Bio Ch 40 Flashcards
Endocrine System
organ system involved in the coordination of body activities; uses hormones as chemical signals secreted into the bloodstream
Hormones
chemical messenger produced in one part of the body that controls the activities of other parts
Exocrine glands
secrete their products into ducts, which take them to the lumens of other organs or outside the body
Endocrine glands
secrete their products into the bloodstream, which delivers them throughout the body
Chemical signals
means of communication between cells, between body parts, and even between individuals
Pheromones
chemical signals that influence the behavior of other individuals
Peptide hormones
most endocrine glands secrete these hormones - peptides, proteins, glycoproteins, and modified amino acids
Steroid hormones
all have the same molecular complex of 4 carbon rings because they are all derived from cholesterol
Cyclic adenosine monophosphate (cAMP)
immediate result of epinephrine binding is the formation of this; contains 1 phosphate group attached to adenosine at 2 locations
First messenger
chemical signal such as a peptide hormone that binds to a plasma membrane receptor protein and alters the metabolism of a cell because a second messenger is activated
Second messenger
chemical signal such as cyclic AMP that causes the cell to respond to the 1st messenger - a hormone bound to plasma membrane receptor protein
Hypothalamus
helps to regulate the internal environment of the body; influences heartbeat, blood pressure, appetite, body temperature, and water balance through the autonomic nervous system; also controls the glandular secretions of the pituitary gland
Pituitary gland
small gland that lies just inferior to the hypothalamus; consists of the anterior and posterior ____, both of which produce hormones
Antidiuretic hormone (ADH)
neurons in the hypothalamus (neurosecretory cells) produce this hormone as well as oxytocin
Posterior pituitary
portion of the pituitary gland that stores and secretes oxytocin and antidiuretic hormone produced by the hypothalamus
Negative feedback
effect of the hormone acts to shut down the release of the hormone; maintains stable conditions and homeostasis
Oxytocin
2nd hormone made in the hypothalamus; causes uterine contractions during childbirth and milk letdown when a baby is nursing
Positive feedback
the stimulus continues to bring about an effect that ever increases in intensity
Hypothalamic-releasing hormones
one of many hormones produced by the hypothalamus that stimulates secretion of an anterior pituitary hormone
Hypothalamic-inhibiting hormones
one of many hormones produced by the hypothalamus that inhibits the secretion of an anterior pituitary hormone
Anterior pituitary
portion of the pituitary gland that is controlled by the hypothalamus and produces 6 types of hormones, some of which control other endocrine glands
Gonadotropic hormones
stimulate the gonads (testes, ovaries) to produce gametes and sex hormones
Adrenocorticotropic hormone (ACTH)
stimulates the adrenal cortex to produce cortisol
Thyroid-stimulating hormone (TSH)
stimulates the thyroid to produce thyroxine (T4) and triiodothyronine (T3)