Chapter 4 - respiratory system

Question 1

Alveoli

Answer 1

Air sac in the lungs

Question 2

Bronchiole
- connected to
- make of
- delivers

Answer 2

Very small air tube in the lungs that are branches off the bronchi. Made of smooth muscle so can constrict and dilate to regulate airflow. Delivers air to alveoli for gas exchange.

Question 3

Concentration gradient

Answer 3

Difference in concentration of a solution often between the inside and outside of a cell. Also called diffusion gradient.

Question 4

Epiglottis

Answer 4

Cartilage flag at the base of the pharynx that covers the trachea during swallowing

Question 5

Expiration

Answer 5

Breathing out - exhalation

Question 6

Inspiration
- pressure
- achieved

Answer 6

Breathing in. Pressure needs to be less in the lungs than atmospheric pressure. Decreasing pressure in the lungs is achieved by increasing the volume.

Question 7

Larynx

Answer 7

Structure at the top of the trachea that contains the vocal cords

Question 8

Oesophagus

Answer 8

Tube that carries food from the throat to the stomach. Undergoes peristalsis from the longitudinal and circular muscles

Question 9

Pharynx

Answer 9

Throat - Joins the mouth cavity to the oesophagus and the larynx

Question 10

Pleural membrane

Answer 10

Membrane that covers the surface of the lungs. Produces pleural fluid for lubrication

Question 11

Bronchi

Answer 11

First branch from the trachea entering the left and right lungs

Question 12

Respiratory system
- facilitate

Answer 12

System specialised to facilitate the intake of oxygen and the removal of carbon dioxide

Question 13

Pulmonary arteries

Answer 13

Artery that takes deoxygenated blood away from the heart to the lungs

Question 14

Trachea

Answer 14

Tube that takes air from the throat to the lungs

Question 15

Ventilation
- air movement

Answer 15

Process of breathing air moves in and out of the lungs from differences in air pressure - air will move from high pressure to low pressure.

Question 16

Diaphragm
- shape
- role

Answer 16

Dome shaped muscle that separates the thoracic and abdominal cavities. Plays a crucial role in creating the pressure differences in the lungs that drive the process of breathing.

Question 17

Nasal cavity

Answer 17

Hollow space lined with mucous membrane and cilia that warms and humidifies air for efficient diffusion in the alveoli.

Question 18

Lungs - respiratory system
Facilitate

Answer 18

Facilitate the gas exchange between air and the blood

Question 19

Intercostal muscles

Answer 19

Muscles in between the ribs that contract to expand the ribcage during breathing

Question 20

Changes to the structure of the lungs in inspiration
- what does it achieve

Answer 20

• diaphragm contracts (become flatter) and intercostal muscles contract (move ribcage upwards and outwards)
• increasing volumn means air pressure inside lungs slightly lower outside
• air will flow through nose and trachea until pressure becomes equal.

Question 21

Lungs are well suited to their role in gas exchange

Answer 21

• lung volume can be changed by movements of the chest muscles so that their is a constant changing of air in the alveoli
• alveoli are very small and numerous large SA for gas exchange
• Each alveolus is well supplied with blood vessels - maintains conc differences - facilitates gas exchange
• alveoli wall very thin (1 cell thick), short distance that gas molecules need to travel means rapid diffusion
• membrane of the alveoli is covered in a thin layer of moisture that enables gas to diffuse in and out of the blood when dissolved in fluid.

Question 22

Conc. gradient is maintained in the lungs to facilitate gas exchange in the lungs
1.
2.

Answer 22

• Constant flow of blood through the capillaries. New blood that meets the alveoli is low in CO2 and high in oxygen
• Movement of air in and out of the alveoli. New air is low in CO2 and high in 02

Question 23

Inspired air
Composition

Answer 23

O - 20.95
CO2 - 0.05
Nitrogen 79

Question 24

Expired air

Answer 24

O - 16
CO2 - 4