Download Venepuncture course - blood components pps

Venepuncture course
Blood and its Components
Rebecca Cachia Fearne
Some characteristics of
blood
• Blood viscosity 4.5 – 5.5 (in comparison
to water)
• Blood temperature is 38 degrees Celsius
• pH value of 7.35 – 7.45
• Salinity concentration of 0.90%
• Blood constitutes 8% of total body weight
• Blood volume average male: 5 – 6 litres
average female: 4 – 5 litres
Functions of Blood
• Transportation (oxygen, carbon dioxide,
nutrients, waste products, hormones,
heat)
• Regulation (of pH through buffers, body
temperature, cellular water content –
sodium pump mechanism)
• Protection (clotting mechanism,
phagocytosis, antibodies, interferon etc.)
Components of Blood in a Normal Adult
Formed Elements
• Erythrocytes (RBC’s)
• Leucocytes (WBC’s)
– Granular Leucocytes - Granulocytes
Neutrophils
Eosinophils
Basophils
– Agranular Leucocytes - Agranulocytes
Lymphocytes
Monocytes
• Thrombocytes - Platelets
Where blood components
can be found
Erythrocytes
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Red Blood Cells or corpuscles
Biconcave discs
Plasma membrane consists of protein and lipids
Also encloses haemoglobin
Antigens present on surface of cells to determine blood
group
Highly specialised for transport function
The percentage of blood volume composed of red blood
cells is called the “haematocrit.” The average hematocrit in
an adult male is 47 percent.
Cell life of about 120 days.
Normal values Males: 5.4 million/cubic millimetre
Females: 4.8 million/cubic millimetre
Leucocytes
• White blood cells
• Do not contain haemoglobin and have a
nucleus
• Two major groups:
Granular (develop from red
bone marrow and are Neutrophils,
Basophils and Eosinophils)
Agranular (develop from
lymphoid and myeloid tissue and are
Lymphocytes and Monocytes)
Leucocytes
(characteristics continued)
• Also have surface proteins (HLA)
• These are unique for each person
And are used to determine tissue
compatibility between donor and
recipient.
Leucocyte functions
• General function is that of phagocytosis
or antibody production.
• Phagocytosis – Neutrophils, Basophils,
Eosinophils and Monocytes
• Antibody production – Lymphocytes
produce proteins that inactivate antigens
or act as T cells.
Leucocytes
• Due to the dynamic nature of leucocytes,
their life span is very short.
• Leucocytes are far less numerous than
RBC’s
• Leucocytosis refers to an increased
number of leucocytes.
• Leucopenia refers to an abnormally low
level of leucocytes
Leucocyte type
Neutrophils
Eosinophils
Basophils
Lymphocytes
Monocytes
High Count
Low Count
Bacterial infections,
burns, stress,
inflammation
Radiation, certain drugs,
vitamin B12 deficiency,
Systemic Lupus
Erythematosus
Allergic reactions,
parasitic infections,
autoimmune disease,
adrenal insufficiency
Certain drugs, stress,
Cushing’s syndrome
Allergic reactions,
leukaemias, cancers,
hypothyroidism
Pregnancy, ovulation,
stress,
hyperthyroidism
Viral infections,
immune diseases,
some leukaemias
Prolonged severe illness,
high steroid levels,
immunosuppression
Viral or fungal
infections, TB,
leukaemia's and
chronic diseases
This is very rare
Thrombocytes
• Also known as platelets
• Break off from megakaryocytes in bone
marrow and enter blood
• Round or oval discs without a nucleus
• They repair slightly damaged blood
vessels and precipitate clotting
• Short life span 5 – 9 days
• 250,000 – 400,000 platelets present in
each cubic millimetre of blood
Plasma
• When formed elements are removed
from blood, straw-coloured liquid
remains
• Water composes 91.5% of plasma.
90% of which is absorbed through
the GI tract and 10% from cellular
respiration
Plasma
• Proteins in plasma (8.5%) can be
divided into: Albumins (55%)
Globulins (38%)
Fibrinogen (7%)
• Nonprotein nitrogen substances e.g.
urea, uric acid, creatinine, creatine
and ammonium salts
Plasma
• Food substances e.g. glucose, amino acids, fatty
acids and glycerol
• Regulatory substances e.g. enzymes and
hormones
• Respiratory gases e.g. oxygen and carbon
dioxide
• Electrolytes e.g. sodium, potassium, calcium,
magnesium, chlorides, sulphates,
Thank You