Urinary System - A&P Textbook Flashcards
What are the three major functions of the urinary system?
- Excretion
- Elimination
- Homeostatic regulation
What are the main components of the urinary system?
- Two kidneys
- Two ureters
- A urinary bladder
Describe the shape and color of the kidneys.
Smooth, bean-shaped organs with a reddish-brown color
Where do the kidneys lie in relation to the vertebral column?
On either side of the vertebral column
What is the hilum of the kidney?
Entrance to the hollow renal sinus
Name the parts of the kidney.
- Renal pelvis
- Calyces
- Renal papillae
- Inner renal medulla
- Outer renal cortex
What is one function of the kidneys related to blood?
Helping to maintain blood volume and pressure
From where do the renal arteries arise?
From the abdominal aorta
What structures branch off from the renal arteries inside the kidneys?
- Interlobar arteries
- Arcuate arteries
- Interlobular arteries
- Afferent arterioles
How many nephrons does each kidney contain approximately?
Approximately 1 million nephrons
What are the two main components of a nephron?
- A renal corpuscle
- A renal tubule
What is the role of the glomerulus in the nephron?
Fluid is filtered via the glomerular capillaries
What surrounds the glomerulus?
Glomerular capsule
What is the function of the proximal convoluted tubule?
Dips toward the renal pelvis to form the descending limb of the nephron loop
What is the function of the efferent arteriole?
Where blood (minus filtered fluids) enters from glomerular capillaries
efferent arteriole carries blood away from the glomerulus after filtration has occurred in the kidneys
What is the function of the distal convoluted tubule?
Contacts the afferent and efferent arterioles while passing between them
What components are part of the juxtaglomerular apparatus?
- Juxtaglomerular cells
- Macula densa
What initiates urine formation?
Glomerular filtration
How much fluid is produced by glomerular filtration every 24 hours?
180 liters
What processes are involved in urine production?
- Tubular reabsorption
- Tubular secretion
What percentage of water reabsorbed by the kidneys is taken up passively?
99%
Which electrolytes require energy for transport in the kidneys?
- Chloride
- Sodium
What is the countercurrent multiplier mechanism?
Involves flow from the tubules into the vasa recta
What is the normal range of urine production per day?
Between 0.6 and 2.5 liters
What hormone is produced when blood pressure is low?
Renin
What effect does angiotensin II have on blood vessels?
Causes vasoconstriction and sympathetic activation
What does aldosterone do in kidney function?
Increases the rate of sodium and chloride ion transport from the tubules to the blood
What hormone regulates the permeability of the distal convoluted tubules?
ADH
What are the three layers of the ureter walls?
- Mucous coat
- Muscular coat
- Fibrous coat
What is the function of the urinary bladder?
Stores urine until it is excreted
What is the trigone in relation to the urinary bladder?
A specific area of the bladder wall
What are the four layers of the urinary bladder wall?
- Mucous coat
- Submucous coat
- Muscular coat
- Serous coat
What is micturition?
The process of expelling urine from the urinary bladder
What does the urethra do?
Drains urine from the bladder, passing it outside of the body
What are the three parts of the male urethra?
- Prostatic urethra
- Membranous urethra
- Spongy urethra
How long is the female urethra?
About 4 cm long
Where does the female urethra end?
Between the clitoris and the vagina
