3 Major types of blood vessels

1.Arteries2.Capillaries 3.Veins

Arteries carry blood away from the heart-”branch,” “diverge” or “fork”

Veins carry blood toward the heart-”join”, “merge,” “converge”

Special features of veins• Valves

– Prevent backflow – Most abundant in legs (where blood has

to travel against gravity)

• Muscular contraction– Aids the return of blood to heart in

conjunction with valves

Mechanical issues…

(really good to know)

Exercise helps circulation (because muscles contract and squeeze blood back to the heart)

heart attack!

Blood Flow through the Human Body

Blood with little oxygen is pumped from the Right Atrium through a valve to the Right Ventricle and through another valve into the Pulmonary artery. The Pulmonary artery sends it to the Lungs to pick up Oxygen. It’s sent from the Lungs through Pulmonary vein to the Left Atrium through a valve to the Left Ventricle. The Left Ventricle sends it through a valve to the Aorta. The Aorta is a series of branches that sends oxygenated blood throughout the body.

Average Heart Rate of some Mammals

28

200

50 30 970 40

376

0100200300400

Mammals

Heart

beats

per

min

ute

• Heart Rate can be determined using a Stethoscope

• Hold out your hand and make a fist. If you're a kid, your heart is about the same size as your fist, and if you're an adult, it's about the same size as two fists.

• Your heart beats about 100,000 times in one day and about 35 million times in a year. During an average lifetime, the human heart will beat more than 2.5 billion times.

• Give a tennis ball a good, hard squeeze. You're using about the same amount of force your heart uses to pump blood out to the body. Even at rest, the muscles of the heart work hard--twice as hard as the leg muscles of a person sprinting.

• If you had a massive cut to the arm and blood was spurting out, is that a cut artery or cut vein?

help the blood drop find his way!• superior vena cava• Aorta and to the body organs & cells. right atrium• tricuspid valve• Left Ventricle• left atrium• Aortic Semilunar Valve• Right Ventricle• Bicuspid Valve• Lungs for oxygen pickup• pulmunary arteries• Pulmonary Veins• Pulmonary Semilunar Valve