Nitrogenous waste product excreted in the urine; end product of protein metabolism
The outer layer of kidney tissue
Contains the renal corpuscles and convoluted tubules of nephrons
The inner layer of kidney tissue
Contains the wedge shaped pieces called renal pyramids
Contains the loops of Henle and the collecting tubes of nephrons
A cavity formed by the expansion of the ureter within the kidney at the hilus
The calyces are funnel-shaped pieces called renal pyramids
Urine enters from the papillae of the renal pyramids
Cluster of capillaries surrounded by the nephron's glomelular capsule.
At the beginning of the nephron, the glomerulus is a network (tuft) of capillaries that performs the first step of filtering blood.
Location of kidneys in relation to peritoneum and backbone
They are not in the peritoneal cavity, but in the retroperitoneal space, behind the peritoneum
At level of last thoracic and first 3 lumbar vertebrae
How do the kidneys regulate BP?
When bp falls, it may limit filtration.
The cells release renin which activates angiotensin. Angiotensin constricts blood vessels, causing BP to raise
ANP is released when blood pressure is too high to lower
Produced when kidneys don't have enough O2Stimulates red cell production in the bone marrow
Behind the peritoneum
Structure of kidney
Right kidney lower than left to accommodate liver
Enclosed in renal capsule on outside, then adipose capsule
fascia anchors kidney to peritoneum and abd wall
Blood path of the kidney
Tubular resportion takes place where
From the renal tubule to the peritubular capillaries
Where does filtration take place in the kidney?
the glomerulus and glomerular capsule
What part of nephron drains to the loop of Henle?
(distal convoluted tubule)
Supplies the gomerulus with blood
carries blood from the glomerulus
Functional unit of the kidney
What drives materials out of glomerulus into glomelurlar capsule?
(3-4 times higher than in other capillaries)
Normal urinary output in 24 hours
1000 - 2000 mL
Where does reabsorption take place?
Proximal convoluted tubules
Where does secretion take place?
Peritubrular capillaries in the renal tubules
Reabsorption of small proteins
Process which water is reabsorbed by renal filtrate
Substances are reabsorbed from the distal convoluted tube into what?
The interstitial fluid, then peritubular capillaries, then return to circulation
Where is urine formed?
Begins with the glomerulus and into the renal tubule
How the kidneys regulate acid-base balance (PH) of body fluids
Active secretion of hydrogen ions and bicarbonate. when body fluids become too acidic kidneys secrete more hydrogen into renal filtrate and return bicarbonate ions back into blood. when too alkaline bicarbonate is excreted to renal filtrate and hydrogen into blood
Average PH of urine
4.6 - 8.0, with an average of 6.0
Kidneys respond to increased acidity in body fluids by doing what?
They secrete more hydrogen ions into renal filtrate and return more bicarbonate ions back into the blood
Normal glomerular filtration rate (GFR)
105 - 125 mL/min
Location of urinary bladder
Inside the peritoneum behind the pubic bones.
In women: bladder is inferior to uterus
In men: bladder is superior to the prostate gland
Ureters go from what to what?
from the hilus of the kidney to the lower, posterior side of the urinary bladder
In men, what does the urethra pass through?
It is 7-8 inches long and extends through the prostate gland and penis.
What sphincter provides voluntary control of urination reflex?
External urethral sphincter
How much urine does the bladder contain after urination?
Substances normally found in urine
Specific gravity measures what
The amount of dissolved solids and gases.
Range is 1.002 (very dilute) - 1.040 (very concentrated)
ADH does what
Increases water reabsorption in the kidney to dilute the excess sodium
Normal characteristics of urine
1000 - 2000 mL/day
Straw or amber colored
Specific gravity: 1.002 - 1.035
PH 4.6 - 8.0
Where does creatinine in urine derive from?
The metaboilism of creatine phosphate, an energy source in muscles
Waste products building up in the blood
Single best indicator of fluid balance
11 Things that are tested in Urinalysis
Good indicator of renal disease
Protein in urine
High creatinine level
If older patient has ↑ BUN, what could be the reason?
What would be considered abnormal if found in urine?
RBC and WBC's
Normal urinary output per hour
or 1 mL/kg per hour
Funnel shaped extensions of the renal pelvis
They enclose the papillae of the renal pyramids
Structures at the hilus of kidney
What provides energy for filtration?
(active transport is energized by ATP or stored energy)
What enzyme does Juxtaglomelular apparatus secrete?