Thalamus and hypothalamus

Question 1

Describe the organisation of the thalamus.

Answer 1

Divided in 2 by third ventricle.
Collection of individual nuclei with separate functions.
Ipsilateral connections with forebrain.
Nuclei are interconnected.

Question 2

What is the function of the thalamus?

Answer 2

Relay centre between cerebral cortex and rest of CNS.
Integrates information.
Involved in virtually all functional systems.

Question 3

What are the different types of thalamic nuclei?

Answer 3

Specific- connected to primary cortical area.
Association- connected to association cortex.
Intralaminar- connected to all cortical areas.
Reticular- not connected to cortex.

Question 4

List the specific nuclei of the thalamus.

Answer 4

Ventral lateral
Ventral anterior
Ventral posterolateral
Ventral posteromedial
Lateral geniculate
Medial geniculate

Question 5

Which cortices are the ventral lateral and ventral anterior nuclei connected to?

Answer 5

Motor cortices (primary, premotor, supplementary).

Question 6

Which cortex is the ventral posterolateral nucleus connected to?

Answer 6

Somatosensory (body).

Question 7

Which cortex is the ventral posteromedial nucleus connected to?

Answer 7

Somatosensory (head).

Question 8

Which cortex is the lateral geniculate nucleus connected to?

Answer 8

Visual cortex.

Question 9

Which cortex is the medial geniculate nucleus connected to?

Answer 9

Auditory cortex.

Question 10

List the association nuclei of the thalamus.

Answer 10

Anterior
Lateral dorsal
Dorsomedial
Lateral posterior
Pulvinar

Question 11

Which cortices do the anterior, lateral dorsal, and dorsomedial nuclei connect to?

Answer 11

Mammillary bodies (anterior).
Hypothalamus (lateral dorsal).
Cingulate and prefrontal.

Question 12

Which cortices do the lateral posterior and pulvinar nuclei connect to?

Answer 12

Parieto-temporo-occipital and prefrontal.

Question 13

Which thalamic nuclei are associated with the reticular activating system?

Answer 13

Intralaminar nuclei- diffuse cortical projections.
Reticular nucleus- intrathalamic projections.
Both receive inputs from reticular formation.

Question 14

What is thalamic syndrome?

Answer 14

Posterior cerebral artery stroke.
Sensation- may be reduced, exaggerated, altered.
Pain.
Emotional disturbance.
a.k.a. Dejerine-Roussy syndrome.

Question 15

Describe the organisation of the hypothalamus.

Answer 15

Divided in 2 by third ventricle.
Collection of individual nuclei with separate functions.
Largely ipsilateral connections with forebrain.

Question 16

What is the function of the hypothalamus?

Answer 16

Coordinates homeostatic mechanisms by:

• the autonomic nervous system
• the endocrine system
• controlling behaviour

Question 17

What forebrain structures are associated with the hypothalamus?

Answer 17

Olfactory system.

Limbic system- hippocampus, amygdala, cingulate cortex, septal nuclei.

Question 18

What behaviours does the hypothalamus control?

Answer 18

Eating and drinking
Expression of emotion
Sexual behaviour
Circadian rhythms
Memory

Question 19

How can the hypothalamus be structurally damaged?

Answer 19

Craniopharyngioma.
Other tumours, e.g. glioma, meningioma, dermoid, chroma, hamartoma.
Sarcoidosis.
Langerhans cell histiocytosis.