Essentials of Human Anatomy & Physiology Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Chapter 22 The System

Functions of the Urinary System Slide 15.1a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Elimination of waste products  N  Toxins  Drugs

Functions of the Urinary System Slide 15.1b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Regulate aspects of homeostasis  Water  Electrolytes  Acid-base balance in the  B  Red blood cell production  Activation of vitamin

Organs of the Urinary system Slide 15.2 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings KUUUKUUU Figure 15.1a

Location of the Kidneys Slide 15.3 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Against the  At the level of  The kidney is slightly lower than the  Attached to ureters, renal blood vessels, and nerves at  Atop each kidney is an

Coverings of the Kidneys Slide 15.4 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Renal capsule  Surrounds each  capsule  Surrounds the kidney  Provides to the kidney  Helps keep the kidney in its correct

Regions of the Kidney Slide 15.5 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Renal cortex – region  Renal medulla – the cortex  Renal pelvis – inner collecting Figure 15.2b

Kidney Structures Slide 15.6 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Medullary – triangular regions of tissue in the medulla  columns – extensions of cortex-like material inward  Calyces – cup-shaped structures that funnel urine towards the pelvis

Blood Flow in the Kidneys Slide 15.7 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 15.2c

Nephrons Slide 15.8 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  The structural and functional units of the  Responsible for forming urine  Main structures of the nephrons  G  R

Glomerulus Slide 15.9a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  A specialized capillary  Attached to on both sides (maintains high pressure)  Large arteriole  Narrow arteriole Figure 15.3c

Glomerulus Slide 15.9b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  The sits within a glomerular capsule (the first part of the renal tubule) Figure 15.3c

Renal Tubule Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Glomerular (Bowman’s) capsule  Proximal convoluted  Loop of  Distal convoluted tubule Figure 15.3b

Types of Nephrons Slide 15.11a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Cortical nephrons  Located entirely in the  Includes most Figure 15.3a

Types of Nephrons Slide 15.11b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  nephrons  Found at the boundary of the cortex and Figure 15.3a

Peritubular Capillaries Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Arise from arteriole of the glomerulus  Normal, low pressure capillaries  Attached to a  Cling close to the renal  Reabsorb (reclaim) some substances from collecting tubes

Urine Formation Processes Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings FRSFRS Figure 15.4

Filtration Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Nonselective process  Water and solutes smaller than proteins are forced through  Blood cells cannot pass out to the capillaries  Filtrate is collected in the glomerular capsule and leaves via the

Reabsorption Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  The peritubular capillaries reabsorb several materials  S  G  A  I  Some reabsorption is passive, most is active  Most reabsorption occurs in the convoluted tubule

Materials Not Reabsorbed Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  waste products  U  C  Excess water

Secretion – Reabsorption in Reverse Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Some materials move from the peritubular capillaries into the tubules  Hydrogen and  Creatinine  Materials left in the renal tubule move toward the

Formation of Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 15.5

Characteristics of Urine Used for Medical Diagnosis Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Colored somewhat yellow due to the pigment (from the destruction of hemoglobin) and solutes  S  Slightly  Normal pH of around (varies 4.5-8)  Specific gravity of to

Ureters Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Slender tubes attaching the kidney to the  Continuous with the  Enter the aspect of the bladder  Runs behind the  Peristalsis aids gravity in transport

Urinary Bladder Slide 15.21a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Smooth, collapsible,  Temporarily Figure 15.6

Urinary Bladder Slide 15.21b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Trigone – three openings  from the ureters  One to the Figure 15.6

Urinary Bladder Wall Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Three layers of smooth muscle ( )  made of transitional epithelium  Walls are thick and folded in an empty  Bladder can expand significantly without increasing

Urethra Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Thin-walled tube that carries urine from the bladder to the outside of the body by  Release of urine is controlled by two  Internal urethral sphincter ( )  External urethral sphincter (voluntary)

Urethra Gender Differences Slide 15.24a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Length  Females – cm (1 inch)  Males – cm (8 inches)  Location  Females – along of the vagina  Males – through the and penis

Urethra Gender Differences Slide 15.24b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Function  Females – only carries  Males – carries urine and is a passageway for

Micturition (Voiding) Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Both muscles must open to allow voiding  The internal urethral sphincter is relaxed after stretching of the  Activation is from an impulse sent to the and then back via the pelvic splanchnic nerves  The external urethral sphincter must be relaxed

Maintaining Water Balance Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Normal amount of water in the human body  Young adult females –  Young adult males –  Babies –  Old age –  is necessary for many body functions and levels must be maintained

Distribution of Body Fluid Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Intracellular (inside cells)  Extracellular fluid (outside cells)  I  B Figure 15.7

The Link Between Water and Salt Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Changes in balance causes water to move from one compartment to another  Alters volume and blood pressure  Can impair the activity of cells

Maintaining Water Balance Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Water intake must water output  Sources for water intake  Ingested foods and  Water produced from metabolic processes  Sources for water output  out of the lungs  Lost in  Leaves the body in the feces  production

Maintaining Water Balance Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  urine is produced if water intake is excessive  Less urine (concentrated) is produced if large amounts of  Proper concentrations of various must be present

Regulation of Water and Electrolyte Reabsorption Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Regulation is primarily by  Antidiuretic hormone ( ) prevents excessive water loss in urine  Aldosterone regulates sodium ion content of extracellular  Triggered by the rennin mechanism  Cells in the and hypothalamus are active monitors

Maintaining Water/Electrolyte Balance Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 15.9

Maintaining Acid-Base Balance in Blood Slide 15.33a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Blood pH must remain between 7.35 and to maintain homeostasis  A – pH above 7.45  A – pH below 7.35  Most originate as byproducts of cellular metabolism

Maintaining Acid-Base Balance in Blood Slide 15.33b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Most acid-base balance is maintained by the  Other acid-base controlling systems  B  R

Blood Buffers Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Molecules react to prevent dramatic changes in hydrogen ion (H + ) concentrations  Bind to H + when pH  Release H + when pH  Three major chemical buffer systems  buffer system

The Bicarbonate Buffer System Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Mixture of carbonic acid (H 2 CO 3 ) and sodium (NaHCO 3 )  Bicarbonate ions (HCO 3 – ) react with strong acids to change them to weak  Carbonic acid dissociates in the presence of a to form a weak base and water

Respiratory System Controls of Acid-Base Balance Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Carbon dioxide in the blood is converted to bicarbonate ion and transported in the  Increases in hydrogen ion concentration produces more  Excess hydrogen ion can be blown off with the release of carbon dioxide from the  Respiratory rate can depending on changing blood pH

Renal Mechanisms of Acid-Base Balance Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  bicarbonate ions if needed  or generate new bicarbonate ions if needed  Urine pH varies from

Developmental Aspects of the Urinary System Slide 15.38a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Functional kidneys are developed by the  Urinary system of a newborn  Bladder is  cannot be concentrated

Developmental Aspects of the Urinary System Slide 15.38b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Control of the voluntary urethral sphincter does not start until age months  Urinary infections are the only common problems before

Aging and the Urinary System Slide Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  There is a progressive decline in urinary function  The bladder with aging  Urinary retention is common in