1 / 46

CHAPTER 15

CHAPTER 15. URINARY SYSTEM. Warm-up. What is the primary function of the kidneys? What hormone helps to control this? Name another organ or structure of the urinary system (other than the kidneys). Name a component of urine. VIDEOS.

weylin
Download Presentation

CHAPTER 15

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. CHAPTER 15 URINARY SYSTEM

  2. Warm-up • What is the primary function of the kidneys? • What hormone helps to control this? • Name another organ or structure of the urinary system (other than the kidneys). • Name a component of urine.

  3. VIDEOS • http://player.discoveryeducation.com/index.cfm?guidAssetId=750436AB-F351-4CE4-89FD-EF903A32826C&blnFromSearch=1&productcode=US • http://www.youtube.com/watch?v=qxb2_d9ilEw

  4. Functions of the Urinary System • Elimination of waste products • Nitrogenous wastes • Toxins • Drugs

  5. Functions of the Urinary System 2.Regulate aspects of homeostasis • Water balance • Electrolytes • Acid-base balance in the blood • Blood pressure (renin) • Red blood cell production (erythropoietin) • Activation of vitamin D • Manufacture urine

  6. Organs of the Urinary system • Kidneys • Ureters • Urinary bladder • Urethra • Storage reservoirs for urine • Transport urine

  7. Location of the Kidneys • Against the dorsal body wall • At the level of T12 to L3 • The right kidney is slightly lower than the left • HILUS – medial indentation • ureters, renal blood vessels, and nerves enter/exit at renal hilus • Atop each kidney is an adrenal gland

  8. Coverings of Kidneys 1. Renal capsule • Surrounds each kidney 2. Adipose capsule • Surrounds the kidney • Provides protection to the kidney • Helps keep the kidney in its correct location

  9. Regions of Kidneys • Renal cortex – outer region • Renal medulla inside the cortex • Medullary pyramids • apex • Renal columns-separate pyramids

  10. Kidney Structures • Renal Pelvis– medial to hilus; continuous w/ ureter exiting hilus • Calyces– extensions of renal pelvis; cup-shaped structures that collect and funnel urine towards the renal pelvis to ureter to bladder

  11. Blood Flow in Kidneys NEED TO KNOW THIS !! PAGE 482

  12. NEPHRONS • The structural and functional units of the kidneys • Responsible for forming urine • 2 Main structures of the nephron: • Glomerulus – a knot of capillaries • Renal tubule – • Closed end is enlarged & cup shaped • Surrounds the glomerulus (Bowman’s capsule)

  13. GLOMERULUS • A specialized capillary bed • Attached to arterioles on both sides (maintains high pressure) • Large afferent arteriole • Narrow efferent arteriole

  14. GLOMERULUS • The glomerulus sits within a glomerular capsule: • Bowman’s capsule (the first part of the renal tubule)

  15. RENAL TUBULE INCLUDE: • Glomerular (Bowman’s) capsule • Proximal convoluted tubule • Loop of Henle • Distal convoluted tubule

  16. TYPES OF NEPHRONS • Cortical nephrons • Located entirely in the cortex • Includes most nephrons

  17. TYPES OF NEPHRONS 2. Juxtamedullarynephrons • Found at the boundary of the cortex and medulla

  18. Video – Nephron function • http://www.youtube.com/watch?v=8T1xrFF39lA&feature=relmfu

  19. Warm-up (5/16) • Into what structure do the nephrons empty their filtrate? • After blood passes through efferent arteriole, where does it go? • What are the 4 parts of the renal tubule? • What 2 hormones regulate salt and/or water balance in the blood?

  20. COLLECTING DUCTS (not in notes) • Receive urine from MANY nephrons • Run downward via medullary pyramids • Deliver final urine product into calyces & renal pelvis

  21. CAPILLARY BEDS (not in notes) • Each nephron has 2 capillary beds • Glomerulus • fed & drained by arterioles • Afferent = “feeder” vessel • Efferent = receives blood from glomerulus • Peritubular capillary bed • Next slide

  22. Peritubular capillary bed • Arise from efferent arteriole of the glomerulus • Normal, low pressure capillaries • Attached to a venule • Cling close to the renal tubule • Reabsorb (reclaim) some substances from collecting tubes • Drain into interlobular veins leaving cortex

  23. Urine Formation Processes • Filtration • Reabsorption • Secretion

  24. Video – filtration, reabsorption, secretion • http://www.youtube.com/watch?v=glu0dzK4dbU

  25. FILTRATION • Nonselective passive process • Filtrate is blood plasma w/o blood proteins • Water and solutes smaller than proteins are forced through capillary walls • Blood cells and proteins cannot pass out to the capillaries • Filtrate is collected in the glomerular capsule and leaves via the renal tubule

  26. REABSORPTION • The peritubular capillaries reabsorb several materials back into the blood stream. • Some water, glucose, amino acids, and ions are reabsorbed. • Some reabsorption is passively transported (water), but most is active. • Most reabsorption occurs in the proximal convoluted tubule & begins as soon as filtrate enters

  27. Materials NOT Reabsorbed • Nitrogenous waste products • Urea • Uric acid • Creatinine • Excess water

  28. SECRETION • Reabsorption in reverse • Some materials (ions (H+, K+) & creatinine) move from the blood of peritubular capillaries into the renal tubules. • Materials left in the renal tubule move toward the ureter • Important for substances not already in filtrate (drugs) or for controlling pH

  29. Characteristics of Urine • Colored somewhat yellow due to concentration of UROCHROME • Sterile • pH is slightly acidic • pH around 6 – can change based on metabolism & food consumed

  30. URETERS • Slender tubes attaching the kidney to the bladder • Continuous with the renal pelvis • Enter the superior aspect of the bladder • Runs _______ the ______ • Peristalsisaids gravity in urine transport

  31. URETERS • Renal calculi – kidney stones; solutes (salts) form crystals

  32. BLADDER • Smooth, collapsible, muscular sac • Temporarily stores urine • Trigone – three openings • Two from the ureters • One to the urethrea

  33. BLADDER • Bladder Wall • Three layers of smooth muscle (detrusor muscle) • Mucosa made of transitional epithelium • Walls are thick and folded in an empty bladder • Bladder can expand significantly without increasing internal pressure

  34. URETHRA • Thin-walled tube that carries urine from the bladder to the outside of the body by peristalsis • Release of urine is controlled by two sphincters • Internal urethral sphincter (involuntary) • External urethral sphincter (voluntary)

  35. URETHRA • Length • Females – 3–4 cm (1 inch) • Males – 20 cm (8 inches) • Function • Females – only carries urine • Males – carries urine and is a passageway for sperm cells

  36. Both sphincter muscles must open to allow voiding The internal urethral sphincter is relaxed after stretching of the bladder Activation is from an impulse sent to the spinal cord and then back The external urethral sphincter must be voluntarily relaxed MICTRITION - voiding

  37. INCONTINENCE • Unable to voluntarily control the E.S. • Normal in children 2 and younger • Occur in children older who sleep soundly

  38. Maintaining Water Balance • Normal amount of water in the human body • Young adult females – 50% • Young adult males – 60% • Babies – 75% • Old age – 45% • Water is necessary for many body functions and levels must be maintained

  39. Distribution of Body Fluid • Intracellular fluid (inside cells) • Extracellular fluid (outside cells) • Interstitial fluid • Blood plasma

  40. Maintaining Water Balance • Water intake must equal water output • Sources for water intake • Ingested foods and fluids • Water produced from metabolic processes • Sources for water output • Vaporization out of the lungs • Lost in perspiration • Leaves the body in the feces • Urine production

  41. Regulation of Water and Electrolyte Reabsorption • Regulation is primarily by hormones • Antidiuretic hormone (ADH) prevents excessive water loss in urine • Aldosterone regulates sodium ion content of extracellular fluid • Cells in the kidneys and hypothalamus are active monitors

  42. Maintaining Acid-Base Balance in Blood • Blood pH must remain between 7.35 and 7.45 to maintain homeostasis • Alkalosis – pH above 7.45 • Acidosis – pH below 7.35 • Most ions originate as byproducts of cellular metabolism 6

  43. Maintaining Acid-Base Balance in Blood • Most acid-base balance is maintained by the kidneys • Other acid-base controlling systems • Blood buffers • Respiration

  44. Developmental Aspects of the Urinary System • Functional kidneys are developed by the third month • Urinary system of a newborn • Bladder is small • Urine cannot be concentrated 4

  45. Developmental Aspects of the Urinary System • Control of the voluntary urethral sphincter does not start until age 18 months • Urinary infections are the only common problems before old age

  46. Aging and the Urinary System • There is a progressive decline in urinary function • The bladder shrinks with aging • Urinary retention is common in males

More Related