The Circulatory System

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The Circulatory System
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I. Purpose of the circulatory system

• To move materials through out the body
• Oxygen
• Carbon dioxide other wastes
• Nutrients
• Hormones
• Antibodies

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II. There are 3 types of circulation

• Systemic between the heart and the body systems
• Pulmonary between the heart lungs
• Coronary to the heart tissues

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A. Coronary circulation

• The flow of blood to and from the tissues of the
  heart
• When the coronary circulation is blocked, oxygen
  and nutrients cannot reach all the cells of the
  heart.
• This can cause a heart attack.

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B. Pulmonary circulation

• The flow of blood through the heart to the lungs
  and back to the heart

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The pathway of blood from the heart to lungs and
back.
1. Blood, high in carbon dioxide and low in
oxygen, returns from the body to the heart. It
enters the right atrium through the superior and
inferior vena cavae.
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Trace the pathway of blood from heart to lungs
and back.
2. The right atrium contracts, forcing the blood
into the right ventricle. When the right
ventricle contracts, the blood leaves the heart
and goes through the pulmonary artery to the
lungs. The pulmonary arteries are the only
arteries that carry blood that is high in carbon
dioxide.
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Trace the pathway of blood from heart to lungs
and back.
3. Oxygen-rich blood travels from the lungs
through the pulmonary vein and into the left
atrium. The pulmonary veins are the only veins
that carry oxygen-rich blood.
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Trace the pathway of blood from heart to lungs
and back.
4. The left atrium contracts and forces the blood
into the left ventricle. The left ventricle
contracts, forcing the blood out of the heart and
into the aorta.
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C. Systemic circulation

• It moves oxygenated (oxygen-rich) blood to organs
  and body tissues.
• It returns deoxygenated (oxygen-poor) blood to
  the heart.

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III. The main parts of the circulatory (or
cardiovascular) system

• Heart
• Blood vessels
• Arteries
• Veins
• Capillaries
• Blood

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Arteries

• Blood vessels that carry blood away from the
  heart
• Have thick, elastic walls made of connective
  tissue and smooth muscle tissue

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Veins

• Blood vessels that carry blood back to the heart
• Have one-way valves that keep blood moving toward
  the heart

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Capillaries

• Arteries carry blood away from the heart.
• Veins carry blood to the heart.
• Capillaries connect arteries veins.
• Diffusion takes place in capillaries.

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Compare contrast the three types of blood
vessels

• All 3 blood vessels transport (move) blood to
  every part of your body, but...
• Capillaries are only one cell thick.
• Arteries veins have 3 layers.
• Veins have valves to prevent back- flow.

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IV. Blood pressure

• The force of the blood on the walls of the blood
  vessels.
• Measured in mm of Mercury and usually given as 2
  numbers ex. 110 over 70
• The top number is the systolic blood pressure
  reading ? the maximum pressure exerted when the
  heart contracts.
• The bottom number is the diastolic blood pressure
  reading ? the pressure in the arteries when the
  heart is at rest.

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Blood pressure

• Healthy adult humans are approximately 120 mmHg
  systolic and 80 mmHg diastolic
• Written as 120/80 mmHg, and spoken as "one twenty
  over eighty"
• Blood pressure is most commonly measured with a
  stethoscope and a sphygmomanometer
• say what???

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V. Blood

• Blood moves oxygen and nutrients to cells
• Carries carbon dioxide and other wastes away from
  the cells
• Sometimes the blood carries substances made in
  one part of the body to another part of the body
  where they are needed
• Ex. Hormones and antibodies

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VI. The Heart

• Made of cardiac muscle tissue
• Located behind your breastbone, called the
  sternum, and between your lungs
• Has four compartments called chambers
• The two upper chambers are called the right and
  left atria (atrium)
• The two lower chambers are called the right and
  left ventricles

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The Heart

• During one heartbeat, both atriums contract at
  the same time
• Then, both ventricles contract at the same time
• A one-way valve separates each atrium from the
  ventricle below it

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The Heart

• The blood flows only in one direction from an
  atrium to a ventricle, then from a ventricle into
  a blood vessel
• A wall prevents blood from flowing between the
  two atriums or the two ventricles
• This wall or septum keeps blood rich in oxygen
  separate from blood low in oxygen
• If oxygen-rich blood and oxygen-poor blood were
  to mix, your body's cells would not get all the
  oxygen they need

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The Heart