21.1 Human Structure and Function

Major function of respiratory system

Gas exchange, supply oxygen rid carbon dioxide

4 processes of respiration

pulmonary ventilation, external respiration, transfer of gases, internal respiration

Pulmonary ventilation

Breathing, Inspiration and expiration take place

Inspiration

Moves air into lungs from the atmosphere

Expiration

Moves air out of lungs into the atmosphere

External respiration

O₂ diffuses from lungs to the blood, CO₂  diffuses from blood to lungs

Cardiovascular system transports gases using blood as transporting fluid, O₂ transported from lungs to tissue cells of body, CO₂ transported from tissue cells to lungs

Internal Respiration

O₂ diffuses from blood to tissue cells, CO₂ diffuses from tissue cells to blood

Two major parts of Nose

External nose, nasal cavity

Nostrils

Opening of external nose to enviornment

External nose

Made of hyaline cartilage, determines shape

Nasal cavity

Internal part of nose, contains olfactory and respiratory mucosa

Olfactory mucosa

Superior region of nasal cavity, Location of smell receptors

Respiratory mucosa

Ciliated columnar epithelium, lines most of nasal cavity

Paranasal sinuses

Ring surrounding nasal cavity, lightens skull, warms air, produces mucus

Sinusitis

Inflammation of nasal cavities, can spread and cause pressure in head

Pharynx

Connects nasal cavity and mouth to larynx and esophagus,

Three parts of pharynx

Nasopharynx, Oropharynx, Laryngopharynx

Nasopharynx

Posterior to nasal cavity, Air passageway only

Oropharynx

Posterior to oral cavity, Swallowed food and air passes through

Laryngopharynx

Lined with stratified squamous epithelium, Passageway for air and food, Posterior to larynx

5 functions of nose

Smell, Passageway for air, warms air, cleans air, Resonance chamber for speech