3. DSA: Hypothalamic and Limbic Systems Flashcards
Small anatomical region of diencephalon that integrates information from forebrain, brainstem, and SC
Hypothalamus
What is the primary role of the hypothalamus?
Maintenance of homeostasis (water and electrolyte balance, food intake, temperature, blood pressure, circadian rhythm, stress responses, body metabolism)
Name the boundaries of the hypothalamus.
Optic chiasma (anterior) and tegmentum/PAG of midbrain (posterior)
What forms the floor and ventral walls of 3rd ventricle?
Hypothalamus
What is continuous through the infundibular stalk with the posterior pituitary?
Hypothalamus
What forms the posterior part of the hypothalamus?
Mammillary bodies
What are adjacent to the cerebral peduncles?
Mammillary bodies
Where is the tuber cinerum?
Small swelling between the mammillary bodies and optic chiasm/tract
Where is the median eminence?
Arises from the tuber cinerum and narrows into the infundibulum (attaches to the pituitary gland)
What are the longitudinal divisions of the hypothalamic nuclei?
Anterior region, tuberal region, and posterior (mammillary) region
Where is the anterior region?
Superior to the optic chiasm extending anteriorly to the lamina terminalis
Where is the tuberal region?
Superior to and including the tuber cinerum
Where is the mammillary/posterior region?
Superior to and including the mammillary bodies
Where is the periventricular zone?
Periaqueductal gray (midbrain) through in the wall of the 3rd ventricle
What divides the hypothalamus into the medial and lateral zones?
Fornix
Where is the median forebrain bundle (MFB) located?
Lateral zone of the hypothalamic nuclei
Damage to the lateral zone of the hypothalamic nuclei results in __.
Decrease in feeding behavior
What nucleus contains oxytocin and ADH?
paraventricular (OT)/Supraoptic(ADH) nucleus
Where does the supraoptic/paraventricular nucleus lead into?
Posterior pituitary
Lesion in the SO/PVN results in __.
Diabetes insipidus (DI), increased H2O intake, and increased urination
What nucleus receives retinal input and is involved in circadian rhythms?
Suprachiasmatic nucleus
Lesion in the SCN results in __.
Modification or elimination of circadian rhythms
What is the anterior nucleus responsible for?
Range of visceral/somatic functions and temperature regulation
Where do afferents leading to the medial mammillary nucleus come from?
Hippocampus (via fornix)
Where do efferents coming from the medial mammillary nucleus go?
Thalamus and brainstem
Lesion in the medial mammillary nucleus results in __.
Inability to process short-term events into long-term memory
What is considered the “satiety center”?
Ventromedial nucleus
Lesion in the ventromedial nucleus results in __.
Excessive eating and abnormal weight gain
What nucleus subserves functions of emotional behavior?
Dorsomedial nucleus
Stimulation of dorsomedial nucleus causes __.
Sham rage
Destruction of dorsomedial nucleus results in __.
Decreased aggression and feeding
Name the blood supply of the anteromedial group of the hypothalamus.
Branches from the anterior communicating and anterior cerebral arteries (A1)
Name the blood supply of the posteromedial group of the hypothalamus.
Perforating arteries from the posterior communicating artery and posterior cerebral artery (P1)
Name the major afferent routes of the hypothalamus.
Fornix, medial forebrain bundle (MFB), and amygdalohypothalamic fibers
Where does the fornix arise from?
Subiculum and hippocampus
What is the largest single input to the hypothalamus?
Fornix
What structures does the MFB interconnect?
Spectal nuclei, hypothalamus, and midbrain tegmentum
Where does the MFB course through?
Lateral hypothalamic zone
What pathways are composed of amygdalohypothalamic fibers?
Stria terminalis and ventral amygdalofugal pathways
What do the stria terminalis and ventral amygdalofugal pathways target?
Septal nuclei, pre-optic area, and medial hypothalamic zone