APHY 102 MIDTERM EXAM (2025/2026)
QUESTIONS AND 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.
What is a paracrine gland?
a secretion that enters interstitial fluid but affects only neighboring cells
What is an autocrine gland?
A secretion that only affects the secreting cell.
What is an endocrine gland?
A gland that secretes a substance (a hormone) into the bloodstream and act on target cells
What is an exocrine gland?
A ducted gland that produces a secretion onto a body surface.
Where is the thymus located?
mediastinum; behind the sternum
Where is the pineal gland located?
center of brain
Where are the reproductive organs located?
abdomen; pelvic
Where is the pituitary gland located?
sella turcica of the sphenoid bone; base of the brain
Where are the adrenal glands located?
on top of each kidney
Where is the pancreas located?
posterior to the stomach
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What are the two steroid hormones?
Sex hormones and adrenal cortex hormones; estrogen and testosterone
Describe steroid hormones
-diffuse through cell membranes into cytoplasm or nucleus
-combine with a receptor molecule binding to DNA
-promote transcription of mRNA
-mRNA enters cytoplasm directing protein synthesis
Describe non-steroid hormones.
Amines, proteins, peptides, and glycoproteins. The endocrine gland secretes nonsteroid
hormones, which body fluid carries hormone to its target cell. Hormone combines with receptor
site on membrane of its target cell, activating G protein. Cellular changes produce the
hormone's effects.
How is the anterior pituitary gland different than the posterior pituitary gland?
The anterior pituitary becomes an endocrine gland producing and secreting hormones for the
body and connects to the posterior pituitary when fully formed. Meanwhile, the posterior
pituitary remains connected to the hypothalamus, functioning as a repository for hormones
produced by the hypothalamus and receiving messages from it that regulate when hormones
are to be released to and through the anterior pituitary
What regulates pituitary gland secretion?
Hypothalamus
Describe tropic hormones
stimulate other endocrine glands to release hormones
anterior pituitary hormones
ACTH - controls manufacture and secretion of certain hormones from the outer layer of the
adrenal gland.
FSH - controls growth and development of follicles that house egg cells in ovaries and stimulate
production of sperm cells in the testes.
GH - stimulates cells to enlarge and more rapidly divide
LH - promotes secretion of sex hormones and allows release of egg cells from ovaries
PRL - promotes milk production
TSH - controls secretion of certain hormones from the thyroid
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posterior pituitary hormones
ADH - reduces volume of water that kidneys secrete
Oxytocin - smooth muscle contraction and allows contraction of the uterus during childbirth
and may stimulate the movement of certain fluids in the male reproductive tract during sexual
activity
Thyroid hormones
Calcitonin - controls blood calcium and phosphate ion concentration
Thyroxine(T4) - more prevalent in circulation
Triiodothyronine(T3) - more potent than T4
Parathyroid hormones
PTH - increases blood calcium ion concentration and decreases blood phosphate ion
concentration through actions in the bones, kidneys, and intestines
adrenal medulla hormones
epinephrine and norepinephrine - increase heart rate, BP, breathing, decrease digestion
adrenal cortex hormones
Aldosterone - helps regulate concentration of sodium and potassium ions
Cortisol - affects glucose metabolism and influences proteins and fat metabolism
Pancreas hormones
Glucagon - stimulates liver to break down glycogen into glucose
Insulin - stimulates the liver to form glycogen from glucose
Somatostatin - helps regulate glucose metabolism by inhibiting secretion of glucagon and insulin
pineal gland hormone
Melatonin - made from serotonin and regulates circadian rhythms
Thymus Gland Hormones
Thymosins - affect production and differentiation of T lymphocytes
How are glucagon and insulin alike?
Both work to keep blood glucose concentration constant
How are glucagon and insulin different?
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