1.1.3 - Mammalian Heart: Structure & Function

Question 1

What Is The Circulatory System?

Answer 1

Transport fluids containing materials needed by the organism, as well as materials which need to be removed.

Question 2

Describe The Closed Circulatory System

Answer 2

Blood is pumped around the body and is always contained within a network of blood vessels.

Question 3

Describe The Open Circulatory System

Answer 3

Blood is inside the body cavity and bathes the organs.

Question 4

Describe The Double Circulatory System

Answer 4

Two loops, one to the lungs and one to the body.

Question 5

Describe The Single Circulatory System

Answer 5

One loop, includes the lungs and the body.

Question 6

What Type Of Circulatory System Do Humans Have & Why?
(2 Points)

Answer 6

~ Closed, double.

~ Because in one complete circle of the body blood is passed through the heart twice.

Question 7

What Is The Function Of The Right Side Of The Heart & What Type Of Circulatory System Is It?
(2 Points)

Answer 7

~ Pumps deoxygenated blood to the lungs for gas exchange.

~ It is the pulmonary circulatory system.

Question 8

What Is The Function Of The Left Side Of The Heart & What Type Of Circulatory System Is It?
(2 Points)

Answer 8

~ Blood returns to this side of the heart, so oxygenated blood can be pumped at high pressure around the body.

~ It is the systemic circulatory system.

Question 9

What Are The 2 Types Of Circulatory Systems?

Answer 9

~ Pulmonary.

~ Systemic.

Question 10

What Is The Heart?

Answer 10

A hollow, muscular organ located in the chest cavity.

Question 11

What Is The Heart Protected By In The Chest Cavity?

Answer 11

Pericardium, which is a tough fibrous sac.

Question 12

What Are The 4 Chambers The Heart Is Divided Into?
(2 Points)

Answer 12

~ Left and right atria (Top).

~ Left and right ventricles (Bottom).

Question 13

What Are The Left & Right Sides Of The Heart Separated By?

Answer 13

Septum, which is a wall of muscular tissue.

Question 14

What Is The Job Of The Septum?

Answer 14

Ensures that blood doesn’t mix between the left and the right sides of the heart.

Question 15

What Are Valves Important For?

Answer 15

Keeping blood flowing forward in the right direction and for maintaining the correct pressure in the chambers of the heart.

Question 16

What Valve Is The Right Atrium & The Right Ventricle Separated By?

Answer 16

A atrioventricular valve called the tricuspid valve.

Question 17

What Valve Is The Left Atrium & The Left Ventricle Separated By?

Answer 17

A atrioventricular valve called the bicuspid valve.

Question 18

What Valve Is The Right Ventricle & The Pulmonary Artery Separated By?

Answer 18

A semi-lunar valve known as the pulmonary valve

Question 19

What Valve Is The Left Ventricle & The Aorta Separated By?

Answer 19

A semi-lunar valve called the aortic valve.

Question 20

What Causes Valves To Open?

Answer 20

When the pressure of blood behind them is greater than the pressure in front of them.

Question 21

What Causes Valves To Close?

Answer 21

When the pressure of blood in front of them is greater than the pressure behind them.

Question 22

How Are Valves Attached To The Heart Walls & What Do These Prevent?
(2 Points)

Answer 22

~ Are attached by valve tendons or cords.

~ Prevent the valves from flipping inside out under high pressure.

Question 23

Describe The Adaptations Of The Left Ventricle

Answer 23

Thicker muscle than right ventricle, for strong contraction to pump blood all around the body.

Question 24

Describe The Adaptations Of The Ventricles

Answer 24

Thicker walls than atria to pump blood out of the heart.

Question 25

Describe The Adaptations Of The Atrioventricular Valves

Answer 25

Prevent back flow of blood from ventricles into atria.

Question 26

Describe The Adaptations Of The Semilunar Valves

Answer 26

Prevent the back flow of blood from the aorta or pulmonary artery into the ventricles.

Question 26

What Blood Vessels Bring Blood Into The Heart & Where Do They Get The Blood From?
(2 Points)

Answer 26

~ Vena cava -> Blood from body.

~ Pulmonary vein -> Blood from lungs.

Question 27

What Blood Vessels Take Blood Away From The Heart & Where Do They Take The Blood To?
(2 Points)

Answer 27

~ Pulmonary artery -> Blood to lungs.

~ Aorta -> Blood to body.

Question 28

How Does The Heart Itself Get Supplied With Blood?

Answer 28

By a series of blood vessels known as the coronary arteries.