Chapter 3: Transport in animals Flashcards
In 11 steps, outline the order into how ventilation in a fish happens
- Mouth opens
- Buccal cavity floor lowered
- this increase the volume + decreases the pressure of buccal cavity
- Water enters mouth down a pressure gradient
- Opercular cavity expands
- Buccal cavity floor raised
- Pressure inside buccal cavity = higher than opercular cavity
- Water moves from buccal cavity into opercular cavity
- Mouth closes and operculum opens
- Sides of opercular cavity move inwards, increasing pressure
- Water rushes out of fish through operculum
What is the function of the operculum?
To cover the gills - helps force water over gills surface
What’s the importance of folded lamellae?
Large surface area = short diffusion path
How does the counter current mechanism ensure that the maximum amount of oxygen passes into the blood?
Large SA of the lamellae - allows the blood and water to flow in opposite direction so gas exchange can occur over the entire surface
Describe inspiration (include the intercostal muscles and diaphragm)
External intercostal muscles contract - pulling ribcage upward and outward
Diaphragm contracts
Volume of thorax and lungs increases, reduced pressure and air moves down the pressure gradient
Compare relaxed expiration (RE) and forced expiration (FE)
In both, the internal intercostal muscles contract
In FE, abdominal muscles contract pushing diaphragm upwards while in RE, the diaphragm relaxes
Describe the function of cartilage
Rigid and flexible to prevent collapsing
Is smooth muscle found in the bronchioles and bronchus?
YES
Purpose of smooth muscle?
Constricts bronchioles and controls airflow
What do elastic fibres do?
Recoil if stretched
What’s the function of goblet cells?
To produce mucus to trap debris to be wafted by cilia
What do ciliated epithelium cells do?
Waft mucus
What’s the equation for the ventilation rate?
Tidal volume x breathing rate
Which factors affect the rate of diffusion across membranes?
Surface area to volume ratio and the thickness of the membrane
What’s the difference between an open and closed circulatory system?
Open - blood goes from the heart into a body cavity
Closed - blood travels from the heart in blood vessels
Define single circulation
Blood goes from the heart to the respiratory surface and then to the body
What’s the difference between partial double circulation and double circulation?
Double circulation - separate circulation to the respiratory surface and to the body
Partial - blood from a single ventricle enters a forked aorta for distribution to the body and gas exchange surface