Biology: Chapter 6

Question 1

External nares of the nose

Answer 1

where air enters into the respiratory tract

Question 2

Nasal cavity

Answer 2

-filters air with mucous membranes and nasal hairs
-where air is transported after the external nares of the nose

Question 3

Pharynx

Answer 3

-resides behind the nasal cavity and at the back of the mouth
-pathway for air and food

Question 4

Larynx

Answer 4

-lies below the pharynx
-pathway for air
-contains two vocal cords

Question 5

Epiglottis

Answer 5

-covers the opening of the larynx (glottis) during swallowing so food doesn’t pass through

Question 6

Trachea

Answer 6

airway that leads from the larynx to the bronchi

Question 7

Air passages of the lungs

Answer 7

-Bronchi (largest)
-Bronchioles
-Alveoli (where gas exchange occurs) (smallest)

Question 8

Surfactant

Answer 8

coats each alveolus which lowers the surface tension and prevents the alveolus from collapsing on itself

Question 9

Organs of the thoracic cavity

Answer 9

heart, lungs, esophagus, trachea, and thymus

Question 10

Pleurae

Answer 10

-surround each lung
-form a closed sac against which the lung expands

Question 11

Visceral pleura

Answer 11

surface adjacent to the lung (touches the lung)

Question 12

Parietal pleura

Answer 12

outer pleura (touches other organs)

Question 13

Intrapleural space

Answer 13

-space between visceral and parietal pleura that contains a thin layer of fluid
-helps lubricate the two pleural surfaces

Question 14

Diaphragm

Answer 14

thin, muscular structure that divides the thoracic (chest) cavity from the abdominal cavity

Question 15

Inhalation

Answer 15

-active process
-use diaphragm and external intercostal muscles to expand thoracic cavity
-The lungs will expand into the intrapleural space, and the pressure in the lungs will drop
-Air will then be sucked in from a higher-pressure environment

Question 16

Exhalation

Answer 16

-not an active process
-Relaxation of the external intercostal muscles will reverse the process of inhalation
-As the diaphragm and external intercostals relax, the chest cavity decreases in volume
-This causes pressure in the intrapleural space to increase to a higher concentration than the pressure in the lungs and air will be pushed out

Question 17

Speeding up exhalation

Answer 17

-the use of internal intercostal muscles and abdominal muscles which oppose the external intercostals and pull the rib cage down
-Decreases the volume of the thoracic cavity

Question 18

Total lung capacity (TLC)

Answer 18

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

Question 19

Residual volume (RV)

Answer 19

the volume of air remaining in the lungs when one exhales completely

Question 20

Vital capacity (VC)

Answer 20

the difference between the minimum and maximum volume of air in the lungs (TLC - RV)

Question 21

Tidal volume

Answer 21

the volume of air inhaled or exhaled in a normal breath

Question 22

Expiratory reserve volume (ERV)

Answer 22

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

Question 23

Inspiratory reserve volume (IRV)

Answer 23

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

Question 24

Ventilation center

Answer 24

-collection of neurons in the medulla oblongata that regulates ventilation
-contain chemoreceptors that are sensitive to CO2 concentration
-As the partial pressure of CO2 rises in the blood, the respiratory rate will increase so that more CO2 is exhaled

Question 25

Gas exchange

Answer 25

-Each alveolus is surrounded by a network of capillaries
-The capillaries bring deoxygenated blood from the pulmonary arteries (originate from the right ventricle of the heart)
-The oxygenated blood returns to the left atrium of the heart via the pulmonary veins
-When it initially arrives at the alveoli, blood has low oxygen and high CO2, facilitating transfer of each down its respective concentration gradient
-No energy is required

Question 26

Thermoregulation (respiratory system)

Answer 26

-As capillaries expand, more blood can pass through these vessels, and a larger amount of thermal energy can be dissipated
-As capillaries contract, less blood can pass through them, conserving thermal energy

Question 27

Nasal cavity (immune function)

Answer 27

-has small hairs that help to trap particulate matter and potentially infectious particles
-contains enzymes, lysozyme, which are found in tears and saliva and is able to attack bacteria

Question 28

Internal airways (immune function)

Answer 28

-lined with mucus which traps particulate matter and larger invaders
-underlying cilia then propel mucus up the respiratory tract to the oral cavity where it can be expelled or swallowed

Question 29

Immune function of the lungs

Answer 29

-contain numerous immune cells including macrophages
-Mast cells have preformed antibodies on their surfaces and when the right substances attaches to the antibody, the mast cell releases inflammatory chemicals into the surrounding area to promote an immune response

Question 30

Respiratory response to pH changes

Answer 30

-When the pH is lower and hydrogen ion concentration is higher (acidic), acid-sensing chemoreceptors just outside of the blood-brain barrier send signals to the brain to increase the respiratory rate
-An increasing hydrogen ion concentration will cause a shift in the bicarbonate buffer system, generating additional carbon dioxide which also promotes respiratory rate
-When pH is higher and hydrogen ion concentration is lower (basic), respiratory rate is slowed so more CO2 can be retained