Respiration def
exchange of oxygen gas and carbon dioxide gas between an organism and its external environment
5 Functions of Respiratory System
- Supplies oxygen which is required by body cells in order to perform cellular respiration
- Removes carbon dioxide which is produced as a waste product and is poisonous
- Controls the pH of body fluids aka blood plasma
- Provides protection from inhaled pathogens and irritating substances
- Allows speech to occur
How does the respiratory system control the pH of blood plasma?
In controlling amount of CO2 and Ox (CO2 + H2O = acid; bicarbonates can neutralize)
Why is carbon dioxide dangerous?
Carbon dioxide serves as competition to oxygen as hemoglobin is 4x more likely to bind to it
Ventilation: def
- Process by which oxygen is taken in from external environment
- Not considered a part of respiration
Ventilation: flow of air (pressure gradient)
- Air flows due to a pressure gradient (more high pressure to low pressure)
- You cannot change the atmospheric gas pressure
- In order for air to move into your lungs, the pressure inside the lungs must become lower than the pressure in the atmosphere
- As you cannot change atmospheric gas pressure, you must change the pressure inside your body by changing the volume
Ventilation: how does the respiratory system do it then?
- The muscles of the thoracic cage (rib cage bones, spine, etc) + diaphragm contract allowing the lungs to expand
- Increasing the volume in the thoracic cavity
- According to Boyle’s Law; pressure decreases and air follows into the lungs
External Respiration: def
- Exchange of gases across the respiratory surface between the alveoli and blood capillaries
- Air in lungs is part of outside world
External Respiration: how does the respiratory system do it then?
- Occurs by diffusion
- Concentration of oxygen is greater in alveoli than in capillary
- Concentration of carbon dioxide is greater in capillary than in alveoli
Internal Respiration: def
Exchange of gases between the capillaries and body tissue cells (air is finally in bloodstream)
Internal Respiration: how does the respiratory system do it then?
Oxygen gas diffuses out of the blood into the cells and carbon dioxide from the cells diffuses in
Cellular Respiration: def + equation + opposite reaction + tie in
- Series of energy-releasing chemical reactions that take place within the cells
- Involves the use of oxygen to produce ATP from food molecules
- C6H12O6 (from digestion) + O2 (from respiration) = ATP + CO2 (bye) + H2O
- Opposite reaction is photosynthesis
- All systems unite to allow the organism to live and thrive
4 stages in order
- Ventilation
- External respiration
- Internal respiration
- Cellular respiration
Nasal Cavity
- Air is warmed, moistened, and filtered
- Has mucus secreting cells that filter the air
- Cilia filters large particles & debris
- Blood capillaries are close to the surface
Pharynx
- Common pathway for air and food
- Muscular to swallow
- Pathway that leads to trachea and esophagus
Epiglottis
- Covers trachea to prevent food from entering it when swallowing
- Tiny flap of connective tissue
Larynx
Contains vocab cords that vibrate and produce sound as air rushes past (usually when breathing out)
- At the top of trachea
- Made up of several pieces of cartilage; the lowest of which is the Adam’s apple
Trachea
Allows air to pass from pharynx into lungs
- Hollow, tough, flexible tube
- Contains C-shaped cartilage rings that reinforce trachea to prevent collapse
- Don’t need full ring because spine protects other side
- We ONLY HAVE ONE WINDPIPE!
- Trachea has cilia and mucus secreting cells that takes dirt and debris toward pharynx when swallowed
What are the 3 forms of respiration?
External, internal, and cellular
HOWEVER cellular is not a TRUE form of respiration as it doesn’t deal with gas exchange.
Cilia w/ mucus
Filters air by trapping dust and debris to prevent from reaching the alveoli
- Line the trachea and bronchi and bronchiole
- Hair-like
Bronchi (a bronchus)
Leads air into air sacs of the lungs
- Lined with smooth muscles
- Hollow tubes supported by cartilage
- Branches into left and right lungs
Bronchioles
Leads air into air sacs of the lungs
- Thinner tubes that branch off the bronchi or the lungs
Lungs
Houses the air sacs; receiver of the air
Alveoli (a alveolus)
Site of gas exchange through diffusion (high concentration to low concentration)
- Tiny air sacs at the ends of the bronchioles
- Occur in grape like clusters (to maximize surface area)
- 1 cell layer thick (shortest distance to maximize diffusion)
- Wrapped around capillaries
