Essential Questions

What are the functions of the urinary system?

What are some disorders of the urinary system?

How are disorders of the urinary system treated?

How do you relate the body’s hormone control to

the urinary system?

4.02 Understand the functions and disorders of the urinary system 2

Functions:

Filtration

Excretion

Formation of urine

Fluid and electrolyte balance

Elimination of urine

4.02 Understand the functions and disorders of the urinary system 3

Filtration: The filtering of the blood to

create a filtrate. • This is the first step in urine formation

• Filtrate contains various substances

• These substances are either reabsorbed back

into the bloodstream, or excreted from the body

as urine.

4.02 Understand the functions and disorders of the urinary

system 4

Excretion

What is excretion? Removal of waste matter from

the body

Why does the body have excretory functions?

What is the composition of wastes excreted by the

urinary system?

• Nitrogenous wastes

• Salt

• Water

4.02 Understand the functions and disorders of the urinary system 5

Filtration

Reabsorption

Secretion

4.02 Understand the functions and disorders of the urinary system 6

•To form urine the

nephron must perform

three processes:

•Glomerular

filtration

•Tubular

reabsorption

•Tubular secretion

4.02 Understand the functions and disorders of the urinary system

• Blood from renal

artery enters

glomerulus

• High pressure in

glomerulus forces

fluid into Bowman’s

capsule, where it is

filtered

7

BOWMAN’S CAPSULE • A tuft of capillaries

Bowman’s capsule filters out 125cc of fluid/min.

…how many cc’s per hour is this?

As the filtrate continues through the tubules,

99% of water is reabsorbed back into the blood

stream

4.02 Understand the functions and disorders of the urinary system 8

What substances are reabsorbed? • Water

• Glucose

• Amino acids

• Vitamins

• Bicarbonate ions

• Sodium

• Potassium

If blood levels of certain substances are high, the substances will not be reabsorbed.

Threshold: the term used to describe the limit of reabsorption

4.02 Understand the functions and disorders of the urinary system 9

4.02 Understand the functions and disorders of the urinary system

•What is secretion? •The transport of substances

from the blood into the urine in

the distal and collecting

tubules.

•It is the opposite of

absorption.

10

What substances are secreted into the

collecting tubules? • Some medications

• Ammonia

• Creatinine

• Hydrogen ions

• potassium

4.02 Understand the functions and disorders of the urinary system 11

Fluid and electrolyte balance Electrolytes are selectively secreted to

maintain body’s acid-base balance.

• What are electrolytes? Electrically charged particles

• What do they do? Help determine fluid and acid-base

balance

4.02 Understand the functions and disorders of the urinary system 12

Fluid and electrolyte balance Chemical control

• ADH (Anti-diuretic hormone)- secreted by the posterior pituitary gland when blood pressure decreases

• Aldosterone- A steroid secreted by the adrenal cortex when plasma sodium decreases or plasma potassium increases.

Nervous control

• Directly through the action of nerve impulses on the blood vessels leading to the kidney

• Indirect nerve control is through stimulation of certain endocrine glands whose hormone secretion will control urinary secretion.

4.02 Understand the functions and disorders of the urinary system

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Fluid and electrolyte balance Chemical control The amount of ADH produced is related to

the level of body hydration

4.02 Understand the functions and disorders of the urinary system 14

Forming more dilute urine:

Define “dilute urine” What are diuretics?

What effect do they have on the production of

urine?

Give examples of substances that have diuretic

effects.

4.02 Understand the functions and disorders of the urinary system 15

Fluid and electrolyte balance

4.02 Understand the functions and disorders of the urinary system

What effect does this cycle have on your blood pressure?

16

4.02 Understand the functions and disorders of the urinary system

Review urine formation, electrolyte exchange,

and some factors that effect urine volume.

17

What do you predict will happen to blood

pressure when the blood volume increases?

What if blood

volume decreases?

4.02 Understand the functions and disorders of the urinary system 18

If more water is reabsorbed back into the

body---what will happen to urine

concentration?

(more or less concentrated?)

4.02 Understand the functions and disorders of the urinary system 19

Elimination of urine What causes the bladder to empty?

•The bladder can hold about 500 ml of fluid

•When it fills, the stretch triggers urination-emptying the

bladder

Is this a voluntary or involuntary action?

What can prevent urination? Internal and external

sphincters

4.02 Understand the functions and disorders of the urinary system 20

Elimination of urine

Urinary output

4.02 Understand the functions and disorders of the urinary system

Average urinary output = 1500 ml per day *How many ounces is this?

What effects

the color of

your urine?

21

An examination of urine

What does normal urine look like?

What constitutes an abnormal urinalysis?

4.02 Understand the functions and disorders of the urinary system 22

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4.02 Understand the functions and disorders of the urinary system 24

4.02 Understand the functions and disorders of the urinary system 25

4.02 Understand the functions and disorders of the urinary system

26

Cystitis

What is cystitis

(cyst= medical term for ____ +itis =___ ) • Inflammation of the mucous membrane lining of the bladder

Most common cause: E. Coli

What are the major symptoms of cystitis? • Painful urination (dysuria)

• Frequent urination (polyuria)

4.02 Understand the functions and disorders of the urinary system 27

Cystitis More common in females—Why ??

• The urethra is shorter in females

4.02 Understand the functions and disorders of the urinary system 28

Glomerulonephritis

4.02 Understand the functions and disorders of the urinary system

Disease which injures

the glomerulus.

What does this mean

for my health? • When the filter is damaged, blood cells

and blood proteins enter the filtrate

• Removal of waste products is

decreased

• Electrolyte balance is abnormal

• Kidney damage can occur

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Glomerulonephritis Two types:

• Acute- can occur in children after a bacterial infection,

usually strep throat

• Chronic- Occurs when the filtration membrane has been

permanently affected. May result in kidney failure.

4.02 Understand the functions and disorders of the urinary system

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Renal calculi Also known as nephrolithiasis nephro lith iasis What are renal calculi made of?

•Calcium phosphate

•Uric acid

What are the symptoms? •Extreme pain

•Nausea and vomiting

•Burning when urinating

•Hematuria

4.02 Understand the functions and disorders of the urinary system

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Renal calculi

What will happen if

the ureters are

blocked? • The renal pelvis and

calyces become enlarged

due to excess fluid

4.02 Understand the functions and disorders of the urinary system

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Renal calculi

How is it treated?

• Increase fluids

• Medications

• Lithotripsy

4.02 Understand the functions and disorders of the urinary system

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Renal calculi How does lithotripsy work?

• Shockwaves are created outside the body that travel through until

the waves hit the dense stones.

Is it a cure?

4.02 Understand the functions and disorders of the urinary system

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Renal failure Acute What causes it?

• Nephritis

• shock

• Injury

• Bleeding

• Heart failure

• Poisoning

• What are the symptoms? Oliguria- diminished production of urine

Anuria- absence of urine

Uremia- when the blood retains urinary waste products

4.02 Understand the functions and disorders of the urinary system

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Renal failure

chronic Symptoms may be none in early stages, urinalysis

may reveal proteinuria

4.02 Understand the functions and disorders of the urinary system

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Renal Failure Chronic kidney

disease leads to a

buildup of fluid

and waste

products in the

body.

4.02 Understand the functions and disorders of the urinary system

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Renal Failure

How is it treated?

• Peritoneal dialysis

Read about it! Page 587

4.02 Understand the functions and disorders of the urinary system

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Renal Failure

How is it treated?

• Hemodialysis Read about it! Page 587

4.02 Understand the functions and disorders of the urinary system

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Renal Failure

Compare the treatment of acute and

chronic renal failure.

4.02 Understand the functions and disorders of the urinary system

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How does hemodialysis mimic

glomerular function?

4.02 Understand the functions and disorders of the urinary system 41

Renal transplant What is involved in this treatment option?

When does a patient get a transplant? Read about it! Page 588

4.02 Understand the functions and disorders of the urinary system 42

Renal transplant

4.02 Understand the functions and disorders of the urinary system

What is the

major

complication of

renal

transplantation?

43

Essential Questions

What are the functions of the urinary system?

What are some disorders of the urinary system?

How are disorders of the urinary system treated?

How do you relate the body’s hormone control to

the urinary system?

4.02 Understand the functions and disorders of the urinary system 44