Lab Quiz 1 - Endocrine System Flashcards
chemical signals that are released in small amounts by specialized epithelial cells
travel through blood to target tissues
hormone
hormones are chemical signals that are released in small amounts by
specialized epithelial cells
proteins are ____________ soluble and _____________
water; polar
steroids are ______________ soluble and _____________-
fat; nonpolar
proteins bind to
membrane bound receptors
steroids bind to
intracellular receptors
what does it mean if a target tissue is “down-regulated” over time
the target tissue becomes less sensitive to the amounts of hormone present
why do steroid hormones utilize intracellular receptors
steroid hormones are fat soluble and can easily cross the cell membrane
why do protein hormones utilize membrane bound receptors
proteins are water soluble, so they activate second messengers
located in the sella turcica of the sphenoid bone, posterior to the optic chiasm
pituitary gland (hypophysis)
the pituitary gland is connected to the hypothalamus via
the infundibulum
the adenohypophysis (anterior pituitary) is composed of what type of tissue
simple cuboidal epithelial tissue
what connects the anterior pituitary to the hypothalamus
hypothalamohypophyseal portal system
releasing and inhibiting hormones of the anterior pituitary (6)
GHRH, GnRH, TRH, CRH, and PIH, and GHIH
what does the releasing of hormones from the hypothalamus trigger the anterior pituitary to do
secrete hormones or inhibit ant. pituitary from releasing
true or false: the adenohypophysis is not vascularized
false
the neurohypophysis consists of what type of cells and tissue?
glial cells and nervous tissue
true or false: the neurohypophysis is the more innervated part of the pituitary gland
true
why does the posterior pituitary not secrete any hormones?
primarily nervous tissue
where do axons from the hypothalamus pass down to terminate at the neurohypophysis + release their hormones
hypothalamohypophyseal tract
hormones secreted by the anterior pituitary gland (6)
growth hormone (GH)
prolactin (PRL)
thyroid stimulating hormone (TSH)
adrenocorticotropic hormone (ACTH)
follicle stimulating hormone (FSH)
lutenizing hormone (LH)
hormones whose targets are other endocrine glands
tropic hormones
what are the tropic hormones
thyroid stimulating hormone (TSH)
adrenocorticotropic hormone (ACTH)
follicle stimulating hormone (FSH)
lutenizing hormone (LH)
clinical implications of growth hormone
pituitary dwarfism and gigantism
acromegaly
response is an amino acid uptake for protein and glycogen synthesis, growth in tissues, stimulates muscle and bone growth
growth hormone (somatotropin)
what is the target of growth hormone
mostly bodily tissues, but especially connective tissues and muscle
not enough growth hormone
pituitary dwarfism
too much growth hormone
pituitary gigantism
too much growth hormone as an adult
acromegaly
structure of growth hormone (GH)
protein
response is to stimulate mammary glands to produce milk soon after birth
prolactin (PRL)
what is the primary target of prolactin
mammary glands
what is the structure of prolactin
protein
response is to increase thyroid hormone production
thyroid stimulating hormone (TSH)
what is the target of TSH
thyroid gland
what is the structure of TSH
glycoprotein
response is to increase hormone secretion from the adrenal cortex (especially glucocorticoids)
adrenocorticotropic hormone (ACTH)
what is the structure of ACTH
peptide
what is the target of ACTH
adrenal cortex
response is follicle maturation and estrogen secretion in ovaries, and sperm cell production in testes
follicle stimulating hormone (FSH)
what is the target of FSH
follicles in ovaries, seminiferous tubules
what is the structure of FSH
glycoprotein
response is ovulation and progesterone production in ovaries, testosterone synthesis and support for sperm cell production in testes
lutenizing hormone (LH)
what is the target of LH
ovaries and testes
what is structure of LH
glycoprotein
which hormones are secreted by the posterior pituitary (neurohypophysis)
antidiuretic hormone (ADH)
oxytocin
response is nephrons reabsorb water instead of losing it as urine
antidiuretic hormone (ADH) or vasopressin
clinical implications of ADH
if there is an ADH deficiency, copious urination can lead to diabetes insipidus
what is the target of ADH
nephrons of the kidney
what is the structure of ADH
small peptide
response causes uterine contractions and milk ejection
oxytocin
what is the target of oxytocin
uterus and mammary glands
what is the structure of oxytocin
small peptide
what is the anterior surface of the thyroid gland responsible for
secreting thyroid hormone (TH) and calcitonin
what does the posterior surface of the thyroid gland consist of
4 small lobes known as the parathyroid gland
2 lateral lobes connected by an isthmus; located inferior to the larynx
extremely vascular and metabolically active
thyroid gland
made up of T3 and T4, response increases metabolism and is essential for normal growth
thyroid hormone (TH)
which part of the anterior thyroid gland secretes TH
follicles
which part of the anterior thyroid gland secretes calcitonin
parafollicular cells
what is the target of TH
most cells in the body
what is the structure of TH
amino acid
clinical implications of TH
hypothyroidism can cause myxedema or cretinism
hyperthyroidism can lead to a condition known as Grave’s disease
triiodothyronine is known as
T3
thyroxine is known as
T4
response decreases osteoclast activity and therefore lowers the amount of calcium in the blood
boosts osteoblast activity
calcitonin
what is the structure of calcitonin
polypeptide
what is the target of calcitonin
bone
filled with colloid that produce and hold TH, look like rings of cuboidal cells
follicles of thyroid gland
between the follicles and secrete calcitonin
parafollicular cells of the thyroid gland
4-6 small glands embedded in the posterior of the thyroid gland
parathyroid gland
response raises levels of blood calcium by breaking down bone, causes reaborption of calcium by kidney, and causes intestines to absorb more calcium and vitamin D
parathyroid hormone (PTH)
clinical implications of parathyroid hormone (PTH)
the parathyroid hormone can sometimes be removed when the thyroid is taken out
what is the structure of PTH
protein
what is the target of PTH
bones, kidneys, small intestine
sit on top of the kidneys
composed of an epithelial cortex layer and a neuronal medulla
adrenal glands
what is the adrenal cortex made up of
epithelial cells (primarily cuboidal)
what is the adrenal medulla made up of
neuronal cells
layers of adrenal cortex
zona glomerulosa
zona fasciculata
zona reticularis
secretes mineralcorticoids (aldosterone)
zona glomerulosa
secretes glucocorticoids (cortisol)
zona fasiculata
secretes sex hormones (androgens)
zona reticularis
response is to increase fat and protein breakdown to free up energy for metabolism and to inhibit the inflammatory response; also known as the stress hormone
cortisol
what is the target of cortisol
most tissues in the body
what is the structure of cortisol
steroid
controls nephron tubule permeability, and reabsorbs salts based on need, thus water will follow the salt back in by osmosis
response: sodium ion reabsorption
aldosterone
what is the target of aldosterone
nephrons of the kidney
what is the structure of aldosterone
steroid
responsible for some secondary sex characteristics in females
androgens
what is the target of androgens
many tissues
what is the structure of androgens
steroid
medullary hormones
epinephrine and norepinephrone
what is the ratio of release of epinephrine and norepinephrine
80-20
responsible for “fight or flight” response
epinephrine and norepinephrine
what is the target of epinephrine and norepinephrine
heart, blood vessels, liver, and fat cells
what is the structure of epinephrine and norepinephrine
amino acid
the adrenal medulla is directly connected to what
the sympathetic branch of the autonomic nervous system
every time you activate the sympathetic branch of the ANS, what happens
the medulla dumps epinephrine and norepinephrine directly in the blood
lies posterior to stomach and small intestine in retroperitoneal space
secretes digestive enzymes (acinar cells) and hormones (islets)
pancreas
what type of pancreatic cells secrete insulin
beta cells
what type of pancreatic cells secrete glucagon
alpha cells
response increases intake of glucose by cells; usually part of the parasympathetic response after a meal when a lot of glucose is present in the blood
insulin
what is the target of insulin
liver, skeletal muscle, fat tissue
what is the structure of insulin
protein
what are adrenal cortical hormones
glucocorticoids (cortisol)
mineralcorticoids (aldosterone)
sex hormones (androgens)
response is associated with sympathetic response to low levels of glucose in the blood; stimulates breakdown of glycogen stores into usable glucose
glucagon
what is the target of glucagon
liver
what is the structure of glucagon
protein
endocrine cells that secrete insulin and glucagon; very distinct from the rest of pancreatic cells
pancreatic islets
surround the islets and secrete enzymes for digestion into the intestines
acinar cells
where are ovaries located
in the abdominopelvic region of the female body
where are the testes located
outside the abdomen in the scrotum
what are the female sex hormones
estrogen and progesterone
what are the male sex hormones
testosterone
responsible for secondary sex characteristics, menstural cycles
estrogen and progesterone
what is the structure of estrogen and progesterone
steroid
what is the target of estrogen and progesterone
most body tissues
responsible for secondary sex characteristics, libido, and sperm production
testosterone
what is the structure of testosterone
steroid
what is the target of testosterone
most body tissue
true or false: gonads only have endocrine functions
false; they have both endocrine and exocrine functions
what is the endocrine function of the testes
lutenizing hormone from the pituitary gland causes Leydig cells to secrete testosterone
what is the exocrine function of the testes
follicle stimulating hormone from the pituitary gland causes sperm cells to be created in seminiferous tubules
what is the endocrine function of the ovaries
follicle cells respond to follicle stimulating hormone from the pituitary gland and produces estrogen and progesterone during the uterine cycle
what is the exocrine function of the ovaries
lutenizing hormone from the pituitary gland causes the follicle to rupture and release the egg into the uterine tubes
which thyroid hormone is more metabolically active at target tissues
T3
which thyroid hormone is converted by enzymes at the target tissue
T4
how is thyroid hormone transported throughout the body
by thyroixine binding globulin
a protein that stabilizes the TH hormones while they are being shuttled to their targets
globulin
