DSA Hypothalamus & Limbic System

Question 1

This is a small, anatomical region of the diencephalon. It integrates info from the forebrain, brainstem, and spinal cord.

Answer 1

Hypothalamus

Question 2

The primary role of this is in homeostasis – water and electrolyte balance, food intake, temperature, BP, circadian rhythm, stress responses, and body metabolism.

Answer 2

Hypothalamus

Question 3

What does the rostral/anterior portion of the Hypothalamus merge with?

Answer 3

Optic chiasm

Question 4

What does the caudal/posterior portion of the Hypothalamus merge with?

Answer 4

Tegmentum

PAG (midbrain)

Question 5

The Hypothalamus forms the floor and ventral walls of which ventricle?

Answer 5

3rd ventricle

Question 6

These form the posterior part of the hypothalamus and are adjacent to the cerebral peduncles.

Answer 6

Mammillary bodies

Question 7

These are small swellings between the mammillary bodies and the optic chiasma and tract.

Answer 7

Tuber cinereum

Question 8

This arises from the tuber cinereum and narrows into the infundibulum and attaches to the pituitary gland.

Answer 8

Median eminence

Question 9

What are the longitudinal divisions of the Hypothalamic Nuclei?

Answer 9

Anterior region – superior to Optic Chiasm

Tuberal region – superior to and including tuber cinereum

Mammillary/Posterior region – superior to and including the mammillary bodies

Question 10

What are the divisions of the Hypothalamus from medial to lateral?

Answer 10

Periventricular zone – periaqueductal gray (midbrain) through in the wall of 3rd ventricle

Medial zone

Lateral zone

Question 11

What divides the medial and lateral zones of the hypothalamus?

Answer 11

Fornix

Question 12

This portion of the hypothalamic nuclei is composed of diffusely arranged neurons with few ‘named’ nuclei. It contains the medial forebrain bundle and damage results in a decrease in feeding behavior with a resultant weight loss.

Answer 12

Lateral zone

Question 13

This portion of the hypothalamus overlaps with the anterior and posterior (mammillary) regions. This is where neurons are arranged in distinct nuclei.

Answer 13

Medial zone

Question 14

What are the nuclei of the Supraoptic region (within medial zone)?

Answer 14

Supraoptic/Paraventricular Nucleus
Suprachiasmatic Nucleus
Anterior Nucleus

Question 15

The Supraoptic/Paraventricular Nucleus contains ________ and ________ that is released from the posterior pituitary.

Answer 15

Oxytocin (PVN)

ADH (SON)

Question 16

Lesions in what nucleus can result in diabetes insipidus (DI) which causes increased water intake and increased urination.

Answer 16

Supraoptic/Paraventricular Nucleus

Question 17

This nucleus receives retinal input and is involved in circadian rhythms (day/night cycles). Damage to this area may modify, or abolish, these rhythms.

Answer 17

Suprachiasmatic Nucleus

Question 18

This nucleus has a range of visceral/somatic functions and temperature regulation.

Answer 18

Anterior Nucleus

Question 19

What are the nuclei of the mammillary/posterior region (within the medial zone)?

Answer 19

Medial Mammillary Nucleus

Question 20

The Medial Mammillary Nucleus has afferents from the _________ via the fornix, efferents to the ________ and _________, and lesions will result in an inability to process short-term events into long-term memory.

Answer 20

Hippocampus
Thalamus
Brainstem

Question 21

What are the nuclei of the tuberal region (within the medial zone)?

Answer 21

Ventromedial Nucleus

Dorsomedial Nucleus

Question 22

This nucleus is considered to be a “satiety center”. Lesions cause excessive eating and abnormal weight gain.

Answer 22

Ventromedial Nucleus

Question 23

This nucleus subserves functions of emotional behavior. Stimulation causes sham rage and destruction results in decreased aggression and feeding.

Answer 23

Dorsomedial Nucleus

Question 24

The blood supply of the hypothalamus is via small perforating arteries of the…

Answer 24

Circle of Willis

Question 25

What arteries supplies the anteromedial group, which includes the preoptic area, supraoptic region, septal nuclei, and rostral portions of the lateral hypothalamic area.

Answer 25

Branches from Anterior Communicating A. and ACA (A1 segment)

Question 26

What arteries supplies the posteromedial group, which includes the tuberal and mammillary regions.

Answer 26

Perforating arteries from the Posterior Communicating A. and PCA (P1 segment)

Question 27

The rostral portion of the Posterior Communicating A. supplies the ________ region, while the caudal part of the artery supplies the _______ region.

Answer 27

Tuberal

Mammillary

Question 28

This is the largest single imputes to the hypothalamus (afferent). It arises from the subiculum and hippocampus.

Answer 28

Fornix

Question 29

This afferent route interconnects the septal nuclei, hypothalamus, and midbrain tegmenjtum. It course through the lateral hypothalamic zone.

Answer 29

Medial forebrain bundle (MFB)

Question 30

These create an afferent route via the stria terminalis and ventral amygdalofugal pathways. Both target septal nuclei, preoptic area, and medial hypothalamic zone.

Answer 30

Amygdalohypothalamic fibers

Question 31

This efferent hypothalamic pathway originates as a well-defined bundle from the medial mammillary nucleus. It bifurcates into mammillothalamic and mammillotegmental tracts that project to the anterior nucleus (thalamus), an important part of circuit of Papez.

Answer 31

Mammillary Fasciculus

Question 32

This efferent hypothalamic pathway is from the lateral preoptic area and projects to the dorsomedial nucleus (thalamus) and amygdaloid nucleus (via the stria terminalis and ventral amygdalofugal pathway).

Answer 32

Hypothalamothalamic fibers

Question 33

T/F. All vital functions of the hypothalamus are controlled through reflexes mediated by autonomic (or endocrine) systems.

Answer 33

True

Question 34

This is the progressive degeneration of mammillary bodies, hippocampal complex, and dorsomedial thalamic nucleus. It impedes the retention of newly acquired memory. Short-term memory can’t be made into long-term memory. Patients will also confabulate, which means they’ll combine fragmented memories into a synthesized memory of an “event” that never occurred.

Answer 34

Korsakoff’s Syndrome

Question 35

What causes Korsakoff’s Syndrome?

Answer 35

Thiamine deficiency (typically associated with chronic alcoholism)

Question 36

This is a result of bilateral temporal lobe lesions that abolish the amygdaloid complex. It results in behavior changes such as visual agnosia, hyperorality, hyper metamorphosis, placidity, hyperphagia, and hyper sexuality.

Answer 36

Kluver-Bucy Syndrome

Question 37

This occurs when the uncus and possibly parahippocampal gyrus move downward over the edge of the tentorium cerebelli. It initially compresses the midbrain, but can cause damage that extends into lower brainstem levels. Signs include dilated pupil and abnormal eye movements with double vision ipsilateral to problem area. Weakness of extremities opposite to dilated pupil, and as it progresses respiration is affected and abnormal reflexes appear.

Answer 37

Uncal Herniation

Question 38

This occurs from bilateral lesions of the hippocami. There is a profound deficit in anterograde episodic memory (cannot learn new material), combined with spared procedural and working memory. Patients IQ and formal reasoning are fairly normal.

Answer 38

Hippocampal Amnesia