Blood composition And Function

Question 1

How many litres of blood do adults have?

Answer 1

Around 5l

Question 2

Purpose of vascular system

Answer 2

provides network for distribution

Question 3

Purpose of aids distribution

Answer 3

provides transport carriers

Question 4

Name 6 contributors to homeostasis

Answer 4

Transport, defence, Regulation of pH, osmotic pressure, ions and temperature, communication, restriction of fluid losses at injury sites, blood volume

Question 5

Why Take a Blood Sample?

Answer 5

Contains information on the function of body systems

Question 6

Function of body systems

Answer 6

Lung - blood gases
Liver - metabolites / enzymes
Kidney - ions
Endocrine - hormones
Infection - white blood cells
Blood Cell Count

Question 7

Process of blood sample (clotted)

Answer 7

Allow blood to clot – clotting time (8-15 min)
Spin : clot and collect serum

Question 8

Define serum

Answer 8

Serum is plasma without fibrinogen and other clotting factors

Question 9

Process of blood sample (unclotted)

Answer 9

Anticoagulant
Heparin
Citrate
EDTA

Blood cell count

Centrifuged - forms two layers

Question 10

What are the layers in a blood centrifuge

Answer 10

Upper fluid (54%)
Plasma - straw-coloured liquid Water 90%, electrolytes, proteins, lipids, sugars etc.

Middle layer (~1%)
White fluffy layer, Buffy Coat – Leukocytes

Lower layer 45%
Erythrocytes, Platelets (Haematocrit)

Question 11

Define haematocrit

Answer 11

Haematocrit is calculated from mean cell volume and red cell count from analysers

Also known as packed cell volume (pcv)

Question 12

Equation for PCV

Answer 12

PCV = height of pc/height of sample x 100

Question 13

Pcv in men and women

Answer 13

Male: 40–54%
Female: 37–47%

Question 14

Pcv in…
Normal haematocrit
Anemia
Polycythemia
Dehydration

Answer 14

Normal = 45%
Anemia = 30%
Polycythemia = 70%
Dehydration = 70%