Respiratory System

Question 1

What are the functions of the respiratory system?

Answer 1

Conduction of inspired air
Pulmonary Ventilation (gas exchange)

Question 2

What are the respiratory system organs?

Answer 2

Nose, nasal cavity, and paranasal sinuses
Pharynx, larynx, and trachea
Bronchi and their smaller branches
Lungs and alveoli

Question 3

Components of the respiratory system?

Answer 3

Nasal cavity + paranasal sinuses
Pharynx
Larynx
Trachea

Question 4

Conducting Zone

Answer 4

Primary bronchi
Lobar bronchi
Segmental bronchi

Question 5

The Nose

Answer 5

Airway for respiration
Filtration of inhaled air
Moistening and warming of the air
Resonating chamber for speech
The site of olfactory receptors (smell is accomplished only through the nasal cavity)

Question 6

Paranasal Sinuses

Answer 6

Can be a resonating chamber for speech
Lightens the weight of the skull
Can fill with fluid (negative function)

Question 7

Pharynx and its 3 subdivisions

Answer 7

A passageway connecting the nasal and oral cavities superiorly to the larynx and esophagus inferiorly, divided into three parts:
Nasopharynx
Oropharynx
Laryngopharynx

Question 8

Larynx Structure

Answer 8

Framework of 9 cartilages connected by ligaments and membranes
Suspended from the hyoid bone
Enclosed laterally by the pharynx
Inferiorly continuous with the trachea

Question 9

Larynx Function

Answer 9

Voice production (voice box)
Open airway
Mechanism of directing air and food into their proper channels- the trachea and esophagus

Question 10

Trachea (windpipe)

Answer 10

Descends from the larynx through the neck into the mediastinum, where it ends by dividing into the two primary bronchi

Question 11

Structure of the Bronchial Tree

Answer 11

Main Bronchi (Primary)
Lobar Bronchi (secondary)
Segmental Bronchi (tertiary)
Bronchioles

Question 12

Main Bronchi (primary)

Answer 12

Largest subdivisions, enter the lungs

Question 13

Lobar Bronchi (secondary)

Answer 13

3 on the right side (right lung)
2 on the left side (left lung)

Question 14

Segmental Bronchi (tertiary)

Answer 14

Branch into each lung segment (bronchopulmonary segment)

Question 15

Bronchioles

Answer 15

Small bronchi, less than 1mm in diameter

Question 16

Aspiration of Foreign Bodies

Answer 16

Since the right bronchus is wider, shorter, and runs more vertically; foreign bodies are more likely to enter and stay on the right bronchus or its branches

Question 17

Respiratory Zone

Answer 17

The terminal part of the respiratory tree in the lungs where gas exchange takes place
Gas exchange occurs in the alveoli (air sacs at the end of respiratory tree)

Question 18

Pleura

Answer 18

A double-layered sac surrounding each lung

Question 19

Parietal Pleura

Answer 19

Lines the pleural cavity

Question 20

Visceral Pleura

Answer 20

Covers the lung

Question 21

Pleaural Cavity

Answer 21

Potential space between the visceral and parietal layers of pleura

Question 22

Lung Features

Answer 22

Right lung: 3 lobes; oblique and horizontal fissures
Left lung: 2 lobes; oblique fissure; cardiac notch

Question 23

Pulmonary Ventilation (breathing)

Answer 23

Compromised of 2 Phases:
Inspiration
Expiration

Question 24

Inspiration

Answer 24

The period when air flows into the lungs:
- The diaphragm contracts, moving inferiorly. This increases the volume of the thoracic cavity
- The external intercostal muscles contract to raise the ribs. This results in an enlargement of both the lateral dimension and the anterior/posterior dimension of the thorax
- The intercostal muscles also function to stiffen the thoracic wall. If the wall is not stiffened, the thorax would just change shape, and not necessarily increase its volume

Question 25

Expiration

Answer 25

The period when gases exit the lungs:
- quiet: relaxation of external intercostals + diaphragm; decreases thoracic volume; increase lung pressure- outflow of air
- forced: involves internal intercostals and abdominal muscles

Question 26

Ventilation

Answer 26

Conceive of the thorax as an expandable container with only one entrance, the trachea
- Enlarging the dimensions of the thorax decreases air pressure within it. This causes air to flow in from the outside. Air always moves from high to low pressure
- During normal inspiration, the diaphragm and intercostal muscles function to increase the volume of the thorax

Question 27

Increases in Thoracic Volume

Answer 27

Vertical dimension (height): diaphragm contracts and descends
Anteroposterior (AP) dimension: increases considerably when the intercostals contract (pump-handle movement)
Transverse Dimension: slight increase with bucket-handle movement

Question 28

Changes in the Thoracic Volume during Inspiration

Answer 28

• As the ribs are raised by the contracting external intercostal muscles, the anteroposterior dimension of the thorax also enlarges
• The external muscles elevate the ribs during inspiration, causing the thorax to expand laterally

Question 29

Diaphragm

Answer 29

• Skeletal Muscle
• Receives somatic motor and sensory innervation from phrenic nerves (C3-C5) centrally and intercostal nerves peripherally (sensory innervation)
• Blood supply: From the musculophrenic and pericardiacophrenic arteries (branches of the internal thoracic artery)