Respiratory Systems

What is the function of the Respiratory System in gas exchange?

Provides extensive gas exchange surfdace area between air and circulating blood

What is the function of the Respiratory System in movement of air?

Moves air to and from exchange surfaces in lungs

What is the function of the Respiratory System in protection?

Protects respiratory surfaces from outside environment

What is the function of the Respiratory System in sound?

Produces sound

What sense does the Respiratory System participate in?

Olfactory

What is the difference in location between the Upper and Lower Respiratory System?

• Upper - Above larynx

• Lower - Below larynx

What does the Respiratory Tract consist of?

Conducting and Respiratory portion

What is the conducting portion?

Nasal cavity to terminal bronchioles

What is the respiratory porton?

Respiratory bronchioles and alveoli

What are the Alveoli?

Air filled pockets w/in lungs where gas exchange takes place

What is the function of the Alveoli?

Filter, warm + moisten air and conduct it to lungs

Describe the features of Alveoli?

• Very thin

• Large surface area

What is the purpose of Cilia?

• In epithelial cells, form a dense layer

• Cilia movement propels mucus across epithelial surface

What is the Alveolar Epithelium?

• Very delicate, simple squamos

• Scattered + specialised cells

• Lines exchange surfaces of alveoli

What is the Respiratory Mucosa?

• Consist of epithelial/areolar layer

• Lines conducting portion of respiratory system

What is another name for the areolar layer?

Lamina propria

What does the Respiratory Defense system consist of?

Mucous cells/glands

What is the role of Mucous cells/glands?

Produce mucus that bathes exposed surfaces

What is the role of cilia in the Respiratory Defense System?

Sweep debris trapped in mucus towards pharynx (mucus escalator)

What is the purpose of filtration in the Respiratory Defense System?

Removes large particles in nasal cavity

What is the role of Alveolar Macrophages in the Respiratory Defense System?

Engulf small particles that reach lungs

What is the benefit of Mucous in protection?

Protects surfaces from damage

What is the benefit of Mucous against pathogens?

Destroys bacteria and viruses

What is the benefit of Mucous against particles?

Traps particles

What is the benefit of Mucous against water loss?

Prevents water loss

What is the benefit of Mucous in passageways?

Humidifies passageways

What is the benefit of Mucous in movement?

Lubricates movement of materials

How does Air enter the respiratory system?

Through nostrils/external nares, into nasal vestibule

What is the purpose of Nasal Hairs?

1st particle filtration system, in nasal vestibule

What is the Olfactory Region in the Upper Respiratory Tract?

Superior portion of nasal cavity, provides sense of smell

What is the role of Mucous Secretions in the Upper Respiratory Tract?

• Secretions from paranasal sinus

• Clean/moisten nasal cavity

What is the Pharynx?

Chamber shared by digestive and respiratory systems

Describe the structure of the Pharynx?

Extends from internal nares to entrances to larynx and esophagus

What are the 3 parts of the Pharynx?

• Nasopharynx

• Oropharynx

• Laryngopharynx

What is the Nasopharynx?

Superior portion of the pharynx

What are the features of the Nasopharynx?

Contains pharyngeal tonsils + openings to left/right auditory tubes

What is the Oropharynx?

Middle portion of pharynx

What is the role of the Oropharynx?

Communicates with oral cavity

What is the Laryngopharynx?

Inferior portion of pharynx

What is the role of the Laryngopharynx?

Extends from hyoid bone to entrance of larynx and esophagus

How does air flow in the Respiratory System?

From Pharynx, enters larynx

What is the Larynx?

Cartilaginous structure surrounding glottis

What are the Hyaline Cartilages in the Larynx?

Thyroid, cricoid

What is the Elastic Cartilage in the Larynx?

Epiglottis

What is the role of the Croniculate Cartilage?

Opening/closing of the glottis

What is the role of the Arytenoid Cartilage?

Production of sound

What is the purpose of the Thyroid and Cricoid cartillages?

Support and protect

Describe the glottis

Consists of vocal cords & slit-line opening between them + entrance to trachea

What happens to the larynx during swallowing?

Larynx is elevated, epiglottis folds back over glottis

What is the benefit of the epiglottis folding over the glottis?

Prevents entry of food/liquis into respiratory tract

How is sound produced?

Air passes through glottis, vibrates vocal folds applying tension on them

How is speed produced?

Phonation and articulation

What is phonation?

Sound production at larynx

What is articulation?

Modification of sound by other structures

Describe the structures of the different bronchi

Right primary is larger in diameter, descends at steeper angle

What is the role of Tracheal Cartilages?

Strengthen and protect airway

How are tracheal cartilages connected?

Ends of each cartilageare connected by elastic ligament & trachealis muscle

What is the Hilum?

Primary bronchi

Where is the Hilum?

Anchored in meshwork of connective tissue

Describe the structure of the right lung

Wider, displaced upward by liver

Describe the structure of the left lung

Larger, displaced left by heart forming cardiac notch

What are the 3 lobes of the right lung?

Superior, middle, inferior

How are the 3 lobes of the right lung separated?

By horizontal and oblique fissures

What are the 2 lobes of the left lung?

Superior and inferior

How are the lobes of the left lung separated?

By oblique fissure

Bronchopulmonary segments of superior lobe

Right - 3, Left - 4

Bronchopulmonary segments of inferior lobe

Right - 5, Left - 5

Bronchopulmonary segments of middle lobe

Right - 2, Left - 0

What is the Bronchial Tree?

Formed by primary bronchi and their branches

What is the Extra-pulmonary Bronchi

Left and right bronchi branches outside lungs

What is the Intra-pulmonary bronchi?

Branches w/in lungs

Describe the walls of the Primary, Secondary and Tertiary Bronchi?

Contain porgressively less cartillage + more smooth muscle

What is the benefit of smooth muscle?

Increased smooth muscle tnesion affects airway constriction and resistance

What is the primary bronchus?

Branches to form secondary bronchi

What is another name for the secondary bronchi?

Lobar bronchi

What is the function of the secondary bronchi?

Branch to form tertiary bronchi

What is another name for the tertiary bronchi?

Segmental bronchi

What is the function of the tertiary bronchi?

Each segmental bronchus supplies air to a bronchopulmonary segment

What is the Bronchiole Structure?

No cartilage + dominated by smooth muscle

What is the benefit of Bronchiole Structure?

Controls their diameter + airflow/resistance in lungs

What is Bronchodilation?

Dilation of bronchial airways

What is Bronchodilation caused by?

Sympathetic ANS activation

What is the ANS?

Autonomic Nervous System

What is Bronchoconstriction?

Constricts bronchi, caused by parasympathetic ANS activation

What is the result of Bronchoconstriction?

Histamine release

What can cause Bronchoconstriction?

Allergic release

What is Anti-Histamine used for?

Dilation of bronchi

What is Asthma?

Excessive stimulation & bronchiconstriction

What is the effect of the stimulation caused by Asthma?

Severely restricts airflow

Describe the structure of the Alveolar Epithelium?

Consists of simple squamos epithelium

What does the Alveolar Epithelium have that is useful for gas exchange?

Thin, delicate type 1 pneumocytes patrolled by alveolar macrophages

What are alveolar macrophages?

Dust cells

What do Alveolar Macrophages do?

Engulf abnormal molecules

Why does the Alveolar Epithelium have Type 2 Pneumocytes?

Produce surfactant

What are Type 2 Pneumocytes?

Septal cells

What i

What does the Surfactant contain?

Phospholipids and proteins

What does the Surfactant do?

Coats alveolar surfaces and reduces surface tension, keeping alveoli open

What is the effect of Respiratory Distress Sydnrome?

Difficult respiration due to alveolar collapse

What causes Respiratory Distress Syndrome?

Type 2 pneumocytes don’t produce enough surfactant