12. Limbic System and Hypothalamus

Question 1

What does the hypothalamus control?

Answer 1

Fluid and electrolyte balance
Food ingestion
Thermoregulation
Reproduction
Immune responses
Circadian rhythm

Question 2

What inputs are brought to the hypothalamus via the blood?

Answer 2

Hormones: growth, catecholamines, sex hormones
Chemical: pH, glucose
Physical: temperature, osmolarity

Question 3

What are the neural inputs to the hypothalamus?

Answer 3

Nucleus solitarius in the medulla: barorecptors, chemoreceptors
Reticular formation in pons and medulla: alertness and arousal

Question 4

What hypothalamic outputs are in the blood?

Answer 4

Direct hormone release (ADH, oxytocin)

Stimulation of pituitary (hypophyseal portal system)

Question 5

What neural outputs does the hypothalamus have?

Answer 5

Autonomic effects

Limbic system

Question 6

Which hypothalamic nuclei are in contact with the posterior pituitary?

Answer 6

Supraoptic

Paraventricular

Question 7

What is produced in supraoptic nuclei?

Answer 7

ADH

Question 8

What are supraoptic nuclei stimulated by?

Answer 8

Increased osmolarity

Question 9

What do paraventricular nuclei produce?

Answer 9

Oxytocin

Question 10

Which hypothalamic nuclei releases trophic hormones for the anterior pituitary?

Answer 10

Median eminence

Question 11

What is Cushing’s syndrome?

Answer 11

Excess cortisol

Question 12

What is Addison’s disease?

Answer 12

Adrenal insufficiency

Question 13

What can the pressure of a hypothalamic/pituitary tumour cause?

Answer 13

Compression of the optic chiasma
Bilateral hemianopsia (visual field loss)

Question 14

What part of the embryonic brain is the hypothalamus part of?

Answer 14

Diencephalon

Question 15

What part of the embryonic brain is the limbic system from?

Answer 15

Junction of the diencephalon and telencephalon

Question 16

What structures are contained in the limbic system?

Answer 16

Cingulate gyrus
Mammillary bodies
Fornix
Hippocampus
Amygdala
Septal nuclei

Question 17

Where are the mammillary bodies found?

Answer 17

Inferior surface of hypothalamus

Between brainstem and cerebrum

Question 18

What is the function of the mammillary bodies?

Answer 18

Short term memory
Smell
Direction

Question 19

What does the fornix connect?

Answer 19

Mammillary bodies to the hippocampus

Question 20

Where does decussation occur in the fornix?

Answer 20

Crus

Question 21

Where is the hippocampus?

Answer 21

Temporal lobe

Under inferior horn of the lateral ventricle

Question 22

What is the function of the hippocampus?

Answer 22

Making new memories

Question 23

What is the name for the 3 layers of cells in the hippocampus?

Answer 23

Allocortex

Question 24

What is Alzheimer’s caused by?

Answer 24

Cortical degeneration, especially in the hippocampus

Question 25

Where is the amygdala found?

Answer 25

Anterior to tip of the hippocampus

Question 26

What does stimulation of the amygdala cause?

Answer 26

Intense emotions: fear and rage

Question 27

What is the result of damage to the amygdala?

Answer 27

Calmness

Question 28

What does stimulation of the nucleus accumbens result in?

Answer 28

Dopaminergic activity | Feeling of wellbeing

Question 29

How does cocaine work?

Answer 29

Inhibits reuptake of dopamine | Dopamine floods the medial forebrain

Question 30

How do amphetamines work?

Answer 30

Stimulate dopamine release

Question 31

What is the motor function of the nucleus accumbens?

Answer 31

Connected to the basal ganglia to cause motor expression of emotion

Question 32

What is the function of the septal area?

Answer 32

Reward and reinforcement

Question 33

What does damage to the septal nuclei result in?

Answer 33

Rage

Question 34

Which components of the limbic system play a role in reward?

Answer 34

Septal nuclei Nucleus accumbens Olfactory regions Brainstem

Question 35

Which components of the limbic system play a role in punishment?

Answer 35

Thalamus Amygdala Hippocampus

Question 36

What is Wernicke-Korsakoff syndrome caused by?

Answer 36

Alcohol abuse | Affects B1 absorption which affects the limbic system

Question 37

What are the symptoms of Wernicke encephalopathy?

Answer 37

Confusion and coma Occular signs Ataxia

Question 38

What is ataxia?

Answer 38

Slurred speech, stumbling, incoordination

Question 39

What are the symptoms of Korsakoff Psychosis?

Answer 39

Memory loss and inability to form new memories after recovery