endocrine system Flashcards
organs that secrete hormones into the blood stream control the function of other target organs long distance communication
Endocrine System
- Organs that secrete hormones into the bloodstream
- Controls the function of other target organs
- Long distance communication
Primary Endocrine Organs
- Hypothalamus
- Pituitary
- Pineal
- Thyroid and Parathyroid
- Thymus
- Adrenal Gland
- Pancreas
- Testes and Ovaries
Hypothalamus Structure
Structure: neural secretory cells and nuclei that connect to the pituitary gland
Hypothalamus function
controls release of pituitary hormones
neural secretory cells
neurons that secrete hormones at axon terminal
hypothalamus secretes
releasing and inhibiting tropic hormones to the anterior pituitary gland
tropic hormones
secreted from one gland, causes another gland to secrete
hypothalamus connections
posterior pituitary
anterior pituitary
Hypothalamus
Structure: neural secretory cells and nuclei that connect to the pituitary gland
neural secretory cells: neurons that secrete hormones at axon terminal
function: controls release of pituitary hormones
secretes: releasing and inhibiting tropic hormones to the anterior pituitary gland
tropic hormones: secreted from one gland, causes another gland to secrete
hypothalamus - posterior pituitary connection
- neurons in hypothalamus synthesizes and secretes hormones
- supraoptic nucleus: oxytocin
- paraventricular nucleus: antidiuretic hormone - hormones stored in terminal vesicles in posterior pituitary
- when stimulated, vesicles release hormones in capillary beds of posterior pituitary
hypothalamus - anterior pituitary connection
- portal system-
1. stimulated neurosecretory cells release hormones in 1st capillary bed
2. 1st capillary bed - portal vein - 2nd capillary bed
3. hormones exit capillaries - stimulate AP endocrine cells
4. AP endocrine cells secrete hormones in capillaries
pituitary gland
posterior
anterior
posterior pituitary gland structure
neural tissue (axon terminals) from hypothalamus
posterior pituitary gland secretes
- Antidiuretic hormone or vasopressin
targets: kidneys
results: increase water reabsorption - Oxytocin
targets: uterus and breasts
results: uterine contraction and milk expulsion
anterior pituitary gland structure
epithelial tissue
anterior pituitary gland secretes
- prolactin
- thyroid stimulating hormone
- adrenocorticotropic hormone
- growth hormone
- luteinizing hormone
- follicle stimulating hormone
prolactin
prolactin- controlled by hypothalamus prolactin releasing hormone prolactin inhibiting hormone (dopamine) acts on breasts results: milk secretion and mammary gland development
thyroid stimulating hormone
TSH-controlled by hypothalamus
thyrotropin releasing hormone causes the release of thyroid stimulating hormone
acts on thyroid gland
results: release thyroid hormones – metabolism
adrenocorticotropic hormone
ACTH-controlled by hypothalamus
corticotropin releasing hormone
acts on adrenal gland
results: glucocorticoids–stress response
growth hormone
GH- controlled by hypothalamus
growth hormone releasing hormone
growth hormone inhibiting hormone (somatostatin)
acts on liver and cells
results: releases insulin like growth factors (liver)
signals growth and metabolism (cells)
another name for growth hormone inhibiting hormone GHIH
somatostatin
another name for antidiuretic hormone ADH
vasopressin
luteinizing hormone
LH-controlled by hypothalamus
gonadotropin releasing hormone
acts on ovaries and testes
results: ovulation, secretion of sex hormones
follicle stimulating hormone
FH - controlled by hypothalamus
gonadotropin releasing hormone
acts on ovaries and testes
results: development of egg and sperm
pineal gland
structure: epithelial tissue in brain
secretes: melatonin
results: regulate circadian rhythms
thyroid
structure: butterfly structure, ventral surface of trachea
secretes: tetraiodothyronine (T4) and triiodothyronine T3) - increase metabolism
calcitonin - lowers calcium levels, deposition in bone
parathyroid
structure: 4 small glands behind thyroid
secretes: parathyroid hormone
results: increase calcium levels
thymus
structure: two lobed gland in front of heart
secretes: thymosin
result: T Cell functional regulation
adrenal gland
structure: multilayered glands above the kidneys (suprarenal)
cortex
medulla
cortex-
what does cortex mean?
what does it secrete? what are the results?
outer layer secretes: mineral corticoids (aldosterone) glucocorticoids (cortisol) androgens results: -stimulate Na+ reabsorption, K+ secretion in kidneys -catabolism of fats and proteins, raises blood glucose, stress response -promotes sex drive
medulla-
the meaning?
what does it secrete?
results?
inner core
secretes: epinephrine and norepinephrine
results: increased heart rate, mobilization of energy sources
pancreas structure
structure: exocrine and endocrine glands below stomach
exocrine cells-acinar cells
endocrine cells-islets of langerhans
exocrine cells function
secrete enzymes to GI tract
endocrine cells
alpha cells
beta cells
delta cells
F cells
-alpha cells-
secretes?
results?
alpha cells
secrete: glucagon
results: raises blood glucose
- - glycogenolysis
- - gluconeogenesis
-beta cells-
secretes?
results?
beta cells
secrete: insulin
results: lowers blood glucose/ promotes energy storage
-delta cells-
secretes?
results?
delta cells
secrete: somatostatin
results: inhibits secretion of pancreatic hormone
-F Cells-
secrete?
results?
F cells
secrete: pancreatic polypeptide
results: inhibits pancreatic exocrine secretions
Testes
secrete, results
testes: males
secrete: androgens
result: sperm production, sex drive, secondary sex characteristics
Ovaries
secrete, results
ovaries: female
secrete: estrogens
result: follicular development, secondary sex characteristics
