Chapter 11 - Endocrine System Flashcards
Target Cell
Cell with specific receptors for the hormone triggering a specific reaction.
Hyper/hyposecretion
To much or to little secretion of a particular hormone.
2 major types of hormones
Steroid and nonsteroid
Nonsteroid hormones
Whole proteins, shorter chains of amino acids or single amino acids. Work according to second messenger mechanism. From endocrine gland to target cells.
Second messengers
Chemical reactions that happen at a specific receptor site. Activates molecules with the cell.
Steroid hormones
Small, lipid soluble hormones that can travel directly through the plasma membrane of the target cell. Slow compared to nonsteroid hormones.
Negative feedback control mechanism
Reverses changes to return to homeostasis.
Positive feedback
Rare as they amplify feedback as in release of oxytocin during labor.
Prostaglandins
Tissue hormones. Powerful lipid found in a wide variety of tissues. Produced in a tissue then diffused a short distance to cells in that tissue.
Pituitary gland
Small. Dividend into 2 parts. Adenopophysis (anterior) neuropophysis (posterior). Deep in the cranial cavity. Connected to hypothalamus.
Anterior pituitary gland
Secretes many tropic hormones that stimulates other endocrine glands to secrete their hormones.
Thyroid stimulating hormone
Released by the anterior pituitary gland. Stimulates thyroid to release thyroid hormone.
Adrenocorticotropic hormone
(ACTH) Acts on the adrenal cortex. Adrenal cortex releases more hormones especially cortisol. Released by anterior pituitary gland
Follicle stimulating hormone
Stimulates ovaries to and mature an egg. In males stimulates sperm growth. Secreted by anterior pituitary gland.
Luteinizing hormone
Anterior Pituitary gland. Stimulates ovum and follicle to grow. Formation of corpus luteum from the the ruptured follicle. In males causes development and secretion of testosterone.
Growth hormone
Secreted anterior pituitary gland. Speeds up movement of digested proteins into the cells and accelerates anabolism (regular growth) Increases blood glucose.
Hypoglycemia
Low blood glucose
Hyperglycemia
Higher than normal blood glucose
Prolactin
Anterior pituitary gland. During pregnancy stimulates breast growth for eventual lactation. After delivery stimulates release of milk.
Posterior pituitary gland
Releases two hormones. Hormones created in hypothalamus but released from axons in the posterior pituitary gland.
Antidiuretic hormone
Regulates fluid balance in the body. Accelerates reabsorption of water from urine in the kidney tubules.