?

Answer 26

Commissural fibres (connect two hemispheres)

Contrast to:

• Association fibres (connect regions within same hemisphere)
• Projection fibres (connect connect each region to other parts of the brain or the spinal cord)

Question 27

Describe how the brain sits in the cranial cavity

Answer 27

On removal of the skull cap, and the encasing meninges, the cerebral hemispheres appear to occupy the whole of the cranial cavity from anterior to posterior and from side to side.
The cerebral hemispheres sit on the floor of the anterior cranial fossa and the middle cranial fossa.
However, posteriorly, the cerebral hemispheres sit on the tantrum cerebella which is a fold of dura mater which covers over the cerebellum.

Question 28

What lobe contains the primary motor cortex?

Answer 28

Frontal

Question 29

What lobe contains the primary visual cortex?

Answer 29

Occipital

Question 30

What lobe contains the primary sensory cortex?

Answer 30

Parietal

Question 31

What lobe contains the primary auditory cortex?

Answer 31

Temporal

Question 32

When removing the laminae from the vertbrae to gain access to the vertebral canal, what is the first thing you would encounter on entering the vertebral canal?

Answer 32

Dura Mater

Question 33

At what level does the spinal cord terminate in the adult and the newborn?

Answer 33

Adult = L1-L2

The newborn = L3

Question 34

At what vertbral level does the dura and arachnoid mater terminate?

Answer 34

S2

Question 35

What happens to the pia mater inferior to the spinal cord?

Answer 35

Becomes the cauda equine

Question 36

What occupies the space between the end of the spinal cord and the termination of the dura and arachnoid?

Answer 36

CSF and cauda equina

Lumber puncture can be performed here at level L3 or L4

Question 37

How many pairs of spinal nerves are there?

Answer 37

31

Question 38

What is the difference between upper motor neurone damage and lower motor neurone damage?

Answer 38

Upper motor neurone lesions are characterised by spasticity, an increase in muscle tone and complex sensory syndromes.

Lower motor neurone conditions are characterised by global sensory changes and or flaccid paralysis depending on the nature of the mixed peripheral nerves

Question 39

Is damage to the cauda equina classified as an upper or lower motor neurone?

Answer 39

Lower motor neurone