Blood Vessels, Blood and the Lymphatic System

Question 1

What are the main features of the blood?

Answer 1

• Blood is highly specialised, mobile connective tissue in which living blood cells are suspended in plasma.
• pH is 7.35-7.45, therefore, slightly alkaline.
• Temperature = 38 degrees celsius.
• Volume: Male = 5-6 litres
  Female = 4-5 litres

Question 2

Functions of the blood:

Answer 2

• Transportation of oxygen from lungs and carbon dioxide from the cells.
• Transportation of nutrients from the gastrointestinal system to cells.
• Transports waste away from cells.
• Transports hormones from the endocrine system to other cells.
• Protects the body by blood clotting and contains proteins to protect against disease.
• Regulation of pH body fluids, temperature and osmotic pressure.

Question 3

Components of the blood:

Answer 3

55% blood plasma
45% formed elements (red blood cells, white blood cells, platelets)
- per cubic mm:
--- platelets = 150,000 - 400,000
--- White blood cells = 5,000 - 10,000
--- Red blood cells = 4.8-5.4 million

Question 4

Components of plasma:

Answer 4

91.5% water
7% plasma proteins
- Albumins: help maintain osmotic pressure
- Globulins: includes antibodies (immunoglobulins)
- Fibrinogen: for formation of blood clots
1.5% other solutes, such as, electrolytes, nutrients, gases, enzymes, hormones, vitamins and waste products.

Question 5

What are the names of the stem cells that produce blood cells?

Answer 5

• All red blood cells are derived from a common stem cell (heamocytoblast)
• Lymphoid stem cell produces lymphocytes
• Myeloid stem cell produces all other formed elements

Question 6

Different types of white blood cells:

Answer 6

Lymphocytes
Monocytes
Eosinophils
Basophils
Neutrophils

Question 7

Through what process are red blood cells formed?

Answer 7

Erythropoiesis

Question 8

Where are red blood cells made?

Answer 8

Red bone marrow

Question 9

What is the life span of a red blood cell?

Answer 9

120 days

Question 10

Where are worn out red blood cells destroyed?

Answer 10

Spleen, liver and phagocytise by macrophages (apoptosis)

Question 11

What shape are red blood cells?

Answer 11

Biconcave

Question 12

What do red blood cells carry?

Answer 12

Red blood cells carry oxygen in haemoglobin.

Question 13

What is the function of white blood cells (leukocytes) ?

Answer 13

Leukocytes combat pathogens and foreign substances that enter the body.

Question 14

How long to white blood cells live?

Answer 14

Most only live a few days during response to infection.

Question 15

Name types of lymphocytes:

Answer 15

B memory cells
T memory cells
T killer cells

Question 16

What 2 groups are leukocytes classed into?

Answer 16

Granulocytes - neutrophils, eosinophils and basophils.

Agranulocytes - lymphocytes and manocytes.

Question 17

What are platelets (thrombocytes) ?

Answer 17

Thrombocytes are cell fragments which are disc shaped and have no nucleus.

Question 18

What is the function of platelets?

Answer 18

When blood vessels are damaged, the platelets form a platelet plug.
Contain clotting factors to aid clotting of blood.

Question 19

What determines blood group?

Answer 19

Antigens (agglutinogens) on the surface of erythrocytes determine blood group.

Question 20

What blood group would someone with only antigen A be?

Answer 20

Type A blood (AA)

Question 21

What blood group would someone with only antigen B be?

Answer 21

Type B blood (BB)

Question 22

What blood group would someone with both A and B antigens be?

Answer 22

Type AB blood (AB)

Question 23

What blood group would someone with neither A or B antigens be?

Answer 23

Type O blood (OO)

Question 24

What blood group would someone with one A antigen and one O antigen be?

Answer 24

Type A blood (AO)

Question 25

What blood group would someone with one B antigen and one O antigen be?

Answer 25

Type B blood (BO)

Question 26

Which antigen does Anti-A (a agglutinin) antibody react with?

Answer 26

Antigen A

Question 27

Which antigen does Anti-B (b agglutinin) antibody react with?

Answer 27

Antigen B

Question 28

Features of the Rhesus blood group?

Answer 28

- Antigen was discovered in the blood of a rhesus monkey. - People are either Rh positive (Rh+) or Rh negative (RH-) - If Rh- has an Rh+ transfusion, then anti Rh antibodies are formed. - If Rh+ receives anti-Rh antibodies, the red blood cells of donated blood will haemolyse (rupture).

Question 29

Describe arteries:

Answer 29

Arteries carry oxygenated blood from the heart. They are thick walled vessels to withstand blood being exerted under a high pressure. They have to expand and recoil as blood pushes through. Arteries are able to contract for vasoconstriction.

Question 30

How many layers are there in the walls of arteries?

Answer 30

3

Question 31

What are the names of the layers in the artery walls?

Answer 31

- Tunica Adventitia - Tunica Media - Tunica Intima

Question 32

Which layer is the Tunica Adventitia?

Answer 32

Outer layer

Question 33

Which layer is the Tunica Media?

Answer 33

Middle layer

Question 34

Which layer is the Tunica Intima?

Answer 34

Inner layer

Question 35

What is the Tunica Adventitia made up of?

Answer 35

Elastic fibres and Collagen

Question 36

What is the Tunica Media made up of?

Answer 36

Smooth muscle with elastic fibres

Question 37

What is the Tunica Intima made up of?

Answer 37

Endothelium lining forms a smooth lining which is contact with blood.

Question 38

What layer in the artery walls is the thickest layer?

Answer 38

Tunica Media

Question 39

What are arterioles?

Answer 39

Very small arteries delivering blood to the capillary beds.

Question 40

What is the role of arterioles in in blood flow to different organs?

Answer 40

Example: In blood loss, arterioles contract/constrict to reduce blood flow to the area and this makes blood more available for essential organs in a stress response.

Question 41

What are veins?

Answer 41

Veins carry deoxygenated blood to the heart to be pumped to the blood tube oxygenated.

Question 42

How do veins differ from arteries?

Answer 42

- Have the same three layers but tunica media and tunica intima are thinner, but the tunica externa is thicker than in arteries. - Veins have semi lunar valves which prevent the back flow of blood. The valves are made up of folds in the tunica intima.

Question 43

What are venules?

Answer 43

Venules are very small veins that transport blood from capillaries to veins.

Question 44

What are capillaries?

Answer 44

Capillaries are microscopic blood vessels with walls only one endothelial cell thick.

Question 45

Why are capillary walls only one cell thick?

Answer 45

They are exchange vessels whereby materials, such a nutrients, gases and tissue waste, can enter and leave the blood.

Question 46

Describe the lymphatic study:

Answer 46

The lymphatic system is a system of vessels that carry fluid from the tissues, cleans it and return it to the blood stream.

Question 47

What is the role of lymphatic capillaries?

Answer 47

They drain excess fluid from the tissues.

Question 48

What is the role of lymph nodes?

Answer 48

Fluid flows through the lymph nodes and microbes are filtered out. These microbes are then dealt with by the immune system.

Question 49

What happens after fluid flows through the lymph nodes?

Answer 49

Clean lymph fluid is returned to circulating blood.

Question 50

Why is immune response so rapid in lymph nodes?

Answer 50

Lymph nodes contain many immune cells.