Human Breathing System

Question 1

organs involved and location

Answer 1

lungs

thoracic cavity

Question 2

nose (nasal cavity)

Answer 2

warms and filters air through mucus in the nostrils

Question 3

epiglottis

Answer 3

flap of tissue that prevents food from entering the trachea

Question 4

larynx

Answer 4

produces sound (voice box)

Question 5

pharynx

Answer 5

connects nose and mouth to larynx

Question 6

trachea

Answer 6

allows air to pass to the lungs

Question 7

bronchus

Answer 7

allows air into the lung

Question 8

rings of cartilage

Answer 8

keep airways open

prevent collapsing of trachea and bronchi

Question 9

mucus

Answer 9

traps small particles, dust, bacteria

defence feauture

Question 10

cilia

Answer 10

small hairs that line the trachea

function: carry mucus and trapped dust/microbes out of lungs

Question 11

bronchioles

Answer 11

smaller branch of bronchi

transport air to the alveoli

Question 12

alveoli

Answer 12

gas exchange (oxygen diffuses into blood here)

Question 13

diaphragm

Answer 13

allows the lungs to inhale, as it contracts, the volume of the thoracic cavity increases and air is drawn into the lungs

Question 14

pleural membrane

Answer 14

protects lungs, allow friction free movement of each lung

Question 15

how alveoli function

Answer 15

1. oxygen enters alveoli from bronchiole
2. oxygen diffuses into blood capillary (originates from pulmonary artery)
3. oxygen goes to the heart via pulmonary vein
4. co2 diffuses into alveoli from blood capillary

Question 16

adaptations of alveoli for gas exchange

Answer 16

• membrane of alveoli are one cell thick
• large surface area
• large capillary network
• moist surface

Question 17

describe the mechanism of breathing

Answer 17

inhaling

1. increase in co2 gas in the blood, brain sends signals to the intercostal muscles to contract, ribcage moves up and out
2. diaphragm flattens downward, volume of lungs increases, pressure in lungs decreases
3. external air pressure increases causing air to flow in

exhaling

1. the intercostal muscles relax, ribcage moves down and in, diaphragm relaxes
2. volume of thorax decreases, so air pressure increases
3. increase in internal pressure causes air to be pushed out from the lungs

Question 18

mechanism of breathing is controlled by

Answer 18

medulla oblongata - detects change in blood pH caused by increase in co2 gas

Question 19

asthma

Answer 19

narrowing of the bronchioles due to inflammation
symptoms: coughing, wheezing, breathlessness
causes: allergens eg pollen, dust, smoke
treatment: 
-bronchodilators (inahlers)
dilate bronchioles to allow air to flow
-identify triggers
avoid or remove