[Maximum number: 1]

The mammalian circulatory system is adapted for the long-distance transport of the respiratory gases, oxygen and carbon dioxide.

The system is described as a closed double circulation.

(a)

In a closed circulation, blood is kept within vessels at all times.

Name the type of blood vessel that connects capillaries and veins.

[ 1 ]

[Maximum number: 2]

The trachea of the gas exchange system branches into two airways, each of which enters a lung.

(a)

The lower part of the trachea receives blood from arteries that branch from the aorta. Different arteries carry blood from the heart to the alveoli of the lungs.

State the differences between the arteries supplying the lower part of the trachea and the arteries that supply blood to the alveoli of the lungs.

[ 2 ]

(a)

Fig. 2.1 is a diagram of the circulation in a mammal.

Fig. 2.1

[ 3 ]

(i)

Complete Fig. 2.1 by naming P and Q. Write your answers on Fig. 2.1.

[ 1 ]

(ii)

Describe the functions of P and Q.

[ 2 ]

[Maximum number: 3]

Tobacco smoking is known to be associated with atherosclerosis and emphysema.

(a)

Outline ways in which tobacco smoking can contribute to atherosclerosis.

[ 3 ]

(a)

Fig. 3.1 is a photomicrograph of a section through two different types of blood vessels, X and Y.

Fig. 3.1

[ 1 ]

(i)

Name the two types of blood vessel shown by X and Y in Fig. 3.1.

X

Y

[ 1 ]

[Maximum number: 1]

As blood flows from an artery to a vein, the blood pressure in the vessels changes. The four graphs represent data for blood vessels in the sequence shown.

Which graph shows these changes correctly?
pressure

blood

pressure

blood

pressure

[Maximum number: 1]

The graph represents data on blood vessels and blood flow.

Which row correctly identifies the curves?

velocity of blood flow

pressure of blood

total crosssectional area

[Maximum number: 1]

Which are present in the walls of arteries?

endothelium

smooth muscle

elastic tissue

collagen fibres

key

✓ = present

$\boldsymbol{\chi}=$ not present

✓

$\boldsymbol{\times}$

✓

$\boldsymbol{\chi}$

✓

$\boldsymbol{\chi}$

✓

[Maximum number: 1]

Which of the tissue types below are present in the walls of all blood vessels?
1 collagen
2 elastic
3 endothelial
4 smooth muscle

1, 2, 3 and 4

1, 2 and 4 only

2 and 3 only

3 only

(a)

Fig. 5.1 shows features that are observed in transverse sections of three types of blood vessel.

Fig. 5.1

[ 3 ]

(i)

Complete Fig. 5.1 by stating the type of blood vessel indicated by D, E and F.

[ 1 ]

(ii)

The inner layer of the walls of D and E is composed of endothelial tissue.

List two structural features of endothelial tissue.
1

2

[ 2 ]