Urinary/Renal System Flashcards
What organs does the renal system include? (4)
Kidneys, ureters, bladder, urethra
What is the purpose of the urinary system? (4)
- Eliminate waste from the body
- Regulate blood volume/pressure
- Control levels of electrolytes/metabolites
- Regulate blood pH
What are the kidneys?
Two bean-shaped retroperitoneal organs in the superior dorsal abdominal cavity (partly protected by lower ribs)
Filters blood and makes urine
What is the ureter?
Tube that carries urine from each kidney to urinary bladder
Located in the inferior ventral pelvic cavity
What is the urinary bladder?
An expandable sac holding urine
What is the urethra?
Tube that transports urine from bladder to outside of body
What is the renal hilum?
Indented area of the kidney
What is the renal hilum an entrance for? (5)
Renal artery and vein, ureter, nerves, lymphatics
What are the functions of the kidney? (7)
(A WET BED)
Control Acid-base balance
Control Water balance
Maintain Electrolyte balance
Remove Toxins and waste from body
Control Blood pressure
Produce Erythropoietin
Activate vitamin D
What is the purpose of erythropoietin (EPO)? (2)
A hormone that acts on RBCs to protect against destruction
Stimulates stem cells to increase RBC production
What produces EPO hormone?
Produced by specialized cells called interstitial cells in the kidney
What is the renal cortex?
Outer layer of kidney
What is the renal medulla?
Inner region of kidney
What are the renal pyramids?
Secreting apparatus and tubules
Where are the renal nephrons?
Mostly in the kidney cortex
Has short/thin segments in loop of Henle
What is the renal pelvis?
Receives urine from collecting tubes of nephrons
What are the layers of renal connective tissue? (3)
Renal fascia - anchors to other structures (most outer)
Adipose capsule - protects/anchors (middle)
Renal capsule - continuous with ureter (inner)
What are nephrons?
Minute/microscopic structural/functional unit of the kidney
About 1m of these filtering units per kidney
What are the two kinds of nephrons? - mostly based on location of glomerulus
- Cortical: about 85% of nephrons and loop of Henle is shorter in medulla
- Juxtamedullary: about 15% and loop of Henle is loner in the medulla
What is the glomerulus?
Mass of fenestrated capillaries fed by the afferent arteriole and drains into efferent arteriole
What do the glomerulus capillaries consist of? (3)
- Glomerular endothelial cells line it
- Basement membrane (barrier) lies below endothelium (external/internal lamina)
- Epithelium attaches to Podocytes of the visceral epithelium of Bowman capsule
What is the glomerular (Bowman’s) capsule?
Where filtrate is collected within its lumen
What are the layers of the Bowman’s capsule?
Parietal
Visceral (covered by Podocytes)
What are podocytes and nephrin of the Bowman’s capsule?
Podocytes: feet-like projections that increase surface area for filtration
Nephrin: proteins linking podocytes together and allows small molecules to pass