1. Gas Exchange

2. Overview of the Respiratory System
Lungs work with the circulatory system to ensure that the cells in the body receive oxygen and eliminate carbon dioxide
It maintains the concentration gradients of oxygen and carbon dioxide between air in alveoli and blood flowing in adjacent capillaries.
The process that requires oxygen and gives off carbon dioxide in the human body is cellular respiration.
Ventilation – the filling the lungs with air and breathing that air out
Spirometer is a device used to measure ventilation
During this time oxygen diffuses into the blood stream and carbon dioxide diffuses into the ling tissue

3. Overview of the Respiratory System
Gas Exchange – the movement/diffusion of gases
Gas exchange occurs in 2 places:
The Lungs - oxygen from the air of the lungs moves into the
blood stream and carbon dioxide moves out
Capillary Bed – opposite gas exchange occurs, oxygen diffusion out
of the blood stream and into a body cell and carbon
dioxide diffuses out of the body into the capillary bed

4. Overview of the Respiratory System
Single cell organisms do not have a ventilation system
As long as the oxygen concentration is high on the outside going into the cell is not a problem
Our bodies contain millions of cells underneath a layer of dead cell meant to protect the living cells
Cells are too far from the outside air to directly make use of the process of diffusion (oxygen and carbon dioxide)
The ventilation system and along with the circulatory system function together to pick up oxygen in the lungs and move the oxygen around the body

5. Overview of the Respiratory System
Ventilation system ensures that the concentration of respiratory gases within the lungs encourages diffusion of gases needed for life.
So, if you stopped breathing the oxygen in the lungs would not exceed the oxygen in the blood STOPPING THE DIFFUSION OF OXYGEN INTO THE BLOOD

6. Anatomy of the Ventilation System
Gas Exchange occurs within the alveoli

7. Anatomy of the Ventilation System
When you take in air through your mouth or nasal passages:
The air first enters your trachea
Then your right and left bronchi
Then smaller and smaller branches
of the bronchi
Then very small branches called bronchioles
Finally, the air enters the small air sacs in
the lungs called alveoli

8. Anatomy of the Ventilation System
Alveoli are found as clusters at the ends of the smallest bronchioles
They look like grapes
Approximately 300 million alveoli in each lung
Each cluster has surrounding capillaries
Blood enters the capillaries from the right
ventricle via the pulmonary artery
Blood is low in oxygen, high in carbon dioxide
Oxygen diffuses through 2 cell membranes
Must be able to draw

9. Anatomy of the Ventilation System
Alveoli gas exchange
Two membranes:
First is a single cell membrane making up the wall of the alveolus
Two types of cells:
Type I pneumocytes are extremely thin alveolar cells that are adapted to carry out gas exchange
Type II pneumocytes secrete a solution containing surfactant that creates a moist surface inside the alveoli to prevent the sides of the alveolus adhering to each other by reducing surface tension.
Second is a single cell membrane making up the capillaries
Carbon Dioxide diffuses in the opposite direction of oxygen in the same locations
As long as you keep breathing and air is refreshed in the lungs the concentration of gases will allow diffusion of both gases

10. Adaptation of Alveoli Adaptation Advantage Spherical shape of alveoli
Provides a large surface area for respiratory gases to diffuse through
Flattened, single cell thickness of each alveolus
Prevents respiratory gases from having to diffuse through more cell layers
Moist inner lining of alveolus
Allows for efficient diffusion
Associated capillary bed nearby
Respiratory gases do not have to diffuse far to reach single cell thick capillaries

11. Mechanism of Ventilation
The lungs are not capable of creating motion on their own
The lungs work based on an inverse relationship between pressure and volume.
This is created by the muscles and structures that surround the lungs
These include the Diaphragm, Intercostal Muscles around the ribs, and muscles in the abdomen
An increase in volume will lead to a decrease in pressure. Whatever pressure does volume will do the opposite and vice versa

12. Mechanism of Inspiration
The diaphragm contracts and at the same time the abdominal muscles and external intercostal muscles help raise the rib cage. Collectively, all of these actions act to increase the volume of the thoracic cavity
Because the thoracic cavity has an increased its volume, the pressure inside the cavity decreases. This leads to less pressure pushing on the passive lung tissue
The lung tissue increases its volume because there is less pressure exerted on it
This leads to a decrease in pressure inside of the lungs, also known as a partial vacuum
Air comes in through your open mouth or nasal passages to counter the partial vacuum within the lungs. (fills alveoli with air)

14. Different muscles are required for inspiration and expiration because muscles only do work when they contract.

15. Mechanism of Inspiration
So the reverse holds true for expiration
Diaphragm relaxes
Internal intercostal muscles bring down the rib cage.
When exercising all motions become more exaggerated

16. Causes and Consequences of Emphysema
Emphysema – a disease whereby the alveoli in the lungs are progressively destroyed.
Leading cause smoking
AKA – COPD Chronic Obstructive Pulmonary Disease
It’s a chronic disease (which means progresses slowly and last a long time)
Turns healthy alveoli into large irregularly shaped structures with gapping holes
Reduces surface area
Less oxygen gets to the blood stream

17. Causes and Consequences of Emphysema
Main symptom:
Shortness of breath
Shortness of breath begins as afflicted does exercise and progresses to an inability to get oxygen at all times
Causes:
Long term tobacco smoking (leading cause)
Marijuana smoke (exposure) – yes this extremely safe drug causes emphysema, watch the statistics go up in states that legalized it.
Fumes from manufacturing plants
Coal dust
Air pollution

18. Causes and Consequences of Emphysema
No cure
Progression can be slowed drastically with the cessation of smoking or exposure to other risk factors
Prevent DON’T SMOKE and wear protective mask when working around dust or chemically fumes

19. Causes and Consequences of Lung Cancer
Lung cancer is a cancerous growth that begins in the lungs.
It is prone to spreading (metastasizing)
Brain, bones, liver, and adrenal glands are likely target to the cancer cells from the lungs
Cancerous growth in the lungs takes over areas of healthy tissue areas that once provided a combination of bronchioles and alveoli
Larger the growth the more dysfunctional the lungs become
Can lead to internal bleeding

20. Causes and Consequences of Lung Cancer
One or more carcinogen (substances known to cause cancer)
Cigarette smoke
Other fumes and smoke
Best treatment is early diagnosis
Lung cancer has a high mortality rate