The hypothalamus and autonomic control Flashcards
What is a vital parameter?
Anything that when changed and disturbed causes disfunction
Where are contextual inputs integrated in during homeostasis?
Into the hypothalamus
What is a contextual input?
Cortical areas which feed in on top of sensory inputs
Where does the paraventricular nucleus feed into?
ANS
Neuroendocrine
Describe adenohypophysis
Troph cells stimulated by releasing hormones from parvocellular neurons of the hypothalamus
Describe neurohypophysis
Releases hormones from the magnocellular neurons directly into systemic circulation
Describe the portal system
Blood goes from one tissue to the other without returning to the heart or the lungs
What is the cascade following hormone release by parvocellular neuron?
Hormone is released ->
Travels into circulatory via portal vein ->
Blood is deoxygenated (doesn’t return to the heart) and carries the hormone to bind to receptors in troph cells ->
These release another hormone and travel in systemic circulation in the body
Describe the release of hormones from the magnocellular neurons
Axons go through the pituitary and directly release neurons into the systemic circulation
Define a trophic hormone?
A hormone that releases a stimulating effect on other hormones
Where are trophic hormones found?
The anterior lobe of the pituitary
Name 3 trophic hormones
TSH
FSH + LH
ACTH
Is the ANS involuntary or voluntary?
Involuntary
What are the 2 efferent pathways of the ANS?
Sympathetic
Parasympathetic
What are the ANS effectors?
Smooth muscle
Cardiac muscle
Glands
Which efferent pathway has the nickname fight or flight?
Sympathetic nervous system
Which efferent pathway has the nickname rest and digest?
Parasympathetic nervous system
Where do the sympathetic neurons come from?
Thoracic
Lumbar
Where do the parasympathetic neurons come from?
Sacral spinal cord
Brain
How does the ANS function without the hypothalamus?
Sensory afferent division ->
Brainstem nuclei ->
Motor efferent division
- The degree of hypothalamic control depends on the parameter
What is the organisation of the sympathetic ns?
Cervical spinal cord
Thoracic
Lumbar
Sacral
What information is processed in the dorsal horn?
Sensory info
What information is processed in the ventral horn?
Motor info
What neurons are in intermediolateral cell column?
Preganglionic sympathetic neurons
Where do sympathetic neurons join the sympathetic chain ganglion?
Higher than T1 and L3
Where do neurons for the sacral parasympathetic organisation come from?
Intermediate via ventral root to ganglia near the target organ
What neurotransmitter does the sacral parasympathetic organisation use? What receptor does this activate?
Acetylcholine
Muscarinic acetylcholine receptor
What nerve controls pupil dilation?
Oculomotor nerve
What is cranial nerve 3?
Oculomotor nerve
What is cranial nerve 10?
Vagus nerve
