Module 7 Flashcards
what are the two types of glands of the endocrine system?
- endocrine and exocrine
what are endocrine glands?
glands that secrete hormones directly from the cells of the gland to the extracellular fluid and bloodstream
what are exocrine glands?
glands that secrete cell products into a duct system
what are hormones?
act as chemical messengers, traveling through the bloodstream to cause an effect on a target organ
what are the five endocrine glands
- pituitary
- thyroid
- parathyroid
- adrenal
- pancreas
the pituitary gland is the size of a ____
pea !
where is the pituitary gland located?
at the base of the brain
- inferior to the hypothalamus and superior to the sphenoid bone
why is the pituitary gland also known as the “master gland”
due to production and release of hormones that control all other endocrine glands
which gland is known as the “master gland?”
pituitary
what is important about the physical contact between the hypothalamus and the pituitary gland?
allows for communication between the nervous and endocrine systems
what is the anterior lobe of the pituitary gland called?
Adenohypophysis
what is the anterior lobe of the pituitary gland composed of?
glandular (adeno) secretory cells
how many stimulating hormones are released by the Adenohypophysis?
seven
what are the seven hormones produced and released by the anterior lobe of the pituitary gland?
- Thyroid Stimulating Hormone (TSH)
- Prolactin (PRL)
- Adrenocorticotropic Hormone (ACTH)
- Growth Hormone (GH)
- Follicle Stimulating Hormone (FSH)
- Luteinizing Hormone (LH)
- Melanocyte Stimulating Hormone (MSH)
function of TSH
causes the thyroid gland to release thyroid hormones
function of prolactin?
stimulates the breast to secrete milk
function of ACTH
causes adrenal glands to release their hormones
what does the growth hormone do?
stimulates growth in all cells
what does FSH do?
causes the maturation of cells in the ovaries and testes
function of LH?
causes the ovary to release the mature egg into the uterine tube
function of MSH?
causes melanocytes in the skin to produce pigment
what kind of tissue makes up the posterior lobe of the pituitary gland?
nervous & connective
how many hormones are released by the neurohypophysis?
2
what is the posterior lobe of the pituitary gland called?
the neurohypophysis
the hormones released by the posterior lobe of the pituitary gland are produced where?
the hypothalamus
what are the two hormones released by the posterior lobe of the pituitary gland?
1) Anti-Diuretic Hormone (ADH)
2) Oxytocin
function of ADH?
promotes reabsorption of water at the kidneys
what does oxytocin do?
- promotes contraction of the uterus during child birth
- plays a role in milk release following birth
what are glandular acini?
small sac-like cavities
glandular acini arranged into small groups are found in which lobe of the pituitary gland?
anterior
in the anterior lobe of the pituitary gland, there is _________ between the small groupings of glandular acini
connective tissue
in staining, which lobe of the pituitary gland appears darker
anterior
the thyroid gland produces hormones important in _____
metabolism
the thyroid gland is involved in _________
calcium homeostasis
where is the thyroid gland located?
sits in the neck anterior to the trachea and inferior to the larynx
what are the three lobes of the thryoid?
- right lobe
- left lobe
- isthmus (between the lobes)
what is the thyroid gland composed of?
many structures called follicles
- each follicle is made up of simple cuboidal follicular cells
what are dispersed between the follicles of the thyroid gland?
parafollicular or “C” Cells
what hormones do follicular cells produce?
- Triiodothyronine (T3)
2. Thyroxine (T4)
what are the functions of T3 and T4
act to increase the rate of metabolism an oxygen consumption
what role to the C - Cells of the thyroid have?
- important in calcium homeostasis
- produce calcitonin, a hormone which lowers blood calcium concentration
parathyroid glands are ____ small glands
four (paired)
where are the parathyroid glands situated?
on the back of the thyroid gland
the parathyroid glands are involved in the maintenance of ______
calcium homeostasis
what kind of cells are the parathyroid glands made of?
mostly principal (or “chief”) cells
what to principal/chief cells produce?
Parathyroid hormone (PTH)
what does PTH do?
acts to increase calcium ion concentration in the blood
where are the adrenal glands located? how are they structured?
two pyramid shaped structures located superiorly on the kidneys
what is another name for the adrenal glands?
suprarenal glands
role of the adrenal glands?
important roles in the production of corticosteroids, as well as the maintenance of fluid balance
what are the two components of the adrenal glands?
- medulla
2. cortex
the medulla is the _____ of the adrenal gland
core
what does the medulla produce? in response to what?
epinephrine and norepinephrine in response to sympathetic nervous system stimulation
how many layers does the cortex have?
3
what does the cortex produce?
over two dozen hormones, collectively called “corticosteroids”
outer layer of cortex produces hormones known as ___
mineralacorticoids
middle layer of cortex produces hormones known as ___
glucocorticoids
inner layer of cortex produces hormones known as ___
androgens (sex hormones)
the pancreas is a _____ gland
mixed. because is has both exocrine and endocrine functions
what is the shape of the pancreas and where is it located?
long lobular organ that lies posterior to the stomach, extending from the duodenum to the spleen
function of the pancreas?
produces enzymes for digestion and the hormone insulin that regulates blood sugar levels
endocrine functions of the pancreas are a result of _______
specialized groups of cells in the pancreatic islets (or islets of Langerhans)
what are the two types of endocrine cells in the pancreas
alpha & beta
alpha cells produce what?
glucagon, a hormone that functions to increase blood glucose level (hyperglycemic hormone)
beta cells produce what?
the hormone insulin, which functions to lower blood glucose levels (hypoglycemic hormone)
what are some other glands not mentioned in this module?
- thymus
- digestive system
- kidneys
- gonads
- heart
