Chapter 23Respiration and Excretion

Excretory System• Many different chemical

changes take place in cells.– As these changes take place

waste products form.– Ex: Cellular Respiration -> CO2

+ H2O

– Other waste products from cells: salts, nitrogen compounds, and heat.

Excretory System cont.• What is the function of the Excretory system?

1) Cell protection2) Blood movement3) Waste removal4) Food breakdown5) Regulations of hormones

• Waste products can be harmful to the body if they build up and collect in the body.

What major components make up the excretory system?

• Kidneys• Ureter• Urinary Bladder• Urethra• Skin

Kidenys• Humans have 2 kidneys

which are located just above your waistline.

• Main job of the kidney is to remove waste products from the blood

• Each minute about 1 L of blood pass through your kidney.

• In 1 day your kidneys remove waste products from about 170 L of blood.

Kidenys cont.• Millions of tiny tubelike structures called

nephrons are located inside the kidney.• Nephrons are the filtering structures of the

kidneys

How do nephrons filter waste products and nutrients from the blood? How are

nutrients returned to the blood?

What is the main function of the kidney?

1) Protections2) Produce hormones3) Waste removal4) Support and Shape5) Kill bacteria

What are the filtering structures of the kidney?

1) Ureter2) Urethra3) Collecting tube4) Artery5) Nephron

Waste removal

• Waste products leave the kidney through the collecting tube as a liquid called urine.

• Urine = H20 + salts + urea

• Excretion is not completed until urine is removed from the body.

• The job of the urinary system is to remove liquid waste (urine) from the body.

How is urine removed?• Urine leave the kidneys through a tube called the

ureter.• 1 ureter from each kidney carries urine to the

urinary bladder, which is a muscular sac that stores urine.

• When the bladder becomes full, muscles from the bladder contract forcing out the urine into the urethra.

• The urethra carries urine to the outside of the body.

What is urine made of?

1) Water2) Salt3) Urea4) Glucose5) 1,2, and 3

What tube carries urine outside of the body?

1) Ureter2) Urinary bladder3) Urethra4) Nephrons5) Collecting tube

Skin• Skin has small structures

called sweat glands, which excrete waste products in the form of perspiration.

• Perspiration = H2O + salts + urea

• Each sweat glands has a small tube that leads to the surface of the skin called a pore.

Skin cont.• You have millions of pores in

your skin.• Sweat produced in the sweat

glands leaves your body through these pores.

• Sweat that reaches the skin’s surface evaporates quickly, which cools your body.

• Excess heat is removed from your body as it cools, which helps regulate body temperature.

What is the major function of the skin?1) Protection2) Sensation (touch)3) Excretion4) Temperature regulation5) All of the above

What other organ besides the skin removes H2O, salts, and Urea?

1) Liver2) Kidney3) Heart4) Stomach5) Intestines

Excretory Problems• Kidney Stones• Acne

Kidney Stones• They are formed from calcium compounds and

nitrogen wastes that are not excreted by the body.

• Small kidney stone can pass through the ureter, but can cause great pain.

• Large kidney stones cannot pass through the ureter, causing a blockage which can destroy kidney cells.

How are large kidney stones removed?• Medication – causes the stone to dissolve and

break apart• Surgery – involves the risk of infection, can lead to

complications.• Sound waves – aim shock waves at the stone

causing it to vibrate and break apart

How are large kidney stones removed?

lithotripsy treatment for kidney stones

Acne• Is a combination of skin

diseases.• Symptoms: whiteheads,

blackheads, and pimples.• Whiteheads &

blackheads develop when oils clog the pores of the surface of the skin.

• A pimple forms when a blackhead is infected with bacteria.

Why would washing your face several times each day help control acne?

1) Helps remove dead skin2) Helps remove excess oil3) Helps prevent clogged pores4) All of the above

Controlling Acne

1. Wash your face several times per day with soap and water

2. Apply a dry lotion to the skin after washing

3. Avoid oily cosmetics

4.Remove all cosmetics before going to bed

5.Eat a well balanced diet

6. Get plenty of rest and exercise