autocrine

cell sends AND receives the signal

cell sends signal to neighboring cells (not very far)

long distance signal through blood stream using hormones

endocrine glands: "ductless" secrete directly into blood

makes and secretes something into a duct

ex. lacrimal (tear) ducts, mammary glands, salivary glands

located in epithalamus; small cone-shaped gland

secretes the hormone melatonin in substantial amounts

melatonin is related to sleep cycles

connected to pituitary gland

controls anterior pituitary function: makes releasing and inhibiting hormones that will affect the anterior pituitary through portal circulation

makes two additional hormones that are sent to posterior pituitary through cells and released from there

anterior: develops from cells at roof of mouth (glandular tissue); 6 hormones made there; controlled by hypothalamus

posterior: comes from brain/nervous tissue; 2 hormones are made in the hypothalamus and released to posterior pituitary

stimulate other endocrine glands to release their hormones (ex. thyrotropic, adrenocorticotropic, and gonadotropic hormones)

located at base of throat; butterfly-shaped

makes: thyroid hormone (T3 and T4) - controls rate at which glucose is "burned"/metabolism

calcitonin - stimulates osteoclasts which causes blood calcium level to decrease

located on posterior surface of thryroid gland

secretes parathyroid hormone which stimulates osteoblasts and causes blood calcium levels to increase

located in upper thorax

large in infants/children, but decreases in size with age

produces thymosin which is essential for normal development of the immune system

pancreatic islets produce insulin (released from beta cells in response to high levels of glucose in the blood) which signals cells to take up glucose from the blood and glucagon which signals cells to release glucose into blood

adrenal medulla releases epinephrine and norepinephrine which are related to short-term stress response

adrenal cortex releases aldosterone (aka mineralcoricoids) which controls ion content of blood and glucocorticoids which controls long-term stress response

organs producing gametes (ovaries or testes)

thyroid is the only gland that takes in iodine so thyroid cancer can be treated with radioactive iodine

1. enter cell across plasma membrane

2. enter nucleus of cell

3. bind receptor

4. affect gene expression (interact with DNA, change mRNA being made)

ex. estrogen, progesterone, testosterone, glucocorticoids, mineralcorticoids (aldosterone)

1. bind to receptor at cell membrane

2. start cascade of chemical reactions

3. change cell physiology

ex. oxytocin, antidiuretic hormone, calcitonin, parathyroid hormone, thymosin

located at back of body between vertebrae T12 and L3; right one is lower because of liver; makes urine; filters blood (1/3 of blood supply goes through kidneys every day)

renal hilium: where things go in/out

renal cortex: outside

medulla: inside

renal pelvis: "basin" urine collects and goes to ureter

calyces: collect urine and send to pelvis

fibrous capsule (encloses each kidney)

perirenal fat capsule (surrounds each kidney and acts as cushion)

renal fascia (outermost capsule that keeps kidneys connected to wall of body)

urethra

thin-walled tube that carries urine by peristalsis from the bladder to the outside of the body

tubes that carry urine from kidneys to bladder

bladder

smooth, collapsable, muscular sac that stores urine temporarily

involuntary sphincter that keeps urethra closed when urine is not being passed

external urinary sphincter

made of skeletal muscle; voluntarily controlled

arterial supply of each kidney; one quarter of blood supply passes through kidneys each minute

renal vein

emerges from renal hilium

concave area of kidney where things go in/out (renal artery and vein)

collect urine and drain to renal pelvis

nephrons

structural, functional units of the kidneys responsible of forming urine

consists of 2 main structures: glomerulus and renal tubule (closed end of renal tubule=Bowman's capsule)

sits in Bowman's capsule; knot of coiled capillaries in the kidney; forms filtrate

filtrate

water, ions, solutes (same as blood plasma minus proteins and cells)

part of renal tubule located between proximal and distal convuluted tubules

bed of capillaries that arises from the efferent arteriole that drains the glomerulus; low pressure vessels designed for absorption (reabsorption)

useful substances (water, glucose, amino acids, ions) are reclaimed from the filtrate beginning in the proximal convuluted tubule

some substances (hydrogen, potassium ions) move from blood of peritubular capillaries into the filtrate to be eliminated in urine

approx. 7.4

increases (alkalinization): bicarbonate ions removed from blood, Hydrogen ions retained by kidney tubules

decreases (acidification): bicarbonate ions reabsorbed from urine and put back in blood, Hydrogen ions removed from blood and put into urine (secretion)

blood buffers

prevent dramatic changes in hydrogen ion concentration when acids or bases are added

ex. bicarbonate buffer system: mixture of carbonic acid and its salt, sodium bicarbonate