Urinary System I Flashcards
(40 cards)
Functions of the urinary system
- removing of waste products from the bloodstream
- storage and excretion of urine
- blood volume regulation
- regulation of erythrocyte production
- maintains constant plasma pH by regulating acid-base balance (excrete Hydrogen ions or bicarbonate)
The urinary bladder is an expandable muscular sac that can hold () amount of urine
1L (400 - 600 mL)
Hormone produced by the kidney in cases of hypoxia
stimulates production of red blood cells in the red bone marrow
Erythropoietin (EPO)
Kidney Location
Retroperitoneal
at the level of T12 to L3
Blood supply to the kidneys
25% of total cardiac output
Ultrafiltrate of blood produced by the kidneys
Urine
Which kidney is lower?
Right kidney
Due to the liver above
Released by the juxtaglomerular cells (JG cells) in response to the macula densa sensing change in blood pressure and blood volume
Renin
catalyzes the conversion of angiotensinogen to angiotensin I
A potent vasoconstrictor that also promotes the release of aldosterone (reabsorbs water and sodium)
Angiotensin II
Angiotensin I is also a weaker vasoconstrictor
Angiotensin I is converted to Angiotensin II by the angiotensin converting enzyme (ACE) in the lungs
Concave medial border or deep fissure of the kidney where the renal blood and lymph vessels, ureter, and nerve enter
Renal Hilum
Internal space in the kidney that houses the blood vessels, lymphatic vessels, nerves, renal pelvis, renal calyces, and fat
Renal sinus
Surrounding tissues of the kidney
(From DEEP to SUPERFICIAL)
1) fibrous capsule - renal capsule
2) perinephric fat - adipose capsule
3) renal fascia
4) paranephric fat
Fibrous renal capsule tissue composition
Dense irregular CT
Functions to cushion and insulate the kidney
Perinephric fat or Perirenal fat
Anchors kidney to the posterior wall and the peritoneum
Renal fascia
Tissue composition - dense irregular connective tissue
2 distinct layers of the fibrous renal capsule:
1) outer layer of fibroblasts and collagen fibers
2) inner layer of myofibroblasts
Cells that resist volume and pressure variation that accompany variation in kidney function
myofibroblasts
Percentage of blood passing through (1) renal cortex and (2) renal medulla
(1) 90% to 95%
(2) 5% to 10%
Characterized by renal corpuscles and their associated tubules - convoluted tubules, straight tubules of the nephron, connecting tubules, collecting ducts and the vascular supply
Renal Cortex
Tissue between the base of the pyrmid and surface of the kidney
show light and dark striations where in the light lines are called medullary rays
Cortical lobule or Renal lobule
Vertical striations on the cortex that emanate from the medulla
approximately 400 to 500 striations
Medullary ray
aggregration of straight tubules and collecting ducts
Regions between medullary rays containing renal corpuscle and convoluted tubules (proximal and distal)
Cortical Labyrinth
Medullary pyramid + associated cortical tissue at its base and sides
Renal Lobe
each kidney has 8 - 18 lobes
Characterized by straight tubule, collecting ducts, and a special capillary network - vasa recta
Medulla
innermost layer consisting of renal pyramids (8-12)
