Cardiovascular System Intro

Cardiovascular System Part 1

Follow Your Heart...

Lesson Objective

11.1 Describe the structure of the heart and the function of each part.

11.2 Trace the flow of blood through the heart.

•The cardiovascular system consists of heart and blood vessels (arteries, veins, capillaries, venules, arterioles)

•2 PARTS:

• PULMONARY CIRCUIT:

–Carries blood to the lungs & returns to heart

–Eliminates CO2 and oxygenates blood

•SYSTEMIC CIRCUIT

–Supplies blood to rest of body

–Circulates waste products to various organs for removal form blood

Where is the heart

• •Cone-shaped organ about the size of a loose fist

  •In the mediastinum

  •Extends from the level of the second rib to about the level of the sixth rib

  •Slightly left of the midline

• Heart is bordered:

  Laterally by the lungs

  Posteriorly by the vertebral column

  Anteriorly by the sternum

  
  

  Rests on the diaphragm (inferiorly)

You have a big heart...

The heart is the hardest working organ in the building. It beats about 70 -80 times a minute... approximately 3 billion times in a person's lifetime.

The heart is about the size of your fist (ball up your hand... that's the size of your heart)

It weighs about 8-10 ounces in women & 10-12 ounces in men

Multiple Select

The heart is

• Slightly right of the midline

• surrounded by lungs

• posterior to the sternum

• 16 ounces

Multiple Select

The cardiovascular system

• Circulates waste products to various organs for removal form blood

• Eliminates O2 from blood

• Supplies blood to rest of body

• Carries blood to the lungs & returns to heart

Structures of the Heart

• •Heart coverings

  –Pericardium

  •Covers the heart and large blood vessels attached to the heart

  •Visceral pericardium

  –Innermost layer

  –Directly on the heart

  •Parietal pericardium

  –Layer on top of the visceral pericardium  

Structures of the heart

•Heart walls:

–Epicardium

•Outermost layer

•Fat to cushion heart

–Myocardium

•Middle layer

•Primarily cardiac muscle

–Endocardium

•Innermost layer

•Thin and smooth

•Stretches as the heart pumps

Multiple Choice

What is the middle layer of the heart

• epicardium

• pericardium

• myocardium

Structures of the Heart cont...

•Four chambers

–Two atria

•Upper chambers

•Left and right

•Separated by interatrial septum

Structures of the Heart cont...

•(Four Chambers)

Two ventricles

•Lower chambers

•Left and right

•Separated by interventricular septum

Heart Valves

•Tricuspid valve – prevents blood from flowing back into the right atrium when the right ventricle contracts

•Bicuspid (mitral) valve – prevents blood from flowing back into the left atrium when the left ventricle contracts

Open Ended

What is the purpose of the valves?

Heart Valves

•Pulmonary semilunar valve – prevents blood from flowing back into the right ventricle

•Aortic semilunar valve – prevents blood from flowing back into the left ventricle 

Poll

How many chambers are in the heart

• 3

• 8

• 6

• 4

Multiple Choice

Ventricles are located

• laterally on the left side of the heart

• superior port6ion of the heart

• laterally to the right side of the heart

• inferior portion of the heart