APHY 102 Practice Questions with Correct
Answers
What is a hormone and how does it act?
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.
A control mechanism in which rising level of a hormone leads to a decrease in hormone
secretion
What is a paracrine secretion?
glands that secrete messenger molecules that affect nearby cells
What is an autocrine secretion?
glands that secrete messenger molecules that affect cells that secrete substances
What is an exocrine gland?
a gland that produces and secretes substances into ducts that lead to body surfaces; external
What is an endocrine gland?
A gland that secretes a substance (a hormone) into the bloodstream, acting only on target
cells; internal
Location of hypothalamus
below the thalamus
Location of pituitary gland
,base of the brain in sella turcica of sphenoid bone
Location of pineal gland
brain
Location of parathyroid glands
posterior surface of the thyroid gland
Location of thyroid gland
neck
Location of thymus
behind the sternum
Location of adrenal gland
on top of the kidneys
Location of adrenal cortex
outer portion of gland
Location of adrenal medulla
inside portion of gland
Location of pancreas
behind the stomach
Location of testes
scrotum
Location of ovary
, lower abdomen
Describe steroid hormones.
poor water-solubility; can diffuse through lipid bilayer of cell membranes; cortisol,
testosterone, sex hormones; derived from cholesterol
Sequence of Steroid Hormone Action
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.
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
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.
Answers
What is a hormone and how does it act?
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.
A control mechanism in which rising level of a hormone leads to a decrease in hormone
secretion
What is a paracrine secretion?
glands that secrete messenger molecules that affect nearby cells
What is an autocrine secretion?
glands that secrete messenger molecules that affect cells that secrete substances
What is an exocrine gland?
a gland that produces and secretes substances into ducts that lead to body surfaces; external
What is an endocrine gland?
A gland that secretes a substance (a hormone) into the bloodstream, acting only on target
cells; internal
Location of hypothalamus
below the thalamus
Location of pituitary gland
,base of the brain in sella turcica of sphenoid bone
Location of pineal gland
brain
Location of parathyroid glands
posterior surface of the thyroid gland
Location of thyroid gland
neck
Location of thymus
behind the sternum
Location of adrenal gland
on top of the kidneys
Location of adrenal cortex
outer portion of gland
Location of adrenal medulla
inside portion of gland
Location of pancreas
behind the stomach
Location of testes
scrotum
Location of ovary
, lower abdomen
Describe steroid hormones.
poor water-solubility; can diffuse through lipid bilayer of cell membranes; cortisol,
testosterone, sex hormones; derived from cholesterol
Sequence of Steroid Hormone Action
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.
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
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.
