Unit 5A: Lesson 1: Heart Structure

Unit 5A: Lesson 1: Heart Structure

Learning Objectives

SW learn about the size, and location of the heart

SW learn the parts of the heart and main vessels

Cardiac Cells

The work together in unison -

Size of the heart

1. The size of the heart would be the size of both your fists together

2. The size your thumb represents the size of your Aorta

3. The heart weighs about 300 grams or 0.5 pounds

Membranes of the heart

1. Serous membranes have a double layer of tissue with a slick serous fluid in between the tissue layers.  

2. The visceral layer of the serous membrane lines the outside of the heart. 

3. The parietal layer of the serous membrane is a tough layer of dense irregular connective tissue. 

4. Serous fluid found between the visceral and parietal layer absorbs the friction of the heart's movement.

Cross-section of the Heart

The layers of the heart :

1. Outerlayer= Pericardium

2. Myocardium- Muscle of the heart

3. Endocardium- Inner lining of the heart

Superior vena cava

Veins always bring blood TO THE HEART.

Superior vena cava brings blood from the upper body to the right atrium.

Inferior vena cava

brings blood from the entire lower part of the body into the Rt. Atrium. 

Right atrium (Right auricle)

Receives deoxygenated blood from the vena cava

Tri-cuspid valve

a one-way valve that allows blood to pass from the Right Atrium to the Right Ventricle. It has three leaflets that have tendons called cordae tendinae. They are anchored into the papillary muscles

Right Ventricle

Pumps blood through the Pulmonary Semilunar valves and into the Pulmonary Trunk, which splits into the two Pulmonary Arteries.

Pulmonary Semilunar Valve:

Pulmonary=lungs

Semilunar=half-moon leaflets

This valve is named after the pulmonary artery

The semilunar valves are comprised of three half-moon leaflets. 

Pulmonary Artery

AAA=Artery Away Always from the heart!

The name is given to this artery because it is going away from the heart to the lungs. Blood goes to the lungs and drops off CO2 and picks up O2.

Pulmonary veins (red)

Pulmonary veins: Pulmonary=lungs;

All Veins=carry blood to the heart 

There are four pulmonary veins. Sets of two pulmonary veins come from the right and left lungs

Left Atrium (Auricle)

Receives blood from the pulmonary veins.

Bicuspid valve/ Mitral valve

This valve is built just like the tricuspid valve except that it only has two leaflets.

Prevents blood from returning to right atrium when the ventricles contract!

Left Ventricle

Pumps blood to the rest of the body. Because it has such a big responsibility to pump blood to all parts of the body, this chamber is the strongest of the heart.

Aortic Semilunar Valve

Built like the pulmonary semilunar valve. Its name is given because it is located in the aorta.

The Aorta Arch

carries blood to the rest of the body. It is the largest artery in the body.

1^st Branch of the Aorta: The brachiocephalic artery

This artery branches into the Right Subclavian artery, which feeds the right arm, and Right Common Carotid, which travels up the right side of the neck to feed the right side of the face and brain.

2^nd Branch of the Aorta: Common Carotid

Travels up the left side of the neck and feeds the left side of the face and brain.

3^rd Branch of the Aorta: Left Subclavian artery

The 3rd branch of the aorta travels and feeds the left arm.

Multiple Choice

Identify

• Pulmonary veins
• Pulmonary artery
• Aorta
• Vena cava

Multiple Choice

Freshly oxygenated blood is delivered to the _____________ and then it passes into the  __________ to be pumped to the entire body.

• right ventricle; right atrium
• left ventricle; left atrium
• left atrium; left ventricle
• right atrium; right ventricle

Multiple Choice

Blood leaves the right ventricle through the ___________.

• pulmonary artery
• aorta
• superior vena cava
• right atrium

Multiple Choice

The two chambers of the heart which receive blood are known as the _________

• atria
• ventricles
• systemics
• pulmonic

Multiple Choice

Which number is the vena cava?

• 1

• 2

• 3

• 8

Multiple Choice

Which number is the vena cava?

• 1

• 2

• 3

• 8