urinary system

• The odor of urine can be affected by diabetes mellitus, which gives it a sweet, "fruity" odor of acetone.
• Pyuria is the presence of pus in the urine.
• Cloudiness or blood in urine could suggest a urinary tract infection, trauma, or stones.
• Hematuria is the presence of blood in urine due to a urinary tract infection, trauma, or kidney stones.
• The appearance of urine can range from clear to deep amber-yellow due to urochrome pigment from the breakdown of hemoglobin from expired erythrocytes.
• Pink, green, brown, black, and other colors in urine can be due to certain foods, vitamins, drugs, and metabolic diseases.
• Angiotensin II works in several ways to restore fluid volume and blood pressure.
• Na + – K + pumps pump Na + out into the extracellular fluid, which is picked up by peritubular capillaries and returned to the bloodstream.
• Tubular reabsorption removes additional wastes from the blood, adds them to the filtrate.
• The Proximal Convoluted Tubule (PCT) reabsorbs about 65% of glomerular filtrate, removes some substances from the blood, and secretes them into the tubular fluid for disposal in urine.
• Sodium is prevented from accumulating in the epithelial cells by Na + – K + pumps in the basal surface of the epithelium.
• Two types of transport proteins in the apical cell surface are responsible for sodium uptake: symports that simultaneously bind Na + and another solute such as glucose, amino acids, or lactate, and Na + – H + antiport that pulls Na + into the cell while pumping out H + into tubular fluid.
• Na + – K + pumps are ATP consuming active transport pumps.
• Tubular reabsorption involves the reabsorption of sodium by transcellular and paracellular routes.
• The Proximal Convoluted Tubule has prominent microvilli and great length, and abundant mitochondria provide ATP for active transport.
• Tubular secretion removes useful solutes from the filtrate, returns them to the blood.
• In the lungs, angiotensin-converting enzyme (ACE) converts angiotensin I to angiotensin II, the active hormone.
• Blood protein, into angiotensin I.
• The Renin – Angiotensin – Aldosterone Mechanism involves Angiotensin II, a potent vasoconstrictor that raises blood pressure throughout the body, constricts efferent arteriole, lowers blood pressure in peritubular capillaries, and stimulates the sense of thirst and encourages water intake.
• The Proximal Convoluted Tubule has two routes of reabsorption: transcellular route and paracellular route.
• The basic stages of urine formation involve the conversion of glomerular filtrate to urine, which involves the removal and addition of chemicals by tubular reabsorption and secretion.
• Efferent signals relax internal urethral sphincter.
• Urine is retained in bladder.
• Renal insufficiency is a state in which the kidneys cannot maintain homeostasis due to extensive destruction of their nephrons.
• When 75% of nephrons are lost and urine output of 30 mL/ hr is insufficient (normal 50 to 60 mL/ hr) to maintain homeostasis, causes azotemia, acidosis, and uremia develop, also anemia.
• Internal urethral sphincter (involuntary) is located in internal urethral sphincter.
• Hemodialysis is a procedure for artificially clearing wastes from the blood.
• Renal insufficiency can survive with one-third of one kidney.
• Full urinary bladder is located in para-sympathetic ganglion in bladder wall.
• Urine is voided.
• If it is timely to urinate, pons returns signals to spinal interneurons that excite detrusor and relax internal urethral sphincter.
• If it is timely to urinate, signals from pons cease and external urethral sphincter relaxes.
• For voluntary control, micturition center in pons receives signals from stretch receptors.
• Motor fibers to detrusor muscle are located in detrusor muscle.
• Wastes leave bloodstream and enter the dialysis fluid as blood flows through a semipermeable cellophane tube; also removes excess body water.
• Causes of nephron destruction include hypertension, chronic kidney infections, trauma, prolonged ischemia and hypoxia, poisoning by heavy metals or solvents, blockage of renal tubules in transfusion reaction, atherosclerosis, or glomerulonephritis.
• Efferent signals excite detrusor muscle.
• Sacral segments of spinal cord contain motor fiber and sensory fiber.
• Somatic motor fiber of pudendal nerve is located in external urethral sphincter (voluntary).
• The internal urethral sphincter and detrusor muscle are part of the skeletal muscle of the pelvic floor in the male urethra.