Circulatory and Respiratory System Flashcards
(30 cards)
What is a gastrovascular cavity (GVC)?
A central cavity with a single opening used for digestion and circulation, found in cnidarians and flatworms.
What is an open circulatory system?
A system where hemolymph is pumped into open spaces, bathing organs directly (e.g., insects, most mollusks).
What is a closed circulatory system?
A system where blood stays in vessels, allowing high-pressure, efficient nutrient and gas delivery (e.g., vertebrates).
What is single circulation?
Blood passes through the heart once per cycle (e.g., fish). Path: heart → gills → body → heart.
What is double circulation?
Blood passes through the heart twice per cycle: once to lungs (pulmonary), once to body (systemic). Seen in amphibians, reptiles, mammals.
How many heart chambers do fish have?
2 chambers – 1 atrium, 1 ventricle.
How many heart chambers do amphibians and reptiles have?
3 chambers – 2 atria, 1 ventricle (with some separation in reptiles).
How many heart chambers do birds and mammals have?
4 chambers – 2 atria, 2 ventricles (complete separation of oxygenated and deoxygenated blood).
What is the function of the right atrium?
Receives deoxygenated blood from the body via the vena cava.
What does the right ventricle do?
Pumps deoxygenated blood to the lungs via the pulmonary artery.
What is the function of the left atrium?
Receives oxygenated blood from the lungs via pulmonary veins.
What does the left ventricle do?
Pumps oxygenated blood to the body through the aorta.
What are the atrioventricular valves?
Tricuspid (right side) and bicuspid/mitral (left side); they prevent backflow into the atria.
What are the semilunar valves?
Pulmonary (right ventricle to lungs) and aortic (left ventricle to body); prevent backflow into ventricles.
What is systole?
The contraction phase of the heart; ventricles pump blood out.
What is diastole?
The relaxation phase; the heart fills with blood.
What is the function of the aorta?
Carries oxygenated blood from the left ventricle to the body.
What are the pulmonary arteries and veins?
Arteries carry deoxygenated blood to lungs; veins return oxygenated blood to heart.
What are the vena cavae?
Large veins that bring deoxygenated blood from the body into the right atrium.
What are arteries?
Blood vessels that carry blood away from the heart; thick walls, high pressure.
What are veins?
Blood vessels that carry blood to the heart; thinner walls, contain valves.
What are capillaries?
Thin, one-cell-thick vessels where gas and nutrient exchange occurs.
What do all respiratory surfaces need to be effective?
Thin, moist, large surface area, and close to capillaries for diffusion.
What are gills used for?
Gas exchange in water; extract oxygen as water flows over them.
