TheCirculatory

System•Blood•Heart

•blood vessels

IN:

• What are four good reasons that blood must be carried to all cells of the body?

• Why doesn’t a unicellular organism need blood?

Function of the circulatory system:

• CIRCULATE blood throughout the body

• Transport nutrients to cells

• Transport wastes away from cells

• Fight disease

• Maintain body temperature

Three kinds of blood vessels:

• Arteries – represented by red– Carry blood AWAY from

the heart

• Veins– Represented by blue– Carry blood back to heart

• Capillaries – Microscopic vessels

that join arteries and veins

• The artery has thick muscular walls so it can Pulsate

• The vein has valves inside to keep blood flowing toward the heart against gravity

• Capillaries are only one cell thick.

• This allows molecules to pass out of the blood to surrounding cells by diffusion while other molecules pass into the blood

What is passing out of the red blood cell at X?What may be passing into the blood at Y?What is passing out of the blood’s plasma at Z?

How does the circulatory system regulate body temperature and

maintain homeostasis?

The Heart is a pump• It’s made of cardiac

muscle tissue with connective tissue and fat tissue on the outside

• It has four chambers

• Blood enters form the vena cava, the largest vein

• Blood leaves through the aorta, the largest artery

The heart has four chambers,(chambers are spaces)

• Two atria- smaller chambers at the top(atrium singular)– They receive blood from

veins, pump it to ventricles

• Two ventricles- larger stronger chambers below– they pump blood out

of heart• Valves (one way doors)

separate the chambers to keep blood flowing the right direction

Why is it essential for the mammal heart to have four chambers?

(hint- mammals are very active)

Frog heart – 3 chambers human heart – 4 chambers

Right side of the heart• The atrium receives

deoxygenated (oxygen is used up) blood from the body through large veins called the vena cava (superior and inferior)

• The blood is pumped to the right ventricle, then to the lungs via the pulmonary artery.

• What happens to blood in the lungs?

Right left(the heart is facing you)

Left side of the heart• Oxygenated blood

returns to the left atrium from the lungs

• It’s pumped through a valve to the left ventricle, then to the body via the aorta, or largest artery

Coronary circulation

• The heart is a hard-working muscle

• It needs a lot of oxygen and nutrients

• this is supplied by the coronary arteries, and wastes are removed by the coronary veins

OUT:

• Draw red arrows (oxygenated) and blue arrows (deoxygenated) on your heart diagram to show how blood circulates through the heart.