Trachea, Bronchus, Bronchiole

What are the 6 organs of the air conducting portion of respiratory system?

• Nostrils

• Nasopharynx

• Larynx

• Trachea

• Bronchus

• Bronchioles

What are the 4 organs that make up the gaseous exchange portion of respiratory system? #009aff

• Terminal bronchioles (maybe not)

• Respiratory bronchioles

• Alveolar duct (passageway branching from respiratory bronchiole)

• Alveolar sac (group of alveoli)

• Alveolus (smallest functional unit of lungs)

Trachea: #fe8c00

• What are the 4 main histological layers of trachea?

4 main layers:

• Mucosa #ffca00

• Submucosa #00b41e

• Cartilaginous layer

• Adventitia

Trachea: Mucosa #ffca00

• What can the mucosa be divided into?

2 layers:

• Epithelium

• Lamina propria

Trachea: Mucosa —> Epithelium #ffca00

• What type

• Contains what cells

What type: Pseudostratified ciliated columnar (typical respiratory epithelium)

Contains what cells:

• Basal cells

• Goblet cells

• Brush cells

• Clara cells

• Neuroendocrine cells

Trachea: Mucosa —> Lamina Propria #ffca00

• What type of layer

• Contains

  • What type of epithelium

What type of layer: Layer of

• Loose connective tissue and

• Elastic fiber

Contains: Glands

• What type of epithelium: Cuboidal

Trachea: Submucosa #00b41e

• Type of layer

• Contains

Type of layer: Irregular dense connective tissue

Contains:

• Tracheal glands (cuboidal epithelium)

• Blood and lymphatic vessels

Trachea: Sometimes the lamina propria and submucosa are merged into propria submucosa

• How can you tell it’s separated or merged?

Separate layers: There’s muscularis mucosae (smooth muscle layer) in between the 2 layers

Merged: There’s no muscularis mucosae in between the 2 layers

Trachea: Cartilaginous Layer

• Shape of cartilage rings

• Composition

• Describe perichondrium

Shape of cartilage rings: C shape

Composition: Chondrocytes in lacunae

Describe perichondrium: Dense connective tissue surrounding the cartilage

Trachea: Adventitia

• What

• Composed of

• Contains

What: Outermost dense connective tissue layer

Contains: Blood vessels, nerves and fat

As the airways divide, what happens to the

• Diameter

• Respiratory epithelium

  • Goblet cells

  • Clara cells

• Glands, CT and cartilage

• Elastic and smooth muscle tissue

Diameter: Smaller

Respiratory epithelium: Shorter

• Goblet cells: Fewer

• Clara cells: More numerous

Glands, CT and cartilage: Less

Elastic and smooth muscle tissue: Increase

What is the organisational chart of the lungs?

Trachea —>

Extrapulmondary bronchi —>

Intrapulmonary bronchi —>

Respiratory bronchioles (gas exchange occurs) —>

Alveolar ducts —>

Alveolar sacs

Lungs: Bronchus

• What

• Epithelium

• Has what type of cartilage

• Type of muscle present

• Mucosa is

  • Lined with

• As diameter decreases, what happens to the

  • Cartilage

  • Smooth muscle

• What type of secretions occur

• What specialised cells are present

What: Air-conducting passage

Epithelium: Pseudostratified ciliated COLUMNAR epithelium

Has what type of cartilage: Hyaline

Type of muscle present: Smooth muscle

Mucosa is: Rugated

• Lined with: Typical respiratory epithelium

As diameter decreases, what happens to the:

• Cartilage: Decline as plates

• Smooth muscle: Increases

What type of secretions occur: Mucous/serous secretions

What specialised cells are present: BALT

Lungs: What is within the yellow circle and then beside it?

Yellow circle: BALT

Beside it: Bronchiole

Lungs: Bronchiole #006dff

• It’s also an air conducting passage, but how is it different from bronchus?

• Epithelium

• Which cells decrease

• Which cells increase

• Lamina propria

  • Are there glands?

  • What is present

• What occurs to the adventitia

Different from bronchus:

• Has only smooth muscle

• No cartilage

Epithelium: Simple cuboidal ciliated epithelium

Which cells decrease:

• Goblet cells

• Basal cells

Which cells increase: Clara cells

Lamina propria:

• Are there glands: No (glandless connective tissue)

• What is present: Smooth muscle

What occurs to the adventitia:

• No cartilage

• But extensive network of elastic fibers around smooth muscle layers

Lungs: Is it bronchus or bronchiole?

Bronchiole

Lungs: Is it bronchus or bronchiole?

Bronchus

Lungs: Respiratory Bronchiole

• Continuation of

• Interrupted by

• What is the epithelium

• What occurs to the epithelium, lamina propria and smooth muscle

Continuation of: Terminal bronchioles

Interrupted by: Thin-walled alveoli (outpocketing)

What is the epithelium: Simple squamous

What occurs to the epithelium, lamina propria and smooth muscle: Altered in the occurrence of alveoli

Lungs: Label 1-6

1: Bronchus

2: Bronchiole

3: Bronchus

4: Bronchiole

5: Alveolar duct

6: Respiratory bronchiole

• Not alveolar duct because it has a wall so it’s a passage