Introduction to the Respiratory System

What are the main functions of the respiratory system?

• Supply body with oxygen for cellular respiration

• Dispose of carbon dioxide waster from cellular respiration

• Olfaction

• Speech

Pulmonary ventilation

Movement of gases into and out of the lungs

External respiration

Occurs in lungs; carbon dioxide exits the bloodstream and oxygen enters the bloodstream

Transport of respiratory gases

Oxygen and carbon dioxide are bound to hemoglobin or dissolved in blood plasma

Internal respiration

Occurs in tissues; carbon dioxide enters the bloodstream and oxygen exits the bloodstream

Which of the four processes occurs within the respiratory system?

• Pulmonary ventilation

• External respiration

What organs are part of the upper respiratory system?

• Nose and nasal cavity

• Paranasal sinuses

• Pharynx

What organs are part of the lower respiratory system?

• Larynx

• Trachea

• Bronchi and branches

• Lungs and alveoli

The nasal cavity is separated from the cranial cavity by the…

Ethmoid and sphenoid bones

The nasal cavity is separated from the oral cavity by the…

Palate

What kind of mucosa is found in the nasal cavity?

• Olfactory mucosa

• Respiratory mucosa

What kind of epithelium does respiratory mucosa have?

Ciliated pseudostratified columnar epithelium

Mucus secreted by the seromucous glands and goblet cells is a part of the body’s ___ defenses.

Innate

How much mucus is secreted a day?

A liter

Paranasal sinuses

Mucosa-lined cavities within the bones of the skull that decrease the weight of the skull

Why does a sinus headache occur?

If drainage of sinuses becomes blocked by inflammation or thick mucus

What tonsils are located in the nasopharynx?

• Pharyngeal tonsils

• Tubal tonsils

What kind of epithelium does the oropharynx contain?

Stratified squamous epithelium

What tonsils are located in the oropharynx?

• Palatine tonsils

• Lingual tonsils

What kind of epithelium does the laryngopharynx contain?

Stratified squamous epithelium

What are the functions of the larynx?

• Patent airway

• Directs air and food into the correct systems

• Produces voice

What kind of cartilage is the thyroid and cricoid cartilage made of?

Hyaline cartilage

What kind of cartilage is the epiglottis made of?

Elastic cartilage

What causes men to have deeper voices?

The enlargement of the larynx lengthens male vocal folds

What causes a higher pitch in voice?

More vibration from tenser vocal folds

Laryngitis

Inflammation of the larynx due to overuse, irritation, or infection

What kind of infection is laryngitis?

An upper respiratory tract infection

Conducting zone

Conducts air down into the lungs but does not permit any gas exchange to occur

Respiratory zone

Smallest structures of the bronchial tree that all permit the exchange of respiratory gases between the air and the blood

What process occurs in the respiratory zone?

External respiration

What are the wall layers of the trachea?

• Mucosa

• Submucosa

• Adventitia

What muscle contracts when a person coughs and pulls the hyaline cartilage rings together?

Trachealis muscle

What triggers a violent coughing reflex when food makes its way down to the bottom of the trachea?

Carina

What has more smooth muscle, a bronchiole or a bronchus?

A bronchiole

What is the flow of the respiratory zone?

Terminal bronchiole → respiratory bronchiole → alveolar ducts → alveoli

What do you usually see next to a bronchi?

A blood vessel

Respiratory membrane

Blood-air barrier

What is the respiratory membrane composed of?

• Alveolar epithelium

• Basement membrane

• Capillary endothelium

What do alveolar pores do?

• Allows air pressures to equalize throughout the lung

• Provide alternate pathways for airflow into alveoli whose bronchioles may have collapsed or become obstructed

What cells are located in the alveoli?

• Type I alveolar cell

• Type II alveolar cell

• Fixed alveolar macrophages

Which alveolar cell secretes surfactant?

Type II alveolar cell

Where do bronchial arteries arise?

Aorta

Which vein anastomoses with pulmonary veins to return blood to heart?

Bronchial veins

What kind of fibers innervate the lungs?

• Parasympathetic fibers

• Sympathetic fibers

• Visceral sensory fibers

Parasympathic innervation is supplied through the…

vagus nerve

Sympathic innervation is supplied through the…

Sympathetic trunk

Where do the nerves enter?

Pulmonary plexus

Parasympathetic innervation causes…

Bronchoconstriction

Sympathetic innervation causes…

Bronchodilation

What does each bronchopulmonary segment have?

Its own artery and vein

What holds the lungs against the wall of the thoracic cavity?

Pleural fluid

Pleurisy

Inflammation fo the pleurae leading to pleurae becoming rough

What can pleurisy lead to?

Pleural effusion

Pleural effusion

Buildup of fluid in the pleural cavity

What can cause a collapsed lung?

Pleural effusion caused by pleurisy