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
Ureter: conveys urine into bladder by peristalsis
Renal pelvis: expanded upper portion of ureter
Major calyces: subdivisions of renal pelvis
Minor calyces: subdivisions of major calyces into which renal papillae discharge
Excretory duct system of the kidneys
•involvement of upper urinary tract from
-ascending infection from the bladder (ascending pyelonephritis)
-carried to the kidneys from the bloodstream (hematogenous pyelonephritis)
•clinical manifestations: similar with an acute infection
-localized pain and tenderness over affected kidney
-responds well to antibiotics
-cystitis and pyelonephritis are frequently associated
-some cases become chronic and lead to kidney failure
Pyelonephritis
-stones may form anywhere in the urinary tract
•predisposing factors
-high concentration of salts in urine saturates urine causing salts to precipitate and form calculi
-UTI reduce solubility of salts in urine
-UT obstruction causes urine stagnation, promotes stasis and infection, further increasing stone formation
Urinary Calculi
Blockage of urine outflow leads to progressive dilation of urinary tract proximal to obstruction, eventually causes compression atrophy of kidneys
- Manifestations:
- hydroureter: dilatation of ureter
- hydronephrosis: dilatation of pelvis and calyces
Urinary Obstruction
-inability to achieve and maintain a penile erection
erectile dysfunction
an enzyme that breaks down cyclic guanosine monophosphate (cGMP). Inhibits cGMP breakdown, which prolongs its action, thereby facilitating penile erection in men with erectile dysfunction.
phosphodiesterase
