BLood

Carry nutrient, fluids, hormones/enzymes to various area of body

Accountable for 7-8% of body weight (5-6L in person)

PH= 7.35-7.45  Temp= 38C


Transportation, defence, heat regulation, prevention of blood loss, creation of blood pressure

• account 55% of total blood volume
• 90% of plasma is body's solvent or water
• 1% consists of electrolytes, nutrients, waste product, respiratory gases
• 9% consists of 3 major plasma proteins
• Albumin- maintains osmotic pressure, a carrier for other protein, aid as blood buffer
• Fibrinogen- Blood clotting during inury to tissue
• Globulin- anitbodies

• Erythrocytes (red blood cell) 45% of blood
• Leukocytes (white blood cell) & platelets less than 1%

Removed by spleen onces cell dies

RBC has longest lifespan of 120days

Formation of blood cells is called hematopoiesis, occurs in red bone marrow

Small flexible cells shaped, no nucleus, few organelles

unable to divide/grow

mature in days

Function is to carry O2 to cells in the body attached to haemoglobin molecules

anemia- decrease in the ability to transport O2

Cruicial to body's defense agains pathogens/disease

Transport in blood and lymph

Complete with nucleus and organelles.

Increased number of leukocytes indicated infection

• Formed into 2 major group
• Granulocytes and agranulocytes- (lymphocytes & monocytes)

Lymphocytes- 2nd most numerous leukocyte in blood and vital to immune response

monocytes are largest in size and change into macrophages to fight chronic infection

• Takes 3 - 7 days
• >Produced in myeloid stem cells leading to production of haemoglobin
• >Fe is vital for haemoglobin
• >Fe is metabolised and stored in bone marrow attached to ferritin(special iron storage protein)
• >large amount of haemoglobin accumulates causing nucleus & organelles to be ejected out of cell
• >young RBC called reticulocytes leave marrow and enters bloodstream
• >reticulocytes mature within two days of being in blood stream

• >Production is controlled by ability of erythrocyte to transport O2
• >controlled by hormones called erthropoietin which released via -ve feedback mechanism in response to decreased of O2 level ( hypoxia)

• Sign of disease
• Not enough haemoglobin in blood resulting in lack of O2 being delivered o tissues
• Cause tiredness, confusion, risk of infection and short of breath.

• production begins from lymphoid and myeloid stem cells
• formation is stimulated by cytokines
• overal formation is stimulated by CSF (coloy stimulating factors hormones) & interleukin-proteins released by cells of immune system, act as messagers to regulate immune function

• irregular shaped produced in bone marrow
• 2/3 found in body, 1/3 found in spleen
• 7-10 days lifespan
• required for blood clotting and preventing blood loss
• production is controlled by thrombopoiein hormone manufactured by liver.