Diencephalon

Question 0

Thalamus

Answer 0

In diencephalon

Paired oval masses of grey matter organized in nuclei with interspersed tracts of white matter.

Relays almost all sensory input to cerebral cortex.

Also involved in motor function and maintenance of consciousness

Question 1

Diencephalon

Answer 1

Thalamus
Hypothalamus
Epithalamus

Develops from prosencephalon

Sensory and motor processing. .

Extends from brain stem to cerebrum, surrounds 3rd ventricle.

Question 2

Intermediate mass

Answer 2

Inter thalamus adhesion

Bridge of grey matter the joins right and left hemispheres of thalamus

(In about 70% of population)

Question 3

Intermedullary lamina

Answer 3

Divides grey matter in each half of the thalamus.

Axons entering and leaving thalamus nuclei.

Question 4

Internal capsule

Answer 4

Thick band of white matter in lateral thalamus

Axons connecting thalamus to cerebral cortex pass through.

Question 5

Ventral posterior nucleus

Answer 5

Thalamus

Relays impulses for somatic sensations like touch, pressure, vibration, itch, tickle, temperature, pain, proprioception

Question 7

Lateral geniculate nucleus

Answer 7

Thalamus

Relays visual impulses for sight from retina to primary visual area of cerebral cortex.

Question 8

Medial geniculate nucleus

Answer 8

Thalamus

Relays auditory impulses from hearing from ear to primary auditory area of cerebral cortex

Question 9

Hypothalamus

Answer 9

Small part of diencephalon.
Inferior to thalamus.
One of the main regulator of homeostasis
4 regions: mammillary, tuberal, supraoptic, preoptic

Question 10

Mammillary Region

Answer 10

Most posterior region of hypothalamus
Adjacent to midbrain
Contains mammillary bodies (relay stations for reflexes associated with smell) and posterior hypothalamic nuclei

Question 11

Tuberal Region

Answer 11

Widest portion of hypothalamus.
Contains dorsomedial, ventromedial, and arcuate nuclei.
Also contains infundibulum and median eminence.

Question 12

Infundibulum

Answer 12

Tuberal region.
Connects pituitary gland to hypothalamus
Encircled by median eminence

Question 13

Supraoptic Region

Answer 13

Hypothalamus.
Superior to optic chiasm.
Contains paraventricular, supraoptic, anterior hypothalamic and suprachiasmatic nuclei

Question 14

Suprachiasmatic nucleus

Answer 14

In supraoptic region of the hypothalamus.

Involved in circadian rhythm.

Question 15

Preoptic region

Answer 15

Hypothalamus; anterior to supraoptic region.
Regulates some autonomic areas
Contains medial and lateral preoptic nuclei

Question 16

Functions of Hypothalamus

Answer 16

Control of ANS
Production of hormones
Regulates emotional and behavioural patterns
Regulates eating and drinking (feeding, satiety, thirst)
Control of body temperature
Regulates circadian rhythm

Question 17

Hypothalamus: role in hormone production

Answer 17

Cooperates with pituitary gland.

1. Release releasing and inhibiting hormones that act on anterior pituitary hormones.
2. Axons from paraventricular and supraoptic nuclei act on posterior pituitary (through infundibulum) to release oxytocin and antidiuretic hormone (vasopressin).

Question 18

Epithalamus

Answer 18

Pineal gland + habenular nuclei

Question 19

Pineal gland

Answer 19

Secretes melatonin

Question 20

Habenular nuclei

Answer 20

Involved in olfaction, especially emotional response to olfactory stimulation

Question 21

Circumventricular Organs (CVO)

Answer 21

Diencephalon
In wall of third ventricle.
Monitor chemical changes (no blood brain barrier)
Include part of the hypothalamus, the pineal gland, the pituitary gland etc.
Coordinate homeostatic activities of endocrine and nervous systems (BP, fluid balance, hunger, thirst)