Clotting of Blood or Haemostasis
When a blood vessel is damaged, it results in coagulation or clotting
of blood. A blood clot is a network of thread like protein fibers, called
fibrin, that traps blood cells, platelets and fluid.
The clotting depends on several proteins in the plasma. They are
called coagulation factors. Normally these factors are in an inactive state.
After injury they are activated to produce a clot. The activation can happen
in three stages.
Stage 1 – Formation of thrombokinase – Damaged tissues release a
mixture of lipoproteins and phospholipids called tissue factor (TF) or
thromboplastin. This factor in the presence of certain factors in the blood
form a complex called prothrombinase or thrombokinase.
Stage 2 – Formation of thrombin – During this stage soluble plasma
protein prothrombin is converted into the enzyme thrombin by
prothrombinase. Prothrombin synthesis in liver requires vitamin K.
Prothrombin
prothrombinase
thrombin
Ca++
Stage 3 – The soluble plasma protein fibrinogen is converted to insoluble
protein, fibrin by thrombin
fibrinogen
thrombin
fibrin
The fibrin forms the fibrous network of the clot.
Related Topics in Zoology:
Bio Zoology All Important Topics
- Human Physiology Introduction
- Nutrition
- Carbohydrates Poly hydroxyaldehydes (or) ketones
- Proteins (Polypeptides)
- Lipids
- Vitamins – Functions Of Vitamins
- Deficiency of Vitamin
- Minerals – Water – Role of water
- Balanced diet
- Obesity
- Digestive System
- Dental Caries (Tooth decay)
- Root Canal Treatment
- Peptic ulcer
- Hernia and Types
- Appendicitis (Appendix)
- Gall Stones
- Hepatitis
- Fractures – Types of fractures
- Mechanism of fracture
- Dislocation of joints
- Arthiritis
- Rickets and Osteomalacia – Orthopedics
- Muscles
- Mechanism of muscle contraction
- Types of muscle contraction
- Myasthenia Gravis
- Respiration – Process of pulmonary respiration
- Mechanism of Breathing
- Regulation of Respiration
- Pneumonia Tuberculosis Symptoms Treatment
- Bronchitis – Acute bronchitis, Chronic Bronchitis Causes
- Circulatory System – Functioning of Human heart
- Cardiac Cycle
- Coronary blood vessel and its significance
- Myocardial infarction
- Angina pectoris
- Angiogram – Angioplasty
- Atherosclerosis
- Heart block Echo cardiography Heart Valves
- Rheumatic Heart Disease (RHD), ICCU – (Intensive Coronary Care Unit)
- Blood Pressure
- Heart transplantation
- Pulse rate
- Cardio Pulmonary Resuscitation (CPR)
- Blood – Composition of plasma – Blood cells
- Clotting of Blood or Haemostasis
- Thrombosis
- Nervous system Co-ordination systems
- The Brain – Fore Brain, Midbrain, Hindbrain
- Memory
- Sleep – Types of sleep
- Stroke – Brain haemorrhage
- Alzheimer – Meningitis (Brain fever)
- Conditioned reflex
- Electroencephalography EEG
- Right and Left brain concept
- Spinal cord functioning
- Chemical co-ordination – Functions of Endocrine glands
- Hypothalamus
- Pituitary gland – hormone
- Hormones of Neurohypophysis – vasopressin
- Thyroid gland
- Parathyroid Gland
- Pancreas
- Adrenal gland
- Gonads
- Receptor Organs – Eye
- Photochemistry of Retinal visual Pigments
- Errors of refraction
- Optometry – Retinopathy
- Cataract – Lens Replacement – Glaucoma – Nyctalopia
- Eye Infections and Eye Care
- Ear
- Mechanism of hearing
- Defects of the ear
- Hearing Aid – Noise pollution
- Skin and functions of skin
- Melanin functions
- Effects of solar radiation / UV radiation – Skin grafting
- Dermatitis
- Tongue – Mechanism of Stimulation
- Excretion Ureotelism Nephron
- Mechanism of urine formation
- Renal Failure, Dialysis, Kidney Machines
- Kidney stone – Kidney transplantation
- Diabetes mellitus
- Functioning of male reproductive system
- Functioning of female reproductive system
- Ovulation and fate of the ovum – Menstrual cycle
- Fertilization
- Birth control