KAH 3.1 EXCHANGE AND TRANSPORT Flashcards
Why do large active organisms need a specialised surface for gaseous exchange?
- large/active organisms have higher demand for oxygen/need to remove CO2
- smaller surface area to volume ratio. Surface area too small/distance too large/diffusion takes too long (to supply needs).
[Lungs] Component of the Lungs
Trachea
Bronchi
Bronchioles
Alveoli
Intercostal muscles
Ribs
Diaphragm
[Tissues of Gas Exchange System] Cartilage
-> Stiff tissue, connective.
-> trachea contains c-shaped rings of cartilage.
-> Provide support and flexibility.
-> resistant to compression and tension.
[Tissues of the Gas Exchange System ] Ciliated Epithelium
-> cells that have cilia on the top that face the airway.
-> Move mucus.
-> wafts mucus up and out of the airways.
-> Beats constantly to move mucus and trapped substances towards top of the trachea.
[Tissues of the Gas Exchange System] Goblet Cells
-> secret mucus
-> traps dirt + pathogens.
-> Like a barrier.
[Tissues of the Gas Exchange System] Smooth Muscle and Elastic Fibres
-> controls diameter.
-> controls movement of air flow.
-> Constrict to reduce air flow. E.g. pollen asthma
Alveoli
-> Thin walls.
-> Large Surface Area
-> Moist
-> Surfactant (water film [thin layer] lining alveoli.
-> stops alveoli collapsing.
Inspiration [breathing in]
- diaphragm contracts, flattens and move downwards.
- intercostal muscles contract.
- ribs move up and out.
- increases volume inside the thorax and lungs.
-reduces pressure inside thorax and lungs and below atmospheric pressure. - air moves into lungs down pressure gradient.
Expiration [breathing out]
- diaphragm relaxes. Move upwards.
- intercostal muscles relax.
- ribs move down and in.
- decreases volume inside thorax and lungs.
- induces pressure inside thorax and lungs above atmospheric pressure.
- air moves out of lungs down pressure gradient.
Fish Gas Exchange and Ventilation
- Mouth opens (operculum is closed).
- The buccal cavity floor is lowered.
- Increases volume and decreases the pressure of the buccal cavity compared to outside.
- Water rushes into mouth down pressure gradient.
- Opercular cavity expands.
- Buccal cavity floor is raised.
- Pressure inside buccal cavity is now higher compared to opercular cavity.
- Water moves from buccal cavity over gills into opercular cavity.
- Mouth now closed and operculum opens.
- Sides of opercular cavity moves inwards increasing the pressure.
- Water moves out of the fish through the operculum.
[Fish] Movement of blood and water in gills of a bony fish
- blood flows into secondary lamellae.
- water flows over secondary lamellae in opposite direction to create a countercurrent flow.
[Insects] How Insects take oxygen into their bodies.
- oxygen diffuses from air into insects body cavity through spiracles into long tubes called tracheae.
- tracheae branch into smaller tubes called tracheoles that have an open ending inside the insect cell filled with tracheal fluid.
- oxygen diffuses into this liquid into the insects cell.
[Fish] Countercurrent Flow
- blood flows opposite direction to flow of water.
[Measuring Lung Capacity] Spirometer
- When person breathes in, take 02 from chamber, causing it to go down.
- Breathe out it pushes air into the chamber, causing it to go up.
- movement recorded on the trace (graph) by data logger.
Spirometer Precautions
- soda lime corrosive.
- make sure everything is airtight so no o2 lost through leaks.
- health of patient.
- disinfect mouthpiece.
- Nose clip.
- Medical grade 02.
