Chapter 16- Cardiovascular system 1 Part 1 (1)

Question 1

What does the cardiovascular system consist of?

Answer 1

Heart and blood vessels

Question 2

How much does the heart roughly weigh?

Answer 2

300 grams

Question 3

Where is the heart located?

Answer 3

Within the mediastinum- a cavity inside the thorax.

Question 4

What is the heart covered by?

Answer 4

A double waled sac called the pericardium

Question 5

The pericardium has two layers:

Answer 5

1- Fibrous pericardium- the layer on the surface which is made up of connective tissue. It protects the heart and anchors it in place.

2- Serous pericardium- a deep layer which is a thin, slippery membrane.

• This is composed of two layers, each made up of simple squamous epithelial cells.
• Between them is a cavity which contains a serous fluid that acts as a lubricant, allowing the two layers to glide past each other.

Question 6

Inflammation of the pericardium can cause what?

Answer 6

Pain and shortness of breath.

Question 7

What will excessive fluid in the pericardial cavity cause?

Answer 7

It can put pressure on the heart, preventing the ventricles from filling.

Question 8

The heart wall is composed of 3 layers:

Answer 8

1- Epicardium- the bottom layer of the pericardium. Often contains fat.

2- Myocardium- where the cardiac muscle tissue resides

3- Endocardium- a squamous epithelium which lines the heart chambers.

Question 9

How many chambers does the heart contain?

Answer 9

4

Question 10

What do the chambers in the heart consist of?

Answer 10

Consists of the 2 superior atria- the left and right atrium

Consists of the 2 inferior ventricles- the right and left ventricles

Question 11

What does the left atrium do?

Answer 11

Receives oxygen rich blood from the lung, via 4 pulmonary veins.

From here, the oxygenated blood travels down to the left ventricle.

Question 12

What does the left ventricle do?

Answer 12

Pumps oxygenated blood out around the body, via the aorta.

Question 13

The left ventricle is the driving force for what circuit?

Answer 13

The systematic circuit

Question 14

Why is the left ventricle more well developed than the right ventricle?

Answer 14

Because it pumps oxygenated blood around the body.

Question 15

How is the left ventricle more well developed than the right ventricle?

Answer 15

It has thicker walls and has much more myocytes

Question 16

What branches off the aorta?

Answer 16

The right and left coronary arteries.

Question 17

What do the right and left coronary arteries do?

Answer 17

These supply the heart muscle itself with blood

Question 18

What does the right atrium do?

Answer 18

Receives deoxygenated blood via 3 veins.

Two of the veins bring back deoxygenated blood from around the body. They are the inferior and superior vena cava.

The third vein collects blood from the myocardium itself. This is called the coronary sinus.

From here, the deoxygenated blood then travels down to the right ventricle.

Question 19

What does the right ventricle do?

Answer 19

Pumps deoxygenated blood back to the lungs via the pulmonary trunk.

It is smaller and weaker than the left ventricle.

Question 20

The right ventricle is the driving force for what circuit?

Answer 20

The pulmonary circuit

Question 21

What is the function of valves?

Answer 21

They are mechanical devices that open and close in response to differences in blood pressure.

Question 22

What do valves ensure?

Answer 22

Valves ensure that blood only flows in one direction

Question 23

There are two main types of valves in the heart:

Answer 23

1- Atrioventricular valves (AV)

2- Semilunar valves