Zhu: Intro to Respiration

Question 1

Most important function of the respiratory system?

Answer 1

Gas exchange

Question 2

External respiration

Answer 2

what happens before mitochondria

Question 3

Internal respiration

Answer 3

O2 reaches mitochondria –> O2 turns into water and CO2 is made

Question 4

_______ ________ is the driving force of net air movement

Answer 4

pressure difference. (this gives net movement from high pressure to low pressure)

Question 5

**2 Main components of dry air and their percent composition?

Answer 5

O2 (21%); N2 (79%)

Question 6

Dalton’s Law

Answer 6

the pressure of a gas mixture is the sum of the partial pressures of the individual components of the gas mixture

Question 7

Atmospheric Pressure?

Answer 7

760 mmHg

Question 8

(Dalton’s Law): Partial Pressures of O2 and N2?

Answer 8

O2: 21% (760) = 160 mmHg
N2: 79% (760) = 600 mmHg

Question 9

Partial Pressure is decided by __________

Answer 9

concentration.

Question 10

Alveolus branches off at generation_____ at the end of the _____________

Answer 10

16; terminal bronchiole

Question 11

What are the three components of the terminal respiratory unit?

Answer 11

respiratory bronchioles, alveolar ducts, alveolar sacs

Question 12

Relationship of cross-sectional area, flow, and velocity?

Answer 12

F=V*A or V=F/A

Question 13

Cross-sectional area _____through first 4 generations of airway, then _________.

Answer 13

falls; increases.

Question 14

Bigger airways in beginning have a much _________ velocity. Air from smaller airways to alveoli is ________.

Answer 14

faster; slower. (v=f/a)

Question 15

3 mechanisms of deposition?

Answer 15

impaction (for particles >5um), sedimentation (0.2-2), and diffusion (

Question 16

Majority of bacteria is deposited via _______ in the ________. Airflow here is ________.

Answer 16

sedimentation; around the terminal bronchioles. slower.

Question 17

Clearance of deposited articles: Two mechanisms?

Answer 17

Mucociliary Transport System, Alveolar Macrophages

Question 18

3 Layers of Mucociliary Transport System?

Answer 18

Mucus Layer, Periciliary Fluid, and Cilia

Question 19

Mucus Layer

Answer 19

secreted by goblet cells, clara cells, and submucosal glands. contains proteins (makes it sticky), glycoproteins, electrolytes, and water

Question 20

Periciliary Fluid

Answer 20

secreted by pseudo stratified, columnar epithelium. contains electrolytes and water (no proteins therefore not sticky)

Question 21

Cilia beat in which direction?

Answer 21

Towards pharynx –> how we can cough it up

Question 22

Alveolar Macrophages

Answer 22

Contain lysozymes to kill bacteria. Destroyed by cigarette smoke. Smokers destroy macrophages with cigarette smoke so smokers end up with more respiratory tract infections.

Question 23

Airway Resistance equation

Answer 23

Air flow = change in pressure/Resistance

Q=Change in P/R

Question 24

Factors that influence Resistance in Airway

Answer 24

RADIUS RADIUS RADIUS. (Think of cross-sectional area!)
also viscosity and tube length.
Resistance and radius are inversely related thus as radius increases, resistance decreases.

Question 25

Major site of airway resistance?

Answer 25

Large and medium bronchi (they have a smaller cross-sectional area!)

Ex: cig smoke increases the size and number of surface secret cells and submucosal gland and their output as well. parasympathetic stimulation can increase submucosal glad secretion. ==> decrease radius, increase resistance

Question 26

Main site we can work on to increase or decrease radius?

Answer 26

Smooth Muscle:
Sympa dilation via B2-adrenergic receptors (**think: dilation is sympathetic - when you’re running, sympathetic takes over so your lungs need to be dilated)
Parasympathetic constriction via vagus nerve
Local secretion - induced constriction (mast cells release histamine; leukotrienes)

Question 27

Pathophysiology of Asthma - example of airway resistance. What are the two key features?

Answer 27

Airway hyperresponsiveness (airway spasms/smooth muscle contracts)
Airway inflammation (occurs over years)

Question 28

4 Main factors of Airway resistance in asthma?

Answer 28

1. edema (capillaries increase in permeability and proteins leak into tissue)
2. increase in mucus (antigen - mast cells)
3. SM hypertrophy d/t increased contraction over time
4. cilia destroyed