Chapter 15: Chemical Control of the Brain and Behavior Flashcards
() communication in sensory and motor systems need mechanisms that restrict synaptic transmission to synaptic cleft
point to point
describe the result of p2p connections in the nervous system
- release minute amt of NTs
- actions are brief and rapid responses
- tightly constrained
3 components of the NS that operate in expanded space and time
- secretory hypothalamus
- autonomic nervous system
- diffuse modulatory systems
main function of the hypothalamus
homeostasis
3 functional zones of the hypothalamus
- lateral
- medial
- periventricular
lateral and medial zones of hypothalamus have extensive connections with ()
brain stem and telencephalon
a group of cells in the periventricular zone constitutes the (), which lies above the optic chiasm and are involved in synchronization of circadian rhythms
suprachiasmatic nucleus (SCN)
how does the SCN regulate circadian rhythm
it receives direct retinal innervation and uses info from light dark cycle
other cells in the periventricular zone control the ANS and regulate outflow of ()
sympathetic and parasympathetic innervation of the visceral organs
the cells in a third group in the periventricular zone called () extend axons towards the stalk of the pituitary gland to secrete hormones
neurosecretory neurons
the posterior pituitary is technically part of the brain because it contains axons of () -> neurons that release chemicals into capillaries of posterior lobe
magnocellular neurosecretory cells
substances released into the blood by neurons
neurohormones
examples of neurohormones
oxytocin, vasopressin (ADH)
- “love hormone”
- promote social bonding
- stimulates lactation and uterine contraction
oxytocin
neurohormone that regulates blood volume and salt concentration
vasopressin (anti-diuretic hormone)
pipeline of angiotensin II production
low BP/BV -> kidneys release renin -> renin is converted to angiotensin I -> angio I breaks down to angio II
angiotensin II is also detected by the (), a part of the telencephalon that lacks BBB
subfornical organ
cells from the subfornical organs also activate hypothalamus in response to angio II -> induces (1) and (2)
- thirst, drinking behavior
- ADH release
“master gland”: anterior pituitary
“true master gland”: ()
hypothalamus
the anterior pituitary is under the control of () in the periventricular zone
parvocellular neurosecretory cells
parvocellular neurosecretory cells control the anterior pituitary by releasing (1) into (2) which then bind to specific receptors on anterior pituitary cells
- hypophysiotropic hormones
- hypo-thalamo-pituitary portal circulation
2 parts of the adrenal glands
- adrenal cortex
- adrenal medulla
the adrenal cortex produces () -> acts throughout the body to mobilize energy reserves and suppress immune system; stress hormone
cortisol
in response to detecting cortisol, parvocellular NCs release a peptide called (1), which travels to the anterior pituitary to stimulate the release of (2)
- corticotropin-releasing hormone
- corticotropin (ACTH)
how do blood cortisol levels self-regulate
cortisol reacts with specific receptors on the brain that lead to inhibition of CRH release
one feature of (Addison’s/Cushing’s) disease is adrenal insufficiency
Addison’s
Cushing’s disease is caused by () that results in elevated levels of ACTH and cortisol
pituitary gland dysfunction
explain an example of iatrogenic Cushing’s disease
excessive use of prednisone (cortisol medication)
preganglionic NT of sympathetic NS + parasympathetic NS
ACh
postganglionic NT of sympathetic NS
NE
postganglionic NT of parasympathetic NS
ACh