Hypothalamus 2

Question 1

Name the nuclei and their functions

Answer 1

1. Suprachiasmatic nucleus (biological clock, input from light-sensitive retinal ganglion cells).
2. Anterior hypothalamus (thermoregulation). Fever
3. Posterior hypothalamic area (sympathetic) - fear and aggression.
4. Supraoptic/paraventricular nucleus (posterior pituitary secretion oxytocin & Anti-diuretic hormone).
5. Median eminence/arcuate nucleus/paraventricular nucleus (control of appetite, metabolic rate, anterior pituitary).
6. Ventromedial nucleus (satiety ‘centre’).
7. Lateral hypothalamus (hunger ‘centre’); Orexin-hypocretin.
8. Mammillary body (memory); Korsakov syndrome

Question 2

Afferents

Answer 2

From sensory receptors, visceral (via reticular formation and solitary tract);

from brainstem (locus coeruleus, raphe, periaqueductal
grey); 

higher centres (hippocampal formation, amygdala, orbitofrontal cortex via mediodorsal thalamus).

Question 3

Efferents

Answer 3

Endocrine control via posterior pituitary, and anterior pituitary via portal system;

descending control of autonomic centres in brainstem and
spinal cord;

mammillothalamic tract

Question 4

Blood supply of hypothalamus

Answer 4

• from the internal carotid → gives superior and interior hypophyseal arteries
• inferior = posterior pituitary directly
• superior = hypothalamus including the CAPILLARY PLEXUS IN THE MEDIAN EMINENCE from which port veins pass to the anterior pituitary

Question 5

Where does the epithalamus lie?

Answer 5

Above the thalamus

Question 6

What is the epithalamus made up of?

Answer 6

the pre-tectal nucleus, the habenular

nuclei and the pineal gland

Question 7

Describe the pretectal nucleus

Answer 7

involved in pupillary constrictor response
– receives inputs from retina and projects bilaterally to
Edinger-Westphal nucleus via posterior commissure

Question 8

Describe the pineal gland

Answer 8

ssecreted melatonin in a circadian cycle
controlled by postganglionic sympathetic fibres
SUPERIOR CERVICAL GANGLION

Question 9

Describe the lateral habenular nuclei

Answer 9

Relay nuclei which regulate serotonin and dopamine in the brainstem

Question 10

What does the medial forebrain bundle do?

Answer 10

Connect the brainstem, hypothalamus and septal region

Question 11

Main neural tracts of the hypothalamus

Answer 11

Fornix
Mammilothalamic tract
Medial forebrain bundle

Question 12

Hormones involved in controlling appetite

Answer 12

leptin
insulin
ghrelin
neuropeptide Y
AgRP
Pancreatic polypeptide 
Cholecystokinin
Peptide tyrosin tyrosin

Question 13

What is the median eminence?

Answer 13

Circumventricular organ

Hormones released into the hypophysioportal stream here to travel to the ANTERIOR hypothalamus

Question 14

What is the infundibulum

Answer 14

Connection between the hypothalamus and the posterior pituitary

Question 15

Death of neurons in which nuclei would lead to diabetes insipidus?

Answer 15

SO/PVN