Chapter 13 - Hypothalamus Flashcards
(True/False)
The hypothalamus can sample the blood chemistry and react accordingly
True
What is the percentage of the total brain that is made up of the hypothalamus?
0.3%
Hypothalamus function
Controls the autonomic nervous system and the endocrine system - indirectly controls body homeostasis
Part of the diencephalon that extends from the region of the optic chiasma to the caudal border of the mammillary bodies
lies below the thalamus
forms the floor and the inferior part of the lateral walls of the third ventricle
Hypothalamus
Hypothalamus relations from anterior to posterior
(1) the optic chiasma
(2) tuber cinereum and infundibulum
(3) mammillary bodies
(4) inferiorly - tegementum of the midbrain
What is the hypothalamus composed of?
small nerve cell that are arranged in groups or nuclei that may not be clearly segregrated from each other
nuclei are divided by an imaginary plane into medial and lateral zones where lying within the plane are the columns of the fornix and the mammillothalamix tract that serves as markers
Hypothalamic nuclei in the medial zone
(1) part of the preoptic nucleus
(2) anterior nucleus
(3) part of the suprachiasmatic nucleus
(4) paraventricular nucleus
(5) dorsomedial nucleus
(6) ventromedial nucleus
(7) infudibular (arcuate) nucleus
(8) posterior nucleus
Hypothalamic nuclei in the lateral zone
(1) part of the preoptic nucleus
(2) part of the suprachiasmatic nucleus
(3) supraoptic nucleus
(4) lateral nucleus
(5) tuberomammillary nucleus
(6) lateral tuberal nuclei
The hypothalamus receives information from the rest of the body through ()
(1) nervous connections
(2) bloodstream
(3) cerebrospinal fluid
Afferent and Effernt Hypothalamic Nervous Connections
Memorize
Hypophysis cerebri
pituitary gland
Hypothalamic-releasing and inhibitory hormones
Memorize
Origin of secreted hormones in the hypothalamus
Memorize
Main hypothalamic Nuclei Functions
Two pathways for the hypothalamus to connect with the hypophysis cerebri
(1) hypothalamohypophyseal tract
(2) hypophyseal portal system
Nerve fibers that travel from the supraoptic and paraventricular nuclei to the posterior lobe of the hypophysis
Hypothalamohypophyseal tract
ex. vassopressin and oxytocin
long and short portal blood vessels that connect sinusoids in the median eminence and infundibulum with capillary plexuses in the anterior lobe of the hypophysis
Hypophyseal portal system
