Vascular systems and structure

Question 1

Vascular system in Insects

Answer 1

• Open circulatory system
• Long tube shaped pseudo heart
• No respiratory pigment in haemolymph
• ->So no respiratory gases

Question 2

Vascular system in Earthworms

Answer 2

• Has vascularisation (blood vessels)
• Closed circulatory system
• Blood carries haemoglobin
• ->So respiratory gases present

Question 3

Vascular system in Fish

Answer 3

-Single circulatory system

Question 4

Vascular system in Mammals

Answer 4

-Double circulatory system

Question 5

Open circulatory system

Answer 5

• Instead of blood fluid is haemolymph
• Very low blood pressure

-Only suitable for animals with low metabolism

Question 6

Closed circulatory system

Answer 6

• Blood transported through blood vessels around the body
• Closed system more efficient in blood distribution

-Suitable for larger organisms with higher metabolisms

Two types:

• Single circulatory systems
• Double circulatory systems

Question 7

Single circulatory system

Answer 7

Blood moves through heart once

Limitations:

• Blood pressure will be lower
• Flow rate will be slower

Question 8

Double circulatory system

Answer 8

Blood passes through the heart twice in one full circulation of the body

• Blood moved through blood vessels by heart pumping
• Lower pressure needed at lungs
• Blood then returned to heart to increase pressure
• Substances delivered quickly to meet high metabolic demands

Question 9

Arteries

Answer 9

Function:
Carry blood under high pressure away from the heart to organs

Structure:

• Thicker wall than vein
• Thicker layer of smooth muscle and elastic fibres than veins
• Proportion of smooth muscle increases further from the heart
• Proportion of elastin decreases further from the heart

Question 10

Arterioles

Answer 10

Function:
Controls blood flow from arteries to capillaries

Structure:

• Thinner wall than artery
• More smooth muscle than artery

Question 11

Veins

Answer 11

Function:
Carry blood under low pressure from the organs to the heart

Structure:

• Larger lumen (hole) than arteries relative to their diameter
• Thin layer of muscle and elastic fibres
• Fairly thin outer wall
• Semi-lunar valves throughout

Question 12

Capillaries

Answer 12

Function:
To allow rapid exchange of material between the tissue fluid and the blood. Friction and resistance of the walls reduces pressure

Structure:

• Very narrow lumen (one cell thick)
• Spaces between endothelial cells in wall make capillary ‘leaky’

Question 13

Structure of the heart

Answer 13

Right side:

• Superior vena cava
• Right pulmonary artery
• Right pulmonary veins
• Semi lunar valves
• Right atrium
• Tricuspid valve
• Right ventricle
• Inferior vena cava

Left side:

• Aorta
• Left pulmonary artery
• Left pulmonary veins
• Semi lunar valves
• Left atrium
• Bicuspid valve
• Left ventricle

-Septum

Question 14

Aorta

Answer 14

Function:

Transports oxygenated blood under high pressure out the left ventricle to the body

Question 15

Pulmonary arteries

Answer 15

Function:

Transports deoxygenated blood under low pressure out of the right ventricle