Hypothalamus Flashcards
Summarize the main body functions under hypothalamic control
Body temp and febrile response
Food, salt, and water intake
Sexual cycles, sexual orientations, onset of sexual milestones
Circadian rhythms
Sleep
Bodyweight
Stress response
Describe the local neuroanatomical relationships of the hypothalamus
Below the hypothalamic sulcus (line formed from the anterior commissure to the posterior commisure)
Describe the hypothalamic tracts and note the pathways they participate in
Fornix to mammilary bodies (from hippocampus)
mammilothalamic tract
medial forebrain bundle
tuberoinfundibular
hypothalamo-hypophyseal (pituitary)
Explain in general terms (at a systems level) how the hypothalamus acts to maintain
homeostasis – how does it work?
Describe the two basic input connections of the hypothalamus
Neural and chemosensory
Describe the relationship of the hypothalamus to endocrine and autonomic nervous
systems
Describe the specific regulatory mechanisms of the hypothalamus as they pertain to:
Maintenance of body temperature
Describe the specific regulatory mechanisms of the hypothalamus as they pertain to:
Circadian rhythms
Describe the specific regulatory mechanisms of the hypothalamus as they pertain to:
Sleep
Describe the specific regulatory mechanisms of the hypothalamus as they pertain to:
Appetite
Describe the specific regulatory mechanisms of the hypothalamus as they pertain to:
Salt and water intake
Describe the specific regulatory mechanisms of the hypothalamus as they pertain to:
Reproductive milestones, cycles and sexual behavior
Localize basic hypothalamic lesions based on regional signs
anterior vs. posterior, medial vs. lateral
Fornix
A hypothalamic tract
From the hippocampus to the mammillary bodies
Shows degenerative changes in Korsakoff’s
Mammillothalamic Tract
A hypothalamic tract
From mammillary bodies to anterior thalamus
Medial Forebrain Bundle
A part of the hypothalamic tract
Runs through the lateral hypothalamus
Connects the hypothalamus to the brainstem (below) and the basal forebrain, amygdala, and cortex (above)
Damage is thought to affect appetite
Hypothalamo-hypophyseal tract
A hypothalamic Tract
Runs from the paraventricular nucleus and supraoptic nuclei –> to the posterior pituitary … via the pituitary stalk
pituitary stalk (aka infundibulum) connects the underside of the hypothalamus to the pituitary gland
Describe the main sources of neural inputs to the hypothalamus
Retina Olfactory system Spino-hypothalamic inputs Viscerosensory inputs Pre-frontal cortex insula amygdala hippocampal formation
Describe the main sources of chemosensory inputs to the hypothalamus
CVO’s
Hypothalamic chemosensory neurons
Hypothalamic hormone and steroid receptors
What are the two hypothalamic autonomic pathways
DLF (PAG) - axons destined for brainstem Hypothalamospinal pathway (Central tegmental tract) - axons destined for spinal cord
Name the common responses to cold
Increase in metabolism
Shivering
Decreased peripheral blood flow (vasoconstriction)
Changes in hair/fur to retain heat
Name the common responses to heat
Sweating
Increased peripheral blood flow
peripheral vasodilation
What are the three hypothalamic outputs?
Autonomic Endocrine Behavioral Modification (drinking)
