Respiratory System Flashcards
What are the functions of the respiratory system?
- transport air into the lungs
- facilitate the diffusion of oxygen from the lungs into the bloodstream
- facilitate the diffusion of carbon dioxide from the blood stream into lungs
- inhalation/exhalation
What is the function of the trachea?
- a cartilage tube
- the first part of the lower respiratory tract
- connects pharynx and larnynix to the lungs and allows passage of air to and from the lungs
What is the structure and function of the bronchus?
- held open by cartilage
- allows air into lungs
- pleural bronchus are lined with mucus membranes and cilcited cells which trap and held the removal of any dirt and dust that enters
What is the structure and functions of the bronchioles?
-the bronchus subdivide into bronchioles which end in alveoli
What is the structure/function of the alveoli/alveolus?
- each bronchiole ends in a cluster called alveoli
- in alveoli gasses are exchanged during respiration
What is the structure/ function of the ribs?
- protects internal organs from damage
- gives structure to the body
- rib cage expands because of cartilage during respiration
What is the structure/function of the intercostal muscles?
- several groups of muscle that run between ribs and help move the chest
- helps to raise and lower chest during ventilation
What is the structure/function of the diaphragm?
- large dome shaped muscle at base of lungs
- makes chest cavity expand when you inhale and contract when you exhale
What happens during breathing in (inhalation)?
1) diaphragm contracts and flattens (moves down)
2) intercostal muscles contract, rib cage moves up and out.
3) volume inside the chest cavity increases
4) pressure inside the chest cavity decreases
5) air rushes in
What happens during breathing out (exhalation)?
1) diaphragm relaxes and becomes raised (dome shaped)
2) intercostal muscle relaxes- the rib cage moves down
3) volume inside chest cavity decreases
4) pressure inside chest cavity increases
5) air forced out
Where does gas exchange occurs?
In the alveolus (high to low)
How are the lungs adapted for gaseous exchange?
- alveoli have a large surface area as there are so many
- very short distance between alveolus and capillary (short diffusion pathway)
- ventilation/breathing maintains a Hugh concentration gradient between the alveolus and the blood in cappilary
- cappilary brings carbon dioxide rich blood and removes oxygen rich blood to and from the lungs
What is each alveoli surrounded by?
A network of blood cappilaries
What are the factors that increase the rate of gas exchange?
1) large surface area of the exchange surface, this is achieved by having millions of alveoli in each lung
2) thin and permeable exchange surface, both the alveolar and cappillary walls are one cell thick, walls are also moist
3) large concentration gradients, diffusion only occurs when there is a concentration gradient, breathing brings oxygen rich air into the lungs so concentration of oxygen is much higher than the blood.
What is the normal Lung and respiratory function in regards to mucus?
The bronchi which leads to the air sacks are lined with cells that produce mucus, this coats the surface of the airways.
When foreign particles enter they become tapped in mucus.
There are tiny hairs called cilia on the surface of breathing tubes. They sweep the mucus and particles up into larger air passages and then to throat where they can be swallowed or coughed up
What are the tiny hairs on the surface of the breathing tubes called?
Cilia
What is emphysema?
- A lung condition common in heavy smokers
- irritation from the tar in tobacco damages the alveolar lining to the extent that the walls of many alveoli break down
