Circulatory System Watch the Brain POP: Circulatory System or Crash Course (circulatory system starts 5 min in)

Function Transport substances (nutrients, oxygen, disease fighting materials) throughout body Also disperses heat to maintain body temperature

Parts of the System Heart Blood Blood vessels Lymphatic system (immune response)

Heart Watch the Brain POP: Heart Label your heart diagram

Label your heart diagram Use the website: https://www.sciencelearn.org.nz/embeds/5-label-the- heart Determine the correct order of the path of blood and highlight your heart diagram to show blood flow. Use 2 colors to represent oxygenated and deoxygenated blood.

Blood Vessels

Blood Vessels Types: Arteries-carry oxygen rich blood from heart to body, thick and durable-high pressure from heart (aorta is the largest artery) Capillaries-microscopic blood vessels, thinner-allows for substance exchange-can change size if higher blood flow needed Veins- largest vessels, carry oxygen poor blood back to heart, not thick like arteries

Factors that affect blood flow Watch Brain POP: Blood Pressure Blood pressure-if pressure is too low, blood won’t flow-tissues die. If too high-vessel stiffen and capillaries can rupture Blood volume Resistance-friction between blood and wall of blood vessel, if resistance increases, blood flow decreases. Viscosity of blood also affects blood flow-viscosity is the resistance to flow, so high viscosity = less blood flow Activity level