Week 13 - CNS

Question 1

A 78-year-old man presents to the emergency department experiencing slurred speech, weakness and reduced sensation of the right upper limb. Which cerebral artery is most likely to be involved in this presentation?

Answer 1

b) Middle cerebral artery
* Supplies the motor cortex

Question 2

An uncal herniation of the brain will most likely compress which cranial nerve?

Answer 2

The cardinal signs of uncal herniation are an acute loss of consciousness associated with ipsilateral pupillary dilation and contralateral hemiparesis. These symptoms are due to compression or displacement of ascending arousal pathways, the oculomotor nerve (CN III), and the corticospinal tract.

Uncal herniation. The uncus of the temporal lobe herniates over the free edge of the tentorium, compressing the midbrain and the oculomotor nerve.

Question 3

From which arteries do the vertebral arteries typically arise?

Answer 3

= Subclavian arteries

Question 4

How many cervical vertebrae are there?

How many pairs of cervical spinal nerves are there?

Answer 4

7 cervical vertebrae

8 pairs of cervical spinal nerves

All spinal nerves, except the first, exit below their corresponding vertebrae. In the cervical segments, there are 7 cervical vertebrae and 8 cervical nerves. C1-C7 nerves exit above their vertebrae whereas the C8 nerve exits below the C7 vertebra.

Question 4

How many cervical vertebrae are there?

How many pairs of cervical spinal nerves are there?

Answer 4

7 cervical vertebrae

8 pairs of cervical spinal nerves

All spinal nerves, except the first, exit below their corresponding vertebrae. In the cervical segments, there are 7 cervical vertebrae and 8 cervical nerves. C1-C7 nerves exit above their vertebrae whereas the C8 nerve exits below the C7 vertebra.

Question 5

The primary motor cortex is found in the ______________________ gyrus of the ______________________ lobe. The primary somatosensory cortex is found in the ______________________ gyrus of the ______________________ lobe.

Answer 5

The primary motor cortex is found in the pre-central gyrus of the frontal lobe. The primary somatosensory cortex is found in the post-central gyrus of the parietal lobe.

Question 6

The respiratory centre is located within which brain structure?

• a) Medulla oblongata
• b) Hypothalamus
• c) Midbrain
• d) Thalamus
• e) Cingulate gyrus

Answer 6

a) Medulla oblongata = respiratory centre

b) Hypothalamus
c) Midbrain
d) Thalamus
e) Cingulate gyrus = A component of the limbic system, it is involved in processing emotions and behavior regulation.