2.2.2 Circulatory System

Question 1

Circulatory system

Answer 1

-made of heart & blood vessels
-closed system as blood remains within these structures
-

Question 2

What does blood do?

Answer 2

Transports substances around body eg. Oxygen and glucose for respiration
Also carries away waste products eg. Carbon dioxide to lunge to get rid

Question 3

Heart does?

Answer 3

Circulates blood around body

Question 4

Type of system

Answer 4

Closed system (blood remains within heart & blood vessels)
Double circulatory system (blood flows through heart twice in one circuit)

Question 5

Cycle

Answer 5

-heart pumps blood to body organs and tissues-oxygen and glucose diffuse out of blood, into cells- CO2 diffuses into blood out of cells- blood travels back to heart- heart pumps blood into lungs- in lungs CO2 diffuses out of blood to be removed- oxygen diffuses into blood from lungs,-oxygenated blood returns to heart - repeat

Question 6

Artery

Answer 6

• carries blood away from heart under high pressure
• thick, muscular outer walls to withstand high pressure waves made when heart beats
• thick layer of elastic fibres
• expands with each contraction and recoils to push blood foreward
• Small lumen
• smooth lining

Question 7

Veins

Answer 7

• veins return blood to heart
• have valves to stop blood from flowing wrong way
• thin walls because of low pressure
• Large lumen
• thin layer of muscle and elastic fibre
• smooth lining

Question 8

Capillary

Answer 8

• links arteries and veins in tissues and organs
• form networks so every cell is close to a capillary
• semipermeable walls one cell thick so substances easily move in/out
• higher pressure than single circulatory system and materials are transported faster=essential for large organisms
• small lumen