Respiratory system abridged

Question 1

Organs of respiratory pathway

Answer 1

• Nose
• Pharynx
• Larynx
• Trachea
• Main Bronchi
• Lungs – alveoli

Question 2

Surfactant

Answer 2

• Lipid fat molecule made by cuboidal alveolar cells
• Coats gas-exposed alveolar surfaces so alveoli don’t collapse between breaths
• 28 to 30 weeks in pregnancy
• Dysfunctional to functional lungs

Question 3

As we age, what happens to our lungs?

Answer 3

• Chest becomes more rigid and lungs slowly lose their elasticity
• By age 70, VC decreases by about 1/3
• More susceptible to sleep apnea
• Ciliary activity of the mucosa decreases
• More at risk for respiratory tract infections (pneumonia and influenza)

Question 4

Physical factors that influence respiratory rate

Answer 4

• Exercise (more signals to resp. muscles)
• Increased body temperature (increase rate)
• Nonrespiratory movements

Question 5

What does Pons do for respiratory system?

Answer 5

• Smooth out basic rhythm of breathing set by Medulla

Question 6

Eupnea

Answer 6

• Normal breathing rate

- 12-15 respirations/minute

Question 7

What does Medulla do for respiratory system?

Answer 7

• Sets basic rhythm of breathing via pacemaker
• Stimulates diaphragm and intercostal muscles
• Helps maintain eupnea (normal breathing)

Question 8

Which nerves transmit respiratory messages from CNS?

Answer 8

• Phrenic

- Intercostal nerves

Question 9

How is carbon dioxide transported in blood?

Answer 9

• Most transported in plasma as bicarbonate ion
• Smaller amount is transported inside RBCs bound to hemoglobin
• For it to diffuse out of blood into alveoli, must be released from bicarbonate form
• Bicarbonate ions enter RBCs and combine with hydrogen to make carbonic acid, this splits to form carbon dioxide and water; carbon dioxide diffuses from blood into alveoli

Question 10

How is oxygen transported in blood?

Answer 10

• Most transported by RBC, via attachment to hemoglobin

- Very small amount is dissolved in plasma and transported that way

Question 11

Nonrespiratory Movements: Yawn

Answer 11

Very deep inspiration

Question 12

Nonrespiratory Movements: Hiccups

Answer 12

Sudden inspirations resulting from spasm in diaphragm

Question 13

Nonrespiratory Movements: Laughing

Answer 13

• Release of air in a number of short expirations
• Primarily an emotionally induced mechanism
  (same as crying)

Question 14

Nonrespiratory Movements: Crying

Answer 14

• Release of air in a number of short expirations
• Emotionally induced mechanism
  (same as laughing)

Question 15

Nonrespiratory Movements: Sneeze

Answer 15

Same as cough, but upward air expels through nose

Question 16

Nonrespiratory Movements: Cough

Answer 16

• Taking a deep breath, closing glottis, forcing air superiorly against glottis
• Glottis opens and blast of air is rushed upwards
• Acts to clear lower passageways

Question 17

Inspiration/Inhalation

Answer 17

• Diaphragm/external intercostals contract
• Thoracic cavity increases
• Lungs adhere to thoracic walls
• Intrapulmonary volume increases
• Gases in lungs spread out
• Decrease in gas pressure in lungs creates parietal vacuum
• Air is sucked into lungs until pulmonary pressure equals atmospheric

Question 18

Exhalation

Answer 18

• Inspiratory muscles relax
• Rib cage descends & lungs recoil
• Thoracic volume decreases
• Gases in lungs forced closer
• Intrapulmonary pressure raises higher than atmospheric pressure
• Gas flows out of lungs to equalize pressure

Question 19

Pulmonary respiration

Answer 19

• “breathing”

- Air moves in and out of lungs so that gases in alveoli are continuously refreshed

Question 20

Internal respiration

Answer 20

• At systemic capillaries, gas exchanges made between blood and tissue cells

Question 21

External respiration

Answer 21

• Gas exchange between pulmonary blood and alveoli

- Alveoli always have more oxygen than blood

Question 22

Cellular respiration

Answer 22

• Cornerstone of all energy-producing chemical reactions in body
• Actual use of energy by cell
• Making energy from fats, carbs, proteins

Question 23

Protective mechanism: laryngal cartilages

Answer 23

Protects pathways

Question 24

Protective mechanism: Alveolar macrophages

Answer 24

• “dust cells”- pick up bacteria, carbon particles, and other debris

Question 25

Pathway of air from main bronchi to blood

Answer 25

• Bronchi
• bronchioles
• terminal bronchioles
• alveolar duct
• alveoli

Question 26

Lungs

Answer 26

• Without mediastinum, lungs occupy entire thoracic cavity
• Site of gas exchange at respiratory membrane
• Apex is deep to clavicle; base rests atop diaphragm
• Covered with pulmonary/visceral serosa
• Stroma is mainly elastic connective tissue

Question 27

Main Bronchi

Answer 27

• Formed by division of trachea
• Right bronchus is wider, shorter, and straighter
• Only warm, mostly cleansed, and well humidified air passes through bronchi

Question 28

Nose

Answer 28

• Only exterior part of Resp. System
• First line of defense when filtering out air
• Palate separates it from oral cavity
• Sinuses lighten the skull

Question 29

Pharynx

Answer 29

• Passageway for food and air, about 5 in.
• Nasopharynx > oropharynx > laryngopharynx > larynx
• Tonsils in nasopharynx and oropharynx
• Ear infections may follow sore throat

Question 30

Larynx

Answer 30

• “Voice box”
• Routes food/air into proper channels
• Epiglottis, thyroid cartilage, vocal folds, cricoid cartilage
• Vestibular/Vocal folds formed by mucous membrane (Glottis between the two)

Question 31

How is a cough triggered?

Answer 31

If anything other than air enters the larynx

Question 32

Effect of hyperventilation on blood pH

Answer 32

• Decreased carbon dioxide retention
• Decreased carbonic acid
• Increase pH, leading to alkalosis

Question 33

Effect of breathing into a bag on blood pH

Answer 33

• Increased carbon dioxide retention
• Increased carbonic acid
• Decrease pH, leading to acidosis

Question 34

Intrapulmonary pressure relative to atmospheric pressure

Answer 34

• Negative during inspiration
• Positive during exhalation
• Intrapleural pressure is always negative*