BLOOD

Dr. B.L. Mtinangi.Dr. B.L. Mtinangi.

Department of PhysiologyDepartment of Physiology

HKMUHKMU

2626thth November, 2015 November, 2015

WHAT IS SO WONDERFUL ABOUT BLOOD?

BLOOD

BLOOD: Is a liquid connective tissue or BLOOD: Is a liquid connective tissue or viscous fluid that:viscous fluid that:

Circulates in a virtually “CLOSED” Circulates in a virtually “CLOSED” system of blood vesselssystem of blood vessels

Has a specific gravity of about 1.050 Has a specific gravity of about 1.050 – 1.060– 1.060

Has a Viscosity of about 5 to 6 more Has a Viscosity of about 5 to 6 more than waterthan water

Components of Blood

BLOOD CONT.BLOOD CONT.

Composition of Blood: Composition of Blood: 45% cells45% cells & & 55% 55% plasmaplasma

A: A: Solid elements (CELLS): 45%Solid elements (CELLS): 45%

1.1. Red blood cells-Rbc (Erythrocytes) 4.5 to Red blood cells-Rbc (Erythrocytes) 4.5 to 5.5 mill/cmm5.5 mill/cmm

2.2. White blood cells- Wbc (Leucocytes) White blood cells- Wbc (Leucocytes) 4000 to 11000/cmm4000 to 11000/cmm

3.3. Platelets (Thrombocytes) 200,000 to Platelets (Thrombocytes) 200,000 to 400,000/cmm400,000/cmm

RED BLOOD CELLS

They are red because they contain a protein called hemoglobin that is red in color.

Red blood cells are round and thinner in the middle (biconcave) like a balloon that is partly filled with water. This lets them squeeze through tiny blood vessels without breaking.

The Formed Elements: Red Blood Cells (erythrocytes)

The Structure of Rbc

Haemoglobin molecule

Normal & Abnormal Red Cell

BLOOD CONT.BLOOD CONT.

B: B: Fluid (PLASMA)Fluid (PLASMA) 55% of the whole blood 55% of the whole blood consist:consist:

Water (91 to 92%), Gases 0Water (91 to 92%), Gases 022, C0, C02 2 & N& N2 2 dissolved in plasmadissolved in plasma

““Solids” (8 to 9%) these are: ORGANIC (7.1 Solids” (8 to 9%) these are: ORGANIC (7.1 toto 8.1%)8.1%) - - Plasma proteinsPlasma proteins (albumin, globulin, fibrinogen (albumin, globulin, fibrinogen & prothrombin& prothrombin).).

- - Internal secretionsInternal secretions (eg antibodies & enzymes) (eg antibodies & enzymes) - - Non Protein Nitroginous substancesNon Protein Nitroginous substances (urea, (urea,

neutral fats, CHO, AA etc) neutral fats, CHO, AA etc)

FUNCTIONS OF BLOOD.FUNCTIONS OF BLOOD.

FUNCTION OF BLOOD:FUNCTION OF BLOOD:Transport of:Transport of: Nutrients: blood carries nutrients of Nutrients: blood carries nutrients of

digestion from the GIT to tissues.digestion from the GIT to tissues. Dissolved respiratory gases: carries ODissolved respiratory gases: carries O22

from lungs to the tissues & COfrom lungs to the tissues & CO2 2 from from tissues to the lungstissues to the lungs

Carries waste products of metabolismCarries waste products of metabolism Carries other substances like hormones, Carries other substances like hormones,

antibodies, enzymes, drugs etc.antibodies, enzymes, drugs etc.

FUNCTIONS OF BLOOD CONT,FUNCTIONS OF BLOOD CONT,

Defence function through:Defence function through:WBC by phagocytosis through WBC by phagocytosis through

neutrophils monocytes & neutrophils monocytes & macrophagesmacrophages

Lymphocytes are involved in Lymphocytes are involved in immunity immunity

Platelets & clotting factors prevent Platelets & clotting factors prevent blood loss due to bleeding blood loss due to bleeding (haemorrhage) after injury(haemorrhage) after injury

FUNCTIONS OF BLOOD CONT,FUNCTIONS OF BLOOD CONT,

Blood is responsible for homeostasis Blood is responsible for homeostasis through:through:

Body temperatureBody temperatureWater concentration of tissues Water concentration of tissues

between ICF & ECFbetween ICF & ECFAcid – Base balance pH through Acid – Base balance pH through

Haemoglobin proteins and Haemoglobin proteins and bicarbonatebicarbonate

Thank you for your attention