Anatomy Practical 2

Question 1

What is the limbic system?

Answer 1

Group of structures
On the medial aspect of the cerebral hemisphere and diencephalon
Encircles upper brainstem
Emotional/affective brain

Question 2

Which parts of the limbic system are important in emotions?

Answer 2

Amygdale

Anterior cingulated gyrus

Question 3

What does the amygdale do?

Answer 3

Recognises angry and fearful facial expressions
Assesses anger
Elicits fear response

Question 4

What does the cingulated gyrus do?

Answer 4

Expresses our emotions through gestures

Resolves mental conflicts when we are frustrated

Question 5

What makes up the basal ganglia?

Answer 5

Caudate nucleus
Putamen
Globus pallidus

Question 6

What does the diencephalon consist of?

Answer 6

Thalamus
Hypothalamus
Epithalamus (pineal gland)
- all enclose the 3rd ventricle

Question 7

What does the cingulate cortex do?

Answer 7

Memory storage

Question 8

What does the hippocampus do?

Answer 8

Formation of memroy

Question 9

What is the function of the fornix?

Answer 9

Pathway from hippocampus to storage (cingulate cortex)

Question 10

What is the function of the parahippocampal gyrus?

Answer 10

Storage of memory

Question 11

What is the significance of the connections between the cortex and the limbic system?

Answer 11

• intimate relationship between our feelings and thoughts
• react emotionally to things we consciously understand
• explains why emotions sometimes override logic and why reasons can stop us from expressing emotions

Question 12

How are smells linked to emotions?

Answer 12

Connections between olfactory bulb and amygdale (emotions) as well as the hippocampus (associative learning)

Question 13

Which parts of the cerebellum have what sensory and motor maps?

Answer 13

Anterior and posterior lobes overlap

• medial portions influence motor activities of trunk
• intermediate parts concerned with distal limbs in skilled movements
• flocculonodular lobe receives input form inner ear to adjust posture and balance

Question 14

How does cerebellar processing for motor activity occur?

Answer 14

• motor areas of the cortex notify cerebellum to initiate voluntary muscle contraction
• cerebellum receives info from proprioceptors of body so cerebellum can evaluate body position and momentum
• cerebellum calculates best way to co-ordinate force, direction and extend muscle contraction preventing overshoot/maintain posture/ensure smooth co-ordinated movement
• superior peduncles (output) allows cerebellum to dispatch info to cerebral motor cortex to co-ordinate movement, cerebellum also sends fibres to neurons in the brainstem influencing motor neurons in cord

Question 15

What does the diencephalon consist of?

Answer 15

Thalamus, hypothalamus and the epithalamus (pineal gland)

All close the 3rd ventricle

Question 16

What are the features of the thalamus?

Answer 16

• bilateral egg shaped masses
• connected ta midline by interthalamic adhesion
• contains nuclei which project to or receive fibres from cerebral cortex
• afferents converge there and synapse with nuclei
• information gets sorted and edited

Question 17

What is the function of the thalamus?

Answer 17

• key role in mediating sensation, motor activities, cortical arousal, learning, memory
• gateway to the cerebral cortex (consciousness)

Question 18

What is the function of the hypothalamus?

Answer 18

Below the thalamus
Contains nuclei
Small size
Main visceral control centre of the body
Body homeostasis

Question 19

What is the function of the epithalamus?

Answer 19

pineal gland which secretes melatonin

together with hypothalamus melatonin regulates sleep and wake cycle

Question 20

What is the purpose of the CSF?

Answer 20

cerebrospinal fluid
cushioning
buoyancy
reduces brain weight by 97% preventing brain from crushing under its own weight
protects brain and spinal cord from blows and other trauma
helps nourish the brain
carries chemical signals from one part of the brain to another

Question 21

What is the composition of the CSF?

Answer 21

similar to blood plasma
formed from blood plasma
fewer proteins
different ion concentrations

Question 22

What is hydrocephaly?

Answer 22

CSF circulation/drainage obstructed so accumulates and exerts pressure on brain
- new born babies = head enlarges as skull bones not fused but in adults occurs more rapidly as skull is rigid so fluid accumulates and compresses blood vessels serving the brain and crushes soft nervous tissue