Hypothalamus

Question 1

What are the three things that the hypothalamus does in the regulation of homeostasis?

Answer 1

1. Control of endocrine system via pituitary.
2. Regulation of feeding, drinking and temp.
3. Emotional responses.

Question 2

What is considered the overall function of the hypothalamus?

Answer 2

To coordinate the endocrine system, the autonomic nervous system, and the somatic motor system in order to achieve homeostasis.

Question 3

What does the periventricular zone control?

Answer 3

Circadian rhythms via retinal input and innervation of internal organs via sympathetic and parasympathetic ANS.

Question 4

Where does the periventricular zone project?

Answer 4

Projects to pituitary to release neurohormones into the bloodstream.

Circadian rhythms via retinal input and innervation of internal organs via sympathetic and parasympathetic ANS.

Question 5

What are the important cells that project into the posterior pituitary and what do they release?

Answer 5

Magnocellular Neurosecretory Cells cause the release of neurohormones into the blood stream. Oxytocin and Vasopresin.

Question 6

How does the anterior pituitary get it’s hormones?

Answer 6

Endocrine cells. Glands.

Question 7

What are the roles of oxytocin?

Answer 7

Uterine contraction during childbirth, mammary gland milk production, trust/bonding.

Question 8

What is the role of vasopresin and what activates it?

Answer 8

Activated by dehydration. Water retention via acting on kidneys and blood vessel constriction.

Question 9

What are parvocellular neurosecretory cells and what do they cause?

Answer 9

They are projections from the periventricular zone to the anterior pituitary. They release hormones into the hypothalamo-pituitary portal circulation, which cause the release of hormones into the bloodstream.

Question 10

What is the hunger center?

Answer 10

Lateral hypothalamus.

Question 11

What is the satiety center?

Answer 11

Ventromedial hypothalamus.

Question 12

What happens when there are lesions in the ventromedial hypothalamus and the lateral hypothalamus?

Answer 12

Lateral-anorexia. Ventromedial-Obesity.

Question 13

What does leptin do? From where is it released? And what does it activate?

Answer 13

Signals satiety. Released from adipose tissue. Activates arcuate cells of the hypothalamus.

Question 14

How does leptin produce a response?

Answer 14

Through 3 systems. Humoral-endocrine system. Visceromoter-ANS. Somatic motor-Lateral hypothalamus.

Question 15

Volumetric vs. Osmometric thirst

Answer 15

Volumetric is triggered by decrease in blood volume. Osmometric is triggered by increase in solute concentration in blood.

Question 16

Neurons in _______ ________ are temperature-sensitive.

Answer 16

Anterior hypothalamus.

Question 17

How do the temperature sensitive neurons in the hypothalamus produce a response.

Answer 17

Humoral response and visceromotor response-medial preoptic area. Somatic motor response-lateral hypothalamus.

Question 18

What system mediates emotions?

Answer 18

The limbic system.

Cingulate gyrus
Pineal gland
fornix
prefrontal cortex
thalamus
pituitary gland
hypothalamus
amygdala
hippocampus
mammillary body

Question 19

What was the Iowa Gambling Task?

Answer 19

Good decks vs. Bad decks. People with disorders can’t make good decisions. The controls developed a skin conductance response to bad decks. Patients did not.

Question 20

What is the skin conductance response?

Answer 20

Sensitive to sweating via the sympatheitic division. There is a proxy for emotional activation. Brought about by stress. Can be used as a measure.

Question 21

In cats what did medial hypothalamic stimulation lead to?

Answer 21

Rage display.

Question 22

In cats, what did lateral hypothalamic stimulation lead to?

Answer 22

Quiet biting.