Hypothalamus Wk3 Flashcards
What is the major function of hypothalamus?
Homeostasis and survival
What are the two functions that the hypothalamus breaks into
Neuroendocrine and autonomic
Neuroendrocrine function occurs via
ant. & post. pituitary gland - connected via infundibulum
Autonnected via
autonomic motor neurons in brainstem and spinal cord
In the posterior pituitary, the 2 neurohormones secreted are
oxytocin and vasopressin (ADH)
Oxytocin is the hormone secreted when
- For milk to be released to feed newborn baby (lactation)
- sexual reproduction
-stimulates uterine contraction during labour
Vasopressin is secreted to
regulate blood volume and salt concentration
In the anterior pituitary, there are 2 types of hormones -
Releasing hormones and inhibiting hormones
Hypothalamis is the highest point of neuroaxis
with input to autonomic nervous system and it regulates and coordiantes autonomic function
What are the inputs to the hypothalamus?
Visual, olfactory somatosensory, sexual behaviour, limbic system
Visual system
- Retinal ganglion cells –
intrinsically photosensitive
(melanopsin) - Circadian rhythm
Olfactory System (smell)
Pheromones – amygdala and hypothalamus – social
behaviours
Somatosensory system to painful stimuli
1) Emotional response to pain: anger, fight or flight
2) Trigger autonomic and endocrine responses assoc w pain – increased blood pressure, heart rate, secretion of cortisol
Somatosensory system in sexual behaviour
Erection, mounting behaviours in males, receptive postures in
females
Milk let-down reflex dependent upon somatosensory input
from nipples
Limbic system
- Cortical to hypothalamus via limbic system
- Hippocampal input via fornix – memory formation
- Amygdala – visceral components of conditioned emotional responses
