BL - Endocrine System Flashcards
Which system is known as the system used for “fight or flight”?
Sympathetic. Parasympathetic is rest and digest.
Which nervous stem controls blood vessels (except capillaries)?
Sympathetic, which allows vessels to brain, skeletal muscle and heart to be prioritised in emergencies, and vessels to skin vasoconstrict to minimise bleeding if injury occurs.
What is neurocrine communication?
An electrical signal causes a secreting cell to secrete transmitter into the blood, where it travels to the target cell.
Give some samples of where neurocrine communication takes place?
Anterior pituitary, posterior pituitary, adrenal medulla.
Which hormone does the thymus produce?
Thymosin, which promotes T cell maturation
What is the main function of the hypothalamus?
To link the nervous system to the endocrine system via the pituitary gland.
What are the two capillary systems in humans?
Hepatic portal system and hypothalamo-hypophyseal portal system.
What is stress often defined as?
A state of real or perceived threat to homeostasis.
Where are the adrenal glands located?
Above the kidneys
What are the two adrenal cortical hormones?
Glucocorticoids (cortisol) and mineralocorticoids (aldosterone).
What are chromaffin cells?
Large, pale-staining epithelioid cells founds in the medulla. They are basically modified neurones.
Why are chromatin cells considered the equivalent of postsynaptic neurones?
When nerve impulses carried by the sympathetic fibres reach the catecholamine-secreting chromatin cells, they release their secretory products of adrenaline and noradrenaline. This is neurocrine secretion.
What does the pineal gland produce?
Melatonin, which controls the circadian rhythm. It also inhibits release of LH and FSH.
Why is the pineal gland visible on adult skull x-rays?
It calcifies in early adulthood.
