Transport systems in mammals

• What is the relationship between structure and function of tissues?

  They perform a common function together
• Why does the heart beat faster during exercise?

  To supply more oxygen to the muscles
• Why does the heartbeat not return to normal immediately after exercise?

  Because the body still needs more oxygen
• How is the heart rate speeded up when the body needs more oxygen?

  By releasing adrenaline and stimulating the heart
• How is the heart rate slowed when the body needs less oxygen?

  By reducing adrenaline and calming the heart
• Do sportspeople have an above average or below-average pulse rate?

  Below-average pulse rate
• Who proved that blood circulated in one direction only?

  William Harvey
• What did William Harvey discover about blood flow?

  Blood flows from veins to arteries
• What invention helped to see capillaries?

  The microscope
• What is the journey of blood after it leaves the heart?

  Through arteries, capillaries, and veins
• What do arteries do?

  Move blood away from the heart
• What are smaller arteries called?

  Arterioles
• What are pulse points?

  Arteries close to the skin
• What do veins do?

  Move blood to the heart
• What feature helps veins move blood towards the heart?

  Tiny one-way valves
• Where are the greatest number of one-way valves found?

  In the legs
• How do skeletal muscles assist veins?

  They squeeze veins during contraction
• What are smaller veins called?

  Venules
• What is the pressure of blood in veins?

  Very low pressure
• What are capillaries?

  Microscopic blood vessels connecting arteries and veins
• What is unique about capillary walls?

  They are one cell layer thick
• Why do capillaries form branching networks?

  To increase surface area for exchange
• What are the functions of different blood vessels?

  • Arteries: Carry blood away from the heart
  • Veins: Carry blood to the heart
  • Capillaries: Connect arteries and veins, facilitate exchange
• What is the inner layer of blood vessels made of?

  Epithelial tissue
• What additional layers do arteries and veins have?

  Smooth muscle and connective tissue
• What does smooth muscle in blood vessels allow?

  Vessels to contract
• What does connective tissue provide to blood vessels?

  Elasticity to stretch
• What are the differences between types of blood vessels?

  • Arteries: Thick walls, high pressure, small lumen
  • Capillaries: One cell layer, very small lumen
  • Veins: Thin walls, low pressure, large lumen
• What is blood?

  A fluid connective tissue
• What is double circulation?

  Blood goes twice to the heart
• What is pulmonary circulation?

  Between the heart and lungs
• What is systemic circulation?

  Between the heart and the body
• How much blood does the circulatory system move?

  About five litres
• What does pulmonary circulation carry?

  Deoxygenated blood to the lungs
• What does systemic circulation carry?

  Oxygenated blood to the body
• What are the main blood vessels in humans?

  Superior vena cava, aorta, pulmonary artery
• What is the lymph system's role?

  To fight infections
• What is a typical lymph pathway?

  From tissue fluid to circulatory system
• How does the structure of a lymph capillary differ from a blood capillary?

  Lymph capillaries are more permeable
• What are common cardiovascular diseases?

  Heart attack, hypertension, and angina