Download Respiratory System

Respiratory System
Unit 4

Ventilation [Breathing]- the act of moving air
in/out of the lungs

Respiration- process where ventilation occurs
along with the exchange of gases in the lungs
and the body tissues
Types of Respiration
External Respiration
-exchange of gases between air in lungs and
blood [alveoli and pulm. capillaries]

Internal Respiration
-exchange of gases between the blood stream
and body’s tissues


Upper Respiratory Tract Organs
- Nose, Nasal Cavity, Sinuses, Pharynx

Lower Respiratory Tract Organs
- Larynx, Trachea, Bronchi, Lungs, Bronchial Tree, Alveoli
Upper Respiratory Tract
Nose
- made of bone and cartilage
- nares/nostrils-openings guarded by hairs that filter
Nasal Cavity
-divided sagitally by nasal septum
-lined with mucous membrane
1. Warms air
2. Moistens air
3. Traps particles
Nasal Conchae [superior, middle, inferior turbinate]
-bony, scroll like projections on lateral wall of each cavity
-increase surface area inside [helps mucous membrane]
-channel and speed up airflow through nose

Sinuses[paranasal]
-air filled hollow spaces inside 4 bones of skull
[ethmoid, sphenoid, maxillary and frontal bones]
- positioned around nose
-lined with mucous membrane
1.
Drain fluids into nasal cavity
2.
Decrease weight of skull
3.
Resonate the voice
Pharynx [throat]
-3 regions: Nasopharynx-posterior to nasal cavity
Oropharynx-posterior to oral cavity
Laryngopharynx- posterior to larynx
[voicebox]

*Pseudostratified ciliated epithelial tissue lines most of
tract.
Cilia encourages flow of mucous
-trapped particles travel down esophagus into stomach
Lower Respiratory Tract
Larynx [voicebox]
-walls made of cartilage
-Thyroid cartilage [adam’s apple]
-Epiglottic cartilage- covered with mucous membrane
-epiglottis blocks opening to trachea [glottis] when
swallowing
False Vocal cords- musc/conn. tissue; same function as
epiglottis
True Vocal cords- musc/elastic fibers; vibrate with air
passage; helps form words

Trachea [windpipe]
-Anterior to esophagus
-4-5 inches long
-Connects larynx to thoracic cavity
-Divides inferiorly at an area called the carina, into R and L
primary bronchi (each lung)
-Lined w/ciliated mucous membrane
-Made of “C”-shaped cartilage rings allowing for expansion
of esophagus when consuming food
-Also smooth muscle

Primary bronchi lead into the lungs and divide to form the
bronchial tree
Primary bronchi  secondary bronchi tertiary bronchi
bronchioles alveolar ducts  alveoli
Lungs [Right and Left]
-Right – 3 lobes (upper, middle, lower)
– divided by 2 fissures (horizontal b/w upper and middle
lobes; oblique fissure b/w middle and lower)
-Left - 2 lobes (upper, lower)
– divide by oblique fissure. Lung is slightly smaller to
accommodate space for the heart
Pleural Cavity
-double-layered membrane covering
-visceral pleura: inner layer on the lung surface
-parietal pleura: outer layer lines the inside of the thoracic
cavity
-space in b/w the pleural layers filled with serous fluid to
reduce friction as lungs inflate and deflate.
Pleurisy- infection of the pleural layers. Reduced serous
fluid and increased friction when breathing
-Serous fluid creates surface tension b/w the pleural layers
-keeps them adhered to each other
-essential for keeping the lungs inflated.
 When the outer pleural membrane (parietal pl.) moves
outward because it is attached to the thoracic wall ,the
inner pleural layer (visceral pl.) moves with it.
 Pneumothorax: air gets in the pleural space
 Atelectasis: too much air gets in the pleural space
disrupting surface tension b/w the pleural layers and
causes collapsed lung.