Chapter 11 : Endocrine System Flashcards
Function of the Endocrine System
Secrete hormones to coordinate and direct activities of target cells or target organs
Hormones influence processes such as
- Growth and development
- Reproduction
- Development of primary and secondary sexual characteristics
- The way the body uses and stores energy called metabolism
- The volume of fluid in the body
- The levels of electrolytes (salts) and sugar in the blood
- Immunity protection and defenses against stress
Gland
Any organ that produces a secretion
Exocrine Glands
Secrete substances into a duct
Exocrine Gland examples
Sweat glands, mammary glands, digestive glands, and sebaceous glands
Endocrine Glands
Secrete hormones directly into the blood stream or surrounding tissues
Hormone
Chemical messenger that causes changes in a target cell with specific binding sites
Steroid Hormones
Lipid hormones that diffuse through the cell membrane and bind with receptors on the DNA which alters gene expression
(determines which proteins will be produced)
The Five groups of hormones
Glucocoticoids mineralcorticoids Estrogens Androgens Prostaglandins
Peptide Hormones
Non-steroid
Protein hormones that bind to receptors on the outside of the cell membrane
(do not enter the cell)
Peptide Hormones Examples
Epinephrine
Norepinphrine
Insulin
Humoral Control
Conditions in the body stimulate a hormone to be released such as blood levels of glucose
Negative Feedback Mechanism
A reversal of increase and decreases in body conditions to maintain homeostasis
Negative Feedback Mechanism examples
Insulin secreted by the pancreas causes a decrease in glucose in the blood
( blood sugar)
Hormonal Control
A hormone released by an endocrine gland stimulates the release of hormones from another endocrine gland
Hormonal Control Example
A hormone from gland A causes the release of a hormone from gland B
Tropic Hormones
Hormone whose target cells are another endocrine system gland
Tropic Hormone example
The anterior pituitary gland releases thyroid - stimulating hormone a tropic hormone
This causes the thyroid gland to release the hormone thyroxine
Neural Control
When the gland has direct contact with nerve fibers that send messages from the brain stimulating the release of a hormone
Neural Control example
Adrenal gland secretes epinephrine (adrenaline) when the brain perceives fear or excitement
