Circulatory System

Ms. Campanicki

Allied Health

Lesson Essential Question

• What parts of the heart control blood flow?

• Why does blood only flow in one direction?

• Why does the heart need a continous supply of oxygen?

Circulatory System

• Body's delivery system

• Completes the process of circulation by pumping oxygenated blood through the body and retuning deoxygenated blood back to the lungs.

• Parts • Heart

• Blood vessels

• Veins

• Lungs

The Heart: PUMP

• Weighs about 350g ( 12.35 oz. = a can of COKE )

• Adult heart is the size of a closed fist

• Pumps over 8000 liters of blood per day

• The heart will beat: • 100,000 times/day

• 35 million times/ year

• 2.5 billion times/ lifetime

Heart Location

• The heart lies 2/3's on the left side of the body

• Mediastinum• extends from the sternum anteriorly to the vertebral column and

lies medially between both lungs

The Pericardium

• What does Pericardium mean?

• Peri =

• Cardium =

• Protective sac that covers the heart

• contains fluid that allows for free movement of the heart with each beat

Anatomy of the Heart : Muscle Microscopic View• Shape

• Branching chains

• Striated

• Uninucleated

• Intercalated discs

• Location• In the heart only

• Regulation of contraction• Involuntary

• Contraction style• Speed: slow

• Rhythmic

Anatomy of the Heart: Heart Wall

• Composed of 3 layers

• From superficial to deep :

1. Epicardium: thin, transparent, comes in contact with the pericardium and pericardial fluid

2. Myocardium: thick middle layer made of muscle (cardiac muscle)

3. Endocardium: thin layer that comes in contact with blood during each contraction, is the anchor for valves of the heart

Anatomy of the Heart: Chambers

• Divided into right and left

• 4 chambers total

• Upper Chambers = Atria (atrium)

• Lower Chambers = Ventricles ( ventricle)

• They are divided by a septum (thick myocardium)

Anatomy of the Heart: Chambers

• Atriums: Thin muscular walls that are highly expandable.

• Ventricles: Thicker walls used to push the blood to the lungs or the whole body. Left side thicker than right.

• Right vs. Left Ventricle• Right does not work as hard and walls are not very thick

• Left walls are much thicker to pump blood to the entire body and will generate 6x the pressure of the right.

Anatomy of the Heart : Valves

• Help to control blood flow to and from the heart

• Found between each atrium and ventricle

• Found in each vessel leading into and out of the heart• Bicuspid Valve : two cusps (flaps) between the Left atrium and ventricle

(MITRAL)

• Tricuspid Valve: three cusps (flaps) between the Right atrium and ventricle

• Pulmonary Valve : Leads to the pulmonary arteries

• Aortic Valve: leads to the aorta

How does blood circulate through the whole body?

Heart House Time

Circulatory System Diseases

and Disorders