Blood & RespirationBlood & Respiration

ByBy

Dr. Mamdouh R El-Dr. Mamdouh R El-SawiSawi

I-BloodI-Blood

First lectureFirst lecture

BloodBlood Blood is a complex mixture of a Blood is a complex mixture of a

reddish fluid that circulates reddish fluid that circulates continuously inside the cardio-continuously inside the cardio-vascular system.vascular system.

Blood has many important functions, Blood has many important functions, which are essential for life.which are essential for life.

Sudden loss of 30% of total volume Sudden loss of 30% of total volume of blood leads to death.of blood leads to death.

Functions of the bloodFunctions of the blood

Respiratory:Respiratory:– It transports OIt transports O22 from lungs to tissues. from lungs to tissues.

– It transports COIt transports CO22 from tissues to lungs. from tissues to lungs.

Nutritional:Nutritional:– It transports digested food from gut to tissue It transports digested food from gut to tissue

cells.cells.

Excretory:Excretory:– It transports wastes from tissues to kidney & It transports wastes from tissues to kidney &

other excretory organs (urea, uric acid, water).other excretory organs (urea, uric acid, water).

Functions of the bloodFunctions of the blood

RegulatoryRegulatory– The water Content of TissuesThe water Content of Tissues– The pH of the blood through the buffer The pH of the blood through the buffer

systemssystems– The body temperature:The body temperature:

Water- high heat capacity, thermal Water- high heat capacity, thermal conductivity, heat of vaporizationconductivity, heat of vaporization

ProtectiveProtective -blood loss from injured vessels by formation -blood loss from injured vessels by formation

of of

platelet plug & blood clot.platelet plug & blood clot.– Antibodies, antitoxins, white blood cells (WBC)Antibodies, antitoxins, white blood cells (WBC)

Composition of the bloodComposition of the blood

Blood is composed of Blood is composed of cells cells and cell like structures and cell like structures suspended in a clear suspended in a clear yellowish fluid calledyellowish fluid called plasma:-plasma:-

Cells - 45% by volume.Cells - 45% by volume.Plasma - 55% by volume.Plasma - 55% by volume.

Plasma

Red blood cells

White blood cells & platelets

Plasma

Hematocrit

Composition of the bloodComposition of the blood

A-CellsA-CellsRed cells (erythrocytes).Red cells (erythrocytes).

5x105x1066/mL blood./mL blood.

White cells (leukocytes).White cells (leukocytes). 7x107x1033/mL blood./mL blood.

Platelets (thrombocytes).Platelets (thrombocytes). 3x103x1055/mL blood./mL blood.

Composition of the bloodComposition of the blood

B-Blood plasmaB-Blood plasma

It is a clear yellowish fluid.It is a clear yellowish fluid.

It is a part of the extra cellular It is a part of the extra cellular

fluid of the body.fluid of the body.

It is identical to the interstitial It is identical to the interstitial

fluid except for its protein content fluid except for its protein content

(2-3%).(2-3%).

Composition of the plasmaComposition of the plasmaB-Blood plasmaB-Blood plasma– WaterWater: 90%.: 90%.– ProteinsProteins: 7%.: 7%.– InorganicInorganic: 1: 1%.%.

Na+, K+, Mg2+, Ca2+, PO43-…Na+, K+, Mg2+, Ca2+, PO43-…– OrganicOrganic: 2%.: 2%.

Metabolic end products:Metabolic end products: e.g. urea, uric e.g. urea, uric acid, creatine & creatinineacid, creatine & creatinine

Nutritive substances:Nutritive substances: e.g. fats, e.g. fats, cholesterol, glucose ...cholesterol, glucose ...

Regulatory substancesRegulatory substances: e.g. enzymes, : e.g. enzymes, hormones, vitamins. hormones, vitamins.

Plasma proteinsPlasma proteins1-Albumin:1-Albumin: (4%) (4%) Form 60-80% of plasma proteins.Form 60-80% of plasma proteins. Provides the osmotic pressure needed to Provides the osmotic pressure needed to

draw Hdraw H220 from interstitial fluid into capillaries.0 from interstitial fluid into capillaries. Maintains blood pressure.Maintains blood pressure. MW 66 000MW 66 000 Single chain, 580 amino acids, sequence is Single chain, 580 amino acids, sequence is

knownknown Dimensions - Heart shaped moleculeDimensions - Heart shaped molecule 50% 50% helix. helix.

Plasma proteinsPlasma proteins

20% of plasma proteins.20% of plasma proteins. ““” ” refers to electrophoretic mobility.refers to electrophoretic mobility. Represents a group of proteins of Represents a group of proteins of

variable structures called variable structures called immunoglobulins.immunoglobulins.

Main functional task: is Main functional task: is immunochemical.immunochemical.– Antibodies - combine with specific Antibodies - combine with specific

antigensantigens

2-Globulins: 2-Globulins: (2.7%)(2.7%)