Name three metabolic byproducts that are excreted via the urinary system.
Urea
Creatinine
Uric acid
What is the byproduct of amino acid metabolism?
Urea
What is the byproduct of the breakdown of nucleotides?
Uric acid
What is the byproduct of the breakdown of creatine phosphate? It serves as a clinical marker for kidney function.
Creatinine
What is formed when ammonia from the liver combines with carbon dioxide?
Urea
What is caused by the buildup of uric acid in joints?
Gout
What are 3 important functions of the urinary system?
Excretion of metabolic wastes
Maintenance of water salt balance (homeostasis)
Secretion of hormones
T or F? Salts prevent osmosis into the blood.
F. Salts cause osmosis into the blood.
T or F? The more water in the blood, the higher the blood pressure.
T.
What organ plays a role in blood pressure regulation through water and salt regulation?
Kidney
To maintain the water salt balance, there is an excretion of what ions? And reabsorption of what?
Hydrogen
Bicarbonate
What is normal urine pH?
About 6, ranges from 4.5 to 8
The kidneys are involved in the secretion of these two hormones.
Renin
Erythropoetin
What hormone is released from the adrenals following the secretion of renin?
Aldosterone
Erythropoetin stimulates red blood cell production and activates what vitamin?
D (for calcium absorption)
The release of aldosterone from the adrenals leads to the reabsorption of what ions?
Sodium
Where are the kidneys located?
Lumbar region behind the peritoneum
Where are the renal artery and vein located?
Hilus or hilum
What is the path of the urinary system once urine is produced in the kidneys?
Transported through the ureters,
Stored in the urinary bladder,
Passed through the urethra.
What urinary organ conducts urine from the kidney to the bladder?
Ureters
What are the three layers of the ureters wall?
Mucosa
Smooth muscle
Outer connective tissue
How is urine conveyed by the ureters?
Peristalsis
What urinary organ stores urine?
Urinary bladder
The wall of the urinary bladder is made up of this unique type of muscle.
Detrusor
What three openings are found in the trigone region?
2 orifice of ureter
Urethra
What layers are responsible for the expandability of the urinary bladder?
Middle layer of circular
Layers of longitudinal muscle
What type of cells line the urinary bladder?
Transitional epithelium
T or F? The bladder neck contains 2 sphincters, the internal and external.
True
T or F? The internal sphincter is involuntary and made of smooth muscle.
True
What external sphincter is made of what type of muscle?
Skeletal
What is the length of the male urethra? The female urethra?
8 in
1.5 in
The male urethra is surrounded by what gland?
Prostate
Stretch receptors in the wall of the bladder send impulses when the bladder fills to how many ml?
250 ml
When the bladder contracts, what occurs?
Micturition or urination
What is the functional unit of the kidneys?
Nephron
How many nephrons are found in the kidney?
Appx. 1 million
A nephron is composed of a system of what?
Tubules
What are the specialized capillaries of a nephron?
Glomerulus
What is the flow of blood from the renal artery to the renal vein?
Renal artery
Segmental artery
Interlobar artery
Arcuate artery
Cortical radiate artery
Afferent arteriole into glomerulus, efferent out
Peritubular capillaries
Cortical radiate vein
Arcuate vein
Interlobar vein
Renal vein (to inf. vena cava)
The kidneys use what percent of the total cardiac output each minute?
25
How many segmental arteries branch from the renal artery?
5
Each segmental artery branches to form these arteries.
Interlobar
At which point do interlobar arteries branch into arcuate arteries?
At the medulla cortex junction
What arteries arch over the medullary pyramids?
Arcuate arteries
What arteries radiate outward from arcuate arteries to supply the cortical tissue?
Cortical radiate arteries
T or F? About 75 percent of the blood entering the kidney perfuses the renal cortex.
False. More than 90 percent.
Is most of the urine collected in the cortical or medullary region of the kidney?
Medullary
Where is urine dumped before travelling down the ureter?
Renal pelvis
What is the variable network of autonomic nerve fibers and ganglia that supplies the kidneys?
Renal plexus
The renal plexus is largely supplied by the sympathetic fibers of which nerves?
Thoracic and lumbar splanchic nerves which run along the renal artery.
Sympathetic vasomotor fibers regulate renal blood flow by adjusting what?
Diameter of renal arterioles
The urine forming role of the nephrons is controlled by sympathetic or parasympathetic vasomotor fibers?
Sympathetic
What is the cuplike structure of a nephron?
Bowman�s capsule, glomerular capsule, or glomerulus
What can be found on the inner layer of Bowman�s capsule?
Podocytes
Podocytes enable a glomerulus to do what?
Cling to glomerular capillaries
Once waste material is absorbed in the glomerulus, where does it travel?
Proximal convoluted tubule (PCT)
What is the cell structure of the epithelium that lines the PCT?
Cuboidal with microvilli
The convolutions of the PCT increase this for absorption.
Surface area
This U shaped tube can be found in 20 percent of nephrons.
Loop of Henle
The loop of Henle is composed of what type of epithelium?
Simple squamous
The distal convoluted tubule (DCT) differs from the PCT in its lack of what?
Microvilli
T or F? DCTs of several nephrons enter one collecting duct.
True
What parts of a nephron lie in the renal medulla?
Long loops of Henle
These are enlarged, smooth muscle cells that have prominent secretory granules that contain renin, and are found in the arteriole wall.
Granular cells or juxtaglomerular cells
Granular cells are this type of receptors that sense the blood pressure in the afferent arteriole.
Mechanoreceptors
The macula densa, or tightly packed cells, are chemoreceptors that respond to the changes in the content of what?
NaCl
What 2 cell populations of the juxtaglomerular apparatus play important roles in regulating the rate of filtrate formation and systemic blood pressure?
Granular and macula densa
Nephrons are found in collections in the kidney known as what?
Pyramids
What pigment in urine is a byproduct of the destruction of hemoglobin?
Urochrome
How much urine is voided daily?
1500 ml
Cloudy urine may be an indication of what?
UTI
Why does urine develop an ammonia odor if allowed to stand?
Bacteria metabolizes the urea
How many L of fluid is processed by the kidney per day?
180 L
Of the 180 L of fluid processed by the kidneys, how many L leave the body as urine?
1.5 L
What are the 3 major processes in urine formation and the adjustment of blood composition?
Glomerular filtration by the glomeruli
Tubular reabsorption
Tubular secretion in the renal tubules
What process filters water, nitrogenous wastes, and salts (ions) during urine formation?
Glomerular filtration
What 4 substances are reabsorbed by nephrons (glomerular filtration)?
Water (99 percent reabsorption)
Sodium (99.5)
Glucose (100)
Urea (44)
What is composed of the same substances as blood plasma but lack the cells and large plasma proteins?
Glomerular filtrate
80 percent of filtrate (most water, nutrients, and required salts) is absorbed in the PCT through which process?
Tubular reabsorption
How is sodium reabsorbed during tubular reabsorption? Chloride? Water?
Active transport
Passive transport
Osmosis
T or F? Urine contains filtered substances that have not been reabsorbed and substances that have been actively secreted.
True
Name 3 things that can affect the regulatory functions of the kidneys.
Alcohol
Caffeine
Diuretics
Alcohol inhibits the antidiuretic hormone secreted by which glands?
Posterior pituitary
This substance increases glomerular filtration rate and decreases tubular reabsorption of sodium.
Caffeine
This substance increases the flow of urine and many inhibit active transport of sodium at loop of Henle or DCT.