A&P2 CHAPT 17 - ENDOCRINE SYSTEM

READ: SAY OKAY 1

OUnderstand that hormones are chemical messengers that are protein based (protein,

peptide) or lipids (steroids, amino acid derivatives, fatty acid derivatives)

         • Both require a receptor to work

         • Both need to be delivered via blood to their target tissue:

o Proteins/ peptides

-    are water-soluble and therefore transported easily as free hormones in the blood stream

-    receptors are present in the cell membrane of target cells

o Lipids/ amino acid derivatives/ fatty acid derivatives

-   are not transported as easily and need a binding protein to be transported in the blood stream

-    enter into cells and bind to receptors in the cytoplasm or nucleus

OKAY 1

a.

a. hormones act as a _______ in these ways:

• ______: secreted by cells in a local area; influences the activity

• _____: produced by a wide variety of tissues

• _____: secreted into the blood by specialized cells; travels to target tissues (anywhere in the body) ex: insulin, GH, etc

chemical messenger, autocrine, paracrine, endocrine

a. understand the types of stimuli for hormone secretions

• ______: when hormones are released when the blood levels of certain chemicals change

• ____: when a neuron releases a neurotransmitter into a synapse with a hormone-producing cell that then secretes its hormone

• ____: certain hormones are secreted in response to another hormone= ____ (what is it called??)

humoral stimuli, neural stimulation, hormonal stimuli

a. increased sensitivity to the hormone results in ____ of receptors

b. decreased sensitivity to the hormone results in ______ of receptors

up regulation, downregulation

a. understand the hormone interactions

• _____ : when one hormone allows another hormone to exert its full effects on a target cell- meaning the second hormone can’t work properly without the presence of the first

• ____: when two or more hormones work together to produce an effect thats grater than the sum of their individual effects

• ____: occurs when two hormones have opposing effects which effectively cancels or counteract each other’s actions to maintain homeostasis

permissive, synergistic, antagonistic

a. what hormone interaction is this describing

• Thyroid hormones are crucial for the normal function of other hormones like epinephrine + norepinephrine on the heart for heart rate, stroke volume, and contractility

b. what hormone interaction is this describing:

• PTH and calcitonin are sensitive to blood calcium levels

• PTH acts to increase blood Ca2+ and calcitonin acts to decrease Ca2+

c. what hormone interaction is this describing:

• Estrogen and progesterone work together to prepare the uterus for pregnancy

permissive, antagonistic, synergistic

a. feedbacks in hormone activity

• _____: the hormone’s secretion is stimulated by the hormone itself-self perpetuating

• ____: the hormone secretion is inhibited by the hormone itself; self-limiting

b. What example does this describe:

• oxytocin from the posterior pituitary gland during labor?

• thyroid hormones inhibit the secretion of their releasing hormones from the hypothalamus and their tropic hormone from the anterior pituitary?

positive feedback, negative feedback, positive feedback, negative feedback

a. know the patterns of hormone secretion

• _____: relatively constant blood levels of hormone over long periods of time (thyroid hormones)

• ____: hormones concentration changes suddenly and irregularly- it’s circulating levels vary at each stimulus (epinephrine)

• ____: hormones are secreted at fairly predictable intervals and concentrations (reproductive hormones)

chronic hormone secretion, acute hormone secretion, episodic

a. know the terms with respect to hormone control

• _____: a drug with similar structure of a specific hormone that can bind to a hormone receptor + activate it

  • ex: drugs in asthma inhalers mimic epinephrine to cause smooth muscles in the lung to relax

• ____: a drug that can bind to a hormone receptor+ INHIBIT its action

  • ex: anti-stroke drugs will inhibit the action of epinephrine to prevent epinephrine-stimulated platelet aggregation

agonist, antagonist