Chapter 30 - Human Breathing

Question 1

Name two functions of the nose

Answer 1

Filters air by hairs and mucous

Moistens and warms the air

Question 2

Why is it important for air to be moist and warm

Answer 2

Helps with diffusion of air from lungs to bloodstream

Prevents alveoli from drying out

Question 3

Name two functions of the pharynx

Answer 3

Epiglottis closes off trachea when swallowing

Voicebox (larynx) contains 2 vocal cords that produce sound

Question 4

What is the trachea made of

Answer 4

Muscle and elastic fibers
Has c-shaped rings of cartilage around it to prevent it from collapsing
Inside is lined with mucous and silia which traps dust and bacteria

Question 5

What is the function of the trachea

Answer 5

Allows air to travel down into the bronchi and bronchioles

Question 6

Describe the lungs

Answer 6

Spongy structure

Enclosed by a pair of pleural membranes - liquid to prevent friction between the lungs

Question 7

What are alveoli

Answer 7

Hollow air sacs at the end of bronchioles
700 million in the lungs
They are surrounded by capillaries

Question 8

What is the function of alveoli

Answer 8

Gas exchange through diffusion

Question 9

How does deoxygenated blood enter the lungs

Answer 9

Pulmonary artery

Question 10

How does oxygenated blood leave the lungs

Answer 10

Pulmonary vein

Question 11

What gases are inhaled

Answer 11

78% nitrogen
21% oxygen
0.04% carbon dioxide
1% water

Question 12

What gases are exhaled

Answer 12

78% nitrogen
16% oxygen
4% carbon dioxide
2% water

Question 13

How does blood travel to the body cells

Answer 13

Oxygenated blood goes to the cell through the aorta
Oxygen diffuses into the cell
Carbon dioxide and water vapor diffuses out of the cell and travels through the vena cava

Question 14

How is oxygen transported

Answer 14

Through hemoglobin

Question 15

How is carbon dioxide and water vapor transorted

Answer 15

By plasma

Question 16

What are three adaptations to improved gas exchange

Answer 16

Alveoli have thin walls
Alveoli are moist
Capillaries are numerous

Question 17

Describe inhalation (inspiration)

Answer 17

1. Diaphragm and intercostal muscles contract - active process
2. Ribs are pulled up and out, diaphragm moves down
3. Volume of thorax increases
4. Pressure in thorax falls
5. External air pressure higher so air is forced into the lungs

Question 18

Describe exhalation (expiration)

Answer 18

1. Diaphragm and intercostal muscles relax - passive process
2. Ribs are pulled down and in, diaphragm moves up
3. Volume of thorax decreases
4. Pressure in thorax increases
5. Air is forced out of lungs

Question 19

What controls rate of breathing

Answer 19

The brain

Question 20

How does the brain control rate of breathing

Answer 20

Detects levels of carbon dioxide in the plasma by the slight drop in ph due to carbonic acid - caused by exercise

Question 21

Name a breathing disorder

Answer 21

Asthma

Question 22

What are symptoms of this breathing disorder

Answer 22

Noisy, wheezy breathing, feeling of breathlessness

Question 23

Causes of this breathing disorder

Answer 23

Attacks triggered by infections, exercise, allergens

Lower bronchioles become constricted

Question 24

Prevention of this breathing disorder

Answer 24

Avoiding allergens

Preventative inhalers

Question 25

Treatment for this breathing disorder

Answer 25

Inhalers (bronchodialators) - dilate bronchioles
Inhalers - steroids may be inhaled
Injections - severe cases