Unit III Flashcards
Urinary System
functions
MAIN-produce urine and perform functions
-adjusting blood volume and pressure
-regulating blood plasma concentrations
-stabilizing blood pH
-conserving valuable nutrients by preventing their loss in urine
-removing drugs and toxins from bloodstream
–accomplish all these functions by producing urine
What do you have to break through to get to the kidneys?
Parietal peritoneum
What is the outermost layer of kidneys called?
Fibrous/renal capsule
Process of urine leaving kidney
Leaves through hilum –> ureter –> urinary bladder
Renal corpuscle
glomerulus - what does it contain
Glomerulus: knot of capillaries with fenestrae
-afferent arteriole (takes blood in)
-efferent arteriole (takes blood out)
Renal Corpuscle
glomerular capsule - what does it contain
Glomerular capsule: two layers of epithelium
-visceral: in contact, layer of podocytes
-parietal: layer of simple squamous epithelium
Renal tubule
what is it
surrounded by peritubular capillaries
_______ _______ is top half; _____ _______ is bottom half
Renal cortex; renal medulla
Juxtaglomerular apparatus is ____ ______ + ______ ______
Juxtaglomerular cells; macula densa
Where is the juxtraglomerular apparatus located?
Next to afferent arteriole (branches off it)
Renal sinus
an internal cavity within the kidney
Renal pelvis
large, funnel shaped chamber that collects urine from major calyces
Major calyces
fusion of 4-5 minor calyces
Minor calyces
at tips of pyramid - collect urine produced by single kidney lobe
Renal medulla
extends from the renal cortex to the renal sinus and contains 6-18 pyramids
Renal columns
band of granular tissue that separates adjacent pyramids
Renal cortex
superficial region of the kidney; in contact with fibrous capsules
Types of Nephrons
Cortical Nephrons 80% - primarily in renal cortex
Juxtamedullary Nephrons 20%
Juxtamedullary Nephrons Info
-Corpuscles are low in the cortex/columns
-nephron loops are long, in the medulla, and surrounded by vasa recta capillaries
-function in water conservation (urine concentration)!!
Pathway for blood flow into kidneys
abdominal aorta, renal artery, segmental artery, interlobar artery, arcuate artery, cortical radiate artery
Blood vessels associated in the nephron (blood flow in nephron)
afferent arteriole, glomerular capillaries, efferent arteriole, peritubular capillaries, vasa recta (juxtamedullary nephrons)
Pathway for blood flow leaving kidneys
cortical radiate vein, arcuate vein, interlobar vein, segmental vein, renal vein, inferior vena cava
Tubular Reabsorption of Electrolytes and Water
what is reabsorbed by active transport?
what is attracted to what?
as concentration of ions (solute) increases in plasma…?
water moves from ____ ____ to capillary by ____?
-sodium ions
-negatively charged ions attracted to positively charged ions
-osmotic pressure increases
-proximal tubule; osmosis
How much urine do you typically make a day?
How much do you get rid of?
What happens to the rest?
180L a day
get rid of 0.6-2.5L a day
most urine is reabsorbed
The descending limb (three things)
what does it do
-permeable to water
-impermeable to solutes
-solute concentration increases
The ascending limb (three things)
what does it do
-impermeable to water
-selectively permeable to Na+ and Cl-
-solute concentration decreases
Metabolites and Nutrients (glucose, lipids, proteins) in blood plasma and urine
higher levels in blood plasma as you want to keep those nutrients
-tubular reabsorption occurs
Nitrogenous Wastes (urea, creatinine, uric acid, ammonia) in blood plasma and urine
higher levels in urine as you want to get rid of those wastes
Increased urine volume = ?
what kind of urine concentration
what happens to blood and blood volume
decreased urine concentration
decreased blood volume and pressure
Decreased urine volume ?
what kind of urine concentration
what happens to blood and blood volume
increased urine concentration
increased blood volume and pressure
If your BP is too high ?
body needs to make more urine
If your BP is too low ?
drink more fluids
Autoregulation for BP
homeostasis disturbed = dilation of afferent arterioles, contraction of mesangial cells, constriction of efferent arterioles
blood concentrations decrease due to _______ and increase due to _____ and _______
tubular reabsorption; tubular secretion; concentration
Central regulation
juxtaglomerular complex increases production of renin - renin activates angiotensin I which is then activated to angiotensin II by angiotensin converting enzyme (ACE) in the capillaries of the lungs
–angiotensin II triggers aldosterone and increases Na+ retention, and triggers neural responses (increased stimulation of thirst and ADH production)
—all increase blood volume and pressure
Angiotensinogen slide
liver produces angiotensinogen , kidney releases renin, renin converts angiotensinogen to angiotensin I and then converted to angiotensinogen II by angiotensinogen converting enzyme (ACE) that is produced in lungs
–causes vasoconstriction, increased aldosterone secretion, increased thirst, increased ADH secretion
Dialysis
def
-procedure used to adjust composition of blood when number of functioning nephrons is too few to keep up (kidney failure)
what are the two main causes of kidney failure?
diabetes and hypertension
hemodialysis
what does it use
def
average of how often
-uses artificial kidney
-wastes and excess ions from the blood cross a dialysis membrane into a dialysis solution
-average 3 times a week/ 3-4 hours per session
Peritoneal dialysis
def
solution being replaced?
-dialysis solution is introduced into the peritoneal cavity and peritoneal membranes serve as the dialysis membrane
-dialysis solution is periodically replaced
-person does this at home
Elimination urine pathway
Nephron -> collecting duct -> renal papilla -> minor calyx -> major calyx -> renal pelvis -> ureter -> urinary bladder -> urethra (carries out)
Ureters
what kind of epithelium
how does urine move to urinary bladder
one way valve?
2 ureters
transitional epithelium
-muscularis produces peristaltic contractions that move urine to urinary bladder
-one way valve occurs at ureter-urinary bladder junction
Urinary Bladder
function
what kind of epithelium
what is muscularis is called ?
-urine storage and elimination
-transitional epithelium
-muscularis is called the detrusor muscle
Urethra
transports?
sphincters?
-transports urine in males and females
-transports semen in males
-internal and external urethral sphincters control movement of urine
—-stratified squamous epithelium
______ muscle contracts _________ urine _________ pressure
detrusor; increasing; hydrostatic
_______ from the brain cause _________ of the _________ urethral ____________
internal = _______ control
impulses; relaxation; internal; sphincter
involuntary
________ urethral sphincter _________
external = ______ control
external; relaxes
voluntary
Types of hormones
- steroid
- prostaglandins (local hormones)
- nonsteroid (proteins, peptides, amino acid deriatives)
steroid hormones (2 things)
-synthesized from cholesterol
-lipid soluble
prostaglandins (local hormones) - 3 things
-synthesized from fatty acid
-lipid soluble
-diffuse through tissue fluid to neighboring cells
nonsteroid (2 things)
synthesized from amino acids
most are water soluble
Modes of hormone action
- steroid and thyroid
- protein and polypeptide
Steroid and thyroid hormones info
can they cross?
where is hormone receptor
what does it promote
what is held responsible
-cross plasma membrane
-hormone receptor in cytoplasm and/or nucleus
-promore gene expression
-gene products responsible for hormone action
Protein and polypeptide hormones info
where is hormone receptor
what activates
what serves as second messenger
-hormone receptor on cell membrane
-binding activates G protein
-Cyclic AMP (cAMP) or calcium serves as second messenger that is responsible for hormone action
Hypothalamus hormones
what do they target and what is action
- Releasing hormone targets anterior pituitary lobe, action = promotes anterior pituitary hormone secretion
- Release inhibiting hormone targets anterior pituitary lobe, action = inhibits anterior pituitary hormone secretion
what hormones are made from anterior pituitary gland
growth hormone (GH)
prolactin (PRL)
Thyroid Stimulating hormone (TSH)
Adrenocorticotropic hormone (ACTH)
Follicle stimulating hormone (FSH)
lutenizing Hormone (LH)
growth hormone
targets
action
various targets
promotes growth through cell division, cell growth, and bone lengthening
prolactin
targets
action
mammary glands
promotes milk production (anterior pituitary)
thyroid stimulating hormone
targets
action
thyroid gland
stimulates secretion of thyroid hormones
adrenocorticotripic hormone
targets
action
adrenal cortexes
stimulates secretion of adrenal cortex hormones
Follicle stimulating hormone
targets
action
gonads
promotes follicle development in females (estrogen and progesterone secretion) and sperm production in males
Lutenizing hormone
targets
action
gonads
stimulates ovulation and corpus luteum formation in females (progesterone and estrogen secretion) and testosterone secretion in males
what hormones does the posterior pituitary secrete
antidiuretic hormone and oxytocin
antidiuretic hormone
targets
action
DCT, collecting ducts
promotes reabsorption of sodium and water
oxytocin
targets
action
uterus, mammary glands
stimulates uterine contraction and milk release
what hormones does the thyroid release
thyroid hormones
—-thyroxine and triiodothyronine
calcitonin
thyroid hormones
targets
action
various
stimulates carbohydrate and lipid metabolism and protein synthesis
*regulated by TSH and negative feedback
Calcitonin
targets
action
bones, nephrons
decreses blood calcium level
Parathyroids secrete
parathyroid hormone
Parathyroid hormone PTH
targets
action
bones, nephrons, small intestine
increase blood calcium level
*stimulates osteoclasts, tubular reabsorption)
