Module 16: The Respiratory System Flashcards Preview

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Flashcards in Module 16: The Respiratory System Deck (28):
1

Pulmonary ventilation

“Breathing”
Inhalation (inspiration) and exhalation (expiration)

2

External respiration

Exchange of gases between the blood and the lungs

3

Transport of respiratory gases

In RBCs and plasma

4

Internal respiration

Exchange of gases between the blood and tissue cells

5

Conducting zone (macroscopic)

Nose
Pharynx (throat)
Larynx (voice box)
Trachea (windpipe)
Bronchi
Terminal bronchioles

6

Epiglottis

Covers the opening of the larynx
Closes off the larynx during swallowing

7

Respiratory zone (microscopic)

Respiratory bronchioles
Alveolar ducts

8

Respiratory bronchioles

Formed from branchings of the terminal bronchioles

9

Alveolar ducts

Respiratory bronchioles lead into alveolar ducts
Alveolar ducts lead into clusters of alveoli

10

Alveoli (air sacs)

300 million in each lung provide a lot of surface area
Found in clusters called alveolar sacs
Where gas exchange occurs

11

Type I alveolar cells

Simple squamous epithelium
Provide the site for gas exchange between the capillaries and the alveoli

12

Type II alveolar cells

Septal cells
Produce surfactant (reduces surface tension between fluid molecules inside the alveoli so they do not adhere to each other and collapse)

13

Macrophages

Dust cells
Wander around “cleaning up” foreign material

14

Hilus

Area in each lung where blood vessels, lymphatic vessels,
nerves, and the bronchus enter and leave the lung

15

Boyle's Law

With a constant temperature, when volume ↓ then pressure ↑

16

Gas exchange in the lung

Air is inhaled
Oxygen diffuses from the alveoli into the capillaries
Carbon dioxide diffuses from the capillaries into the alveoli
Carbon dioxide is exhaled

17

Gas exchange in the body cells

Oxygen leaves the capillary blood and diffuses into the cells where it can be used during cellular metabolism
Carbon dioxide diffuses into the capillary blood as metabolism occurs in the cell

18

Transport of oxygen

Oxygen diffuses across the alveoli into the capillaries
Oxygen then dissolves in the plasma
About 3% of the oxygen is transported as a dissolved gas in the plasma
97% of the oxygen is carried by hemoglobin molecules in the erythrocytes

19

Transport of carbon dioxide

Diffuses from the tissue cells into the capillaries
Blood returns the carbon dioxide to the lungs in three ways:
• dissolved in the plasma (7%)
• combined with hemoglobin in the erythrocytes (23%)
• as bicarbonate ions in plasma (70%)

20

Medullary rhythmicity center

Sets the basic pattern of respiration
In a resting adult, inspiration lasts for about 2 seconds and expiration for about 3 seconds
Normal respiratory rate ranges between 12 and 20 breaths per minute in an adult and from 20 to 40 breaths per minute in a child

21

Central chemoreceptors

Sensitive to increases in carbon dioxide and hydrogen ion levels

22

Peripheral chemoreceptors

Detect decreases in oxygen levels

23

Respiratory distress syndrome (RDS)

Also called hyaline membrane disease (HMD)
Most common cause of death of newborns – almost exclusively in those born before the 37th week of gestation
Caused by a deficient amount of surfactant
Characterized by difficult breathing, which exhausts the infant

24

Aging and the respiratory system

Airways and tissues become less elastic – oxygen delivery to tissue cells is impaired
More susceptible to diseases due to the decrease in activity of the macrophages and ciliary action of the epithelial lining of the respiratory tract

25

Vital capacity

Maximum volume of air that can be expelled from the lungs

26

Tidal volume

The amount of air exchanged with a normal quiet breath

27

Partial pressure

The pressure exerted by each gas in a mixture

28

Inspiratory reserve volume

The volume of air over the tidal volume that can be forced into the lungs