In this articles we shall study about different kinds of medical specialists. Medical specialists are experts in certain fields of medicine. They either treat specific parts of the body, such as the back or the brain, or they specialize in certain diseases, such as cancer. Family doctors keep a list of local specialists and can help patients choose the right specialist for each medical issue.

General Practitioners and Physicians:

General Physician or Family Practitioner:

General Physicians are highly trained specialists who provide a range of non-surgical health care to adult patients. He/she treats many different medical conditions and ailments on an outpatient basis.

They care for difficult, serious or unusual medical problems and continue to see the patient until these problems have resolved or stabilized. They are popularly known as a ‘general practitioner’ or a ‘family physician’ in many countries.

Anesthesiologist:

An anesthesiologist is a doctor who practices anesthesia. Anesthesiologists are physicians specializing in perioperative care, developing anesthetic plans, and the administration of anesthetics. Anesthesiologists help ensure the safety of patients undergoing surgery.

The anesthesiologist provides care for the patient to prevent the pain and distress they would otherwise experience. He/she is responsible for keeping the patient anesthetized (sedated) and for monitoring the vital signs like airway, breathing and circulation during surgery. They monitor input and output during the surgery like delivery of intravenous fluids, blood and other drugs.

Surgeons:

A surgeon is a doctor who specializes in evaluating and treating conditions that may require surgery, or physically changing the human body. Surgeries can be done to diagnose or treat disease or injury.

• : General surgeons are doctors who specialize in surgical procedures. Surgery is any procedure that alters body tissues to diagnose or treat a medical condition. 
• Cardiothoracic Surgeon: A cardiothoracic surgeon is a medical doctor who specializes in surgical procedures of the heart, lungs, esophagus, and other organs in the chest. This includes surgeons who can be called cardiac surgeons, cardiovascular surgeons, general thoracic surgeons, and congenital heart surgeons.
• Neuro-Surgeon: Neurosurgeons are medical doctors that diagnose and treat conditions related to  the brain, spine, and other parts of your nervous system. 
• Oral or Maxillofacial Surgeon: Maxillofacial surgeons, sometimes called oral and maxillofacial surgeons, are trained to handle a wide variety of conditions and injuries that affect the head, neck, mouth, jaw, and face.
• Otolaryngologist Surgeon: Otolaryngologist Surgeon treats issues in ears, nose, or throat as well as related areas in the head and neck. They can do surgeries in these areas.
• Surgical Oncologist: They are surgical counterparts of medical oncologist. They are general surgeons with specialty training in procedures for diagnosing, staging (determining the stage of cancer), or removing cancerous growths.
• Pediatric Surgeon: Pediatric surgeons are doctors who specialize in treating children. They’re trained to do operations on infants, children, and young adults. 
• Plastic Surgeon: Plastic surgeons are focused on reconstructive procedures. They can treat patients who have conditions like birth disorders, injuries, illnesses, or burns. Many plastic surgeons choose to become cosmetic surgeons and do procedures to change a patient’s appearance or aesthetic.
• Orthopedic Surgeon: An orthopedic surgeon is qualified to diagnose orthopedic problems, perform or prescribe treatments, and assist with rehabilitation. 
• Vascular Surgeon: Vascular surgeons are doctors who treat diseases and problems within the vascular system, the network of arteries and veins that carry blood throughout the body. 

Internal Medicine Practitioner/ Internist:

Internal medicine physicians, or internists, are specialists who apply scientific knowledge and clinical expertise to the diagnosis, treatment, and compassionate care of adults across the spectrum from health to complex illness.

They are especially well trained in the diagnosis of puzzling medical problems, in the ongoing care of chronic illnesses, and in caring for patients with more than one disease. Internists also specialize in health promotion and disease prevention. He/she deals with the diagnosis, management and non-surgical treatment of unusual and serious diseases.

Doctors Treating Children:

Pediatrician:

A pediatrician is a medical doctor who manages the physical, behavioral, and mental care for children from birth until age 18. A pediatrician is trained to diagnose and treat a broad range of childhood illnesses, from minor health problems to serious diseases.

They focus on the prevention, detection and management of physical, behavioral, developmental and social problems that affect children. They work to diagnose and treat infections, injuries, and many types of organic disease and dysfunction and bring about improvement in the life of children with chronic problems.

Neonatologist:

A neonatologist is a specialist in caring for premature and ill newborns and generally works in hospital’s neo-natal care or baby special care units. Newborns can present a unique set of health challenges that require a high level of skill and medical expertise to treat.

This specialist does tests to make sure that newborn babies are well- developed and free from infections and organ deformities.

Pediatric Cardiologist:

Pediatric cardiologists specialize in diagnosing and treating heart problems in children. In those children who might need heart surgery, pediatric cardiologists work closely with pediatric heart surgeons to determine the best treatments and interventions.

Pediatric Endocrinologist:

Pediatric endocrinologist specialize in diagnosing and treating hormone or gland problems in children.

Pediatric Oncologist:

Pediatric oncologists are doctors who diagnose and treat cancer in children and teens.

Doctors Treating Old People:

Geriatrician:

Geriatricians are primary care doctors who have additional training in treating older adults, especially those 65 and up. People in that age range often have multiple or complex health matters and need specialized care.

Geriatrician at times requires to take an interdisciplinary approach to a problem as many patients suffer from not only medical but have social problems too. A Geriatrician may work with other physicians, nurses, social workers, occupational therapists and family members to take care of the needs of his patient.

Gerontologist:

A gerontologist is a doctor studying and treating conditions arising in the aging process. He mostly works with senior citizens, studying their biological, medical and social issues at that age. These specialists work in hospitals, nursing homes and laboratories and may form a part of government health policies for the old. A gerontologist is a licensed physician and diagnoses and treats old age diseases like Alzheimer’s disease, Parkinson disease and osteoporosis.

Doctors Treating Heart and Vascular Problems:

Cardiologist:

Cardiologists are qualified to treat heart attacks, heart failure, heart valve disease, arrhythmia, and high blood pressure. He may collaborate with cardiac surgeons to decide the course of treatment for his patients.

Cardiology is a specialty, which has many subspecialties like interventional cardiology, nuclear cardiology, electro physiology, or echocardiography, which help in making diagnostic studies.

Vascular Medical Specialist:

Vascular surgeons are doctors who treat diseases and problems within the vascular system, the network of arteries and veins that carry blood throughout the body. 

Doctors Treating Hormone/Gland Problems:

Endocrinologist:

Endocrinologists are doctors who specialize in glands and the hormones they make. They deal with metabolism, or all the biochemical processes that make the body work, including how the body changes food into energy and how it grows.

He/she diagnoses and treat diseases like diabetes, thyroid diseases, metabolic disorders, over or under production of hormones, menopause, osteoporosis, hypertension, cholesterol disorders, infertility, lack of growth and endocrine glands cancer..

Doctors Treating Stomach/ Liver/Bowel, Colon Related Problems:

Gastroenterologist:

A Gastroenterologist is a physician with dedicated training management of diseases of the gastrointestinal tract and liver. They are specialist in digestive diseases.

He/she is mainly concerned about the prevention, diagnosis, and treatment of conditions and disorders in the gastrointestinal tract involving the esophagus, stomach, small and large intestine, rectum, liver and pancreas of adults.

Hepatologist:

Hepatologists are medical doctors who diagnose, treat, and manage problems associated with liver, gallbladder, bile ducts, and pancreas. He deals in disorders like serious and chronic hepatitis, chronic alcoholism, and liver disorders due to certain medications.

Colorectal Surgeon:

Colorectal surgeon is a doctor, who treats disorders of the rectum, anus, and colon.

Doctors Treating Kidney and Urinary System:

Urologist:

A Urologist specializes and treats the urinary tract problems of both men and women and on the reproductive organs of men.

He/she treats problems in the urinary system, which includes kidneys, bladder, ureters, and urethra. He also treats a man’s reproductive system, which includes the penis, testes, scrotum, and prostate.

Nephrologist:

Nephrologists are doctors who specialize in conditions that affect the kidney. They diagnose, treat, and manage acute and chronic kidney problems and diseases. They also treat associated issues like high blood pressure, fluid retention, and electrolyte and mineral imbalances. In addition, these specialists are in charge of kidney dialysis treatment.

Doctors Treating Reproduction / Sex Problems:

Andrologist:

Andrologists are urologists who focus entirely on the treatment of conditions affecting male fertility and sexuality, rather than practicing a broader form of urology.

This specialty includes the treatment of physical conditions affecting the genitalia, such as undescended testes, as well as injuries and diseases that can affect fertility or sexual function.

Gynecologist:

A gynecologist is a doctor who specializes in female reproductive health. They diagnose and treat issues related to the female reproductive tract. This includes the uterus, fallopian tubes, and ovaries and breasts. They diagnose and treat reproductive system disorders such as endometriosis, infertility, ovarian cysts, and pelvic pain.

They may also care for people with ovarian, cervical, and other reproductive cancers.

Obstetrician:

An obstetrician is a specialist who has specialized in the management of pregnancy, labor, childbirth, and a woman’s reproductive system. They also called an OB/GYN.

They take care throughout pregnancy, and give follow-up care.

Sexologist:

A sexologist is a person who has studied human sexuality. Sexologists have studied the science of sex, which means they have studied human anatomy and physiology (how the body works and why) and psychology (how our minds work) regarding sexuality. Sexologists help people with all things to do with sexuality.

Fertility Specialist:

Fertility specialists are obstetrician or gynecologists who have undergone specialized training for reproductive endocrinology. 

Venereologist:

Venereologists deal with the study and treatment of sexually transmitted diseases caused by sexual contact. A person may just be a carrier without realizing it or may actively suffer the symptoms. They may be engaged in research working out methods of prevention, and innovations in treatment. These specialists may have to deal with social issues and moral norms at times in certain societies, however they do play an important role in educating the patients, their family and general public about sexual infections and diseases and about their preventive measures.

Doctors Treating Immunology/ Allergy Problems:

Allergist:

Allergists are doctors who specialize in treating allergies and other immune problems. As allergies are an overreaction of the immune system, allergists must have a thorough understanding of how your body fights infection to treat the hypersensitivity that leads to allergies.

Immunologist:

Immunologists are doctors who diagnose, treat, and work to prevent immune system disorders. They study the complex immune system consisting of cells and molecules that help fight infection. These specialists treat people born with a defective immune system or those that acquire a defective immune system when they are affected by virus, bacteria and fungi that do not affect healthy persons.

Doctors Treating Cancer:

Medical Oncologist:

Medical oncologist deals with the diagnosis, treatment, and prevention of cancer. He/she takes care of cancer patients by using things like chemotherapy, hormone therapy, targeted therapy, or immunotherapy.

Radiation Oncologist:

Radiation oncologists work closely with medical oncologists, surgeons, and other doctors to determine the most appropriate course of treatment for people diagnosed with cancer. Before performing radiation procedures, radiation oncologists use software to carefully map out where they will deliver radiation to their patients. They also decide which type of radiation therapy to use.

Surgical Oncologist:

They are surgical counterparts of medical oncologist. They are general surgeons with specialty training in procedures for diagnosing, staging (determining the stage of cancer), or removing cancerous growths.

Doctors Treating Lungs and Blood Problems:

Pulmonologist:

A pulmonologist is a doctor who diagnoses and treats diseases of the respiratory system viz: the lungs and other organs that help to breathe. They are concerned with diseases of the respiratory tract, bronchial tubes and lungs as well as the heart. These specialists have extensive training in chest diseases and conditions such as pneumonia, asthma, tuberculosis, emphysema, or complicated chest infections.

Hematologist:

Hematologists are internal medicine doctors or pediatricians who have extra training in disorders related to your blood, bone marrow, and lymphatic system. They may work in specialized areas that aid in diagnosis like electrophoresis, flow cytometry, or coagulation.

Doctors Treating Brain/Nervous System Problems:

Neurologist:

Neurologists are doctors who diagnose and treat problems with the brain and nervous system. neurologists focus on non-surgical treatment.  Neurologists may also specialize in dealing with dementia, epilepsy, headache medicine, Parkinson and Movement Disorders, or Sleep Disorders.

Neuro Surgeon:

Neurosurgeons are medical doctors that diagnose and treat conditions related to the brain, spine, and other parts of your nervous system. They are specifically trained and certified in the use of surgical treatments.

Doctors Treating Joints / Bones/ Muscle Problems:

Orthopedist:

Orthopedist is a doctor who specializes in the branch of medicine concerned with the correction or prevention of deformities, disorders, or injuries of the skeleton and associated structures

Orthopedic Surgeon:

An orthopedic surgeon is qualified to diagnose orthopedic problems, perform or prescribe treatments, and assist with rehabilitation. They also help to develop long-term strategies to treat illnesses, disorders, and issues relating to bones, joints, ligaments, tendons, and muscles. These specialists help treat broken bones, joint problems, like arthritis, and degenerative conditions, like osteoporosis. In addition orthopedic doctors treat sports injuries, infections or congenital conditions related to, and tumors in the bones.

Rheumatologist:

A rheumatologist is a medical practitioner who specializes in treating arthritis, rheumatic diseases, systemic autoimmune diseases and conditions involving the bone, joints and muscles. Since many of these diseases involve the immune system, rheumatologist have an in-depth knowledge of the immune system. Rheumatologists work closely with their patients and orthopedic surgeons, neuro-surgeons, and radiologists who perform joint replacements, soft tissue reconstruction and repair and nerve decompression, and report on X-rays, CT, MRI and ultrasound scans.

Podiatrist:

Podiatrists are medical specialists who help with problems that affect feet or lower legs. They can treat injuries as well as complications from ongoing health issues like diabetes. Podiatrists deal in painful feet irritations like corns, bunions, plantar warts, plantar fasciitis, hammertoes, arch problems and circulatory problems in diabetics.

Osteopath:

Osteopathic medicine is a special science devoted to treating and healing the patient as a whole by using methods called osteopathic manipulative treatment to make sure the body moves freely ensuring that all the body’s healing systems are working efficiently.  Osteopath, is a doctor of osteopathic medicine (DO) who aims to improve people’s overall health and wellness by treating the whole person, not just a condition or disease they may have. This includes osteopathic manipulative medicine, which involves stretching, massaging, and moving the musculoskeletal system.

Doctors Treating Problems of Specific Part of Body:

Otolaryngologist ENT Surgeon:

Otolaryngologist is a doctor who treats issues related to ears, nose, or throat as well as related areas in head and neck. They’re called ENT Specialist for short.

Audiologist:

Audiologists are healthcare professionals who specialize in hearing and balance disorders.

Dentist:

A dentist, also known as a dental surgeon, is a health care professional who specializes in dentistry (the diagnosis, prevention, and treatment of diseases and conditions of the oral cavity).

Periodontist:

A periodontist is a dentist who specializes in the prevention, diagnosis, and treatment of periodontal disease (a chronic inflammatory disease that affects the gums and bone supporting the teeth also known as gum disease), and in the placement of dental implants.

Dermatologist:

A dermatologist is a doctor who specializes in conditions involving the skin, hair, and nails. He/she deals with not only study, research and diagnosis of normal disorders, diseases, cancers, cosmetic and ageing condition of the skin, hair and nails but also includes specializations like dermato-histopathology and topical and systemic medications. It also includes dermatological cosmetic surgery, immunotherapy, laser therapy, radiotherapy and photodynamic therapy. Common skin diseases treated by dermatologists include skin cancer, warts, fungal infections, dermatitis, psoriasis, acne, atomic eczema and herpes simplex.

Ophthalmologist:

Ophthalmologists are medical doctors who specialize in the diagnosis and treatment of eye and vision problems. He/she is a specialist trained in the medical and surgical preventive care of the eyes. He is well trained in giving comprehensive care by carrying out visual examinations, prescribing glasses and contact lens and treating eye ailments and diseases such as glaucoma, cataracts, eye injuries, cornea disorders and also eyelid problems.

Doctors Treating Problems with Blood / Due to Parasites:

Parasitologist:

Parasitologists study the life cycle of parasites, the parasite-host relationship, and how parasites adapt to different environments. They may investigate the outbreak and control of parasitic diseases. They study protozoan and metazoan parasites and try to find ways to spread disease. They work in a close relationship with other sciences such as immunology, cell biology, microbiology, and molecular biology

Microbiologists

A microbiologist works is a lab personnel engaged in the study and analysis of the structure and processes of microorganisms. They may also be engaged in collecting and analyzing cultures and air, water and soil samples to learn about the microorganisms present in them. They work to develop vaccines, biological medicines and biofuels.

Epidemiologist:

Epidemiologists study outbreaks of diseases, the causes, locations, and how various communities are affected, utilizing relative information to aid in the prevention of future outbreaks. Epidemiologists help to keep the public informed of methods to maintain and improve public health. 

Serologist:

A serologist is a medical scientist who specializes in blood serum analysis. He is often associated with forensic investigations related to criminal inquiries, but may also be instrumental in medical diagnostic procedures. A serologist may also examine and analyze blood found in the place of a crime also. A serologist carries on a wide range of laboratory tests by carrying on specific antigen and antibody reactions.

Doctors Treating Psychological Problems:

Psychiatrist:

A psychiatrist is a medical doctor who specializes in the mental health field. He/she deals with rge prevention, diagnosis, and treatment of mental, behavioral, and emotional disorders. He helps to enhance the quality of a person’s life by making assessments of the mind and emotions, providing treatment and rehabilitation care to mentally disturbed patients. They may also deal with phobias of all types. They may offer a mix of treatment in some cases, which includes medication, psychotherapy, and counseling.

• General Psychiatrist: General Psychiatrist is a medical professional who specializes in the study, treatment and diagnosis of mental disorder and behavioural problems.
• Neuropsychiatrists: Neuropsychiatrists is a medical professional who specializes in mental and brain health.
• Geriatric Psychiatrist: Geriatric Psychiatrist is a medical professional who specializes in mental complications in elderly individuals.
• Forensic Psychiatrists: Forensic Psychiatrists  is a medical professional who specializes in the study of correlation between psychology and crime.

Supporting Specialists:

Diagnostician:

A Diagnostician is a doctor who diagnoses and treats medical conditions and solves complex medical mysteries. All Doctors are technically Diagnosticians because they diagnose ailments.

Pathologist:

A pathologist is a specialist who examines body tissues and fluids to analyze the origin of a disease. A pathologist generally works in laboratories on samples collected for investigation and helps physicians and surgeons to diagnose diseases. Such pathologists are called clinical pathologists. Other works of area are anatomical pathology, molecular pathology, surgical pathology, forensic pathology and speech pathology.

Paleopathologist:

Paleopathologists studies evidence of trauma, disease and congenital defects in human remains. This group of specialists may be drawn from archaeologists, geneticists, and physical anthropologists. These specialists research the prehistoric or ancient populations, but also study epidemics in prehistoric times.

Radiologist:

Radiologists are medical doctors that specialize in diagnosing and treating injuries and diseases using medical imaging (radiology) procedures (exams/tests) such as X-rays, computed tomography (CT), magnetic resonance imaging (MRI), nuclear medicine, positron emission tomography (PET) and ultrasound.

Nuclear Medicine Practitioner:

Nuclear medicine physicians, also called nuclear radiologists, are medical specialists that use tracers, usually radiopharmaceuticals administered by injection, swallowing, or inhalation for diagnosis and therapy. These RA tracers are attracted to specific parts of the body and show up as gamma rays detected externally by cameras. Nuclear medicine imaging procedures have been successful in identifying abnormalities much earlier than radiological procedures. Nuclear medicine practitioners carry on bone scans to examine orthopedic injuries, fractures, tumors, or unexplained bone pain and heart scans to identify normal or abnormal blood flow to the heart muscle, measure heart function or determine the existence or extent of damage to the heart muscle after a heart attack. Besides they conduct breast scans to locate cancerous tissues in the breast, and liver, gall bladder and kidney scans to judge the functioning of liver, gallbladder and kidney. Besides they also carry on thyroid and lung scans and also scans to detect the causes of gastrointestinal bleeding.

Diabetologist:

A Diabetologist is a doctor who specializes in the treatment of Diabetes, which is a metabolic disorder and, therefore, forms a part of endocrinology. He deals and specializes in diseases and conditions like diabetes mellitus type 1, diabetes mellitus type 2, non-insulin dependent diabetes, hyperglycemia, hypoglycemia, diabetic ketoacidosis, arteriosclerosis, peripheral neuropathy, foot ulcer and diabetic retinopathy. He may also deal in gestational diabetes.

Dietician:

A dietitian, is an expert in identifying and treating disease-related malnutrition and in conducting medical nutrition therapy. He/she is an expert in the field of food and nutrition. Many individuals, companies, families, schools, hospitals and other institutions seek their help to make meal plans that could be healthy, cost-effective and beneficial to them. They can also help one to plan their diet to lose weight.

Physiotherapist:

A physiotherapist, or physical therapist, works with patients to help them manage pain, balance, mobility, and motor function. He/she helps patients who have been disabled by injury, illness and age to gain their normal range of movements, prevent further damage and increase their functionality. A physiotherapist diagnoses the patient’s problem and helps the patient to do physical exercises that would tone his muscles and strengthen them. They may also do massages and stretch the patient’s muscles and offer advice regarding nutrition, body conditioning and prophylactic care.

Forensic Medicine Expert or Coroner:

A Forensic Medicine Expert or Coroner is a medical professional who works in coordination with others like a coronary investigator to determine the cause of death of a person who may have died in mysterious circumstances. This medical examiner is responsible for performing actual autopsy on the body, while a coroner investigator examines the body, the scene of the crime. So coroner investigators may be from the medical profession, law or with training in criminal law.

Toxicologist:

A toxicologist is engaged in the development and implementation of laboratory and field studies to find out the short- and long- term effects of different toxins on human beings, animals, plants and the environment. He/she also thinks of ways and means to eliminate and minimize the negative effects of the already existing toxins.

Geneticist / Clinical Geneticist:

A clinical geneticist is a medical specialist who applies his knowledge of genetics and is skilled enough to evaluate birth defects, genetic disorders, familial cancers and chromosomal abnormalities. They work closely with genetic counsellors to support patients, families and clinical teams in the management of genetic conditions. Clinical geneticists help identify families at possible risk of a genetic condition by assessing a patient’s physical features and medical history, gathering and analyzing family history and inheritance patterns and calculating chances of recurrence. They provide information about genetic testing and related procedures. A clinical geneticist could easily advice on options, including treatment options, for patients when the doctor suspects a genetic problem.

Physiologist:

Physiologists are highly trained medical person with zeal and expertise in studying how humans, plants, animals and cell function. A physiologist generally focuses on the functioning of the human body such as energy procurement and utilization, blood circulation, excretion, defence systems against infection, repair mechanisms reproduction, nutrition, digestion, absorption, metabolism and diseases.

Conclusion:

This long list of medical specialties and subspecialties shows the many options students have for making their career in medicine. Select a career that challenges you, aligns with your career goals, and provides your desired lifestyle. Narrowing down your options and working toward your intended field of medicine early on in your medical school journey can give you an advantage.

For More Topics in Medical Jurisprudence Click Here

The post Different Medical Specialists appeared first on The Fact Factor.

In the Cardiovascular system, the ‘‘heart’’ (cardi) pumps the blood in a ‘‘little circle’’ (circul), which travels through ‘‘little vessels’’ (vascul). In human, the transportation is done through blood circulatory system and lymphatic system. Thus two fluids move through the circulatory system: blood and lymph. The blood, heart, and blood vessels form the Cardiovascular System. The lymph, lymph nodes and lymph vessels form the Lymphatic System. Human blood circulatory system has three main components. A fluid (blood), tubing (arteries, veins and capillaries) and a pump (the heart).

Study of blood is called haematology. It is a fluid connective tissue. It is bright red, slightly alkaline, salty viscous fluid heavier than water.

The Constituent of the Blood:

In this article, we shall only take an overview of the composition. In the next article, each constituent is discussed in detail.

When a human blood sample is prevented from clotting and spun in a test tube (centrifuged), in a machine called a centrifuge, the blood separates into a   straw coloured liquid called plasma and a dark brown mass of blood cells. The lower layer consists of white blood cells, blood platelets, and red blood cells. Collectively, these are the formed elements, which make up about 45% of the total volume of whole blood; the percentage of blood attributed to red blood cells is called the hematocrit. The hematocrit is defined as the percentage of blood volume that is occupied by erythrocytes. The normal hematocrit is approximately 45 percent in men and 42 percent in women.

The upper layer is plasma, which contains a variety of inorganic and organic molecules dissolved or suspended in water. Plasma accounts for about 55% of the total volume of whole blood.

Characteristics of Human blood:

Study of blood is called haematology. Blood is a fluid connective tissue. It is bright red, slightly alkaline (pH 7.3 to 7.5), salty viscous fluid heavier than water. the pH of blood is more in arteries than that in veins. The viscosity of blood is 5 to 6 times that of water. An adult has a blood volume of approximately 5.5 litres. It forms 6 to 10 % of the body weight. Blood is the only tissue that exists in both the liquid and solid state simultaneously.

Volume of Blood and Different Constituents:

The volume of blood in an average-sized person is approximately 5.5 L. Now hematocrit is 45 percent of the total volume,

Then, Erythrocyte volume = 0.45 x 5.5 L = 2.5 L

Since the volume occupied by the leukocytes and platelets is normally considered negligible, the plasma volume equals the difference between blood volume and erythrocyte volume; therefore, in our average person

Plasma volume = 5.5 L – 2.5 L = 3.0 L

Plasma:

The plasma consists of 90 to 92% water and 8% to 10% proteins, salts, hormones, enzymes, waste products and other various chemicals. Most of the solute part about 7% is proteins. These include antibodies that help to protect the body from diseases, fibrinogen that helps the blood to clot. The waste product includes urea and carbon dioxide. Hormones are the chemical messenger, which help to coordinate different body functions.

Plasma obtained from blood donation may be converted to a powdered form for storage. During the transfusion, it is dissolved in sterile distilled water and can be administered at once. This method saved the lives of many during World war.

Red Blood Cells (RBCs): 

They are also called erythrocyte. They are produced inside the bone marrow. They have a lifespan of about 100 to 120 days after which they are destroyed by the liver. They are the most common type of blood cell (5.1 to 5.8 million per cubic mm). They are non-nucleated, small in size, round and biconvex in shape. They are able to fold and bend as they are forced through the smallest blood vessels.

The strong red colour of blood is due to the large number of RBCs. Red blood cells contain haemoglobin which gives them their red colour and enables them to carry oxygen from lungs to different parts of the body. They also carry carbon dioxide from different parts of the body to the lungs. Their main function is to carry oxygen from the lungs to the tissues.

White blood cells (WBCs):

They are also called leucocytes. Many white cells are made in the bone marrow. Their lifespan is 3 to 4 days. They are colourless and they have a nucleus. WBCs are larger than red cells but they are lesser in number. (About 5000-7000 per cubic millimetre of blood). They are further classified as lymphocytes and phagocytes. The nucleus of each type has a characteristic shape. When they travel in the blood they are more or less spherical, but they flatten and continuously change their shape along the inside walls of the blood vessels.

WBC’s rid the body of pathogens in the process called phagocytosis. In this process, the WBC surrounds, engulfs and “eats” the invading pathogen.

Platelets : 

Platelets are also called thrombocytes. They are made in the bone marrow and have a lifespan of 8-14 days. They are much smaller than red cells. One cubic millimetre of blood contains about a quarter of million platelets. Their function is to help the blood clot. Clotting prevents loss of blood from wounds.

Observing Blood Under Microscope:

• Clean the skin of your finger with a swab of cotton dipped in ethanol. With a sterile needle prick your finger so that a drop of blood comes out.
• Place the drop of blood at one end of a microscope slide. With another slide spread the blood over the surface to form a smear. Let it dry and then examine it under a microscope. We can observe red blood corpuscles.
• Now cover the smear with Leishman’s stain and leave it for five minutes. Then wash the stain off with tap water gently. Let the slide dry and then examine it under the microscope again. Now, we can observe white blood corpuscles.

Functions of Human blood:

Transportation:

The blood moves from the heart to all the various organs, where exchange with tissues takes place across thin capillary walls. Blood collects oxygen from the lungs and nutrients from the digestive tract and transports these to the tissues. It delivers enzymes and chemical messengers to cells and tissues. Various organs and tissues secrete hormones into the blood, and blood transports these to other organs and tissues, where they serve as signals that influence cellular metabolism. It delivers water, vitamins and minerals to cells. It carries carbon dioxide from cells, tissues and carries it to lungs for disposal. It carries waste materials like urea and other chemical wastes and carries them to the liver and kidneys for disposal. It carries antibodies from place to place in the body. It carries vitamins and enzymes.

Protection:

The blood defends the body against invasion by pathogens (microscopic infectious agents, such as bacteria and viruses) in several ways. Certain blood cells are capable of engulfing and destroying pathogens, and others produce and secrete antibodies into the blood. White blood corpuscles  (WBC) fight against disease-causing germs that harm the body.

It prevents the loss of blood after an injury by clotting. Blood helps in the repair process after a cut or other injury. Without blood clotting, we could
bleed to death even from a small cut.

Regulation:

Blood Picks up excess body heat and brings it to the skin to be excreted. The sweat is formed on the skin. Which is evaporated and heat required for it is taken from the body. Hence the body cools down. It controls the amount of water in the body. The salts and plasma proteins in blood act to keep the
liquid content of blood high. In this way, blood plays a role in helping to maintain its own water-salt balance. It also helps to regulate the amount of chemical substance in the tissues of the body. Due to the presence of buffers in the blood, it also helps to regulate body pH and keep it relatively constant.

Blood Donation:

Anybody who is healthy weighs over 50 kg and is between the age of 18 years and 65 years can donate blood. An adult has a blood volume of approximately 5 litres. A donor may give up to half a litre of blood at one time. This is quickly replaced by the body.

Many donors give blood regularly. It is immediately mixed with a chemical which prevents it from clotting and also provides food for the living cells. The blood is then stored in a refrigerator until it is required. Similarly, sodium citrate is added to it to avoid coagulation. The place where the blood is stored is called a blood bank.

Blood groups:

Human blood group is determined by the antigens present on the surface of RBC’s.  Blood groups are inherited and do not change throughout life. Human blood is classified into 4 main groups: A, B, AB and O. Each can be either Rhesus + ve or Rhesus – ve, giving  8 groups in all. Blood grouping is the identification of the antigens in a blood sample. This system is called ABO system.

An individual’s RBC’s may carry an A antigen, a B antigen, both A and B antigens, or no antigen at all. These antigen patterns are called blood types A, B, AB and O, respectively. Type AB is known as a universal recipient, meaning that they can receive any type of blood, while O is the universal donor, meaning they can donate blood to anyone

Blood transfusion:   

Blood transfusion is the transfer of blood that is taken from one person, into the bloodstream of another person. The person who gives blood is called the donor. The person who receives blood is called the recipient. When there is a loss of blood suddenly due to an accident, or because of the bursting of a blood vessel, there is a danger that not enough blood will be left to maintain the circulation. In such a case, the patient may lose consciousness due to low blood pressure and hence less supply of oxygen to tissues. Losing blood is called haemorrhage. To restore the blood volume and to provide more red cells, a blood transfusion is carried out.

Before doing blood transfusion the compatibility between the groups of the donor and the recipient should be checked. If the blood of the donor is not compatible with the blood of the patient, the red cells in the patient’s blood will stick together. This may lead to death.

Clotting of Blood:

Human blood contains heparin and antithrombins as anticoagulants, it prevents the blood to clot inside the blood vessels. As soon as blood vessel ruptures, bleeding starts. The conversion of liquid blood into semisolid jelly is called blood coagulation or blood clotting. Platelets adhere to the site of the wound and release clotting factors known as prothrombin. Prothrombin is inactive. At the site of rupture the platelets and injured tissues release thromboplastin which initiates the formation of enzyme prothrombinase.  In the presence of Ca, ions prothrombinase converts inactive prothrombin to active thrombin. Thrombin converts soluble fibrinogen into fibrin. The fibrin forms a net to enmesh platelets blood cells and plasma to form a clot.

Previous Topic: Circulatory System and its Types

Next Topic: Composition of Blood: Plasma

Science > Biology > Human Anatomy and Physiology > Cardiovascular System > The blood, an Overview

The post The Blood appeared first on The Fact Factor.