Hypothalamus

Question 1

What are the 2 types of drives that the hypothalamus is responsible for?
(give some e.g.’s of each)

Answer 1

• • Homeostatic drives (e.g. feeding, thirst, salt, thermoregulation, sleep, sickness)
• • Species-survival drives (e.g. sex behavior, parenting, social curiosity, aggression)

Question 2

What general part of the limbic system is the hypothalamus associated with?

Answer 2

“reward system”

Question 3

Describe the functional and anatomical boundaries of hypothalamic nuclei.

Answer 3

Vague, nondistinct

Question 4

What are the 3 main input routes to the hypothalamus?

Where do each come from?

Answer 4

• • Fornix (from hippo)
• Stria terminalis (from amygdala)
• Medial forebrain bundle (from amygdala and others)

Question 5

What are the 3 main monoamine NTs that are important in the hypothalamus?

Answer 5

• 5-HT
• NE
• DA

Question 6

Most dopaminergic pw’s leaving the SN and VTA travel through the _____________________ on their way to limbic areas and frontal lobe.

Answer 6

Medial forebrain bundle

Question 7

Before norandrenergic fibers reach the limbic areas, frontal lobe, cingulate gyrus, these fibers pass through the _____________________ and enter the amygdala and thalamus.

Answer 7

Median forebrain bundle

Question 8

The most widespread monoamine NT in the brain is _____________.

Answer 8

Serotonin

Question 9

What are 2 places serotonergic cells originate in?

Answer 9

• Dorsal and median raphe nuclei

Question 10

When traveling to the lateral hypothalamic area, serotonergic axons pass through the __________________.

Answer 10

Median forebrain bundle

Question 11

Mammillary bodies of the hypothalamus function primarily in what type of memory?

Answer 11

Recollective memory (also spatial memory)

[Recollective memory: recalling info from the past]

Question 12

*What are the 3 pw’s associated w/the mammillary bodies, and what brain areas do they project to?

Answer 12

• Mammillothalamic tract (thalamus)
• Mammillotegmental tract (midbrain tegmentum)
• Mammillary peduncles (reticular formation)

Question 13

With what major brain areas does the hypothalamus have bilateral inputs/outputs?

Answer 13

• Cortex
• Midbrain (via dorsal longitudinal fasciculus of Schutz)
• Amygdala (via median forebrain bundle)

Question 14

In what 3 ways does the hypothalamus communicate w/the amygdala? (give directionality of each)

Answer 14

• Input to hypo via stria terminalis
• Input to hypo via diagonal band of Broca
• Bilateral via media forebrain bundle (olfactory cortex, preoptic area, septal area, accumbens, NTS)

Question 15

How do the sc and hypothalamus communicate w/each other? (what direction as well)

Answer 15

Hypo –> sc (via hypothalamospinal tract)

Question 16

How do the eye and hypothalamus communicate w/each other? (what direction as well)

Answer 16

Eye –> hypo (via retino-hypothalamus tract)

Question 17

How do the thalamus and hypothalamus communicate w/each other? (what direction as well)

Answer 17

Hypo –> thalamus (via mammillothalamic tract; info hits cortex and can come back)

Question 18

How do the midbrain and hypothalamus communicate w/each other? (what direction as well)

Answer 18

Bidirectionally (via dorsal longitudinal fasciculus of Schutz)

Question 19

How do the hypothalamus and cortex communicate w/each other? (what direction as well)

Answer 19

Bidirectionally (corticohypothalamic tract)

Question 20

How do the cortex and hippocampus communicate w/each other? (what direction as well)

Answer 20

Cortex –> hippo (via parahippocampal cortex and cingulate cortex)
* There is bidirectionality in other tracts

Question 21

How do the hippocampus and hypothalamus communicate w/each other? (what direction as well)

Answer 21

Hippo –> hypo (via fornix)

Question 22

What system is the Papez circuit associated w/?

Answer 22

Limbic (emotional cognition)

Question 23

What nucleus in the thalamus is strongly associated w/the limbic system?

Answer 23

Anterior nucleus

Question 24

*Follow the BASIC path of the Papez circuit, starting at the hippo.

Answer 24

1. Hippocampus gives output to mammillary bodies of hypo (via fornix)
2. Mammillary bodies give output to ant nuc of thalamus (via mammillothalamic tract)
3. Thalamus gives output to cingulate gyrus
4. Cingulate gyrus gives output to hippo

Question 25

How is the amygdala involved in the modern understanding of the Papez circuit?

Answer 25

It receives input from the hippocampus and gives output to the hypothalamus

Question 26

How is the prefrontal cortex involved in the modern understanding of the Papez circuit?

Answer 26

Receive input from the hypothalamus and communicates w/the association cortex

Question 27

How is the association cortex involved in the modern understanding of the Papez circuit?

Answer 27

Communicates bidirectionally w/cingulate gyrus and hippocampus. - Is also communicating w/PFC

Question 28

The mammillary bodies of the hypo area associated w/emotional _____________. The cingulate gyrus (of limbic system) is associated w/emotional _____________.

Answer 28

- expression | - experiences

Question 29

Regarding pituitary control, the anterior pituitary has ________ control, the posterior pituitary has ________ control.

Answer 29

- Indirect (2 levels of control from hypo) | - Direct from hypo (1 level of control)

Question 30

Random: Most physiologic processes are regulated by some form of "____________."

Answer 30

Servomechanism

Question 31

Biological rhythms that occur less than 24 hrs are deemed ___________. What are e.g.'s?

Answer 31

Ultradian | - HR, RR

Question 32

Biological rhythms that occur ~ 24 hrs are deemed ___________. What are e.g.'s?

Answer 32

Circadian | - Sleep, corticosterone

Question 33

Biological rhythms that occur 24 hrs to 1 year are deemed ___________. What are e.g.'s?

Answer 33

Infradian | - Menstrual cycles

Question 34

Hypothalamic circadian rhythms require a “clock” or timing device. This function is controlled primarily by the ___________.

Answer 34

SCN

Question 35

Which of the following fiber bundles contains bidirectional connections between the septal nuclei, lateral hypothalamic nucleus, tuberal nuclei, and brainstem areas such as the periaqueductal gray and the tegmental nuclei? a. Mammillotegmental tract b. Mammillothalamic tract c. Medial forebrain bundle d. Stria terminalis e. Stria medullaris thalami

Answer 35

c. Medial forebrain bundle

Question 36

A 61-year-old woman presents with a complaint of persistently seeing "two of everything." The examination reveals a dilated left pupil and an inability to look up, down, or medially with that eye. MRI reveals an aneurysm of the basilar bifurcation. During surgery to clip this aneurysm, the small perforating branches of P1 (posterior perforating arteries off the posterior cerebral arteries) are inadvertently occluded by the clip. Which of the following structures would be most adversely affected by this disruption of blood supply? a. Anterior hypothalamic nucleus b. Mammillary nuclei c. Medial preoptic nuclei d. Paraventricular nucleus e. Tuberal region nuclei

Answer 36

(B) Mammillary nuclei

Question 37

The mesolimbic system has cell bodies in the ventral tegmentum that send projections to the ____________________________.

Answer 37

Hypothalamus and other limbic areas

Question 38

The nigrostriatal system is found in the ____________________________.

Answer 38

Basal ganglia (substantia nigra pars compacta)