Respiratory System

The respiratory system is divided into what parts?

1. Ventilating Mechanism

2. Conducting Portions

3. Respiratory Portions

This creates pressure difference that move air in and out of the lungs

Ventilating Mechanism

• This carries air to and from the site of exchange

• Where the wind passes through

• Conditions air by filters, moistening, and warming

Conducting Portions

Functions for gaseous exchange

Respiratory Portions

When we exhale, the pressure goes?

Up

When we inhale, the pressure goes?

Down

Parts of the muscles of respiration in ventilating mechanism

1. Diaphragm

2. Intercoastal Muscles

3. Scalings

4. Abdominal Muscles

5. Elastic Connective Tissue

What is the primary muscle in the ventilating mechanism?

Diaphragm

Where do the conducting portions start?

Nasal Cavity

Where does the conducting portion end?

Terminal Bronchioles

What is the primary part of the conducting portion?

Terminal Bronchioles

Sequence where the air passes through in the conducting portion

1. Nasal Cavity

2. Nasopharynx

3. Oropharynx

4. Laryngopharynx

5. Larynx

6. Trachea

7. Bronchi

8. Bronchioles

9. Terminal Bronchioles

Does gas exchange happen in the terminal bronchioles?

No

Does gas exchange happen in the respiratory portions?

Yes

Where does the respiratory portions start?

Respiratory Bronchioles

Where does the respiratory portions end?

Alveoli

What lines the wall structure of the respiratory system?

Lining epithelium

In the lining of the wall structure of the respiratory system, what is the lining epithelium derived from?

Endoderm

In the lining of the wall structure of the respiratory system, what is underneath the lining epithelium?

Lamina propia with mucus glands and cartilage

In the lining of the wall structure of the respiratory system, what is underneath the Lamina propia?

Smooth muscle layer

In the lining of the wall structure of the respiratory system, what is underneath the Smooth muscle layer?

Adventitia

What are the layers of the wall structure of the respiratory system from superficial to deep?

1. Lining Epithelium

2. Lamina Propia

3. Smooth Muscle Layer

4. Adventitia

The lining epithelium is made up of what type of epithelium?

Pseudostratified columnar ciliated epithelium with goblet cells

What are the major cell types of the respiratory epithelium

1. Ciliated Columnar Cells

2. Mucus Goblet Cells

3. Brush Cells

4. Basal Cells

5. Small Granular Cells

Has free nerve endings and serve as chemo sensory receptors

Brush Cells

Serve as stem and progenitor cells for epithelial cells

Basal Cells

Minor type of cells that contains granules and change into another cell type and prone to metaplasia

Small Granular Cells

Most important cell type in the cell respiratory epithelium

Ciliated Columnar Cells

Lie within the skull as two cavernous chambers separated by the osseous nasal septum

Nasal Cavities

What is conchae?

Bone like projections in the nose

What are the components of the nasal cavities?

1. Vestibule

2. Internal Nasal Cavity

What is the opening of the nose called?

Vestibule

Where does the preliminary filtration happen?

Vestibule

How many nasal cavities do we have?

Two

How many conchae do we have in our nose per nasal cavity?

Three

This part in the nose conditions the air

Conchae

The olfactory epithelium is found in?

Nasal Cavity

Specialized region of the mucous membrane that covers the superior conchae at the roof of the nasal cavity

Olfactory Epithelium

What is the component of the olfactory epithelium?

Olfactory Neurons

Sends nerve impulses that pass through the cribriform plate of the ethmoid bone

Olfactory Neurons

Where does the olfactory nerve come from?

Olfactory Bulb

• Columnar with narrow bases and are broad cylindrical apexes containing the nuclei and extending microvilli into the fluid layer

• Abundant ion channels

• Maintain microenvironment conducive to olfactory function

Supporting Cells

• Small, spherical, or cone-shaped cells near the basal lamina

• Relaces the olfactory neurons (2-3 months)

Stem Cells/Basal Cells

What else can be seen in the lamina propia?

Serous Glands

• Olfactory glands of Bowman

• Produce a constant flow of fluid

• Access of new odoriferous substances

Serous Glands

What are the conducting portions of the pharynx?

1. Nasopharynx

2. Oropharynx

3. Laryngopharynx

Pharynx is being lined with what?

Pseudostratified columnar ciliated epithelium with goblet cells

• Contains 3 parts

• Contains respiratory epithelium

• Connects to the middle ear cavity

Pharynx

This is what we call that connects to the middle ear cavity in the pharynx

Eustachian Tube

Contains hyaline and elastic cartilage

Larynx

Contains stratified squamous nonkeratinized epithelium

Vestibular Folds

• For phonation or sound production

• Underlying vocalis muscles that change the pitch and sound of voice

Vocal Folds

• Flattened structure projecting from the upper rim of the larynx

• Prevents swallowed food from entering air passageways

Epiglottis

• Lines with typical respiratory mucosa

• Contains numerous seromucous glands producing a watery mucous

• Supported by C shaped rings of the hyaline cartilage

Trachea

Relaxes during swallowing and coughing

Trachealis Muscle

What is the trachealis muscle made up of?

Smooth muscle and fibroelastic tissue

• Secondary, tertiary, and smaller bronchi

• Branches are lined by respiratory mucosa

• Branches have bands of smooth muscle and hyaline cartilage

Bronchial Tree

• When the branches of the bronchial tree with diameters of 1mm or less

• Lined by simple columnar or cuboidal ciliated cells

Bronchioles

• Last branches to lack alveoli

• Lined by simple columnar or cuboidal ciliated cells

Terminal Bronchioles

• Non-ciliated low columnar or cuboidal epithelium

• Consists of clara cells

Terminal Bronchioles

• Cuboidal cells

• Responsible for secretion of surfactant lipoproteins and mucins

• Detoxification of inhaled xenobiotic compounds

• Secretion of antimicrobial peptides and cytokines

Clara Cells

What are other terms for clara cells?

Club Cells

• Smalls sacs that open into a bronchiole, alveolar duct, atrium or alveolar sac

• Separated by thin walls of interalveolar septum specialized for gas exchange

• Has continuous capillaries forming a blood-air barrier

• Septum may be interrupted by pores of Kohn to relive or equalize pressure and allow collateral circulation

Alveoli

• Thin cells lining the alveolus

• The fused basal laminae of thin cells and endothelial cells

• The thin capillary endothelial cells

Blood-Air Barrier

Other term for blood-air barrier

Respiratory Membrane

Types of Alveolar Cells

1. Type 1 Pneumocytes

2. Type 2 Pneumocytes

3. Alveolar Macrophages

Gas permeable component of the blood-air barrier

Type 1 Pneumocytes

• Has membrane-bound lamellar/multilamellar bodies and secretory cells that secrete surfactant that decreases surface tension and prevents alveolar to collapse

• Large secretory cells

Type 2 Pneumocytes

• Removes debris that escapes the muco-ciliary apparatus

• Removes blood that enter alveoli in heart failure

Alveolar Macrophages