KEY CONCEPT The endocrine system produces hormones that affect growth, development, and homeostasis.
Ch. 29.6 page 930 • Define the vocabulary and answer the questions • # 1-5
Hormones influence a cell’s activities by entering the cell or binding to its membrane. • Glands are organs of the endocrine system.
target cell hormone bloodstream not a target cell receptor • Hormones are chemical signals that influence cell’s activities. • produced by glands • travel through the circulatory system • affects cells with matching receptors
Steroid hormone Non-steroid hormone Steroid hormone diffuses through the cell membrane Nonsteroid hormone binds to receptor on the cell membrane. receptor Steroid hormone binds to a receptor within the cell. Receptor stimulates a second messenger with in the cell. receptor second messenger Second messenger starts a series of chemical reactions in the cytoplasm. The hormone and receptor enter the nucleus and bind to DNA DNA Steroid hormone causes DNA to make proteins. Second messenger reactions activate enzymes. activated enzymes proteins • Steroid hormones enter the cell. • Nonsteroid hormones do not enter the cell. • There are steroid hormones and nonsteroid hormones. nucleus Chemical reactions
HYPOTHALAMUS PITUITARY THYROID THYMUS ADRENAL GLANDS PANCREAS FEMALE GONADS :OVARIES MALE GONADS : TESTES Endocrine glands secrete hormones that act throughout the body. • There are many glands located throughout the body. • Hormones travel through the bloodstream to cells with matching receptors.
The hypothalamus interacts with the nervous and endocrine systems. • a structure of both the nervous andendocrine systems • produces releasing hormones,sent to pituitary gland • The pituitary gland is found below the hypothalamus in the brain. • controls growth and waterlevels in blood • produces releasing hormones sent throughout the body • The hypothalamus is a gland found in the brain.
Releasing hormones stimulate other glands to produce hormones. • allow glands to communicate with one another • are used in temperature regulation
Hormonal imbalances can cause severe illness. • Abnormal hormone levels affect homeostasis. • Hormonal imbalances might be treated with surgery or medicine. • Steroids, a pituitary tumor, or some prescription drugs can make the pituitary overactive and indirectly cause problems.