double circulation & blood flow

Question 1

which animals have two circuits and what are the two sides of the heart?

Answer 1

amphibians, reptiles, mammals each have pulmonary circuit (right) and systemic circuit (left)

Question 2

how many different chambers do mammals and amphibians have?

Answer 2

mammals: 4
amphibians: 3 (2 atria, 1 ventricle)

Question 3

list the 5 main steps in the amphibian circuit

Answer 3

1. Oxygen-poor blood returns from the body
2. Oxygen-rich blood returns from the lungs and skin
3. Mixing of blood in the ventricle
4. Blood is pumped to the lungs, skin, and body
5. Continuous circulation maintains oxygen supply

Question 4

describe how oxygen-poor blood returns from the body

Answer 4

returns to the right atrium of the heart through the venous system

Question 5

describe how oxygen-rich blood returns from the lungs and skin

Answer 5

Oxygenated blood from these sources flows back to the left atrium of the heart.

Question 6

describe how blood is pumped to the lungs, skin, and body

Answer 6

The ventricle contracts and pumps blood through two main circuits:

Pulmocutaneous circuit: Sends deoxygenated blood to the lungs and skin for oxygenation.

Systemic circuit: Sends oxygenated blood to the rest of the body to supply organs and tissues.

Question 7

list the 7 main steps in mammal circulation

Answer 7

1. Oxygen-poor blood from the body enters the right atrium
2. Right atrium pumps blood to the right ventricle
3. Right ventricle pumps blood to the lungs (Pulmonary Circulation)
4. Oxygen-rich blood returns to the left atrium
5. Left atrium pumps blood to the left ventricle
6. Left ventricle pumps oxygenated blood to the body (Systemic Circulation)
7. Blood returns to the heart, and the cycle repeats

Question 8

describe how oxygen-poor blood from the body enters the right atrium in mammals

Answer 8

returns to the right atrium through two major veins:

Superior/inferior vena cava

Question 9

how does the right atrium pumps blood into the right ventricle in mammals?

Answer 9

through the tricuspid valve

Question 10

how does the right ventricle pumps blood to the lungs (Pulmonary Circulation) in mammals?

Answer 10

pumps blood through the pulmonary valve into the pulmonary arteries, which carry the blood to the lungs.

Question 11

how does oxygen-rich blood return to the left atrium in mammals?

Answer 11

it travels through the pulmonary veins and enters the left atrium

Question 12

how does the left atrium pump blood to the left ventricle in mammals?

Answer 12

pushes blood through the mitral (bicuspid) valve

Question 13

describe how the left ventricle pumps oxygenated blood to the body (Systemic Circulation) in mammals

Answer 13

The left ventricle contracts and pumps blood through the aortic valve into the aorta to all body tissues and organs.

Question 14

where do the inferior and superior vena cava carry blood to?

Answer 14

superior: head, neck, chest, and upper limbs
inferior: receives blood from trunk and lower limbs