Biology 6: The Respiratory System

Question 1

pathway of breathing

Answer 1

nares -> nasal cavity -> pharynx -> larynx -> trachea -> bronchi -> bronchioles -> alveoli

Question 2

surfactant

Answer 2

present at the alveoli

reduces surface tension at the liquid-gas interface, preventing collapse

Question 3

which pleura lies adjacent to the lung itself?

Answer 3

visceral pleura

Question 4

which pleura lines the chest wall?

Answer 4

parietal pleura

Question 5

what is the space that lies between the two pleurae and contains a thin layer of fluid that lubricates them?

Answer 5

intrapleural space

Question 6

diaphragm

Answer 6

thin skeletal muscle that helps create pressure differential required for breathing

under somatic control

Question 7

inhalation

Answer 7

diaphragm + external intercostal muscles

diaphragm flattens, chest expands

increasing intrapleural volume, lowering pressure

air comes in

Question 8

negative-pressure breathing

Answer 8

mechanism of breathing whereby pressure differential ultimately expands the lungs, decreasing pressure

causes air to come into the lungs from the environment

Question 9

exhalation

Answer 9

relaxation of muscles

diaphragm raises back up, decreasing volume, increasing pressure

air leaves lungs

Question 10

active exhalation

Answer 10

internal intercostal muscles + abdominal muscles

contract to further decrease the volume of the cavity

pushing out air

Question 11

total lung capacity

Answer 11

the max volume of air in the lungs when one inhales completely

Question 12

residual volume

Answer 12

minimum volume of air in the lungs when one exhales completely

Question 13

vital capacity

Answer 13

the difference between the minimum and max volume of air in the lungs

TLC - RV

the greatest volume of air that can be expelled from the lungs after taking the deepest possible breath

Question 14

tidal volume

Answer 14

the volume of air inhaled or exhaled in a normal breath

Question 15

expiratory reserve volume

Answer 15

the volume of additional air that can be forcibly exhaled after a normal exhalation

Question 16

inspiratory reserve volume

Answer 16

the volume of additional air that can be forcibly inhaled after a normal inhalation

Question 17

ventilation center

Answer 17

collection of neurons in the medulla oblongata that regulate ventilation

have chemoreceptors that are sensitive to CO2

increased CO2 level, increased respiration

(ventilation can also be consciously controlled by cerebrum)

Question 18

what things protect the respiratory system from pathogens?

Answer 18

• vibrissae, mucous membranes, mucociliary escalator to filter incoming air and trap matter
• lysozyme in nasal cavity and spit can attack peptidoglycan of gram positive bacteria
• macrophages to engulf pathogens
• mucosal surfaces with antibodies
• mast cells with antibodies that release inflammatory chemicals

Question 19

mucociliary escalator

Answer 19

cilia in internal airways propel mucus up respiratory tract in oral cavity