Chapter 3 Flashcards
This refers to as highly complex mixture of cells, enzymes, proteins and inorganic substances. It is the red fluid of the blood vessels.
Blood
Importance of the Study of Blood
- As circumstantial or corroborative evidence against or in favor of the perpetrator
- For disputed parentage
- Determination of the cause of death and the length of time the victim survived the attack
- Determination of the direction of escape of the victim or the assailant
- Determination of the origin of the flow of blood
- Determination of the approximate time the crime was committed
Nature of Blood
- Largest circulating tissue of the body
- Consists of vital substances
- Fluid that circulates into the Cardiovascular System (CVS)
Function of Blood
- Transport of gases (O2 and CO2), nutrients, and wastes
- Blood regulates body temperature.
- Blood regulates pH of the body fluids.
- Blood carries injected and otherwise given medicines to the affected parts of the body.
Kinds of Blood
- Arterial Blood
- Venous Blood
It is also known as capillary blood. It is bright red in color and which is oxygenated blood.
Arterial Blood
It is dark red in color, contains increased amount of carbon dioxide and which is non-oxygenated blood.
Venous Blood
It is responsible for red color of blood which contains iron protein called globin (protein) and hematin (organic compound of iron).
Hemoglobin
Types of Hemoglobin
- Abnormal derivatives of HB
- Normal derivatives of Hemoglobin
Abnormal derivatives of HB
a) Methemoglobin (Hbm)
b) Sulfhemoglobin (HbS)
c) Carboxyhemoglobin (HbCO)
Normal derivatives of Hemoglobin
a) Oxyhemoglobin (HbO2)
b) Reduced Homoglobin (HbCO2)
It is found in Nitrates and Nitrites poisoning which is chocolate brown in color.
Methemoglobin (Hbm)
It is found in the presence of bacteria (clostridium perfringens) in severe constipation, enterogenous cyanosis, and blood is lavender is color.
Sulfhemoglobin (HbS)
It is the excessive inhalation of gas from defective stoves and from automobiles which is cherry red color of blood.
Carboxyhemoglobin (HbCO)
It is a hemoglobin that is combined with oxygen that gives color to the arterial blood.
a) Oxyhemoglobin (HbO2)
It is a hemoglobin that is combined with carbon dioxide that gives color to the venous blood.
Reduced Homoglobin (HbCO2)
Composition of Blood
45% formed elements or the solid materials consisting chiefly of cells
Liquid Portion – 55% plasma is the fluid or portion of blood where the cells are suspended.
Solid portion of blood
- Red Blood Cells (Erythrocytes)
- White Blood Cells (Leucocytes)
- Platelets (Thrombocytes)
This contains hemoglobin and carry oxygen to various cells in the body. It is circular, biconcave discs or rounded edges.
Red Blood Cells (Erythrocytes)
These are masses of nucleated protoplasm. It defends the body from invading microorganisms. It also fights infection.
White Blood Cells (Leucocytes)
Types of Leucocytes
a) Monocytes
b) Lymphocytes
c) Neutrophils
d) Basophils
e) Eosinophils
These have a longer lifespan than many white blood cells and help to break down bacteria.
Monocytes
These create antibodies to fight against bacteria, viruses, and other potentially harmful invaders.
Lymphocytes
These kill and digest bacteria and fungi. They are the most numerous types of white blood cell and your first line of defense when infection strikes.
Neutrophils
These small cells seem to sound an alarm when infectious agents invade your blood. They secrete chemicals such as histamine, a marker of allergic disease, that help control the body’s immune response.
Basophils
These attack and kill parasites and cancer cells, and help with allergic responses.
Eosinophils
Liquid portion is principally composed of:
- Water (90%)
- Solid (10%) – largely protein in nature and consist of albumen, several globulins and fibrinogen.
Methods of Collecting Blood
- Capillary Blood Sample
- Venous Blood Sample
- Arterial Blood Sample (Venipuncture Method)
Skin/finger/ring puncture, arterial blood and small quantity of blood
Capillary Blood Sample
Larger volumes of blood and blood taken from the vein
Venous Blood Sample
Larger volumes of blood and blood taken from the arteries
Arterial Blood Sample (Venipuncture Method)
Puncture sites
a) Ring finger (adult and children);
b) Ear lobes (adults); and
c) Heal or toe (infants and children) – use of lancet or pricker.
Preliminary Test for Blood
- Benzidine Test
- Phenolphthalein Test
- Guaiacum Test
- Leucomalachite Green Test
- Luminol Test
Positive Result: Intense blue color produced immediately.
Benzidine Test
Positive Result: Rose color develops/deep pink/permanganate color.
Phenolphthalein Test
Positive Result: Beautiful blue color that appears immediately.
Guaiacum Test
Positive Result: Malachite green or bluish green.
Leucomalachite Green Test
Positive Result: Luminescence or emission of light.
Luminol Test
Confirmatory Test for Blood
- Microscopic Test for Blood
- Microchemical Test and Microcrystalline Test for Blood
- Precipitin Test for Blood
Microchemical Test and Microcrystalline Test for Blood
a) The Teicmann Test
b) Acetone-Haemin Test
c) Haemochromogen Crystal Test of the Takayama Test
Methods of Blood Typing
- Direct or Forward Typing
- Indirect Blood Typing
It uses anti-sera A and B. It came from Lectins.
Direct or Forward Typing
This is reverse or backward typing. Principle: blood type of the serum is the opposite of the antigen where agglutination occurs.
Indirect Blood Typing
These are plant seed extracts. It is capable of agglutinating A and B antigens.
Lectins
