11.3 - Blood Vessels & Lymphatic System

Question 1

Arteries

Answer 1

• take blood away from heart & toward body tissues
• Pulmonary artery carries deoxygenated blood. All others carry oxygenated blood (Ex. aorta).

Question 2

Arterioles

Answer 2

• Arteries branch out into arterioles.
• They control blood flow to different areas by nerves controlled smooth muscles in arterioles

Vasodilation - an increase in the diameter (dilation) of arterioles that increases the blood flow to tissues - to cool down body (warm blood close to surface of body loses thermal energy)

Vasoconstriction a decrease in the diameter of arterioles that decreases the blood flow to tissues - to preserve body heat

Question 3

Capillaries

Answer 3

• Smallest blood vessels
• Site of gas, nutrients, waste, & entry/exit
• No body cells is further than 2 cells away from a capillary.
• Blood flow to capillaries is controlled by precapillary sphincters.

Question 4

Veins

Answer 4

• take blood towards the heart from body tissue. Usually carries deoxygenated blood (ex. vena cava) except pulmonary vein (the only vein to carry oxygenated blood)

Question 5

Sphygmomanometer

Answer 5

Machine that measures blood pressure. 2 readings

• systolic pressure - blood pressure in arteries when heart contracts
• diastolic pressure - blood pressure in arteries when heart relaxes

Question 6

Lymphatic system & its roles

Answer 6

• Is a network of lymph nodes & vessels.

Has roles in both circulatory & immune systems.

• Circulatory: helps to maintain blood volume. Excess tissue fluids (lympth) are collected in lymph vessels & returned to body
• Immune: removes bacteria & other harmful components from blood. Leukocytes (WBCs) gather in lymph nodes to destroy bacteria/viruses/etc. When swollen, it means body is fighting infection.

Question 7

Spleen

Answer 7

• Removes harmful microorganisms & old/damaged erythrocytes (RBCs)
• Contains erythrocytes & leukocytes