HUMAN SYSTEMS:

Circulatory System

BLOOD

BLOOD

Fluid connective tissue

Circulates various substances

About 5L of blood in human adults

Blood is a part of the cardiovascular system (other include the heart and blood vessels)

COMPONENTS OF BLOOD

Blood contains plasma (fluid component) Blood cells (suspended component)

Plasma Contains dissolved substances (water, minerals, proteins,

carbohydrates, other complexes, etc.)

Blood cells RBC - Red blood cells (hemoglobin – transport of gases) WBC - White blood cells (immune system – defense

against infections) Platelets (involved in blood clotting)

BLOOD CELLS

Red blood cells Transport oxygen Contain hemoglobin Most abundant cell type

BLOOD CELLS Platelets

Small in size, pieces of larger cells found in bone marrow Remain in circulation for 5-10 days Role in blood clotting

BLOOD CELLS White blood cells

Destroy pathogens Help in wound cleaning

Modes of action Some search tissues for pathogens Some WBCs produce antibodies Some WBCs produce other chemicals against pathogens Other eliminate dead or damaged body cells

FUNCTIONS OF BLOOD

Transport of oxygen

Transport of nutrients and minerals

Transport hormones and other substances

Regulation of body temperature

BLOOD PRESSURE When heart contracts, blood is pushed out The force blood exerts on the walls of arteries is known as

blood pressure

Expressed in terms of millimeters of mercury (mm Hg) Blood pressure is expressed by two numbers - systolic and

diastolic

Systolic pressure – pressure in arteries when heart contracts

Diastolic pressure - pressure in arteries when heart relaxes

Healthy blood pressure: systolic 120 mm Hg, diastolic 80 mm Hg

Pulse – rhythmic throbbing of arteries when blood is pumped by heart (around 60 - 70 per minute)

BLOOD TYPES

ABO system A, B, AB or O Depends on the type of antigens on RBC Blood groups and transfusion

BLOOD TYPES

Rh System Another type of antigen on RBC If antigen if present then Rh+ If absent then the individual is Rh-

Rh system and transfusion

BLOOD DISORDERS Hemophilia

Problem in blood clotting Protein required for clotting is missing

Leukemia Blood cancer Healthy blood cells are not produced

Sickle cell anemia Mutation in hemoglobin Results is deformed RBCs

CARDIOVASCULAR SYSTEM

CARDIOVASCULAR SYSTEM

Circulatory fluid (blood) Channels / tubes (blood vessels) Pumping device (heart)

Transport of substances Regulation of body temperature Maintenance of homeostasis

THE HEART

Muscular organ Divided into four compartments (chambers) Upper chambers: Atrium Lower chambers: Ventricles Left and right sides of the heart are separated by

wall

Valves prevent back flow of blood Repeated opening and closing of valves produce

heart beat

BLOOD VESSELS Hollow tubes for flow of blood Some contain valve to prevent backward blood flow Three typesArteries

Carries blood away from the heartPulse is caused by flow of blood into arteries

CapillariesNarrow blood vesselsAllows exchange between body cells and blood

VeinsBlood enters from arteries to veinsCarry blood towards heart

BLOOD VESSELS

TYPES OF CIRCULATION

1. Pulmonary circulation2. Systemic circulation

CARDIOVASCULAR PROBLEMS

Atherosclerosis Cholesterol and lipids accumulate in blood vessels This causes narrowing of vessels and decrease in

elasticity

High blood pressure Hypertension Narrowing or constriction of blood vessels increases

pressure Stroke - blockage or rupture of blood vessels in

brain

CARDIOVASCULAR PROBLEMS

CARDIOVASCULAR PROBLEMS

Heart attack and failureHeart attack - when heart muscle cells do not

get enough foodDamage to heart cells If damage is excessive, heart may stop

Heart failure occurs when heart is too weak to pump sufficient blood to meet body’s need

Organs such as lungs, brain or kidneys may get damage