Practical 3 - Endocrine Flashcards
What is homeostasis?
state of balance among all the body systems needed for the body to survive and function correctly
What two systems focus on intracellular communication?
nervous and endocrine
What is the function of the endocrine system?
produce and secrete hormones that regulate the activity of cells/organs to maintain homeostasis
What are some of the endocrine structures/locations?
pituitary gland, pineal gland, thyroid gland, parathyroid glands, thymus, adrenal glands, pancreas, ovaries, and testes
Do endocrine glands have ducts? What is their function?
they do not have ducts
they secrete hormones into the bloodstream
Do exocrine glands have ducts? What is their function?
they do have ducts
they secrete products through the ducts to the outside
What are tropic hormones? What are two examples?
hormones that target another endocrine gland, such as CRH and ACTH
What are the three types of cell signaling, and give a basic explanation?
autocrine - bind to receptors on itself
paracrine - bind to receptors on cells nearby
endocrine -aka circulating hormones, travel through the bloodstream to reach faraway cells
What are the three factors that differentiate nervous and endocrine signaling? What is the difference between nervous and endocrine?
speed - nervous is fast, endocrine is slow
distance/targets - nervous is nearby, endocrine is far away
duration of effects - nervous is short lasting, endocrine is long-lasting
What hormones also act as neurotransmitters? Definition and examples.
those which are produced by nervous tissue
ADH, oxytocin, melatonin, epinephrine, and norepinephrine
What is the function of the pituitary gland?
“master gland,” monitors and regulates many bodily functions
What types of tissue are the anterior and posterior pituitary gland composed of?
posterior - nervous (terminal axons of the hypothalamic neurons)
anterior - glandular epithelial
What does the posterior pituitary do? (include target cells)
stores and secretes hormones made by the hypothalamus, like oxytocin and ADH, into the bloodstream
oxytocin - uterus and mamary glands
ADH - kidneys
What does the anterior pituitary do? (include target cells)
produce various hormones and secrete them when stimulated by hormones from the hypothalamus
GH, TSH, FSH, LH, ACTH, and PRL, MSH
GH - cartilage, bone, skeletal muscle, liver, etc.
TSH - thyroid
FSH - testes/ovaries
LH - testes/ovaries
ACTH - adrenal cortex
PRL - mammary glands
MSH - skin
How are the anterior and posterior pituitary connected to the hypothalamus?
posterior - nerve axons
anterior - portal system
What is GH and what does it do? (include target cells)
growth hormone (also HGH) stimulates widespread tissue growth including bone, skeletal muscle, liver, cartilage, and fat
What is TSH and what does it do? (include target cells)
thyroid
thyroid stimulating hormone stimulates growth of the thyroid gland and secretion of its hormones
What is FSH and what does it do? (include target cells)
testes and ovaries
follicle-stimulating hormone stimulates sperm and oocyte production and estrogen secretion
What is LH and what does it do? (include target cells)
testes/ovaries
luteinizing hormone
females - ovulation, estrogen, progesterone
males - testosterone
What is PRL and what does it do? (include target cells) (include target cells)
mammary gland
prolactin, stimulates milk synthesis
What is ACTH and what does it do? (include target cells)
stimulates the growth of adrenal cortex, secretion of glucocorticoids
adrenal cortex
What is ADH and what does it do? (include target cells)
anti-diuretic hormone, promotes water retention
kidneys
What is OT and what does it do? (include target cells)
oxytocin stimulates uterine contraction and milk release during suckling
uterus and mammary glands
Where is the pineal gland located? What does it do? (include target cells)
posterior to the thalamus in the brain
secretes melatonin which may influence mood, sexual maturation, and circadian rhythm
What is different about the pineal gland in kids?
It is much larger
Describe the physical and histology features of the thyroid gland.
bi lobed connected by an isthmus
histology shoes follicles which contain the precursor to hormones
C cells (parafollicular cells)
What does the thyroid gland do? (include target cells)
secrete T3 and T4 (triiodothyronine and thyroxine) which target most tissues and increase metabolic rate and heat production
C cells secrete calcitonin which targets/inhibits osteoclasts and decreases the blood calcium levels