What are the functions of the urinary system?
Removal of waste product from the body.
Regulation of electrolyte balance.
Controlling blood volume and maintaining blood pressure.
What hormones are produced by the kidney and what are their functions?
Renin - regulation of blood pressure
Erythropoietin - Regulation of red blood cells
What is renal ptosis? What is the cause and consequences of this disorder?
One or both of the kidneys drop to a lower position in the body.
Rapid weight loss and may cause ureter to kink forcing urine to
backup in the kidney. Hydronephrosis - Necrosis and renal failure.
Starting in the medullary pyramids to the urethra�what is the flow of urine?
Renal Pyramid --> minor calyx --> major calyx --> renal
pelvis --> ureter --> urinary bladder --> urethra
Infection of the renal pelvis is called__________.
Pyelitis
Infection of the entire kidney is called__________.
Pyelonephritis
Blood flow in the kidney.
aorta -> renal artery -> afferent arteriole -> glomerulus
-> efferent arteriole -> renal vein -> inferior vena cava
What are the parts of the renal corpuscle?
Glomerulus, glomular capsule
Regarding the structure of the glomerulus, why is it efficient at
filtering the urine?
...
What are the parts of the renal tubule?
Proximal convoluted tubule
Nephron loop
Distal convoluted tubule
The proximal convoluted tubule is a site for _________ and
__________. It is located entirely in the _________(region) of the
kidney. It consist of _______ cells
with _____ that make up the brush border.
Reabsorption and secretion.
Cortex.
Cuboidal cells with dense microvilli.
The nephron loop consists of a ______(thin) limb and a
________(thick) limb.
Descending thin
Ascending thick
The _____________ has cuboidal cells and very few microvilli. It
functions more in ________ than reabsorption and is confined to the
__________(region of the kidney.
Distal convoluted tubule.
Secretion.
Cortex.
The collecting ducts run through the ________ and give it a striped appearance.
They fuse together to deliver urine through the _______ to the
minor calyces.
Medullary pyramids.
Papillae.
85% of the nephrons are found in the _________.
cortex. (cortical nephrons)
_________nephrons are long nephron loops that deeply invade medulla
and are important in production of concentrated urine
Juxtamedullary
Juxtamedullary nephrons also associated with the ______.(Capillary bed)
Glomerulus
Peritubular capillaries
VASA RECTA
Why is blood pressure (hydrostatic pressure) high in the glomerulus?
Afferent arterioles are larger in diameter than efferent arterioles.
What is the function of the peritubular capillaries?
Absorption of water and solutes.
What is the function of the vasa recta?
Formation of concentrated urine.
What are the three processes in urine formation and what adjustments
do they make to the blood composition?
Glomerular filtration - produces cell and protein-free filtrate
Tubular reabsorption - selectively returns 99% of substances from
filtrate to blood in renal tubules and collecting ducts
Tubular secretion - selectively moves substances from blood to
filtrate in renal tubules and collecting ducts.
What is the filtrate?
Blood plasma minus protein
What are the components of the filtration membrane?
What materials are normally able to pass through the filtration membrane?
Fenestrated endothelium, basement membrane, foot processes of podocytes.
Molecules smaller than 3nm (water, glucose, amino acids,
nitrogenous wastes.)
The colloid osmotic pressure of the blood is maintained by ______
produced in the ______.
...
Be able to calculate net filtration pressure given the variables.
55 mm Hg forcing out; 45 mm Hg opposing = net outward force of 10 mm Hg
What is the normal glomerular filtration rate GFR?
What factors can affect it?
120-125 ml/min
systemic blood pressure
What is the effect of GFR on urine output and blood pressure?
GFR goes up - �urine output goes up - blood pressure goes down, and
vice versa
What are the extrinsic controls of GFR?
Nervous and endocrine mechanisms that maintain blood pressure.
Can negatively affect kidney function.
Extrinsic controls take over when blood pressure is less than _______
and greater than _______.
< 80 or > 180 mm Hg
How does the intrinsic myogenic mechanism work to decrease blood pressure?
Smooth muscle contracts when stretched.
BP goes up - muscle stretch - constriction of afferent arterioles -
restricts blood flow into glomerulus
BP goes down - dilation of afferent arterioles
How does the intrinsic tubuloglomerular mechanism work to decrease GFR?
If GFR goes up - filtrate flow rate goes up - reabsorption time goes
down - high filtrate NaCl levels - constriction of afferent arteriole
- NFP & GFR - more time for NaCl reabsorption
Intrinsic tubuloglomerular mechanism
directed by macula densa cells.
respond to filtrate NaCl concentration.
How does the sympathetic nervous system increase blood pressure?
If the blood pressure is low, epinephrine is released by adrenal
medulla which causes systemic vasoconstriction and then increased
blood pressure.
The transcellular absorption route is as follows:
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