Edited Invalid date
32.2 Transport in Vertebrates
In the earthworm, there are five pairs of anterior hearts that pump blood into a branch of the blood vessel.
Blood moves through the branches into the capillaries, the smallest of the blood vessels.
Most cells in an animal's body are close to a capillary.
Blood moves from small veins into a vein in an earthworm.
The blood vessel returns the blood to the heart.
The earthworm has red blood.
Hemoglobin is not contained in blood cells.
The earthworm does not have a specialized organ for gas exchange.
The body wall must always be moist for gas exchange to take place.
The path of blood in animals can be compared to a two-circuit pathway.
List the number of atria and ventricles in each type of animal.
All animals have a closed circulatory system.
The atria receive blood from the blood vessels and the muscular ventricles pump blood.
The "hair" and the "blood vessel" exchange materials with each other.
There is a thick middle layer of elastic tissue and smooth muscle on the walls of arteries.
One cell thick capillary walls are what they are.
Veins have flabby walls because the middle layer is not as thick as in arteries.
One-way flow of blood back to the heart is ensured by veins.
Smooth muscle and elastic tissue are in the middle layer.
The innermost layer is similar to the rest of the body.
Arteries have thick walls, and those attached to the heart are resistant, meaning that they are able to expand and accommodate sudden increases in blood volume.
Blood pressure can be affected by arterioole constriction and dilation.
The lower the number of vessels, the lower the blood pressure.
In humans, almost all cells are within 80 um of a capillary because of the arterioles branch into them.
About 5% of the capillary beds are open at the same time.
After an animal has eaten, the precapillary sphincters relax and the capillary beds in the digestive tract are usually open.
The capillary beds of the muscles are open during exercise.
Capillaries, which are usually so narrow that red blood cells pass through in a single file, allow exchange of waste and nutrition.
When a capillary bed is open, the muscles that control the flow of blood are relaxed.
The veins form after the blood from the capillaries is drained.
The wall of a vein is thinner than the arteries, and this may be associated with a lower blood pressure in the veins.
When the veins close, a backflow of blood is prevented.
There are two different types of circulatory pathways in animals.
Blood flows through a single-loop circulatory pathway in fishes.
The heart has two chambers.
After the blood passes through the gill capillaries, blood pressure is dissipated.
The one-circuit system has a disadvantage.
Amphibians and most reptiles have a two-circuit system in which the heart pumps blood to both the lungs and the body.
Although there is a single ventricle, little mixing of oxygen-rich and oxygen-poor blood takes place.
In crocodiles and birds and mammals, the heart is divided into the right and left halves.
The pumping action of the ventricle causes blood to go under pressure in the gills.
After passing through the gills, the blood returns to the aorta, which distributes it throughout the body.
Veins return oxygen-poor blood to an enlarged chamber, which leads to the heart.
The blood goes back to the heart.
The gill capillaries receive oxygen-poor blood and the systemic capillaries receive fully oxygen-rich blood from the single circulatory loop.
After leaving the gills, the blood pressure is reduced.
Page 600 has a double-loop circulatory pathway.
Breathing air on land is an adaptation.
The blood from the lungs goes to the left atrium.
Oxygen-rich and oxygen-poor blood are separated because oxygen-poor blood is pumped out of the ventricle before the oxygen-rich blood enters.
The main arteries help keep the blood separated when the ventricle contracts.
Oxygen-rich blood is distributed to the body, and oxygen-poor blood is delivered to the lungs, and perhaps to the skin.
A septum divides the ventricle.
Oxygen-rich and oxygen-poor blood is kept to a minimum in these animals.
The ventricle is divided into two separate chambers in crocodilians.
There is a four-chambered heart in these reptiles.
The heart of birds and mammals is divided into two halves.
The right and left ventricles pump blood to the lungs and the rest of the body.
Blood pressure is provided for both the pulmonary and systemic circuits.
Review flashcards and saved quizzes
Getting your flashcards
Privacy & Terms