Transport in Animals Flashcards
(34 cards)
Why do multicellular animals need transport systems?
To move oxygen, nutrients and remove waste efficiently
Larger organisms have a low surface area to volume ratio and high metabolic rates, making diffusion alone insufficient to meet their needs
What is the effect of size and metabolic rate on the need for transport?
Larger animals have lower SA:V and high metabolic demand.
What are the types of circulatory systems?
Single, double, open, closed.
What is a single circulatory system?
Blood passes through the heart once
What is a double circulatory system?
Blood passes heart twice per circuit.
What is an open circulatory system?
Blood not always enclosed in vessels.
What is a closed circulatory system?
Blood remains enclosed in vessels.
What are the structures and functions of arteries?
Thick muscular walls. Elastic tissue. Carry blood from heart.
What are the structures and functions of arterioles?
Smaller branches of arteries. Control blood flow.
What are the structures and functions of capillaries?
Thin walls. Exchange of substances.
What are the structures and functions of venules?
Collect blood from capillaries to veins.
What are the structures and functions of veins?
Thin walls, valves. Carry blood to heart.
How is tissue fluid formed from plasma?
Plasma forced out by high hydrostatic pressure
What is the role of hydrostatic pressure in tissue fluid formation?
Pushes fluid out of capillaries
What is the role of oncotic pressure in tissue fluid formation?
Pulls water back in by osmosis.
What is the difference between blood, tissue fluid and lymph?
Blood has cells and proteins. Tissue fluid lacks both. Lymph similar to tissue fluid
but with more lymphocytes.
What are the external and internal structures of the mammalian heart?
Four chambers. Atria, ventricles, septum, valves
What happens during the cardiac cycle?
Atria contract → ventricles contract → relaxation phase.
What causes the opening and closing of valves?
Pressure differences across valves.
What is the equation for cardiac output?
cardiac output = stroke volume × heart rate
How is heart action initiated and coordinated?
Myogenic stimulation begins at SAN.
What is the role of the SAN in heart coordination?
Sends wave across atria.
What is the role of the AVN in heart coordination?
Delays signal before passing to ventricles.
What is the role of Purkyne tissue in heart coordination?
Conducts signal to ventricle walls.
