Exchange Surfaces - Lung structure and Breathing

Question 1

where is cartilage found in the lungs

Answer 1

trachea and bronchi

Question 2

what is the function of elastic fibres in the lungs

Answer 2

recoil of elastic tissue widens the airways (after contraction) and forces air out of alveoli (after expansion)

Question 3

what is the function of cartilage in the lungs

Answer 3

support, holds them open and prevents collapse

Question 4

where is smooth muscle found in the lungs

Answer 4

walls of trachea, bronchi and bronchioles

Question 5

what is the function of smooth muscle in the lungs

Answer 5

involuntary muscle that contracts to narrow the lumen (allows air to move in and out)

Question 6

where are goblet cells found in lungs

Answer 6

throughout ciliated epithelium

Question 7

what is the function of goblet cells in lungs

Answer 7

secrete sticky mucus to trap particles and prevent them drying out

Question 8

where is ciliated epithelium found in lungs

Answer 8

lines the trachea, bronchus and bronchioles

Question 9

what is the function of ciliated epithelium in lungs

Answer 9

cilia move in a synchronised pattern to waft mucus up the airway to the back of the throat

Question 10

describe cartilage in the trachea

Answer 10

large c-shaped pieces

Question 11

which tissues are found in the trachea

Answer 11

• cartilage
• smooth muscle
• elastic fibres
• goblet cells
• ciliated epithelium

Question 12

describe cartilage in bronchi

Answer 12

smaller pieces

Question 13

which tissues are found in the bronchi

Answer 13

• cartilage
• smooth muscle
• elastic fibres
• goblet cells
• ciliated epithelium

Question 14

which tissues are found in the larger bronchiole

Answer 14

• smooth muscle
• elastic fibres
• goblet cells
• ciliated epithelium

Question 15

which tissues are found in the smaller bronchiole

Answer 15

• smooth muscle
• elastic fibres
• ciliated epithelium

Question 16

which tissues are found in the smallest bronchiole

Answer 16

• elastic fibres
• epithelium

Question 17

which tissues are found in the alveoli

Answer 17

• elastic fibres
• epithelium

Question 18

describe inspiration

Answer 18

• contraction of external intercostal muscles causes ribcage to move up and out
• contraction of muscles in the diaphragm causing it to go downwards/flatten
• increases volume of the thoracic cavity
• pressure within the thoracic cavity is lowered (below outside pressure)
• air flows in through nose and mouth down the pressure gradient into the thorax

Question 19

describe expiration

Answer 19

• external intercostal and diaphragm muscles relax
• elastic fibres between the alveoli recoil back to their normal length
• volume decreases and pressure increases forcing air out

Question 20

describe forced breathing out

Answer 20

• more air can be forced out by the contraction of the internal intercostal muscles moving ribcage down and in
• contraction of abdominal muscles raises diaphragm

Question 21

how is the nasal cavity adapted for efficient gas exchange

Answer 21

• large surface area and good blood supply
• mucus
• moist surfaces