Chapter 25 Flashcards
urinary system
Name and describe the major function of the kidneys
filtration of blood, stimulation of red blood cell formation (erythropoietin), blood pressure regulation (renin), regulating water/solute/ion concentration, excreting waste
Name the functions of the bladder
holds urine
Name the functions of the ureter
brings urine to bladder from kidneys
Name the functions of the urethra
excretes urine out of the body
Name the 3 distinct regions of the kidneys
renal cortex (granular appearing) , renal medulla (pyramids), renal pelvis (funnel shaped tube)
Describe the flow of urine out of the kidney
Urine flows out of the kidney through a series of structures. It starts in the renal pyramid, moves into the minor calyx, then to the major calyx, and enters the renal pelvis. From there, it goes into the ureter and down to the bladder.
What is pyelonephritis?
Infection or inflammation of entire kidney that can result is abscess formation or kidney damage. Can normally be treated with antibiotics.
What is the function of the renal artery?
carry oxygenated blood to the kidneys
What is the nephron?
functional unit of the kidneys, filter blood, form urine
What is the function of the glomerulus?
a group of tiny blood vessels inside the nephron that filters blood, removes waste, water, and small molecules from the blood to form urine. allows for efficient filtrate formation (plasma dervived fluid that is used to form urine)
Name the components of the renal tubule and describe their functions
Proximal convoluted tubule - reabsorption and secretion
nephron loop - transportation?
distal convoluted tubule - functions more in secretion than reabsorption ***
What are the peritubular capillaries?
low-pressure, porous capillaries that arise from efferent arterioles that function in absorption of water and solutes that empty into venules
What is the function of the macula densa?
Contains chemoreceptiros that sense NaCl content of filtrate
What is the function of granular cells?
act as mechanoreceptors to sense BP in afferent arteriole and they contain secretory granules that contain renin
What is glomerular filtration rate?
the volume of filtrate formed per minute by both kidneys. normal is 120-125 ml/min
What is the function of tubular filtration, reabsorption, and secretion?
filtration - produce cell and protein free filtrate
reabsorption- tubes to blood. returns substances from filtrate to blood in renal tubules and collecting ducts
secretion- blood to tubes. moves substances from blood to filtrate in renal tubules and collecting ducts.
Describe the renal autoregulation via the myogenic mechanism
increased BP causes muscles to stretch, leading to constriction of afferent aertioles. this restricts blood flow into the glomerulus and protects it from damaging high BP. Decreased BP causes dilation of afferent arterioles. Help to maintain normal GFR.
What is anuria?
abnormally low urinary output, less than 50 ml/day. can indicate glomerular BP is too low or the nephrons not functioning.
Describe the steps in the renin angiotensin aldosterone system
drop in BP –> kidney releases renin –> angiotensinogen –> angiotensin 1 –> ACE –> angiotensin 2 –> aldosterone –> blood vessels constrict
What is the function of the renin angiotensin aldosterone system?
regulate blood pressure
What is the effect of the sympathetic nervous system on the afferent arterioles?
normal conditions at rest. renal blood vessels dilated and renal autoregulation mechanisms prevail. under abnormal condtions like low BP, norepinephrine is released causing vasoconstriction, constriction of afferent arterioles, increased BP, BV, and decreases GFR
What is secondary active transport?
when the gradient created by other solutes gives enough of a push for the transport of other solutes.
What part of the renal tubule is most active in reabsorption? What solutes get reabsorbed?
proximal convoluted tubule. all nutrients like glucose and amino acids, Na+, water, ions, almost all uric acid, about half of urea
Where is aldosterone released from?
kidneys ***
