Chapter 15- Urinary & Male Reproductive Systems Flashcards
- stores urine
- discharges urine into urethra during voiding
- anatomic configuration of bladder and ureters normally prevents reflux of urine into ureters
Bladder
Conveys urine from the bladder for excretion
Urethra
Three basic functions:
-excrete waste products of food metabolism
•(CO2 and H2O: end products of carbohydrates and fat metabolism)
•urea and other acids
-regulate mineral and H2O balance
-produces erythropoietin and renin: specialized cells in the kidneys
Functions of the kidneys
Regulates RBC production in marrow
Erythropoietin
Helps regulate blood pressure - (cell produced by the kidneys)
Renin
- basic structural and functions unit of the kidney
- about 1 million nephrons in each kidney
- consists of glomerulus and renal tubule
Nephron
-tuft of capillaries supplied by an afferent glomerular arteriole that recombine into an efferent glomerular arteriole
-material is filtered by a 3-layered glomerular filter
•inner: fenestrated capillary endothelium
•middle: basement membrane
•outer: capillary endothelial cells
Glomerulus
Reabsorbs most of filtrate; secretes unwanted components into tubular fluid; regulates H2O balance
- proximal end: Bowman’s capsule
- distal end: empties into collecting tubules
Renal tubules
- free flow of blood through the glomerular capillaries
- normally functioning glomerular filter that restricts passage of blood cells and protein
- normal outflow of urine
Requirements for normal renal function
Released in response to decreased blood volume, low blood pressure, and low sodium
Renin
Angiotensin 1 — angiotensin 2 by angiotensin converting enzyme (ACE) as blood flows through the lungs
Renal regulation of blood pressure
-powerful vasoconstrictor: raises blood pressure by causing peripheral arterioles to constrict
-stimulates aldosterone secretion from adrenal cortex:
increases reabsorption of NaCl and H2O by kidneys
-Net effect: higher blood pressure, increased fluid in vascular system
Angiotensin 2
Failure of one or both kidneys to develop
- bilateral: rare, associated with other congenital anomalies, incompatible with life
- unilateral: common, asymptomatic; other kidney enlarges to compensate
Renal agenesis
- complete duplication: formation of extra ureter and renal pelvis
- incomplete duplication: only upper part of excretory system is duplicated
Duplications of urinary tract
One or both kidneys, associated with fusion of kidneys; horseshoe kidney; fusion of upper pole
Malposition of kidneys
-inflammation of the glomeruli caused by antigen-antibody reaction within the glomeruli
Glomerulonephritis
- usually follows a beta-steptococcal infection
- circulating antigen and antibody complexes are filtered by glomeruli and incite inflammation
- leukocytes release lysosomal enzymes to cause injury to the glomeruli
Immune-complex glomerulonephritis
Autoantibodies attack glomerular basement membrane
Anti-glomerular basement membrane (anti-GBM) glomerulonephritis
Marked loss of protein in the urine -urinary excretion of protein > protein production -protein level in blood falls -causes edema due to low plasma osmotic pressure Clinical Manifestations: -marked leg edema -ascites Children: complete recovery Adults: severe progressive renal disease May result from: -glomerulonephritis -diabetes -systemic lupus erythematosus
Nephrotic syndrome
-complication of severe hypertension
-renal arterioles undergo thickening from carrying blood at a much higher pressure than normal
-glomeruli and tubules undergo secondary degenerative changes causing narrowing of lumen and reduction in blood flow
•reduced glomerular filtration
•kidneys shrink
•may die of renal insufficiency
Arteriolar nephrosclerosis
-complication of long standing diabetes
-nodular and diffuse thickening of glomerular basement membranes (glomerulosclerosis), usually with coexisting nephrosclerosis
•manifestations:
-progressive impairment of renal function
-protein loss may lead to nephrotic syndrome
-no specific treatment can arrest progression of disease
-progressive impairment of renal function may lead to renal failure
Diabetic nephropathy
-elevated blood uric acid levels lead to increased uric acid in tubular filtrate
-urate may precipitate in Henle’s loops and collecting tubules
-tubular obstruction causes damage
•manifestations:
-impaired renal function
-may lead to renal failure
-common in poorly-controlled gout
Gout nephropathy
- very common, may be acute or chronic
- most infections are caused by gram-negative bacteria
- organisms contaminate perianal and genital areas and ascend urethra
Urinary tract infections (UTI)
-affects only the bladder
-more common in women than men
-common in older men- enlarged prostate interferes with complete bladder emptying
•clinical manifestations:
-burning pain on urination
-desire to urinate frequently
-urine contains bacteria and leukocytes
-responds well to antibiotics
-may spread upwards into renal pelvis and kidneys
Cystitis
