Section 2

Question 1

What does the conducting portion of the respiratory system function to do?

Answer 1

Carries air to and from the lungs WITHOUT contributing to gas exchange.

Question 2

What are all the anatomical structures that make up the conducting portion of the respiratory system?

Answer 2

• Paranasal sinuses
• Nose and nasal cavity
• Pharynx
• Larynx
• Trachea
• Primary bronchi
• End of the conducting portion

Question 3

What are the paranasal sinuses/what are they used in?

Answer 3

• The paranasal sinuses are a collection of air filled spaces within the bones of the skull communicating with the nasal cavity
• Aid in the conditioning of air (warming and humidifying), defence against pathogens, and act as resonance chambers for speech as well

Question 4

Which bones contain paranasal sinuses?

Answer 4

The paired sinuses are named after the bones of the skull that contain them:
- frontal sinus (2)
- maxillary sinus (2)
- ethmoid sinus (2)
- sphenoid sinus (2)

Question 5

What are the paranasal sinuses lines with, and what does this contribute to?

Answer 5

• Lined with respiratory tract epithelium
• Contributes to its function in defense and conditioning

Question 6

*interesting fact
What happens when epithelial lining of the sinuses becomes inflamed or swollen due to infection?

Answer 6

Pressure can build up due to blockage of mucus flow, which can result in a sinus cold or a headache!

Question 7

Describe the first line of defence against invading pathogens and debris.

Answer 7

• The nose and nasal cavity
• Traps pathogens and debris in coarse hairs and mucus
• Air enters the vestibules (openings) of the nostrils and is passed into the nasal cavity where it is conditioned

Question 8

What are the nasal cavity boundaries?

Answer 8

The nasal cavity is surrounded by bony structures that create the boundaries of the cavity:
- Roof (ethmoid bone)
- Floor (hard palate/roof of mouth)
- Medial wall (nasal septum)
- Lateral wall (contains nasal conchae)
- Anterior (nares/opening between nose and nasal cavity)
- Posterior (opening to nasopharynx (choanae))

Question 9

What is the bone of the roof of the nasal cavity?

Answer 9

A bone in the skull called the ethmoid

Question 10

What is the bone of the floor of the nasal cavity?

Answer 10

The floor is composed of the hard palate (roof of mouth)

Question 11

What does the medial wall of the nasal cavity make up?

Answer 11

Makes up the nasal septum.
The septum is composed of the vertical bones in the skull, and separates the two halves of the nasal cavity.

Question 12

What do the lateral walls of the nasal cavity contain?

Answer 12

• Contains structures called nasal conchae
• These structures create turbulence in the air as it passes through the cavity
• This allows for conditioning and catching debris

Question 13

What is the anterior border of the nasal cavity made by?

Answer 13

• made by the nares (this is the opening between the nose and nasal cavity)

Question 14

What is the posterior border of the nasal cavity?

Answer 14

• The opening to the nasopharynx (choanae), where the nasal cavity connects to the pharynx
  *note: nasal conchae and nasal choanae are SEPARATE structures, don’t get them confused!!

Question 15

What type of epithelium is the nasal cavity mostly covered in? And why?

Answer 15

• respiratory tract epithelium (RTE)
• because of its role in protection from airborne debris and microorganisms, as well as the conditioning of air

Question 16

What type of epithelium is the roof of the nasal cavity lined with?

Answer 16

Olfactory epithelium, which contains sensory receptors for smell

Question 17

What type of epithelium is olfactory epithelium composed of?

Answer 17

Pseudostratified ciliated columnar epithelium

Question 18

What type of neurons does olfactory epithelium contain?

Answer 18

Bipolar olfactory receptor neurons

Question 19

What is the pharynx?

Answer 19

• A muscular tube that connects the nasal cavity and the larynx in the respiratory system.
• Also connects the oral cavity with the esophagus in the digestive system

Question 20

What components make up the pharynx? In order from most superior to most inferior.

Answer 20

1. Nasopharynx
2. Oropharynx
3. Laryngopharynx

Question 21

Which part of the pharynx is part of both digestive and respiratory systems?
a) Nasopharynx
b) Oropharynx
c) Laryngopharynx

Answer 21

BOTH oropharynx and laryngopharynx

Question 22

What is the nasopharynx?

Answer 22

Most superior aspect of the pharynx

Question 23

What is the oropharynx?

Answer 23

• Middle aspect of the pharynx
• Part of both the respiratory and digestive systems
• Muscular tube that passes air from the nasopharynx AND food from the oral cavity into the laryngopharynx

Question 24

What is the laryngopharynx?

Answer 24

• The most inferior aspect of the pharynx
• Part of both the respiratory and digestive systems
• Passes both food and air into the respective systems

Question 25

Describe the histology of the pharynx.

Answer 25

- Nasopharynx: mostly RTE because it has mainly a respiratory function - Oro and laryngopharynx: stratified squamous epithelium. allows for durability when swallowing food

Question 26

On an airplane, the change in altitude can cause pain in the ears due to differences in air pressure between the cabin and the middle ear. What would be a good solution to equalize the pressure, and what part of the pharynx would be associated?

Answer 26

Swallow forcefully, nasopharynx

Question 27

What is the larynx?

Answer 27

- the organ that produces sound ("voice box") - made up of a variety of cartilages, ligaments and associated muscles that serve that purpose

Question 28

What is the position of the larynx?

Answer 28

- Sits anterior to the esophagus - Connects the pharynx with the trachea - Prevents food from entering the trachea

Question 29

What are the three main cartilages of the larynx?

Answer 29

- they serve to protect, attach, and aid in the function of the vocal cords 1. Epiglottis 2. Thyroid cartilage 3. Cricoid cartilage

Question 30

What is the epiglottis?

Answer 30

- a large spoon shaped elastic cartilage in the larynx - functions to prevent food from passing into the trachea (windpipe) - during swallowing, the epiglottis flips downwards and covers the opening of the trachea

Question 31

What is the thyroid cartilage?

Answer 31

- a 'shield shaped' hyaline cartilage in the larynx - provides attachment for many muscles as well as the vocal cords

Question 32

What is the cricoid cartilage?

Answer 32

- a complete ring of hyaline cartilage in the larynx - narrow anteriorly and broad posteriorly - functions as an attachment for muscles and vocal cords

Question 33

Where does the trachea extend from and to?

Answer 33

- from the larynx to approximately the level of T4/T5, where it splits at a junction called the carina

Question 34

What is the main function of the trachea?

Answer 34

- (windpipe) - function in the conduction of air to the lungs

Question 35

What is the structure + how does it contribute to the function (of the trachea)?

Answer 35

- made up of 15-20 C-shaped cartilaginous rings, which are incomplete posteriorly - the rings function to keep the airway open - they are connected posteriorly by the trachealis muscle

Question 36

*interesting fact What is a tracheostomy, and why is it done on certain individuals?

Answer 36

It is performed on individuals whose upper airways are blocked. It is done by making an incision between cartilaginous rings in the neck and inserting a tube so that air can bypass the blockage and breathing through the neck is achieved.

Question 37

Describe the histology of the trachea

Answer 37

Mucosa: - the trachea is lined with RTE in order to clear any debris or pathogens that make it into the lower respiratory tract Submucosa: - Lies between the mucosa and adventitia - Made up of loose (areolar) connective tissue, containing larger vessels and nerves, as well as mucus secreting glands Adventitia: - it is the outer layer of the connective tissue surrounding the trachea - this layer also encloses the "C-shaped" cartilaginous rings made up of hyaline cartilage - the rings make the trachea flexible and durable (important as the organs in the thoracic cavity shift with the movements of breathing)

Question 38

What type of cartilage are the cartilaginous rings of the trachea?

Answer 38

Hyaline

Question 39

What results from the splitting of the trachea?

Answer 39

The splitting of the trachea results in two primary bronchi, left and right, which have the same functional and histological features as the trachea.

Question 40

Compare the left and right primary bronchus

Answer 40

- Each one enters its respective lung on the medial side at the hilus (the aspect of the lung where the primary bronchi enter the lung) - the right primary bronchus is wider, shorter, and more vertical than the left

Question 41

What is the end of the conducting portion divided into, in order?

Answer 41

Bronchi divides into smaller and smaller tubes. Larger diameter, thick walled tube 1. primary bronchi 2. secondary bronchi 3. tertiary bronchi 4. terminal bronchioles Smaller diameter, thin walled tube