What is the primary function of the urinary system?
to help maintain homeostasis by controlling the composition, volume, and pressure of the blood.
What is NOT the primary function of the urinary system?
to rid the body of wastes
Outer portion of kidney?
What are the renal columns formed by?
the renal cortex dipping between the pyramids
What arches above the pyramids and dips between them to form renal columns?
the renal cortex
What part of the kidney is the darker than the cortex and consists of the the renal pyramids?
12 striated cone shaped masses which form the medulla of the kidney
renal pyramids or medullar pyramids
another name for the renal pyramids
Where are the bases of the pyramids directed towards?
Where are the apices of the pyramids pointed toward?
the center of the kidney
the functional unit of the kidney?
3 functions the nephron performs
nephron consists of what 2 portions?
- renal corpuscle
- renal tubule
part of nephron where fluid is filtered
part of nephron into which filtered fluid passes
renal tubule begins as an epithelial cup known as...
Bowman's capsule or Glomerular capsule
capillary network contained within Bowman's capsule
3 layers of the glomerular capillary of the glomerulus
- 1. Endothelium (innermost layer)
- 2. Basement membran (middle layer)
- 3. Epithelium (outermost layer)
contains fenestrations (very small pores) that allow water and solutes to exit while retaining large molecules and formed elements of the blood
endothelium (inner layer) of the glomerular capillary in the bowman's capsule
consists of crisscross of fibrils which act as a filter
basement membrane of the glomerular capillary in the Bowman's capsule
strangely shaped epithelium arranged similar to the plastic spine on a notebook
epithelium (outermost layer) of the glomerular capillary in the Bowman's capsule
the long portion of that forms the backbone on the outside of the glomerular capillary of the glomerulus
the short rung-like "feet" that run perpendicular to the podocyte in the glomerular capillary of the glomarulus
- between the pedicels are filtration slits
after leaving the renal corpuscle the renal tubule becomes the...
proximal convoluted tubule
order of flow of fluid through the renal system
- Bowman's capsule
- renal tubule
- proximal convoluted tubule (doesn't extend beyond cortex)
- descending loop of Henle
- loop of Henle
- ascending loop of Henle (going back toward cortex)
- distal convoluted tubule (back in cortex)
- collecting duct (pass through renal pyramids)
- renal papillae
- minor calyces
- major calyces
- renal pelvis
renal tubule cells are the JGA which monitor salt concentration of the fluid in the ascending loop of Henle tubule are called...
the juxtaglomerular cells secrete _______ which influences constriction of the glomerular arterioles to help regulate___________ ____________ _______
- kidney filtration rate
the right and left renal arteries transport....
about 1/4 of total cardiac output to the kidneys
division of arteries in the kidney
- renal arteries
- several short segmental arteries
- interlobar arteries (pass through renal columns)
- arcurate arteries (arch over renal pyramid bases)
- interlobular arteries (branch from arcurate arteries)
- enter parenchyma
Unfiltered blood enters the capillary network of the glomerulus through a large diameter.....
afferent glomerular arteriole
Filtered blood leaves the glomerulus through a smaller diameter...
efferent glomerular arteriole
the forcing of fluids and dissolved substances through a membrane by pressure
When the blood enters the glomerulus, the pressure forces water and dissolved components through the endothelial pores of the capillaries, through the basement membrane, and finally through the pedicel filtration slits. The resulting fluid is called....
What is the amount of plasma filtered by both kidneys each minute called?
What is it in a normal adult?
glomerular filtration rate (GFR)
125 ml per minute
The movement of certain components of the filtrate back into the blood along the course of the renal tubule
What percentage of filtrate is reabsorbed through tubular reabsorption?
Where does most tubular reabsorption occur?
the proximal convoluted tubule
2 principle processes of tubular reabsorption
- obligatory water reabsorption (90%)
- facultative water reabsorption (10%)
obligatory water reabsorption is driven by...
- sodium transport
- (water follows sodium ion back into the blood in the proximal convoluted tubule by osmosis)
Facilitative water reabsorption is driven by __________ and occurs in the _________ ______ __ ________.
- hormones (ADH & Renin-angiotensin system)
- descending loop of Henle
Renin-angiotensin system cascade
- renin (produced by juxtaglomerular cells of the JGA when the blood pressure drops or when blood sodium is low)
- angiotensinogen (precursor produced in liver)
- angiotensin I
- lungs (I is changed to II in presence of plasma cells)
- angiotensin II
- alterosterone (secreted by adrenal cortex)
- sodium retention by kidneys
- bp increases
internal urethral sphincter is composed of
external urethral spinter
- voluntary muscle
- skeletal muscle allows for voluntary control of micturition (urination)
the lack of control over mictrition
inability to urinate
the byproduct of the kidneys' activities
normal urine contains...
it should be...
condition associated with abnormally high concentrations of uric acid
- crystals deposit in joints, kidneys, and soft tissues
inflammation of the glomeruli from destructive toxins given off by streptococci bacteria, usually untreated pharyngitis
Glomerulonephritis (Bright's disease)
infection anywhere in the urinary system
UTI (urinary tract infection)
UTI is characterized by...
- large numbers of bacteria in urine
pain with urination
- bladder infection
- indicated by pain over the symphysis pubus
back and flack pain suggests
pyelonephritis (kidney infection)
- kidney stones
- crystals of salts concentrate and solidify
- anywhere in urinary tract, usually in calyces and pelvis
generation of high intensity sound waves that pulverize the renal calculi (kidney stones)
Nephrons form urine by 3 principle processes...
- glomerular filtration
- tubular reabsorption
- tubular secretion