15-09-23 - Structure and Function of the Brain interactive lecture

Question 1

Space occupying lesions can affect pathways in the brain. In the classical story of David and Goliath, David slays the giant with a slingshot. The giant Goliath’s body has undergone abnormal body growth so what might be happening to allow David to slay the giant?

Hint: his peripheral vision is defective

Answer 1

• ANSWER: PITUITARY ADENOMA causing acromegaly.
• EXPLAINER: abnormal body growth + loss of peripheral vision would suggest pituitary enlargement, causing compression of the optic chiasma and loss of peripheral vision (bitemporal hemianopia)
• Pituitary secretes Growth Hormone (GH) – and excess secretion of this is called acromegaly. This is usually caused by a benign tumour of the pituitary called pituitary adenoma

Question 2

This gyrus lies in front of the central sulcus.

What is it called?

What is the function here?

Which lobe?

Answer 2

• Precentral gyrus is Infront of the central sulcus
• Primary motor cortex is found here
• The primary motor cortex is responsible for motor activity e.g. force direction and speed of muscle contraction
• It is located in the posterior frontal lobe

Question 3

This gyrus lies behind the central sulcus.

What is it called?

What is the function here?

Which lobe?

Answer 3

• Postcentral gyrus is located behind the central sulcus
• The somatosensory cortex is found here
• It receives sensory information from the entire body
• The somatosensory cortex is located in the parietal lobe

Question 4

What are the functional differences between primary and association cortex and which has the bigger area?

Answer 4

• Primary Cortex – receives or sends information with little to no processing beforehand (raw data)
• Association Cortex – this has the bigger area. A
• Association cortex interprets/ analyses information and can integrate information for different areas (remember unimodal vs. multimodal inputs)
• Remember association cortex can still send signals/ actions but these tend to be more complex than those formed in primary cortex. e.g. Broca’s area is a type of association cortex involved in language production.

Question 5

Name the labelled structures in this axial slice image

Answer 5

Question 5

Match the pairs with respect to the ventricle system and its location in the brain:
1) Lateral ventricle
2) Lateral ventricle to third ventricle junction
3) Third Ventricle
4) Fourth ventricle
5) Fourth ventricle
6) Cerebral aqueduct

Answer 5

• Match the pairs with respect to the ventricle system and its location in the brain

1) Lateral ventricle + Caudate nucleus

2) Lateral ventricle to third ventricle junction + interventricular foramen

3) Third Ventricle + Thalamus/ Hypothalamus

4) Fourth ventricle + Pons/ Medulla

5) Fourth ventricle + Foramen of Magendie

6) Cerebral aqueduct + Midbrain

Question 6

This imaging shows a stroke in which structure?

What type of scans are these?

Answer 6

• This scan shows Internal capsule infarct
• Images starting from left are 1) CT scan 2) T2 MRI 3) DWI Sequence

Question 7

What fluid filled structure with the similar shape is the caudate nucleus closely associated with?

Which component of the basal ganglia structures is degenerated in Parkinson’s disease?

Which elements of the basal ganglia make up the dorsal striatum?

Answer 7

1) Q1: What fluid filled structure with the similar shape is the caudate nucleus closely associated with?
* A: lateral ventricle

2) Q2: Which component of the basal ganglia structures is degenerated in Parkinson’s disease
* A: substantia nigra

• Q3: Which elements of the basal ganglia make up the dorsal striatum?
• A: putamen and caudate nucleus

Question 8

Match the pairs of juxtaposed (side by side) structures:
1) Third ventricle
2) Lateral ventricle
3) Insula
4) Putamen
5) Amygdala

Answer 8

• Pairs of juxtaposed (side by side) structures:

1) Third ventricle + thalamus/ hypothalamus

2) Lateral ventricle + caudate nucleus

3) Insula + Lateral fissure

4) Putamen + globus pallidus (putamen and globus pallidus together form the lentiform nucleus)

5) Amygdala + hippocampus (both part of the limbic system. Amydala = emotions/ memory/ decisions; hippocampus = memory)

Question 9

Identify structures labelled (in picture)

Answer 9

• Identify structures labelled (in picture)
  a) Diencephalon
  b) midbrain
  c) pons
  d) medulla

Question 10

Match the function with the brain region (in picture)

Answer 10