Open Vs Closed Circulatory Systems
This type of circulatory system keeps blood enclosed within vessels at all times.
Closed Circulatory System
Fish have this many heart chambers, the fewest among vertebrates.
Two
This circuit carries blood from the heart to the lungs and back
Pulmonary Circuit
This term describes the relaxation phase of the heart during the cardiac cycle.
Diastole
In organisms with an open circulatory system, this fluid bathes the organs directly.
hemolymph
Amphibians and reptiles have this type of circulation, where blood passes through the heart twice in one cycle.
Double Circulation
This circuit delivers oxygen-rich blood to the rest of the body.
Systemic Circuit
Known as the heart’s natural pacemaker, this structure initiates the heartbeat.
Sinoatrial Node
These two major animal groups have closed circulatory systems.
vertebrates and annelids
This class of vertebrates has a three-chambered heart with a partially divided ventricle, reducing blood mixing.
Reptiles
In pulmonary circulation, blood becomes oxygenated in this organ.
The lungs
This phase of the cardiac cycle involves contraction of the ventricles to pump blood.
Ventricular Systole
One major advantage of a closed circulatory system over an open system
More efficient oxygen and nutrient delivery
These two groups of animals have a four-chambered heart and the most efficient circulatory system.
Mammals and Birds
This blood vessel carries oxygen-rich blood from the lungs to the heart.
The pulmonary vein
This node receives the electrical impulse from the SA node and delays it slightly before passing it to the ventricles.
Atrioventricular Node
Respiratory pigments are not present in open circulatory systems because ...... (2 words) does not occur.
Gas Transport
This special structure in crocodiles allows blood to bypass the lungs when underwater.
Foramen of Panizza
The key difference between pulmonary and systemic circulation is this.
Pulmonary circulation moves blood between the heart and lungs, while systemic circulation moves blood between the heart and the rest of the body.
This is the sequence of events in one complete heartbeat, including both electrical and mechanical actions.
The Cardiac Cycle