Hypothalamus Flashcards
(22 cards)
What are the three things that the hypothalamus does in the regulation of homeostasis?
- Control of endocrine system via pituitary.
- Regulation of feeding, drinking and temp.
- Emotional responses.
What is considered the overall function of the hypothalamus?
To coordinate the endocrine system, the autonomic nervous system, and the somatic motor system in order to achieve homeostasis.
What does the periventricular zone control?
Circadian rhythms via retinal input and innervation of internal organs via sympathetic and parasympathetic ANS.
Where does the periventricular zone project?
Projects to pituitary to release neurohormones into the bloodstream.
Circadian rhythms via retinal input and innervation of internal organs via sympathetic and parasympathetic ANS.
What are the important cells that project into the posterior pituitary and what do they release?
Magnocellular Neurosecretory Cells cause the release of neurohormones into the blood stream. Oxytocin and Vasopresin.
How does the anterior pituitary get it’s hormones?
Endocrine cells. Glands.
What are the roles of oxytocin?
Uterine contraction during childbirth, mammary gland milk production, trust/bonding.
What is the role of vasopresin and what activates it?
Activated by dehydration. Water retention via acting on kidneys and blood vessel constriction.
What are parvocellular neurosecretory cells and what do they cause?
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.
What is the hunger center?
Lateral hypothalamus.
What is the satiety center?
Ventromedial hypothalamus.
What happens when there are lesions in the ventromedial hypothalamus and the lateral hypothalamus?
Lateral-anorexia. Ventromedial-Obesity.
What does leptin do? From where is it released? And what does it activate?
Signals satiety. Released from adipose tissue. Activates arcuate cells of the hypothalamus.
How does leptin produce a response?
Through 3 systems. Humoral-endocrine system. Visceromoter-ANS. Somatic motor-Lateral hypothalamus.
Volumetric vs. Osmometric thirst
Volumetric is triggered by decrease in blood volume. Osmometric is triggered by increase in solute concentration in blood.
Neurons in _______ ________ are temperature-sensitive.
Anterior hypothalamus.
How do the temperature sensitive neurons in the hypothalamus produce a response.
Humoral response and visceromotor response-medial preoptic area. Somatic motor response-lateral hypothalamus.
What system mediates emotions?
The limbic system.
Cingulate gyrus Pineal gland fornix prefrontal cortex thalamus pituitary gland hypothalamus amygdala hippocampus mammillary body
What was the Iowa Gambling Task?
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.
What is the skin conductance response?
Sensitive to sweating via the sympatheitic division. There is a proxy for emotional activation. Brought about by stress. Can be used as a measure.
In cats what did medial hypothalamic stimulation lead to?
Rage display.
In cats, what did lateral hypothalamic stimulation lead to?
Quiet biting.
