human anatomy and physiology
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Human Anatomy and Physiology. The Urinary System. Functions of Kidney. Salt and water balance pH balance Excretion of nitrogenous waste (ammonia, urea, uric acid, creatinine ). Functions of the Kidney. Activation of Vitamin D - PowerPoint PPT PresentationTRANSCRIPT
Human Anatomy and Physiology
The Urinary System
Functions of Kidney
• Salt and water balance• pH balance• Excretion of nitrogenous waste
(ammonia, urea, uric acid, creatinine)
Functions of the Kidney
• Activation of Vitamin D–Vitamin D made in the skin is converted
to Vitamin D3 by the kidney–Active Vitamin D (D3) assists
homeostasis by increasing calcium absorption from the digestive tract
Unit 1 - Objective 1
Functions of Kidney• Maintain salt and water balance• Maintain pH balance• Excretion of nitrogenous waste
(ammonia, urea, uric acid)
Functions of the Kidney
• Release of Erythropoietin by the kidney–Erythropoietin stimulates new RBC
production–New RBC’s assist homeostasis by
insuring adequate Oxygen and Carbon Dioxide transport
Unit 1 - Objective 1
Functions of the Kidney
• Release of Renin by the kidney–Renin stimulates the formation of a
powerful vasoconstrictor called Angiotensin II
–Angiotensin II assists homeostasis by causing vasoconstriction which increases blood pressure
Unit 1 - Objective 1
Urinary System
Renal arteryKidney
Ureter
Urinary Bladder
Renal Vein
For sphincters, see next slide
Kidney Diagram
Capsule
Renal VeinRenal ArteryCortex
PyramidCalyx
Pelvis
Ureter
Medulla
Nephron
Nephron• Structural and functional units of
kidney- over 1 million in each kidney!• Nephron composed of
–Glomerulus – knot of capillaries–Renal tubule
Diagram of Kidney Nephron
Efferent arteriole
Afferent arteriole
Bowman’s capsule
Collecting duct
Proximal convoluted tubuleGlomerulus
Peritubular capillaries
Vasa recta
Decending limb of loop of Henle
Ascending limb of loop of Henle
Distal convoluted tubule
Unit 1 - Objective 4
Location of the Glomerulus
Afferent Arteriole
Efferent Arteriole
Bowman’s Capsule
Proximal Convoluted Tubule
Glomerulus
Afferent Arteriole
Efferent Arteriole
DCT
Macula Densa Cells
Granular Juxtaglomerular (JG) Cells
PCT
Bowman’s Capsule
nephron
Diagram of Kidney Nephron
Efferent arteriole
Afferent arteriole
Bowman’s capsule
Collecting duct
Proximal convoluted tubuleGlomerulus
Peritubular capillaries
Vasa recta
Decending limb of loop of Henle
Ascending limb of loop of Henle
Distal convoluted tubule
Unit 1 - Objective 4
Normal Urine
Abnormal components - Urine• Protein Renal disease,
severe anemia Glucose Diabetes mellitus
• Blood Renal disease• Hemoglobin Renal disease• Bacteria Infection
Urinary System
Internal urethral sphincterExternal Urethral Sphincter
Male Sphincters Female Sphincters
Functions of Nephron Structures
• Proximal Convoluted Tubule (PCT)–A thick, constantly actively segment of the
nephron that reabsorbs most of the useful substances of the filtrate: sodium (65%), water (65%), bicarbonate (90%), chloride (50%), glucose (nearly 100%!), etc.
–The primary site for secretion (elimination) of drugs, waste and hydrogen ions
Unit 1 - Objective 4
nephron
Diagram of Kidney Nephron
Efferent arteriole
Afferent arteriole
Bowman’s capsule
Collecting duct
Proximal convoluted tubuleGlomerulus
Peritubular capillaries
Vasa recta
Decending limb of loop of Henle
Ascending limb of loop of Henle
Distal convoluted tubule
Unit 1 - Objective 4
nephron
Functions of Nephron Structures
• Decending Limb of the Loop of Henle– freely permeable to water and relatively
impermeable to solutes (salt particles)– receives filtrate from the PCT, allows water
to be reabsorbed and sends “salty”filtrate on the the next segment. “Saves water and passes the salt”
Unit 1 - Objective 4
Functions of Nephron Structures
• Ascending Limb of the Loop of Henle– impermeable to water and actively
transports (reabsorbs) salt (NaCl) to the interstitial fluid of the pyramids in the medulla. “Saves salt and passes the water.”
– the passing filtrate becomes dilute and the interstitium(medulla) becomes hyperosmotic
Unit 1 - Objective 4
nephron
Functions of Nephron Structures
• Distal Convoluted Tubule (DCT)– receives dilute fluid from the ascending
limb of the Loop of Henle –Variably active portion of the nephron–When aldosterone (hormone) is present,
sodium is reabsorbed and potassium is secreted. Water and chloride follow the sodium.
Unit 1 - Objective 4
nephron
Functions of Nephron Structures
• Collecting Duct– receives fluid from the DCT–variably active portion of the Nephron–when antidiuretic hormone (ADH) is
present, this duct will become porous to water. Water from the collecting duct fluid then moves by osmosis into the “salty” (hyperosmotic) interstitium of the medulla.
–The last segment to save water for the bodyUnit 1 - Objective 4
Functions of Nephron Structures
• Peritubular Capillaries– transport reabsorbed materials from the
PCT and DCT into kidney veins and eventually back into the general circulation
–help complete the conservation process (reabsorption) that takes place in the kidney
Unit 1 - Objective 4
Aldosterone• Hormone secreted
from the adrenal cortex
• Stimulates kidneys– Retain sodium
• Retain water– Secrete potassium– Increase blood volume
and blood pressure
Antidiuretic HormoneADH
ADH- CD permeable to water
Reabsorb water
Collecting Duct
H2O
Urine
Increase blood volumeIncrease blood pressure
Dialysis Therapy
Dialysis is a process that artificially removes metabolic wastes from the blood in order to compensate for kidney (renal) failure. Kidney failure results in the rapid accumulation of nitrogen waste (urea, etc.) which leads to azotemia. Uremia and ion disturbances can also occur. This condition can cause acidosis, labored breathing, convulsions, coma and death.
Unit 1 - Objective 11
Dialysis TherapyThe most common form of dialysis is hemodialysis which uses a machine to transfer patient’s blood through a semipermeable tube that is permeable only to selected substances. The dialysis machine contains an appropriate dialysis fluid that produces a diffusion gradient. This gradient allows abnormal substances to diffuse from the patient’s blood and produce a “cleaning” effect. Unit 1 - Objective 11
Dialysis TherapySome key aspects of hemodialysis are: - blood is typically transferred from an arm artery - after dialysis, blood is typically returned to an arm vein - to prevent clotting, blood is typically heparinized - dialysis sessions occur about three times a week - each dialysis session can last four to eight hours! - long term dialysis can lead to thrombosis (fixed blood clots), infection and death of tissue around a shunt (the blood access site in the arm)
Unit 1 - Objective 11