Ventilation System Quiz

Question 1

Ventilation

Answer 1

Ventilation: The exchange of air between lungs and atmosphere (through breathing)

Question 2

Structure/Function: Trachea

Answer 2

Tube that allows air to travel into and out of the lungs to and from the atmosphere

Question 3

Structure/Function: Lungs

Answer 3

Take in fresh air (oxygen) from atmosphere and get rid of carbon dioxide from blood

Question 4

Structure/Function: Bronchi

Answer 4

Tubes (right and left) that carry air into lungs (from trachea) and out of lungs

Question 5

Structure/Function: Bronchioles

Answer 5

Smaller tubes that carry air to and from the alveoli (from the bronchi) - ↑SA

Question 6

Structure/Function: Alveoli

Answer 6

Alveoli are TRIM!
Thin walls – surrounded by a single layer of epithelial cells (minimizes diffusion distance) - capillary walls only one cell thick too

Rich capillary network surrounding each alveolus – maintains high concentration gradient (O2/ CO2) between lungs and blood for diffusion

Increased SA:V ratio – small, spherical shape
increases surface area while decreasing volume

Moist – cells lining each alveolus secrete fluids
to allow gases to dissolve (dissolved oxygen diffuses easier into blood) and prevent alveoli from collapsing on themselves/ sticking together

Question 7

Type 1 pneumocytes

Answer 7

Type I: squamous (flattened) and extremely thin to minimize diffusion distance and increase surface area for gas exchange
Note: these cells are amitotic
(do not divide)

Question 8

Type 2 pneumocytes

Answer 8

Type II: cuboidal with granules (store
components to make surfactant); function
is to secrete pulmonary surfactant - a liquid substance that reduces/ decreases surface tension (ensuring all alveoli expand
at the same rate and none of them collapse in on themselves due to unequal pressure)
Note: these cells can divide and make both type I and type II pneumocytes if needed

Question 9

antagonistic muscle action

Answer 9

Application: External and internal intercostal muscles, and diaphragm and abdominal muscles, as examples of antagonistic muscle action.

Question 10

muscles and breathing in

Answer 10

Inspiration (breathing in)
Diaphragm muscles contract (flatten downwards) and external (on outside) intercostal muscles contract (pull ribs up and out)
b. Thoracic cavity volume and lung volume increase (pressure of air in lungs drops below atmospheric pressure – air rushes in through mouth or nasal passage to equalize)

Question 11

muscles and breathing out

Answer 11

Expiration (breathing out)
Diaphragm muscles relax (curves upward), abdominal wall muscles contract (pushing diaphragm up), external intercostal muscles relax (ribs fall), and internal (on inside) intercostal muscles contract (pulling ribs back down)
Thoracic cavity volume and lung volume decrease (pressure of air in lungs rises above atmospheric pressure – air rushes out to equalize)

Question 12

gas exchange in the alveoli

Answer 12

gas exchange is a passive process (diffusion)
high concentration of O2 AND a low concentration of CO2 in the alveoli in the lungs
Ensures that O2 diffuses from the lungs through the alveoli walls INTO the blood (capillaries) and CO2 diffuses OUT of the blood (capillaries) through the alveoli walls and into the lungs

Question 13

causes and consequences of emphysema

Answer 13

Emphysema is a chronic/progressive disease where the walls of the alveoli are damaged and lose their elasticity (feeling of shortness of breath) - a form of COPD (chronic obstructive pulmonary disease)
Consequences: Healthy alveoli break down/ rupture, turn into large, irregularly shaped structures with gaping holes, ↓ elasticity (so ↑total lung volume at rest), ↓ SA, ↓O2 can reach the bloodstream
Causes: SMOKING/ tobacco/marijuana/fumes/coal dust/air pollution (irritants cause damage, then phagocytes (WBC’s) come to “help” damaged tissue/ secrete elastase, which breaks down elastic fibers in alveolar walls) - in rare cases, hereditary gene mutation causes deficiency in elastase enzyme inhibitor (which causes hereditary emphysema)
Treatments: No cure, but certain treatments can help alleviate symptoms/ delay disease = bronchodilators (improve airflow by relaxing bronchial muscles), inhaled steroids (reduce inflammatory response/ phagocytes), oxygen supplementation, elastase enzyme inhibitors, surgery (remove damaged tissue/ lung transplant)

Question 14

causes and consequences of Lung Cancer

Answer 14

Lung Cancer is a cancerous growth (uncontrolled cell division) within the lungs.
Malignant cancer cells can take over healthy tissues of the bronchioles & alveoli – then eventually spread (metastasize) to the brain/bones/liver/adrenal gland
Lung tissues become dysfunctional, can lead to internal bleeding, coughing up blood, wheezing, respiratory distress and weight loss
Causes: carcinogens (smoking, asbestos)/air pollution/ certain infections/genetic predispositions

Question 15

tidal Volume

Answer 15

tidal volume - amount of air in or out in in one breath. measured by a Spirometer

Question 16

the effects of increased exercise on ventilation rate

Answer 16

Exercise increases metabolism, which increased O2 demands
Chemoreceptors in the carotid artery (neck) and the aorta (heart) detect CO2/ O2 levels and blood pH; Chemoreceptors in the medulla detect CO2 changes (as pH changes in cerebrospinal fluid)