mastering a&p urinary system
renal cortex
-most superficial region of kidney -filtration of blood
functions of the urinary system
-regulates plasma concentrations of electrolytes -contributes to stabilizing blood pH -regulates blood volume -eliminates organic waste products
parts of the urinary system
-ureter. -urethra. -kidney. -urinary bladder.
A healthy adult typically produces ________ of urine per day.
1200 mL
Typical renal blood flow is about ________ percent of cardiac output under resting conditions.
25
order in which blood passes through these vessels to the kidney
4. renal artery 3. interlobar artery 2. arcuate artery 6. cortical radiate artery 1. afferent arteriole 5. glomerulus 7. efferent arteriole 8. peritubular capillary
flow of newly produced urine
5) renal papilla 1) minor calyx 4) major calyx 2) renal pelvis 3) ureter
direction of urine flow from formation to exiting the kidney
Cortex, medulla, renal pelvis, ureter
cortex
Eighty-five percent of nephrons in the human kidney are located in the ________ and have short nephron loops.
Where filtration exclusively occurs in the kidney
across the filtration membrane in the renal corpuscle
Substances larger than ________ do not pass through the filtration membrane.
albumin
diffuse into the bloodstream as diffusion takes place across the dialysis membrane
bicarbonate ions
When the level of ADH (antidiuretic hormone) decreases,
both more urine is produced and the osmolarity of the urine decreases.
The ability to form concentrated urine depends on the functions of
both the distal convoluted tubule and the collecting duct.
minor calyx
collects the urine produced by a single kidney lobe
mesangial cells
control capillary diameter and the rate of capillary blood flow.
Juxtamedullary nephrons
essential to water conservation and the production of concentrated urine
The nephron loops of juxtamedullary nephrons have an important function that other parts of the nephron do not share. What is this function?
establishing the concentration gradient in the renal medulla
not a function of the urinary system
excretes abundant protein molecules
glomerular hydrostatic pressure
favors the filtration pressure
renal corpuscle
filters the blood
three distinct processes of urine formation in the kidney
filtration, reabsorption, and secretion
structures of the renal corpuscle
glomerular capsule and glomerulus
chronic renal failure
gradual loss of renal function
Acute renal failure
immediately life-threatening condition. However, if an individual survives the incident, full recovery is often possible
Stretch receptor impulses activate sympathetic outflow.
inhibits micturition by relaxing the detrusor and contracting the internal urethral sphincter
uric acid
lowest concentration (mg/dL) in normal urine
urea
most abundant waste solute in urine
dysuria
painful or difficult urination
proximal convoluted tubule
portion of the nephron and collecting system where the most reabsorption occurs
hilum
prominent indentation on the medial surface of the kidney
NOT a normal constituent of urine
proteins
filtrate first passes from the glomerular capsule to the
proximal convoluted tubule
primary function of the proximal convoluted tubule
reabsorbing nutrients
filtration
results from blood pressure that forces water and solutes across the membranes of the glomerular capillaries and into the capsular space
The left kidney lies ________ to the right kidney.
slightly superior
secretion (kidney function)
solutes are transported from the peritubular fluid across the tubular epithelium and into the tubular fluid
renin
triggers formation of angiotensin I
normal constituents of urine
uric acid. urea. hydrogen ions. creatinine.
produced by kindeys in response to increased levels of aldosterone
urine with a lower concentration of sodium ion
When does urine production end?
when the fluid enters the renal pelvis
Renal medulla
where renal columns are located
pyelogram
x-ray image of the urinary system
All of the following are true of the kidneys except that they are
TRUE: -held in place by the renal fascia. -surrounded by a fibrous capsule. -located in a position that is retroperitoneal. -covered by peritoneum. NOT TRUE: -located partly within the pelvic cavity.
Blood colloid osmotic pressure tends to draw water out of the filtrate and into the plasma. Why?
The solute concentration in the blood exceeds that within the filtrate.
renal pyramids
Triangular or conical structures located in the renal medulla
nephron loop
U-shaped segment of the nephron
collecting system
Variable secretion of potassium and hydrogen ions is a specific function of which renal structure?
fibrous capsule
Which structure is composed of a layer of collagen fibers that covers the entire outer surface of the kidney?
acute renal failure
sudden loss of renal function
renal failure
the inability of the kidneys to excrete adequately to maintain homeostasis
Dialysis
the process of using an artificial semipermeable membrane to remove wastes and retain plasma proteins in the blood of a person whose kidneys are not functioning properly.
What structures enter and exit the kidney at the hilum?
the renal artery and renal nerves enter; the renal vein and ureter exit at the hilum
renal papilla
tip of the medullary pyramid
What is the function of the vasa recta?
to collect and transport water and solutes within the renal medulla in association with the juxtamedullary nephron
