The Circulatory System

The circulatory system includes the Heart, Blood Tissue and the Blood Vessels.

The Circulatory System-Transport

• The absorption and circulation of materials throughout an organism

What does the circulatory system do?(What is its function?)

1. Delivers food and oxygen to body cells.

2. Carries carbon dioxide and other waste products away from cells.

Movement of materials into and out of cells occurs by

diffusion (from an area of high concentration to low concentration– no energy required)

Movement also occurs by active transport (from an area of low concentration to high– this requires energy)

• ** In general, the blood is a fluid tissue helping to maintain homeostasis for all cells in the body.

• Transport of needed substances to body cells. (oxygen, amino acids, glucose, fatty acids, glycerol, salts, etc.)

The heart functions as a double pump beating in unison.

1. Deoxygenated blood--relatively low in oxygen

2. Oxygenated blood--relatively high in oxygen

** Heartbeat is stimulated by an electrochemical impulse.

Pacemaker - in the right atrium - initiates the heartbeat

2. Transport of wastes from cells. (urea, water, carbon dioxide in the form of the bicarbonate ion)

3. Helps to maintain a constant body temperature.

4. Aids the body in fighting disease.

The Human (Mammalian) Heart Structure

1. septum: muscular central wall dividing the mammalian heart into two halves

2. atria: thin walled upper heart chambers which receive blood pump blood to the ventricles

3. Ventricles: muscular thick walled chambers which pump blood from the heart -- the lower chambers

4. Valves - prevent the backward flow of blood in the heart

A = aorta F = left ventricle

B = pulmonary arteries G = right ventricle

C = pulmonary veins H = valve

D = left atrium I = vena cavae

E = valve J = right atrium

1. Inferior & superior vena cava 2. Right atrium

3. valve 4. Right ventricle

5. valve 6. Pulmonary arteries

(BLOOD TO THE LUNGS – GAS EXCHANGE) …

7. Pulmonary veins 8. Left Atrium

9. valve 10. Left ventricle

11. valve 12. Aorta

Blood Vessels

1. Arteries

--carry blood away from the heart

--usually spurt blood when cut

--all except the pulmonary artery carry oxygenated blood

--thick walled and elastic

pulse: expansion and contraction of the artery walls in response to the heartbeat

Veins

--carry blood toward the heart --contain valves --closer to the body surface than the

arteries --all except the pulmonary vein carry

deoxygenated blood --thinner, less muscular and elastic than

arteries --depend upon muscle and diaphragm

movements for blood flow

Capillaries

--most numerous vessels

--connect arteries to veins

--microscopic, one cell thick walls

--site of much exchange between the blood and the intracellular fluid (lymph) by diffusion

Lymph vessels

-have walls one cell thick

-present around all body cells

-Lymph composition is similar to that of blood except for the absence of

RBC and some plasma proteins.

-chief site of material exchange with the tissues

Major lymph vessels have lymph nodes which contain phagocytic white blood cells which filter bacteria and dead cells from the lymph.

X = lymph nodes

Valves are present in some lymph vessels--aiding in the movement of the lymph.

Respiratory movements also aid lymph flow.

Which Way Did it Go?

Blood Pressure

Causes of HBP implicated:

1. excess sodium intake

2. stress

3. cigarettes (nicotine)

4. saturated fats

5. alcohol & caffeine

6. obesity

7. heredity & aging

No cure--may be treated by medication & diet.

"Silent killer"--millions don't know they have it

Blood

Blood = a connective tissue made up of blood cells and a liquid called blood plasma.

About 7 % of your body mass About 4.5- 5.6 Liters in an adult human

Men = 5.6 LitersWomen = 4.5 LitersPregnant woman = 5.0 Liters

The Functions of BloodDelivers: Picks Up:

- Nutrients - waste kidneys- Oxygen, Water, minerals - carbon dioxide lungs- Hormones and enzymes - heat skin- pollutants

The Parts of Blood1. Plasma =carries everything

2. Red Blood Cells =(RBC) gas exchange

3. White blood Cells =(WBC) fight infection

4. Platelets = clotting

Components of Blood

Blood Composition

• Plasma 55% (liquid part of the blood); Blood Cells 45%

55% plasma

45 %

RBC, WBC and platelets

Plasma- nonliving

• Yellow liquid (92% H2O)

• 8 % nutrients, salts, urea, hormones

• Carries:

RBC, WBC, Platelets, Carbon dioxide, food and waste

BLOOD CELL TYPES • Red Blood Cells:

– most numerous – biconcave disc shaped – smaller than white blood cells, larger than

platelets – no nucleus when mature – produced in the red marrow of long bones – destroyed in the liver and spleen – contain the iron protein compound

HEMOGLOBIN whose chief function is to combine with oxygen and carry it to the cells

Red Blood Cells- living

• 5 million in 1 drop of blood (most common)

• Shape = donut

Draw here:

• Made in bone marrow

• Live approximately 120-125 days

Hemoglobin = oxygen containing pigmentBinds to oxygen and carries it to the cellsGives red blood cells its red color

White blood cells- living• AKA- Lymphocytes or Leukocytes• White blood cells are larger than red blood

cells, but there are less of them.• 8000 in one drop of blood

Function of White Blood Cells surround and digest bacteriaAttack bacteria and viruses

**Pus = WBC + dead bacteria

YouTube - White Blood Cell Chases Bacteria

White Blood cells

--largest blood cells--several different types

--about 8,000 per drop of blood

--most are formed in the bone marrow or in the lymph tissue

--most protect the body against diseases by forming antibodies or engulfing bacteria

Main White Blood Cell Types

1. Phagocytes-- engulf bacteria and viruses by phagocytosis

--able to leave the bloodstream

and move between the cells of

the body by squeezing through

the capillary walls

2. Lymphocytes--produce antibodies which clump bacterial poisons or bacteria (antigens) (antigens--foreign substances in the body)

Platelets- living• Bits of cells

• Live for approximately 10 days

Function of Plateletscreates fibrin = enzyme that helps clot

blood (tiny threads seal cuts)

3. Platelets

--smallest blood cells (fragments)

--150,000 to 300,000 per drop of blood

--needed for clotting

Clotting:

Involves a series of enzyme controlled reactions resulting in the formation of protein fibers that trap blood cells and form a clot.

Pacemaker-Pacemaker-•Uses electrical impulses from Uses electrical impulses from wire leads inserted into the Heart. wire leads inserted into the Heart. •Keeps the Heart in perfect Keeps the Heart in perfect rhythm.rhythm.

Diseases and Disorders of the Circulatory System

• Myocardial Infarction- heart attack• Hypertension- high blood pressure• Hypotension- low blood pressure• Stroke- clot in the brain• Angina Pectoris- severe pain in chest• Sickle Cell Anemia- sickle shaped rbc’s• Pernicious Anemia- very low rbc count• MVP- prolapsed mitral valve• Pericarditis- inflammation of outer membrane covering the heart• Leukemia- cancer of the blood, elevated wbc count• Varicose veins- enlargement of veins• Arrhythmias- irregularities in heart rhythm• Endocarditis- inflammation of inner lining of heart• Cardiomyopathy- weakening of the heart muscle• Hemophilia- no clotting factor in the blood• Thalassemia- low rbc count, genetic, low hemoglobin count

Heart Disease

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Mitral Valve Surgery

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Aortic Aneurysm

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Aortic Valve Replacement

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