Respiratory system

For breathing purposes

Major function of the Respiratory System

To supply the body with oxygen and dispose of carbon dioxide.

Pulmonary Ventilation

Air is moved into and out of the lungs so the gases there are continuously changed and refreshed.

External Respiration

Oxygen diffuses from the lungs to the blood and carbon dioxide diffuses from the blood to the lungs

Transport of Respiratory Gases

Oxygen is transported from the lungs to the tissue cells of the body and carbon dioxide is transported from the tissue cells to the lungs. The cardiovascular system accomplishes this transport using blood as the transporting fluid.

Internal Respiration

Oxygen diffuses from blood to tissue cells, and carbon dioxide diffuses from tissue cells to blood.

What does the respiratory system contain

nose, nasal cavity, paranasal sinuses, pharynx, larynx, trachea, bronchi, lungs

The respiratory zone

the actual site of gas exchange is composed of the respiratory bronchioles alveolar ducts and alveoli, all microscopic structures.

The conducting zone

includes all other respiratory passageways, which provide fairly rigid conduits for air to reach the gas exchange sites. The conducting zone organs for air to reach the gas exchange sites. The conducting zone organs also cleanse, humidify and warm incoming air. As a result, air reaching the lungs has fewer irritants. Than when it entered the body, and it is warm and damp, like the air of the tropics.

The nose

1) provides an airway for respiration
2) moistens and warms entering air
3) filters and cleans inspired air
4) serves as a resonating chamber for speech
5) houses and olfactory receptors

Surface Features of External Nose

Root (area between the eyebrows)
Bridge and Dorsum Nasi (anterior margin)
Apex (tip of the nose)
Nostrils or Nares (external openings)
Alae (bounds the external openings laterally)

what is on the roof of nasal cavity

Olfactory Epithelium

Nasal Cavity Function

Receptors for sense of smell

Paranasal Sinuses

Mucosa-lined, air filled cavities in cranial bones surrounding nasal cavity
Same as for nasal cavity except no receptors for smell, also lighten skull

Pharynx

Passageway for air and food
Facilitates exposure of immune system to inhaled antigens.
Three subdivisions: nasopharynx, oropharynx, larygopharynx

Larynx

Air passageways prevents food from entering lower respiratory tract
Voice production

Trachea

Air passageways; cleans, warms, and
moistens incoming air

Bronchial tree

Air passageways connecting trachea with alveoli; cleans, warms, and moistens incoming air

Alveoli

Main sites of gas exchange
Reduces surface tensions; helps prevent lung collapse

Lungs

House respiratory passages smaller than the main bronchi

Pleurae

Produce lubricating fluid and compartmentalize lungs

Nasopharynx

Serves as an air passageway, prevents food from coming in the airway

Oropharynx

Both food and air pass through it. Has a protective stratified squamous epithelium to help protect from the increased friction caused by food and chemical trauma.

Laryngopharynx

Serves as a passageway for food and air. Extends to the larynx where respiratory and digestive pathways diverge.

Epiglottis

is composed of elastic cartilage and is almost entirely covered by a taste bud-containing mucosa. Called the guardian of the airways because it prevents food from going into the respiratory system.

Vocal Folds

Produce sounds as air rushes up from the lungs.

Intrapulmonary Pressure

is the pressure in the alveoli. Intrapulmonary pressure rises and falls with the phases of breathing, but it always equalizes with the atmospheric pressure eventually.

Intrapleural pressure

fluctuates with breathing phases but us always 4 mm Hg less than P pul.

Transpulmonary pressure

the difference between the intrapulmonary and the intrapleural pressure that keeps the air spaces of the lungs open or phrased another way, keeps the lungs from collapsing