Neuroendocrine Flashcards
What are hormones?
They are chemical messenger produced in one location and transported to a second location
What does the endocrine system do?
- maintain homeostasis
- regulate growth and development
- control energy storage and use
- mediate the body’s response to environmental cues
What is neurocrine communication?
When a hormone is a neurotransmitter
What is paracrine communication?
When a hormone acts on neighbouring cells
What is autocrine communication?
When a hormone hits back on its origin cell
What is the synergistic effect?
The effect of two hormones together is greater than the addition of the two effects
What is melatonin?
It is a product of tyrosine and it produced by the pineal gland. it is produced when it is dark, in order to adjust the circadian rhythm
What is the GHRH axis stimulated by?
exercise, stress, fasting, low glucose and sleep
What is the result of excess growth hormone production?
Giganticism (can be caused by a pituitary gland tumor, usually benign)
How do the hypothalamus and posterior pituitary communicate?
Hypothalamus neurons have their axon terminal projecting to the posterior pituitary
What hormones does the posterior pituitary produce?
oxytocin and vasopressin
What is vasopressin?
also called anti-diuretic hormone. VP is secreted in response to increased plasma osmotic pressure or increased blood volume. inhibits urine production and causes blood vessel contraction
what does oxytocin to?
- it acts upon the kidney to promote sudium excretion,
- increases release of atrial natriuretic factor from the heart,
- contracts mammary ducts for milk let-down
- causes uterine contraction during delivery
What 2 structures make up the matrix of the adrenal gland?
- cortex - capsulated the medulla, it on the outside
2. medulla - on the inside
Where are androgens secreted in the adrenal gland?
The reticularis zone
What does the adrenal medulla secrete?
E and NE
What is the steroid precursor?
cholesterol
What are the cardiovascular effects of adrenaline?
- increase cardiac contractility
- increase heart rate
- dilate smooth muscle around arterioles
- constrict other arterioles
- shunt blood to exercising muscles and the brain