chapter 8 - the respiratory system

Question 1

what are the functions of the respiratory system

Answer 1

• continual supply of oxygen, and continual removal of carbon dioxide
• elimination of volatile waste substances
• elimination of excess heat from the body

Question 2

what is the nasal cavity

Answer 2

• filters (hairs/cilia), moistens (mucous) and warms (capillaries) air before entering the lungs
• contains smell receptors and acts as a resonating chamber for speech sounds

Question 3

what is the pharynx

Answer 3

• where air from the nasal cavity passes through

Question 4

what is the epiglottis

Answer 4

• a flap of tissue that closes off the trachea so food cannot enter the lungs when swallowing

Question 5

what is the larynx

Answer 5

• air passes through the larynx

- contains vocal chords which vibrate to make sound

Question 6

what is the trachea

Answer 6

• carries air to and from the lungs

- cilia beat to move mucous and trapped particles upwards to throat to be swallowed

Question 7

what is the bronchi

Answer 7

• two primary bronchi branch from the trachea

- divide into secondary and tertiary bronchi

Question 8

what is the bronchioles

Answer 8

• very fine tubes with walls of smooth muscle

- ends in groups of air sacs (alveoli)

Question 9

what is the alveoli

Answer 9

• tiny / millions = increased SA = increased EOG
• very thin walls (one cell) = less distance = increased EOG
• network of capillaries = increased EOG
• film of moisture lines the alveoli = allows gas to dissolve = increased EOG

Question 10

what are the ribs

Answer 10

• form the framework of the chest

Question 11

what are the intercostal muscles

Answer 11

• muscles between the ribs

- move upwards and outwards to increase chest cavity

Question 12

what is the diaphragm

Answer 12

• muscle separating chest from abdomen

- contracts and flattens downwards to increase chest cavity volume

Question 13

what is the structure of the lungs

Answer 13

• covered by a pleural membrane, that also lines the inside of the chest
• pleural fluid between he two holds the lungs against the inside of the chest

Question 14

function of the lungs

Answer 14

• to enable the blood to take up oxygen from he air, and carbon dioxide to pass from the blood to the air in lungs

Question 15

why are the lungs well adapted to their function (gas exchange)

Answer 15

• large surface area: large amounts of gas can be exchanged in a short amount of time
• little travel distance: alveoli have a very thin membrane
• positioned deep in body: prevents excessive exasperation of the pleural fluid and the gases during gas exchange
• lung volume: can be changed by movements of respiratory muscles, air is continually flowing in and out of the lungs

Question 16

what are the mechanics of breathing

Answer 16

• the process by which air is moved into and out of the lungs (ventilation)

Question 17

what is air pressure

Answer 17

• air flows from places of a higher pressure to that of a lower pressure
• air flows due to the difference in air pressure

Question 18

describe the process of inspiration

Answer 18

• intercostal muscles contract (extending rib age upwards and outwards), pulls on pleural membrane
• diaphragm contracts (extending chest cavity downwards)
• lung volume increases and pressure in alveoli is reduced
• air flows from area of higher pressure to lower pressure in the lungs

Question 19

describe the process of expiration

Answer 19

• intercostal muscles contract, extending rib cage downwards and inwards
• diaphragm relaxes, pushing up into the chest cavity
• lungs recoil and lung volume decreases, increasing pressure in the lungs
• air flows from higher pressure in lungs to lower pressure outside the body

Question 20

what is the respiratory system

Answer 20

made up of those organs which are concerned with the exchange of gases between the organism and the environment