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Question 1

Differences between arteries and veins

Answer 1

1. Arteries: Blood vessels that carry blood away from the heart
   * Systemic circulation: Oxygenated blood from the left Side of the heart towards body tissues
   * Pulmonary circulation: Deoxygenated blood from the right side of the heart towards the lungs
2. Veins: Blood vessels that carry blood towards the heart
   * Systemic circulation: Carry deoxygenated blood towards the right side of the heart from the body tissues
   * Pulmonary circulation: Carry oxygenated blood towards the left side of the heart

Question 2

Arterioles

Answer 2

• Arterioles are small blood vessels branching from arteries
• Lead to capillaries where gas exchange occurs
• Surrounded by smooth muscle
• Main site of vascular resistance (controls blood flow and pressure)

Question 3

Capillaries

Answer 3

• Capillaries are the smallest blood vessels.
• They enable the exchange of water (H2O), oxygen (O2), carbon dioxide (CO2), and other nutrients.
• Facilitate the transfer of waste substances between blood and body tissues.

Question 4

Venules

Answer 4

• Venules are small blood vessels.
• Collect deoxygenated blood from capillaries.
• Transport blood to veins for return to the heart.

Question 5

Three tools to assist with venous return to the heart

Answer 5

• Skeletal Muscle Pump: Each contraction of skeletal muscles pushes blood through the veins.
• Thoracic Pump: During breathing, chest pressure briefly lowers, and abdominal pressure increases, helping blood flow back to the heart.
• Nervous System: During increased activity, nerves signal veins to slightly constrict, aiding blood flow.

Question 6

Components of blood

Answer 6

• Plasma: Fluid component, mostly water, makes up about 55% of blood.
• Blood Cells: Make up the other 45% of blood, consisting of:
  
  • Red Blood Cells: 99% of blood cells, carry oxygen.
  • White Blood Cells: 1% of blood cells, help fight infections.

Question 7

What is a typical hematocrit?

Answer 7

• Hematocrit measures the percentage of red blood cells in the blood.
• Typical values:
  
  • Men: 41–50%
  • Women: 36–44%
• Average hematocrit is around 45% of blood.
• Can vary with age, altitude, and health.