T1L2 Blood Vessels

Question 1

Name and describe the 4 parts of the artery and their function

Answer 1

Lumen - narrow to MAINTAIN high blood pressure

Endothelium - the inner layer of the artery wall

Smooth muscle - made of smooth muscle and elastic tissue. Allows the artery to flex to MAINTAIN high blood pressure through elastic recoil. The muscle helps to WITHSTAND the pressure.

Connective Tissue - made of tough collagen as a protective layer

Question 2

Name and describe the 5 parts of the vein and their function

Answer 2

Lumen - wider as blood is not as a high of a pressure

Endothelium (unlikely to get damaged here)

Smooth muscle wall - thinner than arteries as it does not need to maintain and withstand high pressures

Connective tissue

Valves - prevent backflow of blood

Question 3

Explain two features of preventing backflow in veins

Answer 3

Valves

Skeletal muscles - contract to shunt blood towards the heart

Question 4

Describe and Explain the features of capillaries that make them adapted for their function

Answer 4

• Walls are one cell thick to reduce the distance for diffusion
• There are many in the network of capillary beds which increases surface area available
• There is a good concentration gradient between the cells and blood in the capillaries

Question 5

Describe the two vessels that link the capillaries to other vessels

Answer 5

Arterioles decrease blood pressure between the arteries and capillaries to stop the capillaries from exploding

Venules are at a higher pressure than capillaries as they lead into the vein

Question 6

What is the bond angle in a water molecule

Answer 6

104.5

Question 7

What are the slight charges in a water molecule

Answer 7

O is slightly negative
(2nd most electronegative element)
Hs are slightly positive

Electrons spend more time near O so that causes dipole to form

Question 8

Which type of bond forms between water molecules (between which atoms)

Answer 8

Hydrogen bonds
O of one H of another

Question 9

Explain why water is a good solvent and a good coolant

Answer 9

Water is a polar molecule so it can dissolve ionic substances. Positively charged ions attracted to - O and negatively charged ions attracted to + H. This makes it a good solvent

Water has a high specific heat capacity and the Hydrogen bonds are strong. This means with large energy input the temperature only increases by a small amount. This makes it a good coolant