Chemical Control of the Brain Flashcards
Where is the hypothalamus located?
under the thalamus and above the optic chiasm
What are the two hypothalamus hemispheres separated by?
The 3rd ventricle
What are the three principal subdivisions of the hypothalamus?
The periventricular zone, the median zone, and the lateral zone
What subdivision of the hypothalamus is most adjacent to the 3rd ventricle?
The periventricular zone
What kind of neuron is found in the periventricular hypothalamus?
Neurosecretory neurons
Where do neurons project from the periventricular hypothalamus?
The posterior pituitary gland
What NTs are secreted by the hypothalamus?
Vasopressin, oxytocin, corticotrophin releasing hormone (CRH)
What are the roles of the periventricular zone secretions?
Control of circadian rhythms and the ANS
What is the role of the median and lateral divisions of the hypothalamus?
Thirst/Hunger and ANS
What three large brain divisions is the positioning of the hypothalamus the junction of?
(telencephalon, diencephalon, mesencephalon)
What information does the hypothalamus integrate?
Visceral and emotional
What system is responsible for emotional information found in the hypothalamus?
The limbic system
What does the hypothalamus directly regulate, and what does it regulate through the pituitary gland?
Direct regulation: ANS and brain stem (short term)
Through pituitary: Hormones and blood (long term)
What body systems are the hypothalamus responsible for?
Metabolic system, behaviour system, and the sleep-wake cycle
What three kinds of responses does the hypothalamus coordinate?
Behavioural, autonomic, and neuroendocrine responses
What specific body functions does the hypothalamus regulate? (6)
- Body Temp
- BP (thirst/salt/urination)
- Defensive behaviour (fight or flight)
- Energetic metabolism (hunger/digestion/growth)
- Reproductive behaviour
- Sleep-wake cycle and alertness
What important role does the hypothalamus play in energetic metabolism?
Gluconeogenesis
What mechanisms does the hypothalamus start to respond to cold temperature?
Shivering/Goose bumps to generate heat
What mechanisms does the hypothalamus start to respond to hot temperature?
Sweating/Flushing
What kind of feedback loop is homeostasis?
Negative feedback loop
What is another term for the posterior lobe of the pituitary?
The neurohypophysis
What classification of secretory neurons is found in the periventricular hypothalamus that secrete hormones to the posterior pituitary?
Magnocellular neurons
What is the mechanism of hormone secretion by the periventricular hypothalamus to the posterior pituitary?
Nerve terminals secrete hormones directly into the blood
What hormones do the single network of capillaries use to regulate the body?
Vasopressin (Antidiuretic hormone ADH)
Oxytocin