The Respiratory System Flashcards
what is included in The Respiratory System
the System includes the lungs, pathways connecting them to the outside environment, and structures in the chest involved with moving air in and out of the lungs
Respiratory system principles
Movement of an oxygen-containing medium so it contacts a moist membrane overlying blood vessels.
Diffusion of oxygen from the medium into the blood.
Transport of oxygen to the tissues and cells of the body.
Diffusion of oxygen from the blood into cells.
Carbon dioxide follows a reverse path
Air components Air breathed in & Air breathed out
Air breathed / in Air breathed out
21 % oxygen / 15 % oxygen
0.04 % carbon dioxide. / 4 % carbon dioxide
What is breathing?
Breathing or external respiration is the inhalation and exhalation of air and the gases it contains
The human respiratory system is categories into two type
Upper respiratory tract (nose, nasal cavity, sinuses, pharynx, larynx)
Lower respiratory tract (trachea, bronchial tree, and lungs).
The nose - structure
1-the nose Acts as the first passageway for air entering the body Lined with a mucous membrane pseudostratified columnar ciliated epithelium
2-Nares – two nostrils that lead into the nasal cavity
3-Septum – divides the nasal cavity into two chambers. Composed of cartilage
4-Nasal cavity – each side contains 3 nasal conchae. Connects to the paranasal sinuses – hollow spaces.
The nose - function
- Works as the organ of smell
- Moistens and warms the air entering the nostrils
- Filters dust, bacteria and other matter from the air
- Mucous membrane and cilia
- Cilia push mucous to throat - swallowed
The pharynx - structure
- A tube that leads from the back of the nose and mouth and divides into the oesophagus (posteriorly) and larynx (anteriorly)
- 12-14cm in length
Pharynx - function
-Has roles in both the respiratory and digestive systems
-Acts as an air passage and also warms and moistens the air
-Provides an enclosed space that will allow speech muscles to initiate sound and resonate it so that it projects even better
Larynx - structure
-A tube positioned between the tongue at the back of the mouth and the trachea
-Composed of rungs of cartilage attached to each other by membranes and ligaments
-Thyroid cartilage is found at the top of the larynx
-Adam’s apple - a projection at the front of the neck formed by the thyroid cartilage
what are Vocal cords
– 2 pairs of folds of muscle and connective tissue (elastic ligaments) covered with mucous membrane
* The upper pair = false vocal cords.
* The lower pair = true vocal cords
Larynx - function
- A passageway for air between the pharynx and trachea
- Filters bacteria
- Warms and moistens air
- Helps in voice production
Trachea - structure
- A continuation of the larynx
- A tube around 10cm long
- Made of 20 incomplete rings of hyaline cartilage and involuntary muscle and connective tissue
- Lined with pseudostratified ciliated epithelium
Trachea - function
- Passageway for air between the larynx and bronchi
- The lining of the trachea has a sticky mucous lining that traps foreign substances
- If a foreign object accidentally gets into the trachea, the ciliary cells get irritated and induce coughing to expel the object
- When the air is cold, the trachea helps to humidify and warm the air entering the lungs
Bronchi – structure and function
- Connect the trachea to the lungs
- Two – left and right
- Enter the lungs at the hilium – concave depression
- Subdivide into different branches for the lobes of the lungs
- Made of hyaline cartilage, involuntary muscle and connective tissue
- Lined with ciliated epithelium
- Pass air from the trachea into the bronchioles