Endocrine Glands & Feedback Loops

Hormones

chemical released from one part of the body and carried through the bloodstream

Steroid Hormones

lipid-soluble

can pass directly through the target cell membrane formatting a hormone receptor

Non-Steroid Hormones

water- soluble

amino acid based molecules

not able to pass through the membrane

Bind to receptors on the outside of the target cell, which activate a 2nd messenger to meditate the response to the target cell 

How are endocrine glands activate?

Hormonal, Humoral, & Neural 

Hormonal Stimuli

glands are encourages by hormones secreted by other glands

Hypothalamus Stimulates Pituitary

Humoral Stimuli

levels of nutrients and ions in the blood can cause gland to secrete hormones

Neural Stimuli

nerve impulses cause Glands to secrete hormones

Sympathetic nervous System during stress cause release of epinephrine from adrenal glands

Pituitary Gland

small bulb found on the underside of the brain

2 lobes: anterior & posterior

Hypothalamus

located just above the pituitary gland and is about the size of an almond

to control the pituitary gland by hormonal and nueral stimulation.

Pineal Gland

is a tiny & bean-shaped near the cerebellum.

main secretion I melatonin, which regulates your sleep cycle

Thyroid Gland

located at the base of the neck (butterfly shape)

Calcitonin- Reduces the calcium levels in the blood

regulates calcium & metabloism

Parathyroid Glands

attached to the back of the thyroid 

they produce parathyroid hormone, which is the opposite function of calcitonin.

brings calcium out of the bones and into the blood stream

Adrenal Glands

producing epinephrine & norepinephrine —> fight or flight

also producing Glucocorticoids —> regulate ions levels for quick energy

Pancreas

using ducts and ductless glands

tiny islands

insulin = lowering blood sugar levels

glucagon = raising blood sugar levels

Thymus Gland

small gland found near the sternum

produces thymopoietin, thymic factor, and thymosin I involved in the development of the immune system

Gonads

reproductive organs that produce sex cells and secrete sex hormones

Ovaries & Testes

Produces Estrogen & Progesterone + Testosterone