The Urinary System Flashcards
Name the basic urinary system parts and functions
a. Kidneys are major excretory organs
b. Urinary bladder is the temporary storage reservoir for urine
c. Ureters transport urine from the kidneys to the bladder
d. Urethra transports urine out of the body
What is the function of the kidneys?
a. Removal of toxins, metabolic wastes, and excess ions from the blood
b. Regulation of blood volume, chemical composition, and pH (through buffer system)
c. Endocrine functions
i. Renin: regulation of blood pressure and kidney function
ii. Erythropoietin: regulation of RBC production
Describe the general parts of the kidney
a. Retroperitoneal, in the superior lumbar region
b. Right kidney is lower than the left
c. Ureters, renal blood vessels, lymphatics, and nerves enter and exit at the hilum
Name the layers of supportive tissue
a. Renal fascia- The anchoring outer layer of dense fibrous connective tissue
b. Perirenal fat capsule- A fatty cushion
c. Fibrous capsule- Prevents spread of infection to kidney
Describe the internal anatomy of the kidney
a. Renal cortex- A superficial region with over 1 million renal corpuscles
b. Renal medulla- Triangular renal pyramids separated by renal columns
c. Papilla- Tip of pyramid; releases urine into minor calyx
What are the major calyces?
a. The branching channels of the renal pelvis that
b. Collect urine from minor calyces
c. Empty urine into the ureter
Describe blood and nerve supply to the kidneys
a. Renal arteries deliver 25% of cardiac output to the kidneys each minute
b. Arterial flow into and venous flow out of the kidneys follow similar paths
What are nephrons?
a. Structural and functional units that form urine
b. ~1.5 million per kidney
What are the two main parts of the nephrons?
a. Glomerulus: a tuft of capillaries
b. Renal tubule: begins as cup-shaped glomerular (Bowman’s) capsule surrounding the glomerulus
Describe the arterial pathway into the kidney
a. Renal artery
b. Segmental artery
c. Interlobar artery
d. Arcuate artery
e. Cortical radiate artery into the nephron
f. Afferent arteriole
g. Glomerulus capillaries
h. Efferent arteriole
Describe the vein pathway out of the kidney
a. Peritubular capillaries and vasa recta
b. Cortical radiate vein
c. Arcuate vein
d. Interlobar vein
e. Renal vein
f. Inferior vena cava
Describe renal corpuscle of nephron
a. Renal corpuscle = Glomerulus + its glomerular capsule
b. Afferent arteriole → glomerulus → efferent arteriole
c. Specialized for filtration
d. Blood pressure is high because afferent arterioles are smaller than efferent arterioles*
Describe the PCT of the renal tubule
a. Proximal convoluted tubule (PCT)
b. Found only in the cortex
c. Functions in reabsorption and secretion
Describe the loop of Henle of the renal tubule
a. Loop of Henle with descending and ascending limbs
i. Descending limb
ii. Simple squamous epithelium
b. Freely permeable to water
c. Ascending limb
i. Cuboidal and columnar cells
ii. Impermeable to water
Describe the DCT of the kidney
a. Distal convoluted tubule (DCT)
b. Function more in secretion than reabsorption
c. Confined to the cortex
Describe the collecting ducts of the kidney
a. Receive filtrate from many nephrons
b. Fuse together to deliver urine through papillae into minor calyces
Describe the peritubular capillaries
a. Surround PCT and DCT of cortical nephrons
b. Low-pressure, porous capillaries adapted for absorption
c. Arise from efferent arterioles
d. Empty into venules, then into the cortical radiate vein