A + P Endocrine System Flashcards
endocrine system main purpose
release hormones that regulate the body’s activities
hormones…
bind with specific receptors on target cells/organs to produce a specific response
endocrine system works with…
the nervous system to coordinate these activities
endocrine and nervous systems and different in 2 ways
chemical messengers -endocrine system uses hormones -nervous system uses neurotransmitters messenger transport -endocrine system uses circulatory system -nervous system uses nerves
hormone types
amino acid derivatives
peptide hormones
lipid derivatives
amino acid derivatives
- related to
- bind to
- binding results in
- examples
small molecules that are structurally related to AAs
bind to receptors on cell surface - do not enter the cell
binding results in a cascade of events that produce a response inside the cell
examples: Tri-iodothyronine (T3), Thyroxine (T4), epinephrine, norepinephrine
peptide hormones
- composed of
- bind to
- binding results
- examples
composed of small chains of AAs
bind to receptors on cell surface - do not enter the cell
binding results in a cascade of events that produce a response inside the cell
examples include: ADH, GH, prolactin, oxytocin, MSH, TSH, ACTH, LH, FSH, calcitonin, PTH, insulin glucagon, thymosin
lipid derivatives
-types
eicosanoids
steroid hormones
eicosanoids
derived from arachidonic acid, a 20-C fatty acid
steroid hormones
derived from cholesterol
both eicosanoids and steroid hormones…
bind to receptors inside the cell
hormone-receptor complex enters the nucleus, binds with chromatin, and activates specific genes (DNA) to manufacture specific proteins
examples include: androgens, estrogens, cortisol, and aldosterone
endocrine organization/glands
hypothalamus pituitary gland thyroid gland parathyroid gland adrenal cortex adrenal medulla gonads pancreas thymus gland pineal gland
hypothalamus
- controls
- helps
controls emotions, autonomic functions, and the pituitary gland
helps to maintain homeostasis by regulating the internal environment (heart rate, body temp., H2O balance, and pituitary secretions)
pitiuitary gland
-divided into
posterior lobe
anterior lobe
posterior lobe
- synthesized
- hormones
hormones synthesized by neurons in the hypothalamus
hormones
-oxytocin
-antidiuretic hormone (ADH)
oxytocin
-functions
stimulates the uterine contractions of labor needed to move the child through the birth canal
stimulates release of milk from the mammary glands
antidiuretic hormone
-functions
increases the permeability of the DCT and collecting duct in the kidney nephron, which conserves H2O and concentrates urine
anterior lobe
- how many hormones
- -how do they work
produces its own hormones, although production of these is stimulated by specific hypothalamic-releasing hormones
three hormones released affect the body
the other three regulate other glands
anterior pituitary gland hormones
-growth hormone (GH)
-prolactin
-melanocyte-stimulating hormone (MSH)
thyroid-stimulating hormone (TSH)
andrenocorticotropic hormone (ACTH)
gonadotropic hormones (LH and FSH)
growth hormone
stimulates body cells to grow
acromegaly and gigantism
genetic metabolic disorders where too much GH is secreted over time and the body tissues gradually enlarge
prolactin
stimulates the development of mammary glands and production of milk
involved with fat and carbohydrate metabolism
melanocyte-stimulating hormone (MSH)
stimulates the melanocytes to synthesize melanin
thyroid-stimulating hormone (TSH)
stimulates the thyroid gland to produce thyroxin
adrenocorticotropic hormone (ACTH)
stimulates the adrenal cortex to produce cortisol
gonadotropic hormones (LH and FSH)
stimulate the ovaries and testes to produce sex hormones and control gamete production
thyroid gland
- size
- location
one of the largest endocrine glands in the body
surrounds the anterior portion of the trachea, just inferior to the larynx
thyroid gland hormones
Tri-iodothyronine (T3) and Thyroxin (T4)
Calcitonin
Tri-iodothyronine (T3) and Thyroxin (T4)
- in response
- functions
in response to TSH from the anterior pituitary, both of these hormones are produces
collectively, they influence meatbolic rate, cell growth, and development
Calcitonin
stimulates Ca2+ deposition in bones
calcitonin production is not regulated by the anterior pituitary
-secretion stimulated by increased Ca2+ levels in the blood
iodine
needed to manufacture thyroid hormones
deficiency prevents synthesis of thyroid hormones, which results in an excess of TSH production by the anterior pit.
a goiter may result due to constant stimulation of the thyroid and possibly other conditions associated with hyperthroidism
hypothyroidism
- occurs when
- results in
- -adults
- -infants
occurs when the thyroids produce too little T3, T4, and/or calcitonin
in adults, it results in lethargy and weight gain
in infants, it causes cretinism: combo of dwarfism, mentral retardation, lack of sexual maturity
parathyroid gland
4 small glands embedded in the posterior surface of the thyroid gland
parathyroid gland hormone
parathyroid hormone
parathyroid hormone
- function
- secretion stimulated by
increases Ca2+ levels in the blood by
-increasing the reabsorption of Ca2+ in the kidney
-activating Vitamin D to enhance Ca2+ absorption in the small intestine
secretion stimulated by decreased Ca2+ levels in the blood
adrenal cortex
- location
- three kinds of steroid hormones
the outer layer of the adrenal glands produces three kinds of steroid hormones -glucocorticoids -mineralocorticoids -sex hormones (small amounts)
adrenal cortex hormones
cortisol
aldosterone
cortisol
- in response to
- functions
in response to ACTH from the anterior pit., cortisol stimulates the liver to produce glucose from AAs and lipids to increase blood glucose levels
reduces swelling by inhibiting the effects of the immune system
aldosterone
- functions
- secretion stimulated by
stimulates the kidneys to absorb Na+ and excrete K+ to ultimately retain H2O, which increases blood volume and pressure
secretion stimulated by renin released by the kidneys
adrenal medulla
- location
- composed of
- innervated by
the inner layer of the adrenal glands in the adrenal cortex
-composed of modified neurons that produce “stress” hormones
innervated by sympathetic nerves and as such is not stimulated by pituitary hormones - stimulated by the SNS
adrenal medulla hormones
norepinephrine
epinephrine
norepinephrine
-functions
stimulates the heart to beat faster (helps increase cardiac output)
dilates the bronchioles (helps increase ventilation)
causes widespread vasoconstriction (to shunt blood away from “non-working” tissues and stimulate the liver to release glucose
epinephrine
works the same as norepinephrine
gonads
-comprised of
testes (males) and ovaries (females)
LH from the anterior pituitary stimulates the gonads to produce
androgens
estrogen and progesterone
androgen
-functions
develop male secondary sex characteristics, such as deepening of the voice (enlarged larynx), facial hair growth, and muscle development
notable androgen
testosterone
estrogen and progesterone
-function
develop female secondary sex characteristics, such as breast tissue development, broadening of the pelvis, and uterine enlargment
FSH from the anterior pit. stimulates the gonads to produce
sperm in the testes
eggs in the ovaries
goiter (thryoid gland)
unusual swelling of the neck
pancreas
digestive gland that secretes digestive enzymes into the duodenum, but also produces specific hormones for the endocrine system
pancreas hormones
insulin
glucagon
insulin
-functions
stimulates glucose uptake by the muscles and liver to reduce blood glucose levels
promotes fat and protein synthesis/storage
diabetes mellitus
disease in which glucose is not sufficiently metabolized due to low/no insulin production (Type I) or insulin insensitivity (Type II)
glucagon
stimulates glucose release from the liver to raise blood glucose levels
thymus gland
-location
specialized organ of the immune system located in front of/superior to the heart
thymus gland hormones
thymosins
thymosins
- stimulate
- -function of what is stimulated
stimulate the development and differentiation of T-lymphocytes (T cells), which primarily identify and destroy infected body cells
pineal gland
specialized structure within the diencephalon, located inferior to the posterior portion of the thalamus
pineal gland hormone
melatonin
melatonin
darkness (lack of light) perceived via the optic nerves stimulates the production of melatonin, which induces drowsiness and sleep
-light reduces or inhibits the production of melatonin
melatonin supplementation/medication
often used to treat individuals who have difficulty sleeping
