Blood

Question 1

Red blood cells / erythrocytes

Answer 1

Are tiny biconcave discs, 2um by 7.5

Are most numerous

3-6 m per mm of blood

Highly specialised cells, have no nucleus or mitochondria

Each last 120 days

Made in red bone marrow, erythropoietin

Principle function is to carry oxygen

Also carriage of carbon dioxide and buffering

Question 2

White blood cells leukocytes

Answer 2

Are true cells account for less than 1% of total blood volume

4000-11000 per mm3 but this increases in infrection called leukocytosis

Part of immune system

Can enter tissues by diapadesis when received chemical signals

Move by chemotaxis

Amoeboid motin

Distinguish between granulocytes and agranulocytes

Question 3

Granulocytes

Answer 3

Neutrophils 40-70%

Eosinophils 1-4%

Basophils 0-1%

Roughly spherical, larger than red blood cells but live less

Question 4

Neutrophils

Answer 4

Normally account for at least half of wight blood cell count

Some granules contain peroxidases and hydrolytic enzymes and these act as lysosomes

Other contain chemicals rather like antibiotics called defensins

Question 5

Work of neutrophils

Answer 5

Move by chemotasis

Are phagocytes

Particularly active agains bacteria and some fungi

Respiratory burst

Question 6

Eosinophils

Answer 6

Nucleus in 2 lobes connected by band of nuclear material

Has coarse granules that stain red and contain non specific enzymes

Particularly important in destroying worms

Reduce severity of allergy

Question 7

Basophils

Answer 7

Rarest of white blood cells

Cytoplasm contain large granules with histamine

Mast cells are similar

Question 8

Agranulocytes

Answer 8

Lymphocytes 20-40%

Monocytes 4-8%

Question 9

Lymphocytes

Answer 9

Second most abundant white blood cell

Are very variable in size

Can be further classified as T or B lymphocytes and these can be further classified T helper cells

Question 10

Monocytes

Answer 10

Are largest of white blood cells

In tissue become macrophages

Have phagocytes function own and also assist lymphocytes in their action

Question 11

In order of decreasing abundance

Answer 11

Neutrophils

Lymphocytes

Monocytes

Eosinophils

Basophils

(Never let monkey eat bananas

Question 12

Platelets

Answer 12

Thrombocytes not correct

Fragments of cytoplasm from very large cells called megakaryocyte, found in bone marrow

Do not contain a nice use

The inner area contains granules that have variety of enzymes that promote haemostasis

Question 13

Haemostasis

Answer 13

Very complex and strictly controlled process involving

Vascular spasm

Platelets plug formation

Coagulation

Question 14

Vascular spams

Answer 14

Vasoconstriction

Chemicals released by injured blood vessel causes it to constrict so limiting blood loss

This can last 20-30 mins slowing time for the platelets plug to form

Question 15

Platelets plug

Answer 15

When exposed to injured vessel platelets swell spunky and sticky so that they stick to exposed collagen of vessel

Chemicals released that prolong vasoconstriction or attract more platelets

Question 16

Coagulation

Answer 16

Blood transformed from free flowing liquid into sticky fell

Is a cascade of over 30 substances called clotting factors or procoagulants

Need vitamin k to make 3 of them

End result is that fibrinogen becomes fibrin mesh