Lange Pulmonary (8th)-Ch. 1

Question 1

What is the main function of the respiratory system?

Answer 1

Gas exchange.

Question 2

What makes up the respiratory system?

Answer 2

Lungs, conducting airways, CNS, skeletal muscles, & chest wall.

Question 3

What muscles make up the respiratory system?

Answer 3

Diaphragm, intercostals, abdominal muscles & the rib cage

Question 4

What are other functions of the respiratory system?

Answer 4

Acid-base balance, phonation, pulmonary defense and, and handling of bioactive materials.

Question 5

How does the respiratory system participate in acid-base balance?

Answer 5

It removes CO2 from cellular metabolism via the carbonic acid cycle and chemoreceptors for hydrogen levels in blood and CSF.

Question 6

Trace the pathway air takes in the respiratory system, starting from the nose/mouth.

Answer 6

Via nose it is humidified, via mouth it is not > nasopharynx or oropharynx > glottis > larynx > tracheobronchal tree > conducting airways > alveoli > pulmonary capillaries (diffusion)

Question 7

What zone includes generations 1-16?

Answer 7

Conducting Zone.

Question 8

What is the conducting zone incapable of doing? and why?

Answer 8

Gas exchange bc it has no alveoli.

Question 9

What is the conducting zone also referred to as?

Answer 9

Anatomical dead space.

Question 10

When do alveoli start to appear? What zone is this considered?

Answer 10

17 - 19th generations in the respiratory bronchioles.
Transitional Zone.

Question 11

What is considered the respiratory zone? and why?

Answer 11

20-22nd generations.
They are lined with alveoli (alveolar ducts and alveolar sacs - terminate the tracheobronchial tree.)

Question 12

What are airways with no cartilage called?

Answer 12

Bronchioles

Question 13

Define acinus. Do they participate in gas exchange?

Answer 13

Small, saclike cavity in a gland surrounded by secretory cells. They contain 10-12 respiratory bronchioles.
Yes.

Question 14

Does the trachea have smooth muscle? Does it have cartilage?

Answer 14

Yes and yes. The cartilage starts as C-shaped rings and is completely on the dorsal side by smooth muscle. As the bronchi enter the lungs, the cartilage rings disappear and replaced with irregularly shaped plates. These will help support the larger airways and will eventually disappear when airways reach 1mm in diameter.

Question 15

Why are bronchioles and alveolar ducts susceptible to collapse?

Answer 15

Bc they contain no cartilage. However, they do contain elastic tissue (bc of their attachment to alveolar septa walls) that PARTLY opposes collapse.

Question 16

What specific cell secretes surfactant and where are they located?

Answer 16

Clara cells - located distal in the bronchioles (replacing goblet cells)

Question 17

What cells help protect the lung and how?

Answer 17

Clara cells - secretory products (surfactant, lipids, glycoproteins and inflammatory modulators)
Ciliated epithelial cells - help remove substance from the lower lung
Goblet cells - mucous secretion
Mast cells - inflammatory mediators (histamine, proteoglycans, lysosomal enzymes and AA metabolites)

Question 18

About how many alveoli are there in a normal adult?

Answer 18

~480 million

Question 19

How many capillaries per alveoli are there? (typically)

Answer 19

~ 500-1000 per alveolus

Question 20

What type of cell/layer composes the alveolar surface?

Answer 20

Mainly, cuboidal type II alveolar cells. Produces the fluid layer that lines the alveoli.

Question 21

What is the ratio between Type II and Type I alveolar cells?

Answer 21

~2:1
However, Type I cover 90-95% of the alveolar surface d/t its larger surface area.

Question 22

Does gas exchange occur on Type I or Type II alveolar epithelial cells?

Answer 22

Type I - they also actively pump Na and water from the alveolar surface into the interstitium removing liquid.

Question 23

What is the third type of cell found on the extracellular lining of the alveolar surface?

Answer 23

A free-ranging phagocytic alveolar macrophage. These cells patrol and phagocytize bacteria.

Question 24

What are capillaries formed by?

Answer 24

A single later of squamous cells forming tubes.

Question 25

What must gases pass through during diffusion? How large is the gap?

Answer 25

Alveolar epithelium (including the fluid lining it) the interstitial space, the capillary endothelium and the plasma inside the capillary.
0.2-0.5 um thick.

Question 26

Can the respiratory muscles contract spontanously?

Answer 26

No. They must be controlled by the brain (medulla) and spinal cord.