The Urinary System Urinary or Excretory System - PowerPoint Presentation

Slide1

The Urinary System

Slide2

Urinary or Excretory System

Functions:

Removes certain wastes and excess water from the body

Maintains

the acid-base balance of the body

Slide3

Parts include

two

kidneys, 2 ureters, the bladder, and the urethra

Slide4

Kidneys

Two bean-shaped organs

Located

on either side of the vertebral column behind the upper part of the abdominal cavity and separated from this cavity by the peritoneum

Protected

by the ribs and a heavy cushion of fat

Connective

tissue helps hold the kidneys in position

Each

kidney is enclosed in a mass of fatty tissue called the adipose capsule

Cover

externally by a tough, fibrous tissue called the renal fascia or fibrous capsule

Slide5

Kidney Sections:

Cortex

(

1) Outer section of the kidney

(

2) Contains most of the nephrons that aid in the production of urine

Medulla

(

1) Inner section of the kidney

(2) Contains

most of the collecting tubules that carry the urine from the nephrons on through the kidney

Slide6

Hilum of Kidney

:

Notched or indented area on each kidney

Area where ureter, nerves, blood vessels, and lymph vessels enter and leave the kidney

Slide7

Nephrons

Microscopic

filtering units located in the kidney

Over one million per kidney

Each

nephron consists of a glomerulus, Bowman’s capsule, a proximal and distal convoluted tubule, and a collecting duct (tubule)

Slide8

Renal arteries carry blood to the kidney

Branches

of the renal artery pass through the medulla to the cortex where the blood enters the first part of the nephron, the

glomerulus

Slide9

Glomerulus of the Nephron:

(1) Cluster of capillaries

(

2) As blood passes through water, mineral salts, sugar, metabolic products and other substances are filtered out of the blood

(3) Red blood cells and proteins are not filtered out

Slide10

Glomerulus continued:

Filtered blood leaves the glomerulus and eventually is carried to the renal vein, which carries it away from the kidney

Substances filtered out in the glomerulus enter the next section of the nephron, Bowman’s capsule

Slide11

Bowman’s Capsule

:

(1) C-shaped structure that surrounds the glomerulus

(2) It is the start of the convoluted tubule

(

3) Picks up the materials filtered from the blood in the glomerulus

(

4)Passes the materials into the convoluted tubule

Slide12

As these materials pass through the various sections of the tubule, substances needed by the body are reabsorbed and returned to blood capillaries

At

the end, most of the water, sugar, vitamins, and mineral salts have been reabsorbed

Excess sugar and salts, some water, and wastes, including urea, uric acid, and creatinine, remain in the tubules and become known as the concentrated liquid called urine

Convoluted Tubules:

Slide13

Collecting Ducts:

Urine now enters collecting ducts or tubules located in the medulla

Collecting

tubules empty into a funnel-shaped structure, the renal basin or pelvis, which is the first section of the ureter

Slide14

Ureters

Two muscular tubes about 10 to 12 inches long

One

extends from the renal pelvis of each kidney to bladderPeristalsis, a rhythmic wavelike motion of the involuntary muscle, moves the urine through the ureter from the kidney to the bladder

Slide15

Bladder

Hollow muscular sac

Lies

behind the symphysis pubis at the midline of the pelvic

cavity

Has

lining of mucous membrane

Arranged

in a series of folds called

rugae

Rugae

disappear as muscles of the bladder allow it to expand and fill with urine

Three

layers of visceral (smooth) muscle form the walls

Slide16

Bladder Functions:

Receives the urine from the ureters

Stores

the urine until it is eliminated from the bodyUrge

to void (urinate or

micturate

) occurs when the bladder contains about 250 cc (1 cup) of urine, but bladder can hold

much

more urine

Slide17

Circular Sphincter Muscles:

Control the bladder opening to prevent emptying

When

bladder is full, receptors in the bladder will send out a signal for a reflex that will open the muscleReflex action cannot be controlled by infants, but as children get older, they learn to control this reflex

Slide18

Urethra:

Tube that carries the urine from bladder to the outside

External

opening is called the urinary meatus

Different

in females than males

Slide19

Urethra cont.

Females

Tube

about 1 ½ inches (3.75cm) longOpens in front of the vaginaCarries

only urine to the outside

Slide20

Urethra

cont

:

MalesS-shaped tube about 8 inches (20 cm) longPasses

through the prostate gland and out through the penis

Carries

both urine from the urinary system and semen from the reproductive system

Slide21

Urine

1. Liquid

waste product produced by the urinary system

2. About 95 percent water3. Waste products dissolved in this water are urea, uric acid,

creatinine

, mineral salts, and various pigments

4. Excess useful products, such as sugar, can also be found in urine but their presence usually indicates disease

5. About 1,500 to 2,000 cc (1½ to 2 quarts) of urine are produced daily from the approximately 150 quarts of liquid that is filtered through the kidneys

 

Slide22

Conditions affecting urination

1. Polyuria: excessive urination

2. Oliguria: below normal amounts of urination

3. Anuria: absence of urination4. Hematuria: blood in the urine5. Pyuria: pus in the urine6.

Nocturia

: urination at night

7. Dysuria: painful urination

8. Retention: inability to empty the bladder

9. Incontinence: involuntary urination

Slide23

http://www.youtube.com/watch?v=aQZaNXNroVY