3.2.2 Circulatory Systems

Question 1

Why need a circulatory System?

Answer 1

• Supply all cells with oxygen and glucose for metabolism
• Diffusion distances too great for efficient exchange

Question 2

Adv of double circulatory system

Answer 2

• Maintains higher blood pressure and average speed of flow (when blood enters capillary beds, pressure and speed drops a lot. In a single circulatory system blood passes through capillary network twice before returning to heart. In double circulatory system blood passes through capillary network once before returning to heart)
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• Steeper concentration gradient allowing for efficient exchange

Question 3

What is a single and double circulatory System?

Answer 3

• Blood passes through heart once in 1 complete circuit of body
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• Blood passes through heart twice in 1 complete circuit of body

Question 4

Single Circulatory System in fish Notes

Answer 4

• Deoxygenated blood pumped to gills from heart
• Gills are exchange site where O2 and CO2 are exchanged with water and blood
• Oxygenated blood flows from gills to rest of body
• Capilaries
• Returns to heart
• 1 atrium, 1 ventricle

Question 5

Double circulatory System in mammals notes

Answer 5

• Blood passes through heart twice in 1 complete circuit of body
• Heart has left and right side with septum dividing 2
• Left side oxygenated blood, right side deoxygenated

Question 6

Open circulatory System :

Answer 6

• Blood is not contained within vessels
• Pumped into body cavities

Question 7

Closed circulatory system :

Answer 7

• Blood contained within vessels

Question 8

Insects circulatory System

Answer 8

1 main blood vessel called the DORSAL VESSEL

Tubular heart pumps haemolymph into the dorsal vessel

Haemolymph is delivered into body cavity (haemocoel

Contains one way valves like veins do called Ostia

O2 is delivered directly to tissues via trachea