Endocrine System Overview
Have ducts -- secrete products onto a surface (i.e. sweat glands onto skin) or into a cavity (i.e. salivary glands into the mouth)
What are exocrine glands?
Hormones made of proteins/amino acids -- work by a second messenger system -- they do not enter the target cell.
These hormones attach to receptors on the target cell's membrane -- a chemical reaction occurs in the target cell -- this reaction activates molecules in the target cell to act as second messengers which communicate the hormone's message to the target cell causing the target cell to respond and perform its function.
What are nonsteroid hormones?
**Remember "no"nsteroid = NO entry -- they do not enter the cell**
What is adenohypophysis?
"Adeno" means gland -- cellular structure of glandular tissue.
Regulates fluid balance -- accelerates reabsorption of water from urine
What is antidiuretic hormone (ADH)?
This mineralocorticoid secreted by the outer zone of the adrenal cortex increases the amount of sodium and decreases the amount of potassium in the blood
What is aldosterone?
"Ductless" glands -- secrete hormones that enter the bloodstream and are carried throughout the body.
What are endocrine glands?
Lipid soluble hormone -- easily passes through the cell membrane and enters the cell.
These hormones directly enter the target cell's nucleus and bind to a receptor forming a hormone-receptor complex.
The hormone-receptor complex acts on the cell's DNA which produces a response from the target cell.
What are steroid hormones?
Another name for the posterior pituitary gland.
What is neurohypophysis?
**Cellular structure of nervous tissue**
Stimulates uterine contractions
What is oxytocin?
This is the main glucocorticoid secreted by the middle zone of the adrenal cortex
What is cortisol?
Chemical/substance secreted by an endocrine gland
What is a hormone?
AKA "tissue hormones"
Often produced in a tissue and then act on nearby cells in that tissue
Influence respiration, BP, GI secretions, inflammation, and reproduction.
What are prostaglandins?
Type of hormone that stimulates another gland to grow and secrete its hormones.
What is a tropic hormone?
The two thyroid hormones that control metabolism
What are triiodothyronine (T3) and thyroxine (T4)?
The adrenal medulla produces ___________ and ___________, which are responsible for producing the "fight-or-flight" response
What is epinephrine and norepinephrine?
Cells with SPECIFIC receptors for SPECIFIC hormones.
What are target cells?
Another name for tissue hormones (i.e. prostaglandins, leukotrienes, thromboxane) which means "secrete beside".
What is paracrine agents?
The two hormones release by the posterior pituitary gland
What are antidiuretic hormone (ADH) and oxytocin.
This thyroid hormone will decrease blood calcium level because it prevents the breakdown of bone
What is calcitonin?
This hormone increases blood glucose levels by accelerating glycogenolysis
What is glucagon?
Too much hormone production is called ___________ while too little hormone production is called ____________.
What is hypersecretion and hyposecretion.
Type of feedback that regulates most hormone levels.
What is negative feedback?
Part of the brain that produces "releasing" and "inhibiting" hormones that stimulate or inhibit the release of anterior pituitary hormones.
What is the hypothalamus?
This hormone works opposite of calcitonin. It will increase blood calcium levels by stimulating the breakdown of bone.
What is parathyroid hormone (PTH).
This hormone secreted by the pineal gland helps regulate the body's internal clock and sleep cycles.
What is melatonin?