Transport in Animals: Features of Transport System Flashcards
(22 cards)
Features of Transport
How does blood move in an open circulatory system?
Blood leaves the heart and enters a large open space called the haemocoel, where it directly bathes the organs and tissues.
What is the fluid in an insect’s open circulatory system called?
Haemolymph – it is the insect’s form of blood.
What type of heart do insects have?
A long, dorsal tube-shaped heart that runs the length of the body.
Do Insects pump blood at high pressure, and where does the blood go for what?
It pumps blood at low pressure into the haemocoel, where materials are exchanged between blood and body cells.
How does exchange occur in an open circulatory system?
Exchange happens as haemolymph directly bathes the organs and tissues, allowing nutrients (e.g., glucose) to diffuse into cells.
Does the circulatory system transport oxygen in insects?
No – oxygen transport is handled by the tracheal system, not haemolymph.
What is a closed circulatory system and why is this advantageous?
A system where blood is enclosed in blood vessels, allowing it to move at higher pressure and flow faster.
What are the two types of closed circulatory systems?
- Single circulation
- Double circulation
How many times does blood pass through the heart in single circulation?
Once per complete circuit.
How does circulation work in earthworms?
- Dorsal vessel moves blood forward toward the aortic arches (pseudohearts)
- Aortic arches pump blood downward into the ventral vessel
- Ventral vessel moves blood backwards, supplying capillaries for exchange
- Blood returns to the dorsal vessel, repeating the cycle
How does circulation work in fish?
- Heart pumps deoxygenated blood to the gills
- Oxygen diffuses in at the gills, but pressure falls drastically
- Oxygenated blood moves to tissues at reduced pressure (less efficient)
- Deoxygenated blood returns to the heart, repeating the cycle
Why is single circulation less efficient than double circulation?
Lower Pressure, resulting in
slower circulation
How many times does blood pass through the heart in double circulation?
Twice per complete circuit.
What are the two circuits in double circulation?
- Pulmonary circulation – blood moves from the heart to the lungs and back
- Systemic circulation – blood moves from the heart to the body and back
Why does double circulation allow higher metabolic rates?
Because it delivers oxygen more efficiently and at a higher pressure.
Why does blood return to the heart after passing through the lungs?
The blood pressure is too low after passing through lung capillaries, so the heart raises the pressure before sending it to the rest of the body.
What prevents oxygenated and deoxygenated blood from mixing in mammals?
The four-chambered heart keeps oxygenated and deoxygenated blood separate.
What carries oxygen in the blood?
Haemoglobin (Hb) binds to oxygen in the lungs and releases it in body tissues.
Why don’t organs come into direct contact with blood in a closed circulatory system?
Blood is confined to blood vessels, and tissue fluid is used to bathe the cells instead.
What is tissue fluid, and what does it do?
Tissue fluid seeps out of capillaries, surrounding cells to allow gas and nutrient exchange. Most of it returns to the blood.
What happens at the gills as oxygen diffuses in, making it less effective than a double circulatory system?
Blood pressure falls heavily, so it is slower and less efficient
