Biology Term 1 - Gaseous Exhange Flashcards
Gaseous Exchange
- Movement of CO2 and O2 between membrane (lungs) and environment
- between alveoli and blood and body cells
Breathing
Movement of air/water over gaseous exchange surface (lungs)
Respiration
Metabolic reaction where energy in glucose used to create ATP
What is gaseous exchange?
- Movement of CO2 through a membrane and the environment
- Movement of oxygen between blood and body cells
What does gaseous exchange do?
Supply body with oxygen at cellular level
Define breathing
Movement of air over gaseous exchange surface
Define respiration
Metabolic reaction where energy in glucose is turned into high energy ATP
Requirements for gaseous exchange
- Large surface area
- Moist surface
- Thin surface
- Transport system
- Adequate ventilation
- Adequate protection
Why is a large surface area required for gaseous exchange?
To allow sufficient surface area for CO2 and O2 to diffuse across
Why is a moist surface required for gaseous exchange?
Because gases must first dissolve in water before diffusion can take place
Why is a thin surface required for gaseous exchange?
For rapid diffusion
Why is a transport system required for gaseous exchange?
So gases can be carried away from the exchange surface to maintain diffusion gradient
Why is adequate ventilation required for gaseous exchange?
Has to be method of ventilating so surfaces to maintain concentration gradient
Why is adequate protection required for gaseous exchange?
Because surfaces are thin and easily damaged
What do air passages protect the lungs from?
Dehydration, cold, particles in the air
What do nostril hairs stop?
Larger particles from entering
Why are air passages lined with a mucous membrane?
To trap smaller particles, and Cilia sweep mucous to nose
What do turbinate bones do?
They warm the air before it enters the lungs
What does the epiglottos do?
Stops food from entering the trachea and go down the esophagus
What is at the top of the trachea?
The larynx
What is the larynx?
The vocal chords
What is the function of the c shaped cartilage rings lining the trachea?
The c shaped allows the esophagus to swell/open large enough against the trachea to swallow food
What does the trachea divide into?
The bronchi which divide into smaller bronchioles inside the lungs
Why do bronchioles not have cartilage rings?
Because they are too small
What do intercostal muscles do between the ribs?
Contract and relax when breathing to lift and push down the rib cage
What is the diaphragm?
A large sheet of muscle that contracts during inhalation and springs outward when exhaling
Name the process of air entering air passages:
Enters nasal cavity/oral cavity then passes through the pharynx and to the epiglottis that stops food go down the trachea, then passes through the larynx and to the trachea which divides into bronchi then bronchioles
What is the protective layer around the lung membrane
Pleura
What is the trachea also known as?
The wind pipe
What type of appearance do the lungs have?
Spongy
Where are lungs located?
Above thoracic cavity and above diaphragm muscle
How does blood enter and exit the lungs?
- Enters from pulmonary arteries
- Exits via pulmonary veins
How many lobes does the right and left lung have?
- Right: 3
- Left: 2
Why does the left lung have 2 lobes?
To make space for the heart
Why is the pleura separated with a thin film fluid?
The film fluid acts as a lubricant to reduce friction when breathing in and out
What is at the end of the bronchioles?
Air sacs (alveoli)
What are the walls of the alveoli?
Very thin wall of cells
What closes around alveolis
Many blood capillaries
What type of blood enters from pulmonary Veins and pulmonary artery,
- oxygenated blood from pulmonary veins
- deoxygenated blood from pulmonary arteries
Explain breathing in terms of pressure increasing or decreasing
When air is drawn in or forced out of the lungs by decreasing or increasing pressure within the lungs air will always flow from a low pressure to a high pressure if the air passages are open.
Explain the process of inhalation
In order for air to flow into lungs, the air pressure inside lungs must be relatively low
For their to be a low enough pressure the body must first:
1. The diaphragm must contract and flatten
2. External intercostal muscles contract to lift ribcage up
These two processes increase the volume of the thoracic cavity allowing for air to flow in
Increased volume = decreased pressure
Explain the process of exhalation
- The diaphragm with relax back to its resting position
- External intercostal muscles relax and the ribcage sinks back down due to the force of gravity
These two process decrease the volume in the thoracic cavity = increased pressure which then forced air out of the lungs
Explain the process of forced exhalation
- Internal intercostal muscles contract and pull the ribcage downward (decreased volume of thoracic cavity = increased pressure)
- Abdominal muscles contract forcing organs against the diaphragm (therefore it domes more than normal)
Decreased volume = increased pressure resulting is air flowing out of the lungs
