The Mammalian Heart: Part 2

Biology 11

6 facts about arteries

• Take blood away from the heart

• have thick walls

• All arteries carry oxygenated blood from the heart except for the pulmonary arteries which carry deoxygenated blood from heart to lungs.

• Blood enters the arteries each time the heart contracts.

• Arteries stretch to accommodate the rush of blood and have valves to keep blood flowing in one direction, away from the heart.

• Pulse is the change in diameter of the arteries following heart contractions (heart beat).

4 facts about veins

• Carry blood to the heart.

• Veins are collapsed and not as thick as arteries.

• All veins carry deoxygenated blood except for the pulmonary veins which carry oxygenated blood from the lungs to the heart.

• Veins contain valves to keep the blood flowing in one direction toward the heart; skeletal movement also helps this.

arterioles

arteries branch into these, smaller arteries. more numerous in the body than arteries

venules

veins branch into these, smaller veins. more numerous in the body than veins

capillaries

very thin blood vessels between the arterioles and venules. their thickness is one cell, which helps with diffusion of nutrients and gases into/out of our body cells

in all active tissues

how is brusing caused

Capillaries that are broken under the skin cause bruising

important arteries / veins of the heart

Aorta

Pulmonary Artery & Pulmonary Vein

Coronary Artery

Superior and Inferior Vena Cava

aorta

Largest artery in human body

Blood leaving the left ventricle passes through the aorta on its way to the bodies other arteries.

pulmonary artery

• start at the end of pulmonary circuit

• deoxygenated blood from the right ventricle and leads it to arterioles and capillaries within the lungs.

pulmonary vein

• start at the end of pulmonary circuit

• oxygenated blood from the capillaries and venules within the lungs and leads to the left atrium.

coronary artery

• Branches off of the aorta.

• Supplies the heart’s muscle tissue with the necessary oxygen.

• Blockage of these arteries can lead to angina or heart attacks.

superior vena cava

• Veins that return deoxygenated blood to the heart.

• Superior Vena Cava delivers blood from the head and arms

inferior vena cana

Veins that return deoxygenated blood to the heart.

Inferior Vena Cava delivers blood from the lower body.

sinotral (SA) node

• controls the heart’s rythym, tempo, or beat rate

• a bundle of nerves that acts like a pacemaker for the heart

• nerve impulses are send from the SA node to the atrioventricular (AV) node

atrioventricular (AV) node

• nerve impulses are sent from the SA node to the AV node

• The AV node then signals the heart muscle tissue to contract.

• The atria contract first, followed by the ventricles