The Urinary System Flashcards
Organs of the Urinary System:
Two Kidneys
two Ureters
The Urinary Bladder
THe Urethra
What are the functions of the kidneys?
-filter blood and excrete toxins
-regulate blood volume, pressure, and osmolarity via H2O out put
-regulate acid-base and electrolytes
-secrete erythropoietin
-regulate calcium homeostasis
- clear hormones and drugs from system
detox radicals
- in cases of starvation, help support blood glucose levels
What are the major nitrogenous waste and their sources?
Ammonia - toxic and come from liver.
Urea - liver converts ammonia to urea, which is less toxic.
Uric Acid - produced by catabolism of nucleic acids and creatine phosphate.
Creatinine -produced by catabolism of nucleic acids and creatine phosphate.
What is excretion and the systems used in excretion?
Excretion is the process of separating wastes from the body fluids and eliminating them. 4 organ systems are involved: -resp. system excretes -integumentary system -digestive system -urinary system
Where is the location of the kidneys?
located against the posterior abdominal wall at the level vertebrae T12 to L13. The right kidney is a little lower because of the liver.
What is the appearance of the kidneys?
They are about the size of a bar of soap. Laterally convex and horizontally concave. They have a slit called hilum where the renal veins/arteries enter.
What are the external features of kidneys?
Renal fascia - immediately deep to the parietal peritoneum.
Perirenal fat capsule - cushions kidneys and holds in place
Fibrous capsule - protects from trauma and infection
What are the three regions of the kidneys?
Cortex, Medulla (pyramids and columns), Renal sinus.
What is the blood flow through the kidney?
abdominal aorta, renal artery, segmental artery, arcuate artery, cortical radiate artery, afferent arteriole, glomerulus, efferent arteriole, peritubular cap./vasa recta, cortical radiate vein, arcuate vein, interlobar vein, renal vein, and IVC.
What is the flow of fluid (urine) through kidneys?
Glomerulus, glomerular capsule, PCT, loop of henle, DCT, collecting duct, papillary duct, minor calyx, major calyx, renal pelvis, ureter, urinary bladder, and urethra.
Contrast the juxtamedullary nephrons and the cortical nephrons.
juxtamedullary nephrons - close to medulla, very long nephron loops that extend as far as the apex of renal pyramid.
cortical nephrons - farther from medulla, have short loops that dip just into the outer layer of medulla before turning back.
Describe the nerve supply to the kidney.
Renal plexus - nerve and ganglia wrapped around each renal artery that branch inside kidney.
—Sympathetic innervation - stimulates glomerular blood flow and rate of urine production.
responds to falling BP by simulating the kidneys to secrete renin.
—Parasympathetic — unknown functions
How do kidneys filter blood plasma?
- Glomerular filtration - creates a plasmalike filtrate of the blood.
- Tubular reabsorption - removes useful solutes from the filtrate, and returns them to blood.
- Tubular secretion - removes additional wastes from the blood and adds them to the filtrate.
- Water conservation - removes water from the urine and returns it to blood and concentrates waste.
The relevant cellular structure of the glomerulus.
Fenestrated Glomerular Capillaries - cells are honeycombed with large pores.
The Basement Membrane - have proteoglycan gel.
Filtration Slits - podocyte cells have arms that wrap around capillaries to form a barrier with slits.
Explain the forces that promote and oppose filtration.
PROMOTES-
Blood hydrostatic pressure (BHP) - 60mm Hg
OPPOSE-
Capsular hydrostatic pressure - 18 mm Hg
Blood Colloid Osmotic Pressure (COP) - 32 mm Hg
Filtration Pressure calculation
60 out - 18 in - 32in = 10 mm Hg out