Gross structures & CSF

Question 1

What is the alternative name for the forebrain?

Answer 1

Prosencephalon

Question 2

What are the components of the forebrain?

Answer 2

1. Telencephalon:
   - Cerebral cortex
   - Basal ganglia
2. Diencephalon:
   - Thalamus
   - Hypothalamus

Question 3

What are the components of the hindbrain?

Answer 3

1. Medulla
2. Pons
3. Cerebellum

Question 4

What are the components of the brainstem?

Answer 4

1. Medulla
2. Pons
3. Midbrain

Question 5

What is the alternative name for the midbrain?

Answer 5

Mesencephalon

Question 6

What is the alternative name for the hindbrain?

Answer 6

Rhombencephalon

Question 7

What are the constant sulci present in the cerebral cortex?

Answer 7

1. Longitudinal sulcus (between 2 hemispheres)
2. Central sulcus (between frontal and parietal lobes)
3. Lateral/Sylvian sulcus (between temporal and frontal/parietal lobes)
4. Parieto-occipital sulcus (between parietal and occipital lobes, on medial surface)

Question 8

How are the lobes named?

Answer 8

After the bones of the skull they are located beneath.

Question 9

What is significant about arrangement of grey matter and white matter in the brain compared to spinal cord?

Answer 9

Grey matter on the outside in brain but inside in spine (apart from the deep nuclei).

Question 10

What are the major cortices in the cerebral cortex?

Answer 10

1. Primary motor cortex: Anterior to central sulcus.
2. Primary somatosensory cortex: Posterior to central sulcus.
3. Primary visual cortex: On occipital pole (especially in calcarine sulcus).
4. Primary auditory cortex: Lateral temporal lobe (beneath lateral sulcus).
5. Primary olfactory cortex: Medial temporal lobe.

Question 11

What are the functions of glial cells?

Answer 11

1. Supports neurone
2. Produces myelin
3. Removes debris from injured cells
4. Take up neurotransmitters
5. Guides axons in development
6. Regulates synaptic properties
7. Forms BBB

Question 12

Where is pain represented?

Answer 12

• Primary somatosensory cortex
• Insula
• Anterior cingulate cortex

Question 13

What is the ventricular system of the brain?

Answer 13

Lateral ventricles (2) → Inter-ventricular foraman (of Munro) → 3rd ventricle (1) → cerebral aqueduct → 4th ventricle (1) → central canal of spinal cord (or → foramina of Magendie & Luschka → subarachnoid space)

Question 14

What are the horns of the lateral ventricles?

Answer 14

1. Anterior horn
2. Posterior horn
3. Inferior horn

Question 15

What are the important cisterns?

Answer 15

1. Cisterna magna: Between medulla and cerebrellum.
2. Lumbar cistern: Inferior to conus medullaris (L1).

Question 16

What are the locations of the coroid plexuses?

Answer 16

All ventricles

Question 17

What is the course of CSF?

Answer 17

Blood → Choroid plexus → Ventricles → Subarachnoid space → Arachnoid villi → Venous sinuses → Blood

Question 18

What are the main sources of arterial supply to the brain?

Answer 18

• Internal carotid artery (ICA, anterior cerebral circulation)
• Vertebral arteries (posterior cerebral circulation)

Question 19

What are the branches of the ICA?

Answer 19

1. Anterior cerebral artery (ACA)
2. Middle cerebral artery (MCA)

Question 20

What does the ACA supply?

Answer 20

• Frontal lobe
• Medial aspects of parietal/occipital lobe
• Medial aspects of motor/somatosensory cortex supplying lower limbs.

Question 21

What does the MCA supply?

Answer 21

• Basal ganglia
• White matter
• Lateral motor/somatosensory cortex supplying the upper limbs/head and neck
• Internal capsule

Question 22

What are the branches of the vertebral artery?

Answer 22

1. Posterior inferior cerebellar artery (PICA)
2. Anterior spinal artery

Question 23

What are the branches of the basilar artery?

Answer 23

1. Posterior cerebral artery (PCA)
2. Anterior infereior cerebellar artery (AICA)
3. Superior cerebellar artery
4. Pontine arteries

Question 24

What does the PCA supply?

Answer 24

• Occipital lobe
• Infero-posterior surface of temporal lobe

Question 25

How is the circle of willis formed?

Answer 25

- ACA connected to each other by the anterior communicating artery. - ICA/MCA connected to the posterior cerebral arteries by the posterior communicating arteries.

Question 26

What is the nature of venous drainage of the brain?

Answer 26

- Superficial veins → Venous sinuses - Deep veins → Great cerebral vein

Question 27

What is the structure of the venous sinuses?

Answer 27

Question 28

Where are the major blood vessels supplying the brain mostly located?

Answer 28

Subarachnoid space

Question 29

What types of stains are used to visualise different types of tissue in the brain microscopically?

Answer 29

- Grey matter: Nissl stains (e.g. toluidine blue) - White matter (e.g. Weigert-Pal method)

Question 30

What are the types of contrasts in MRI scans?

Answer 30

1. T1: 1. Dark fluid 2. Bright white matter 3. Dark grey matter 2. T2: 1. Dark white matter 2. Bright fluid 3. Bright grey matter

Question 31

What is the nature of somatotopic representation in somatosensory cortex?

Answer 31

1. The legs are represnted in the medial aspects 2. The arms and hands are represented in the superior and superolateral aspects 3. The head is represented in the lateral aspects