What is the function of the endocrine system?
Communication and Control
What is the endocrine system composed of? (3)
Endocrine Glands
Hormones
Transport of hormones to target tissue
Secrete molecules and/or hormones via ducts; local effects on neighboring cells and tissues; not part of the endocrine system
Exocrine Glands
Secretes hormones in extracellular spaces which are then picked up by the blood stream to affect a cell, tissue, or organ elsewhere in the body
Endocrine Glands
Hormones secreted in extracellular spaces which are then picked up by the blood stream to affect a cell, tissue, or organ elsewhere in the body; “typical” hormone
Endocrine Hormone Action
A hormone is secreted by a cell, which influences a neighboring cell… total distance traveled is very short
Paracrine Hormone Actions
A hormone secreted by a cell that affects the same cell from which it came
Autocrine Hormone Actions
Area of the brain that acts as the major switch board of the endocrine system. Controls the endocrine glands of the body as well as produces its own hormones.
Hypothalamus
Acts on the thyroid to stimulate release of thyroid hormone
Thyroid-Stimulation Hormone
Acts on adrenal cortex to stimulate hormone secretion
Adrenotropic Hormone
Stimulates ovarian follicles to continue follicle development; stimulates follicle cells to release estrogen
Follicle Stimulating Hormone
Stimulates estrogen release by ovarian follicles; promotes ovulation; promotes formation of corpus luteum
Luteinizing Hormone
Stimulates milk production
Prolactin
Promotes normal growth by increasing movement of digested proteins into the cells to accelerate anabolism; increase blood glucose levels by maintaining glucose in the cell
Growth Hormone
Stimulates reabsorption of water by the kidney; recall: made in hypothalamus, but stored and released from the pituitary
Antidiuretic Hormone
Stimulates contraction of uterine walls and stimulates the release of milk from the breast ducts; recall: made in hypothalamus, but released from the pituitary
Oxytocin
Increases osteoblast activity
Calcitonin
Increases osteoclast activity
PTH
Released when blood glucose is low
Glucagon
Released when blood glucose is high
Insulin
Small gland hanging from the roof of the third ventricle of the brain; secretes melatonin
Pineal Body (Gland)
Produces atrial natriuretic peptide: reduces blood pressure, blood volume, and blood sodium concentration
Heart
Enteroendocrine cells release local-acting digestive hormones
Gastrointestinal Tract
Released hormones that influence the course of pregnancy
Placenta
