Unit 2 Topic 5

The Respiratory System

What is respiration? Exchange of gases between the internal

environment and the external environment Need O2 in (for cellular respiration)

Need CO2 out (waste product)

O2

C6H12O6

CO2

Cell

ATP

Respiratory systems General characteristics

of respiratory systems:

1. Thin, moist surfaces

2. Large surface area: volume ratio

Mechanisms of gas exchange in animals:

1. Direct with the environment

2. Tracheae

3. Gills

4. Lungs

Lungs: Our system of gas exchange

A

B

C

DE

E

F

G

H

I

Negative pressure breathing

inhale exhale

Sort of random video…

How do you think this information relates to gas exchange?

78% nitrogen21% oxygen

0.04% carbon dioxideQuickTime™ and aH.264 decompressor

are needed to see this picture.

Alveoli

Moving gases into bloodstream Step 1: Inhale to fill lungs with “fresh” air

O2 passes from alveoli to blood by simple

diffusion (high to low concentration)

CO2 passes from blood to alveoli by simple

diffusion (high to low concentration)

Step 2: Exhale to empty lungs.

Capillaries carrying low O2 / high CO2

concentration blood back from body.

Capillaries carrying high O2 / low CO2

concentration blood out to the body.

Red blood cells and hemoglobin

Blood=

45% cells (red, white, platelets)

55% “plasma” (nutrients, water, vitamins, hormones, cellular waste, ions)

Respiratory System

Special Topics

Chronic Respiratory Diseases

OBJ 28

Common respiratory infections Pneumonia Bronchitis

Smoking and the lungs

Cigarette smoke: carbon coated in 4,000 toxic chemicals

Benzene Ammonia Formaldehyde Arsenic Cyanide

Smoking: Causes cilia to stop moving (for 20 minutes) Increases amount of mucus in the air passages

(cilia no longer clearing mucus) Kills immune cells on respiratory tract Decreases the amount of oxygen carried by

blood Leads to tar build-up in your lungs Second-hand smoke also contains many toxins

Lung Cancer

Tumors form in the lungs

OBJ 28

www.lungcancer.au.com

Cystic Fibrosis Genetic disorder that affects the structure of 1 protein. Chloride ions protein pumps in cells of the trachea don’t work Results in production of abnormally thick and sticky mucus Mucus builds up in lungs and pancreas People with this disorder live much shorter lives (now up to late

30s/early 40s, only a couple of decades ago, most died in childhood)

OBJ 30