introduction to blood & blood vessels

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INTRODUCTION TO BLOOD

& BLOOD VESSELSDR ZAHOOR ALI SHAIKH

LECTURE ----6

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BLOOD

Blood transports O2, nutrients to tissues and CO2 to lungs and other products of metabolism to kidneys.

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BLOOD VOLUME Blood Volume: - Men - 5.5 LITERS - Women - 5 LITERS

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BLOOD COMPOSITION Blood Composition Blood consists of liquid PLASMA , in

which cellular elements are present. Cellular Elements are -- Red Blood Cells(RBC) or

Erythrocytes -- White Blood Cells (WBC) or

Leukocytes -- Platelets or Thrombocyte

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Normal Values Normal Value

Red Blood Cell [RBC] – 5 millions / mm3 Hemoglobin [Hb] – 15 gm / dl White Blood Cell [WBC] – 4000-11000/mm3 Platelet – 150,000-400,000 /mm3

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BLOOD In Blood we have - Plasma – 55% ( 3 liters). - Cells – 45%

Packed cell volume is called ‘Hemotocrit’. In Hemotocrit, most of the cells are RBC.

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BLOOD We will discuss:

Plasma RBC or Erythrocyte WBC or Leukocyte Platelets or Thrombocyte

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PLASMA Plasma is transport medium for inorganic and organic

substances. Plasma Composition: - Water – 90% - Electrolytes [1%]– mainly Na+, Cl-, K+, HCO3-, Ca2+ - Plasma protein [6-8%] - Organic Substances - Glucose, Amino acids, Lipids,

Vitamins - Waste products – urea, creatinine - Dissolved gases – O2 and CO2 - Hormones

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Plasma Protein Plasma protein present are: - Albumin – helps in transport of substances - Globulin i. Alpha Globulin – blood clotting factors ii. Beta Globulin – blood clotting factors iii. Gamma Globulin – for defense of body - Fibrinogen – helps in blood clotting Most of the plasma protein are synthesized

in liver.

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RED BLOOD CELL [RBC] RBC have hemoglobin inside which

transports O2. RBC are biconcave disc. RBC diameter – 8 um RBC life span – 120 days

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WHITE BLOOD CELL [WBC]

WBC work as mobile defense units and are transported in the blood to the site of infection.

WBC work as immune system also.

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DIFFERENT TYPES OF WBC & THEIR FUNCTIONS

WBC FUNCTION1. Neutrophil (60-70%) Phagocytosis (engulf

bacteria)2. Eosinophil (1-4%) Important in allergic

reactions3. Basophil (0.5-1%) Important in allergic

reactions and have heparin

4. Lymphocytes (25-33%)

For immunity

5. Monocyte (2-8%) Tissue macrophage

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PLATELETS or THROMBOCYTES

Platelets are important for hemostasis i.e. they prevent blood loose from damaged blood vessels.

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CLINICAL APPLICATION Anemia – decrease in RBC & Hb Polycythemia – increase in RBC & Hb Leukocytosis – increase in WBC count

(more than 11,000 /mm3 Leukopenia – decrease in WBC count (less

than 4000 /mm3 Thrombocytosis – increase in platelet count Thrombocytopenia – decrease in platelet

count

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BLOOD VESSELS

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BLOOD VESSELS Blood is transported to all parts of the

body through blood vessels to supply O2, nutrition and remove the waste products e.g. CO2, Urea.

Oxygenated blood is pumped by left ventricle to Aorta and goes to blood vessels to supply oxygen and nutrition to body.

Blood is returned to right side of the heart as Deoxygenated blood through veins.

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BLOOD VESSELS (cont) The vascular tree consists of: 1. Arteries 2. Arterioles 3. Capillaries 4. Venules 5. Veins

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ARTERIES Large arteries act as pressure reservoir. Has thick, highly elastic wall. Has elastic fibers in the wall. Has large radius. Take blood from heart to the organs.

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ARTERIOLES Arterioles are highly muscular (smooth

muscle). Have small radius. Are major resistance vessels. Have no elastic fiber.

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CAPILLARIES Capillaries are thin walled, have

endothelial lining only between blood and tissues.

Are exchange vessels. Bring blood within reach of every cell. 10 billions in number.

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Veins Veins are thin walled as compared to

arteries. Bring blood to heart. Act as blood reservoir (65% of blood

is in veins). As they can store blood, they are called

‘CAPACITANCE VESSELS’.

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‘USEFUL INFORMATION’ Normal Pulse Rate – 72 beats/min (range 60-100 beats/min) Normal Blood Pressure (BP) – 120/80 mmHg (range for systolic BP – 100-140 mmHg) (range for diastolic BP – 60-90 mmHg) Hypertension (high blood pressure) – when

BP is above 140/90 mmHg. Hypotension (low blood pressure) – when

BP is below 100/60 mmHg.

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What You Should Know From This Lecture

Composition of Blood - Plasma - Cells Composition of Plasma and Types of Cells Present [RBC, WBC, Platelets] Normal Values for Hb, RBC, WBC, PLT Different types of WBC [N,E,B,L,M] and their Function Blood Vessels - Arteries – pressure vessel - Arterioles – resistance vessel - Capillary – exchange vessel - Veins – capacitance vessel or blood reservoir Normal Blood Pressure, Hyper tension, Hypo tension Normal Heart rate Clinical terms – Anemia, Polycythemia, Leukocytosis, Leukopenia,

Thrombocytosis, Thrombocytopenia

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Thank you