PDBio 220 lecture 19

upper respiratory tract

- sinuses
- nasal cavity
- pharynx

lower respiratory tract

- larynx
- trachea
- bronchial tree
- lung alveoli

pulmonary ventilation

breathing

gas exchange

- external respiration (air to blood, blood to air)

gas conditioning

(warm, humidify, and cleanse air)

functions of the respiratory system

- pulmonary ventilation
- gas exchange
- gas conditioning
- sound production
- olfaction
- defense

nasal cavity skeleton

- hyaline cartilage

nasal cavity functions

- airway for respiration
- pseudo stratified ciliated columnar epithelium
- warm, humidify, and clean inhaled air (blood vessels and mucous)
- resonating chamber for speech and sound
- houses olfactory receptors

pharynx

- throat
- connects nasal cavity and mouth to larynx and esophagus
three regions:
- nasopharynx
- oropharynx
- laryngopharynx

nasopharynx

pseudo stratified ciliated columnar epithelium

oropharynx

stratified squamous epithelium

laryngopharynx

stratified squamous epithelium

layrnx

- voice box

trachea

- C-shaped hyaline cartilage rings
- posterior wall is not rigid, but muscular
- pseudo stratified ciliated columnar
- mucus producing goblet cells

Secondary Bronchi

lobar bronchi

tertiary bronchi

segmental bronchi

bronchioles

- microscopic
- no longer contain cartilage
- smooth muscle (bronchoconstriction or bronchodialation)

terminal bronchiole

smallest bronchioles without alveoli

alveolar type I cells

simple squamous

alveolar type II cells

secrete surfactant. thick, help keep aveoli pattent.

alveolar macrophages

dust cells

root of the lung goes through what

the hilum

the pleural cavity is filled with what

serous fluid

go look at pulmonary ventilation slides

...

external respiration

- gas exchange in the lungs between blood and air (at the alveoli)
- O2 diffuses from air into blood
- CO2 diffuses from blood into air

internal respiration

- gas exchange between blood and tissue cells (at systemic capillaries)
- O2 diffuses from blood into body cells
- Co2 diffuse from body cells into blood

asthma

- airway hypersensitivity leads to inflammation and bronchoconstrcition
- symptoms include wheezing, coughing, shortness of breath, excess mucous
- treatment may include inhaled steroids mixed with bronchodilators
- may occur in response to pollen, smoke,

emphysema

- chronic destruction of alveoli and loss of lung elastic tissue
- decrease in gas exchange surface area
- loss of elastic tissue makes it difficult to exhale, old air is trapped in alveoli
- usually caused by smoking

pneumonia

- infection of the alveoli of the lungs resulting in swelling and red
- may be caused by viruses, bacteria or fungi
- symptoms include cough, fever, rapid breathing and sputum

Lung Cancer

- usually caused by cigarette smoking
- adenocarcinoma
- squamous cell carcinoma
- small cell carcinoma
- most effective treatment is complete removal of diseased lung

3 common types of lung cancer

- adenocarcinoma (cancer of mucus producing cells)
- squamous cell carcinoma (cancer or squamous cells)
- small cell carcinoma (cancer in the bronchioles)