Presentation on theme: "The Urinary System: Anatomy and Physiology"— Presentation transcript:
1 The Urinary System: Anatomy and Physiology ComponentsKidneysUretersUrinary bladderUrethra
2 Organs of the Urinary System KidneysUretersUrinary bladderUrethra
3 Function Remove nitrogenous wastes (urine) Maintain electrolyte, acid-base, and fluid balance of bloodHomeostatic organActs as blood filterRelease hormones: calcitriol & erythropoietinCalcitriol increases the level of calcium (Ca2+) in the blood by increasing the uptake of calcium from the gut into the blood, and possibly increasing the release of calcium into the blood from bone
4 The Urinary System: Anatomy and Physiology Kidneys are supplied with blood from renal arteriesLocated RetroperitoneallyLateral to T 12 – L 3 Vertebra
9 Formation of Urine Glomerular filtration initiates urine formation. Plasma is filtered by the glomerular capillaries.Most of this fluid is reabsorbed into the bloodstream.
10 Formation of Urine Urine formation summary: Glomerular filtration Reabsorption of substancesSecretion of substances
11 General Functioning of the NEPHRON bloodGeneral Functioning of the NEPHRONfiltrationtubular reabsorption and secretionurine“refreshed” blood
12 Formation of Urine Renin also controls the filtration rate. Responds to three types of stimuli:Drop in blood pressureSympathetic stimulationDecrease in chloride, potassium, and sodium ions
13 Formation of UrineRenin reacts with angiotensinogen to form angiotensin I.Angiotensin-converting enzyme converts to angiotensin IIHelps maintain sodium and water balanceVasoconstricts the efferent arterioleHelps decrease glomerular filtration rateStimulates kidneys to secrete aldosterone
14 Formation of UrineAtrial natriuretic peptide(ANP) increases sodium excretion by increasing the glomerular filtration rate.
15 Formation of Urine Urea is a result of amino acid catabolism. Uric acid is a result of the metabolism of certain organic bases in nucleic acids.Urine is about 95% water.Contains urea and uric acid
16 Formation of Urine Ureter drains into the urinary bladder Bladder empties to the outside of the body through the urethra1.5 to 2 L of urine is extracted every day.
17 Sphincter Muscles on Bladder Internal urethral sphincter:Smooth muscleInvoluntary controlMore superiorly locatedExternal Urethral sphincter:Skeletal muscleVoluntary controlPosteriorly located