The Blood

General Info Blood is part of the circulatory system Blood is part of the circulatory system It is a connective tissue (relatively small number of cells suspended in a large matrix) It is a connective tissue (relatively small number of cells suspended in a large matrix) The cellular elements of blood are collectively referred to as “formed elements” The cellular elements of blood are collectively referred to as “formed elements” The matrix consists of protein and other molecules suspended in a watery fluid called plasma The matrix consists of protein and other molecules suspended in a watery fluid called plasma

Microscopic View of Blood

Functions of Blood It maintains homeostasis in the following ways: It maintains homeostasis in the following ways: –Transportation – moves nutrients from the digestive system to body tissues as well as oxygen from lungs, and hormones from endocrine glands; also moves waste materials such as carbon dioxide and nonprotein nitrogen substances to places for disposal

Functions Continued Protection – protects body from foreign invaders such as microorganisms and their toxins using phagocytic WBCs and specialized proteins called antibodies; protects against fluid loss by clotting Protection – protects body from foreign invaders such as microorganisms and their toxins using phagocytic WBCs and specialized proteins called antibodies; protects against fluid loss by clotting Regulation – regulates pH with a system of buffers; also regulates body temperature by cooling or heating parts of the body Regulation – regulates pH with a system of buffers; also regulates body temperature by cooling or heating parts of the body

Properties of Blood In spite of individual differences from person to person, the following are shared characteristics of all blood and may be used as an indicator of a person’s health: In spite of individual differences from person to person, the following are shared characteristics of all blood and may be used as an indicator of a person’s health: –Color, volume, viscosity, and pH

Color Blood is RED because of a protein called hemoglobin (contains iron atoms) which forms a chemical bond with oxygen Blood is RED because of a protein called hemoglobin (contains iron atoms) which forms a chemical bond with oxygen Oxygenated blood (found in arteries) has a bright red, crimson color Oxygenated blood (found in arteries) has a bright red, crimson color Deoxygenated blood (found in veins) has a dark-red color with a slightly bluish tinge Deoxygenated blood (found in veins) has a dark-red color with a slightly bluish tinge

Arterial (Oxygenated) Blood

Venous (Deoxygenated) Blood

Volume Represents approximately 8% of total body mass (density is approx 1.05 g / ml) Represents approximately 8% of total body mass (density is approx 1.05 g / ml) Average male has 5 – 6 liters, average female has 4 – 5 liters Average male has 5 – 6 liters, average female has 4 – 5 liters

Viscosity Blood is thicker, denser, and more adhesive than water Blood is thicker, denser, and more adhesive than water Blood flows about 5 times more slowly than water Blood flows about 5 times more slowly than water The resistance to flow is called viscosity The resistance to flow is called viscosity

pH Blood is slightly alkaline (or basic) with a pH that usually ranges between 7.35 and 7.45 Blood is slightly alkaline (or basic) with a pH that usually ranges between 7.35 and 7.45 Maintained by a buffering system that removes Hydrogen ions Maintained by a buffering system that removes Hydrogen ions Low pH called acidosis or acidemia and body cells stop functioning Low pH called acidosis or acidemia and body cells stop functioning High pH called alkalosis or alkalemia High pH called alkalosis or alkalemia Both conditions represent major disruptions to homeostasis Both conditions represent major disruptions to homeostasis

Plasma Liquid portion of blood Liquid portion of blood Yellow-ish fluid that suspends the formed elements of blood Yellow-ish fluid that suspends the formed elements of blood Also contains gases, metabolic wastes, nutrients and hormones Also contains gases, metabolic wastes, nutrients and hormones Made up of mostly water (92%) and primary solute is protein Made up of mostly water (92%) and primary solute is protein

Plasma Proteins Most of these are synthesized in the liver Most of these are synthesized in the liver More than 50 different types of protein found can be classified into one of 3 groups: albumins, globulins, and fibrinogen More than 50 different types of protein found can be classified into one of 3 groups: albumins, globulins, and fibrinogen

Albumins Albumins – compose 55% of blood’s proteins; increase blood’s viscosity which determines how easily blood can flow through vessels and how easily plasma can pass trough blood vessel walls to the interstitial fluid Albumins – compose 55% of blood’s proteins; increase blood’s viscosity which determines how easily blood can flow through vessels and how easily plasma can pass trough blood vessel walls to the interstitial fluid

Globulins Globulins make up 38 % of proteins found in plasma Globulins make up 38 % of proteins found in plasma There are several types of globulins but the most important are called gamma globulins, which function as antibodies in the immune response There are several types of globulins but the most important are called gamma globulins, which function as antibodies in the immune response

Fibrinogen Remaining 7 % of blood proteins are fibrinogen Remaining 7 % of blood proteins are fibrinogen Play a major role in blood-clotting, also known as hemostasis Play a major role in blood-clotting, also known as hemostasis When fibrinogens and other blood-clotting factors are selectively removed from blood, the remaining product is called blood serum When fibrinogens and other blood-clotting factors are selectively removed from blood, the remaining product is called blood serum This makes the storage and reuse of blood much more convenient This makes the storage and reuse of blood much more convenient

Other Plasma Solutes One category of these solutes and called nonprotein nitrogenous (NPN) substances; includes amino acids, urea, and uric acid One category of these solutes and called nonprotein nitrogenous (NPN) substances; includes amino acids, urea, and uric acid Gases – Oxygen and carbon dioxide (plus a significant amount of nitrogen, but it plays no physiological role Gases – Oxygen and carbon dioxide (plus a significant amount of nitrogen, but it plays no physiological role Nutrients include simple sugars, fats, and amino acids Nutrients include simple sugars, fats, and amino acids Electrolytes – sodium, chloride, bicarbonate, potassium, calcium, phosphate, sulfate, and magnesium ions – concentrations regulated by kidneys to control variations due to diet Electrolytes – sodium, chloride, bicarbonate, potassium, calcium, phosphate, sulfate, and magnesium ions – concentrations regulated by kidneys to control variations due to diet