Midline Structures, Limbic System and Basal Ganglia

Question 1

What makes up the limbic system (tracts and gyrus)

Answer 1

(1. ) Uncus –> parahippocampal gyrus –> cingulate gyrus

(2. ) Amydgala -> hippocampus -> fimbrae -> fornix -> columns of fornix -> mammillary body

Question 2

What is the limbic system responsible for?

Answer 2

(1. ) Emotion
(2. ) Memory
(3. ) Olfaction
(4. ) Behaviour

Question 3

where does the hippocampus lie and what is it important for? what disease is implicated here?

Answer 3

(1. ) Lies within the inferior horn of the lateral ventricle
(2. ) Important for long-term memory and emotional response
(3. ) AD shows atrophy of hippocampus

Question 4

What are the different types of white matter fibres in the brain? Name some examples for each type

Answer 4

(1. ) Association fibres = links cortical regions within one hemisphere, ‘U’ shaped fibres e.g. uncinate fasciculus
(2. ) Commissual fibres = links simlar functional areas of the two hemisphere e.g. corpos callosum, anterior an dposterior commisural fibres
(3. ) Projection fibres = links cortex with subcortical areas e.g. internal capsule

Question 5

Where does the amydgala receive info + where is it located in the brain

Answer 5

(1. ) Lateral striate of the olfactory nerve

(2. ) Amydgala nucleus is found within the uncus, and is superior and anterior to the hippocampus

Question 6

What makes up the basal ganglia

Answer 6

Caudate, lentiform nucleus, subthalamic nucleus, sub. nigra, red nucleus

Question 7

What makes up the lentiform nucleus and the corpus striatum

Answer 7

(1. ) Putamen and Globullis Pallidus

(2. ) Caudate and Putamen

Question 8

Why is the internal capsule a common site for strokes?

Answer 8

It is supplied by the lenticulostriate arteries (MCA)

Question 9

Describe where you’d find the internal, external and extreme capsule

Answer 9

(1. ) Caudate and lentiform nucleus
(2. ) Lentiform nucleus and claustrum
(3. ) Claustrum and insular cortex

Question 10

What is the Corona radiata

Answer 10

(1. ) White matter tracts that follow on from the internal capusule
(2. ) Contains sensory and motor tracts

Question 11

What brain structures are affected in parkinsons and what (5) signs and Sx may you see?

Answer 11

(1. ) DA neurons in the sub nigra

(2. ) Cog-wheel rigidity, tremor at rest, shuffling and festinant gait, bradykinesia, loss of facial expression

Question 12

What brain structures are affected in huntington’s and what (4) signs and Sx may you see?

Answer 12

(1. ) Corpus Striatum

(2. ) Chorea, personality change, depression, progressive dementia

Question 13

What is the homunculus?

Answer 13

(1. ) Topograpphic representation of body parts along the pre- (motor) and post- (sensory) central gyrus.
(2. ) Lower limbs are found medially whereas the upper limbs are found more laterally

Question 14

What would you see if ACA is damaged?

Answer 14

ACA supplies medial aspect so weakness/loss of in CONTRALATERAL lower limbs

Question 15

What would you see if MCA is damaged?

Answer 15

MCA supplies lateral aspects so weakness/loss in CONTRALATERAL upper limb and face

Question 16

What sulcus would you find the primary visual cortex

Answer 16

Calcarin sulcus

Question 17

Where is the paracentral lobule

Answer 17

This is a U shaped lobule that surrounds the central sulcus (seen on midsagital section)

Question 18

What makes up the diencephalon

Answer 18

(1. ) Thalamus, hypothalamus, subthalamus, epithalamus

(2. ) Thalamus = dorsal, hypothalamus = ventral

Question 19

What are the LGB and MGB important for?

Answer 19

(1. ) LGB relays visual info from optic nerve, visual cortex and superior colliculi
(2. ) MGB relays info from midbrain, auditory cortex, inferior colliculi

Question 20

What is the the function of the hypothalamus?

Answer 20

(1.) Involved in ANS function, neuroendocrine systems, body homeostasis