Lecture 17 Respiratory System

Question 1

What are the 4 functions of respiration?

Answer 1

1. Pulmonary ventilation
2. External respiration
3. Transport of respiratory gases
4. Internal respiration

Question 2

Describe External Respiration

Answer 2

The movement of oxygen from the alveoli to the pulmonary capillaries and CO2 from the pulmonary capillaries to the alveoli.

Question 3

Describe Pulmonary Ventilation

Answer 3

Air must be moved in and out of lungs to continually replace gases in lung alveoli

Question 4

Describe Transport of Respiratory Gases

Answer 4

Transport of O2 and CO2 between lungs and cells of body via cardiovascular system

Question 5

Describe Internal Respiration

Answer 5

Gas exchange between systemic capillaries and cells

(O2 leaves blood in systemic capillaries and enters surrounding tissues and then cells while CO2 is opposite)

Question 6

In lecture (slide 12)
1 6
3 4
2 5
a b

Answer 6

External respiration
Internal respiration
Transport of gases
Pulmonary ventilation

Question 7

Name the 3 components of the respiratory membrane

Answer 7

• Type 1 alveolar cells
• Pulmonary capillary endothelial cells
• Basal Lamina

Question 8

How many layers of plasma membrane does O2 need to pass through in order to get into the RBC?

Answer 8

5

Question 9

What are the first 3 steps of gas exchange and transport?

Answer 9

1. Oxygen enters blood at alveolar capillary interface
2. Oxygen is transported in blood dissolved in plasma or bound to hemoglobin inside RBCs
3. Oxygen diffuses into cells

Question 10

What are the last 3 steps of gas exchange and transport?

Answer 10

4. CO2 diffuses out of cells
5. CO2 is transported dissolved in plasma, bound to hemoglobin or as HCO3-
6. CO2 enters alveoli at alveolar-capillary interface

Question 11

What is the pathway of air in the respiratory system?

Answer 11

nose > pharynx > larynx > trachea > primary bronchi > 2 > 3 > 4 > 5th bronchi > bronchioles > terminal bronchioles > respiratory bronchioles > alveoli

Question 12

True or False: Gas exchange occurs ONLY in respiratory bronchioles to alveoli

Answer 12

TRUE: all other structures constitute the conducting zone

Question 13

Which is NOT part of the conducting zone?

Nose, pharynx, larynx, trachea, alveoli, most of bronchial passageways

Answer 13

Alveoli (part of respiratory zone along with respiratory bronchioles)

Question 14

In what ways does the conducting zone passageway perform conditioning of air?

Answer 14

Warming (through BVs in lamina propria), humidifying (through water secretions), and filtering inspired air (breathing in cold air HURTS we need to warm it up)

Question 15

What is the function of mucus secreted by goblet cells?

Answer 15

To trap foreign pathogens and dust particles

Question 16

What are alveoli covered in a “cobweb” of?

What are they surrounded by which enable stretch and recoil during inhalation and exhalation?

Answer 16

• Pulmonary capillaries
• Elastic fibers

Question 17

What is the alveolar layer of the respiratory zone made up of?

Answer 17

A single layer of squamous epithelial cells (type I cells) surrounded by basal lamina

Question 18

What is the second half of the respiratory zone made up of?

Answer 18

Capillary endothelial cell layer

Question 19

What is surfactant?

What does it do?

Answer 19

It is a fluid secreted by type II cells

It coats the internal alveolar surfaces and prevents alveoli from collapsing on themselves by reducing surface tension

Question 20

How is passage of air allowed between alveoli?

Answer 20

They have pores within the alveolar walls that allow air to slip through

Question 21

Why does quiet respiration occur and what is it due to?

Answer 21

Occurs because diaphragm contracts, increasing thoracic volume vertically

Due to passive recoil

Question 22

What is Boyle’s law?

Answer 22

Relationship between volume and pressure is inversely proportional

Question 23

How does intrapulmonary pressure (IPP) occur and what does the increase/decrease of it cause?

Answer 23

Occurs as a result of changes in lung volume

Increase in IPP causes expiration (lung volume -)

Decrease in IPP causes inspiration (lung volume +)

Question 24

Atmospheric pressure is 760 mmHg. What is the intrapulmonary pressure of the lungs at rest, during inspiration and during expiration?

Answer 24

Rest: 760 mmHg
Inspiration: 757 mmHg
Expiration: 763 mmHg

Question 25

STUDY QUIZ FLASHCARDS TOO OKAY????!?!!!!?!!?!?!?!!??!!!

Answer 25

okay :)

Question 26

Ventilation is affected mostly by what two factors?

Answer 26

1. Compliance (stretchability) of lungs
2. Resistance of airways to airflow

Question 27

What is the effect of surface tension on alveoli, resistance to stretch, and compliance?

Answer 27

• Raises pressure in alveoli
• Increases resistance
• Decreases compliance

Question 28

How is surface tension created?

Why is there so much ST in alveoli?

Answer 28

Created by intermolecular forces within fluid molecules that attract molecules to each other.

High in alveoli because of hydrogen bonding of fluid secreted by the lungs

Question 29

Sympathetic activation results in _________ which _______ resistance whereas parasympathetic activation results in _________ which _______ resistance

Answer 29

BRONCHODILATION, DECREASES

BRONCHOCONSTRICTION, INCREASES

Question 30

What are two additional factors that can increase resistance of the brochial tube? (bronchoconstrictor)

Answer 30

Histamine and accumulation of mucus