Urinary System
What % of filtrate is actually excreted?
1%
Describe the location of the left and right kidney.
1. Located at back of the abdomical cavity 2. protected by the 12th rib 3. right kidney lower than left kidney (due to liver).
What are the 5 main functions of the urinary system?
1. excretion 2. Control fluid volume in blood 3. Electrolyte balance 4. Control of Blood Cell Formation 5. Regulation of Blood Pressure
What is the main function of the renal corpuscle?
1. site of filtration 2. located in cortex 3. Composed of Glomerulus + Bowman's Capsule 4. No blood cells pass, so NO BLOOD IN URINE
How much urine is the bladder able to hold?
2 cups
How much filtrate is filtered through the renal corpuscle each day?
45 gallons
What main substances are reabsorbed?
99% of water, some ions, proteins, all glucose
The renin-angiotensin cascade causes the release of which hormone from the adrenal gland?
Aldosterone
The hormone released from the adrenal gland causes what changes to the blood pressure and blood volume?
Causes elevated blood pressure. when renin is released, blood pressure increases.
What is the smooth muscle of the bladder called?
Detrusor muscle (3 muscles together)
How is urine prevented from backflowing from the bladder to the ureters?
Enters slit-like opening (to empty urine into bladder, acts like one way door): Contraction of bladder closes the one-way valve opening to prevent backflow into ureter.
Which two structures form the renal corpuscle?
Glomerulus and Bowman's Capsule.
What are the names of the 2 sphincter muscles of the urethra?
Internal Urethra sphincter (Smooth muscle) External Urethral Sphincter (Skeletal muscle)
The distal convoluted tubule (DCT) joins up with the afferent arteriole to form what important structure?
Juxtaglomeruler (JG) apparatus
trace the flow of the production of urine, through the urinary structures, to the point of exit from the body.
Kidneys → (renal Pelvis) → Ureters → Urinary Bladder → Urethra
What is the functional subunit of the kidney?
Nephron. place where urine is formulated. necessary for excretion. 1 million per kidney.
If our nephrons filter blood, why do we need to have the ability to secrete certain substances from the blood into the urine?
Remove H+ from blood (control blood pH)
The ureters extend from the kidneys to the urinary bladder. What structure connects the ureters to the kidneys?
The Renal Pelvis
How is urine moved through the ureters?
Through peristalsis
What is the "trigone" and why is it clinically important?
Triangular area just above the urethra inside the bladder that is the primary site for urinary tract infections
Are the renal pyramids located within the cortex or medulla?
Within the medulla in the inner layer of the kidney.
What is the glomerulus?
a leaky capillary "BOW" that acts as the site of filtration for blood.
Glucose is filtered from the blood and is found in the filtrate. Why is glucose not found in the urine?
because RBCs are too large
Why is a woman more likely than a man to get cystitis (bladder infection)?
because a woman's urethra is only 1- 1 ½ inches where a man's is 7-8 inches so bacteria is more likely to get in there.
Why would blood in the urine possibly indicate a problem with the urinary system?
because both proteins and blood cells are normally too large to pass through the filtration membrane so when either appear in the urine there is a fair bet that there is a problem with the glomerular filters.
Why are kidney stones so painful when they pass?
because they are crystallized calcium and acid salts that form hard, sharp "stones", which can cause bleeding and pain while they pass through the ureter
During reabsorption, substances are moved from the filtrate within the renal tubules to the_________?
blood
What chemical is produced by the kidneys that is responsible for red blood cell formation?
erythrpoeitin
What are the 3 main processes of urine formation?
filtration, reabsorption, secretion
Antidiuretic hormone (ADH) causes what changes to the blood pressure and blood volume?
increased permeability to H20 of kidney tubulus → H20 re-absorbed in kidneys → Elevated blood pressure
Where is the medulla?
inner layer of kidney
Which of the 2 sphincter muscles of the urethra is under involuntary control and which is under voluntary control?
internal is involuntary smooth muscle , external is voluntary skeletal muscle.
How does antidiuretic hormone (ADH) affect the distal tubules & collecting ducts?
it increases the permeability of H20 of kidney tubules causing it to be reabsorbed into the kidneys.
Where is the cortex of the kidney?
outer layer of kidney
Most reabsorption of filtrate occurs within which renal tubule?
proximal convoluted tubule (65%)
How does secretion control the pH of blood?
removes H+
Which blood vessels supplies blood to the kidney?
renal artery
What chemical is produced by the kidneys that is responsible for raising the blood pressure?
renin
Which kidney is located lower in the abdominal cavity, and Why?
right kidney lower than left kidney (due to liver).
What occurs during the process of "micturition," or voiding?
urination, or emptying of the bladder
