Circulatory Circulatory SystemSystem

HeartHeart

BloodBlood

Blood vesselsBlood vessels

Circulatory SystemCirculatory System

Simple animals (sponge, hydra) have Simple animals (sponge, hydra) have no circulatory systemno circulatory system

Complex animals have circulatory Complex animals have circulatory systems that are either:systems that are either:

Open – blood circulates inside the Open – blood circulates inside the body without blood vesselsbody without blood vessels

Closed – blood is inside vesselsClosed – blood is inside vessels Humans have a closed systemHumans have a closed system

Types of circulatory Types of circulatory systemssystems

The Human HeartThe Human Heart The heart is a muscleThe heart is a muscle It pumps blood It pumps blood

through the bodythrough the body There are upper and There are upper and

lower chambers on lower chambers on the two sides of the the two sides of the heartheart

The upper are called The upper are called atriaatria

The lower are called The lower are called ventricles ventricles

Pumping of the HeartPumping of the Heart

Heart pumps 60-80 Heart pumps 60-80 times a minute times a minute while you are while you are restingresting

May pump up to May pump up to 150 times a minute 150 times a minute after runningafter running

Will pump more Will pump more than 2 billion times than 2 billion times in your lifetimein your lifetime

Heart ValvesHeart Valves

For a pump to work right the liquid For a pump to work right the liquid must go only in one directionmust go only in one direction

Valves are flaps in the heart that Valves are flaps in the heart that keep blood flowing in one directionkeep blood flowing in one direction

The tricuspid valve is between the The tricuspid valve is between the right atrium and the right ventricleright atrium and the right ventricle

The bicuspid valve is between the The bicuspid valve is between the left atrium and the left ventricleleft atrium and the left ventricle

Heart Valves (cont.)Heart Valves (cont.)

The other valves The other valves are the semilunar are the semilunar valves between the valves between the ventricles and ventricles and their arteries.their arteries.

If you listen to If you listen to your heart you are your heart you are hearing the main hearing the main valves closingvalves closing

Jobs of the Circulatory Jobs of the Circulatory systemsystem

Main job is to pump oxygen from your Main job is to pump oxygen from your lungs to the bodylungs to the body

Right side of your heart pumps blood Right side of your heart pumps blood through the lungsthrough the lungs

Blood from the lungs is pumped by Blood from the lungs is pumped by the left side to all the parts of the the left side to all the parts of the bodybody

Blood coming back from the body Blood coming back from the body parts goes into the right sideparts goes into the right side

Exchange of gasses in Exchange of gasses in the lungsthe lungs

More jobsMore jobs

Gets nutrients from the gastric Gets nutrients from the gastric system and distributes to the tissuessystem and distributes to the tissues

Gets wastes from the tissues and Gets wastes from the tissues and takes them to the lungs (CO2) and takes them to the lungs (CO2) and kidneys (waste chemicals)kidneys (waste chemicals)

Helps regulate temperature of the Helps regulate temperature of the bodybody More blood to the skin to lower tempMore blood to the skin to lower temp Less blood to the skin to raise tempLess blood to the skin to raise temp

Blood VesselsBlood Vessels

You have about 96,000 Kilometers of You have about 96,000 Kilometers of blood vessels in your body (2.5 times blood vessels in your body (2.5 times around the world)around the world)

Three types of blood vesselThree types of blood vessel Arteries – away from heartArteries – away from heart Capillaries – very small, one cell thickCapillaries – very small, one cell thick Veins – back to heartVeins – back to heart

ArteriesArteries

Carry blood away Carry blood away from the heartfrom the heart

Carry blood under Carry blood under high pressurehigh pressure

Round in shape Round in shape and have thick, and have thick, muscular wallsmuscular walls

VeinsVeins

Carry blood to the Carry blood to the heartheart

Carry blood under Carry blood under low blood pressurelow blood pressure

They are flat in They are flat in shape and have little shape and have little musclemuscle

They have one-way They have one-way valves to keep blood valves to keep blood flowing in one flowing in one directiondirection

CapillariesCapillaries Are very small and Are very small and

only one cell thickonly one cell thick Some blood cells can Some blood cells can

pass between the pass between the cells of the capillary cells of the capillary wallwall

All the pickups All the pickups (Carbon dioxide and (Carbon dioxide and waste) and waste) and deliveries (Oxygen deliveries (Oxygen and nutrients) occur and nutrients) occur in the capillariesin the capillaries