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Chapter 42 – October 7, 2009

Closed Circulatory System- when blood is contained within vessels and is pumped around body. Blood is separate from interstitial fluid.

- Humans have closed Circulatory system called Cardiovascular System containing a heart with Atria and Ventricles.

Types of blood vessels: arteries, veins, capillaries

- Arteries pump blood away from heart into smaller arteries

- Capillaries form capillary bed which turn into veins that bring blood back to the heart

Vein: Large diameter, thin wall, contains valve to prevent backflow

Artery: Small diameter, thick wall

Double Circulation in Mammals

1. Right ventricle pumps blood to lungs through Pulmonary Artery
2. Blood flows through capillary bed in the lungs and receives oxygen and release carbon-dioxide
3. Blood returns to Left Atrium of Heart via Pulmonary Vein
4. It flows through Left Ventricle
5. Then it leaves the Heart via Aorta, which sends the blood to arteries throughout the body
6. Blood enters capillary beds in neck, head, arms
7. Blood enters capillary beds in abdomen and legs – giving up oxygen and picking up carbon-dioxide from cell respiration
8. Capillaries continue into venules which progress to veins, carrying blood from neck, head, and arms travel back to Right Atrium via Anterior Vena Cava
9. Blood from legs and abdomen travel through Posterior Vena Cava to Right Atrium

1. Blood returning to the heart in a pulmonary vein will drain first into the

1. vena cava
2. left atrium
3. right atrium
4. left ventricle
5. right ventricle

2. All of the following are blood vessels except:

a. veins

b. arteries

c. capillaries

d. venuoles

e. lymphatics

3. Which of the following is true of the mammalian Circulatory System

a. All arteries carry oxygenated blood to the body.

b. All veins carry deoxygenated blood

c. Right ventricle pumps blood to lungs through the Pulmonary Artery

d. Left atrium pumps blood to the body through the Aorta

Answer 1 b, 2e, 3c