APHY 102 Midterm
What is a hormone and how does it act? - ANS-Hormones are chemical messengers
that are responsible for regulation. They are secreted into body fluids, mainly blood. It
has specific actions on target tissues, which are any tissue that has specific receptors
for that particular hormone.
Understand the role of negative feedback in control of hormone secretions. - ANS-A
control mechanism in which rising level of a hormone leads to a decrease in hormone
secretion
What is a paracrine secretion? - ANS-glands that secrete messenger molecules that
affect nearby cells
What is an autocrine secretion? - ANS-glands that secrete messenger molecules that
affect cells that secrete substances
What is an exocrine gland? - ANS-a gland that produces and secretes substances into
ducts that lead to body surfaces; external
What is an endocrine gland? - ANS-A gland that secretes a substance (a hormone) into
the bloodstream, acting only on target cells; internal
Location of hypothalamus - ANS-below the thalamus
Location of pituitary gland - ANS-base of the brain in sella turcica of sphenoid bone
Location of pineal gland - ANS-brain
Location of parathyroid glands - ANS-posterior surface of the thyroid gland
Location of thyroid gland - ANS-neck
Location of thymus - ANS-behind the sternum
Location of adrenal gland - ANS-on top of the kidneys
Location of adrenal cortex - ANS-outer portion of gland
, Location of adrenal medulla - ANS-inside portion of gland
Location of pancreas - ANS-behind the stomach
Location of testes - ANS-scrotum
Location of ovary - ANS-lower abdomen
Describe steroid hormones. - ANS-poor water-solubility; can diffuse through lipid bilayer
of cell membranes; cortisol, testosterone, sex hormones; derived from cholesterol
Sequence of Steroid Hormone Action - ANS-1. endocrine gland secretes steroid
hormone
2. blood carries hormone throughout body
3. steroid hormone diffuses through target cell membrane & enters cytoplasm or
nucleus
4. hormone combines with a receptor molecule in the cytoplasm or nucleus
5. steroid hormone-receptor complex binds to DNA & promotes transcription of
messenger RNA
6. messenger RNA enters the cytoplasm & directs protein synthesis
7. newly synthesized proteins produce the steroid hormone's specific effects
Describe non-steroid hormones. - ANS-Amines, proteins, peptides, and glycoproteins;
cannot penetrate lipid bilayer; bind to receptors on target cell membrane; 1st
messenger, cAMP is 2nd messenger
Sequence of non-steroid hormone using cyclic AMP - ANS-1. Endocrine gland secretes
non-steroid hormone.
2. Blood carries hormone throughout body.
3. Hormone combines with receptor site on membrane of target cell, activating G
protein.
4. Adenylate cyclase molecules are activated in target cell membrane.
5. Adenylate cyclase converts ATP into cyclic AMP.
6. Cyclic AMP activates protein kinases.
7. Protein kinases activate protein substrates in cell that change metabolism.
8. Cellular changes produce the hormone's effects.
How is the anterior pituitary gland different than the posterior pituitary gland? - ANS-The
anterior pituitary receives signaling molecules from the hypothalamus, and in response,
synthesizes and secretes seven hormones. The posterior pituitary does not produce
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