Goal 4 - Human Health and Diseases
HUMAN DISEASE AND HEALTH
The human body is an amazing machine.
Often time microorganisms enter the body and attempt to infect the body causing a disease.
Several factors like genetics, age, or nutrition can lead to disease in humans.
PATHOGENS
Microorganisms or any other organisms that causes disease are often called pathogens.
Communicable or infectious diseases are often transmitted by pathogens.
A pathogen can be a bacteria, virus, protist, or fungi.
Viruses are still considered pathogens even through they are not technically microorganisms.
The human body is an amazing machine.
- Has the ability to repair itself, to fight off attacking microorganisms and adapt to a variety of situations.
Often time microorganisms enter the body and attempt to infect the body causing a disease.
- A disease is a condition where an organism experiences impaired function often with detrimental symptoms.
- A symptom is a response of the body to a disease and often is an indicator used to diagnose the type of disease.
Several factors like genetics, age, or nutrition can lead to disease in humans.
PATHOGENS
Microorganisms or any other organisms that causes disease are often called pathogens.
- A pathogen is a specific microorganism that causes a specific disease.
Communicable or infectious diseases are often transmitted by pathogens.
- Communicable diseases are diseases that can easily be spread from one person to another through contact and proximity.
- Communicable disease can spread through the air, water or soil or animal intermediates.
A pathogen can be a bacteria, virus, protist, or fungi.
Viruses are still considered pathogens even through they are not technically microorganisms.
Bacteria
BACTERIA
Bacteria are prokaryotic, unicellular microorganism that are found everywhere
Bacteria are found in the soil, water and air – EVERYWHERE
Bacteria are found on human skin and in the digestive tract
Bacteria often cause disease by releasing toxins into the organism body.
Bacterial infections are often accompanied by a fever or rash as the body mounts a defense against the foreign invaders.
Name of Disease Symptoms Causative Agent
Syphilis Painless chancre, skin rash, heart problems,
mental problems, blindness or dead Treponema pallidum
Tooth Decay Tooth pain and rotting tooth Several Types
Leprosy (Hansen’s Disease) Skin lesions and sometime stuffy nose Mycobacterium Leprae
Tetanus Muscle spasms in the jaw, spasms of skeletal
muscles, difficulty swallowing, and muscle stiffness Clostridium tetari
Legionnaires’ Disease Fever, chills, muscle aches and a cough that
is initially nonproductive Legionella pneumophilia
Tuberculosis Fever, ongoing cough that brings up thick, cloudy
and sometimes bloody mucus, fatigue, weight loss,
night sweats, and rapid heartbeat Mycobacterium tuberculosis
Plague Fever, muscle aches, stomach pains, vomiting
and eventually blood begins to seep into tissues
turning them black Persinia pestis
Food Poisoning Fever, chills, severe diarrhea, vomiting,
and stomach cramping Several Types
Peptic Ulcers Burring pain in the stomach Helicobacter pylori
Bacterial infections are treated using antibiotics.
Best defense against bacterial infections are proper hand washing, using cleaners like bleach and ammonia and cooking food properly.
Bacteria are prokaryotic, unicellular microorganism that are found everywhere
Bacteria are found in the soil, water and air – EVERYWHERE
Bacteria are found on human skin and in the digestive tract
- Bacteria can enter other body systems and cause infections or disease.
- Bacteria can enter the body through a cut in the skin, the respiratory tract or the digestive tract.
Bacteria often cause disease by releasing toxins into the organism body.
- A toxin is a chemical substance that has a negative effect on the body by inhibiting normal body functions
Bacterial infections are often accompanied by a fever or rash as the body mounts a defense against the foreign invaders.
Name of Disease Symptoms Causative Agent
Syphilis Painless chancre, skin rash, heart problems,
mental problems, blindness or dead Treponema pallidum
Tooth Decay Tooth pain and rotting tooth Several Types
Leprosy (Hansen’s Disease) Skin lesions and sometime stuffy nose Mycobacterium Leprae
Tetanus Muscle spasms in the jaw, spasms of skeletal
muscles, difficulty swallowing, and muscle stiffness Clostridium tetari
Legionnaires’ Disease Fever, chills, muscle aches and a cough that
is initially nonproductive Legionella pneumophilia
Tuberculosis Fever, ongoing cough that brings up thick, cloudy
and sometimes bloody mucus, fatigue, weight loss,
night sweats, and rapid heartbeat Mycobacterium tuberculosis
Plague Fever, muscle aches, stomach pains, vomiting
and eventually blood begins to seep into tissues
turning them black Persinia pestis
Food Poisoning Fever, chills, severe diarrhea, vomiting,
and stomach cramping Several Types
Peptic Ulcers Burring pain in the stomach Helicobacter pylori
Bacterial infections are treated using antibiotics.
- The use of antibiotics has caused the development of several drug resistant bacterial strains.
Best defense against bacterial infections are proper hand washing, using cleaners like bleach and ammonia and cooking food properly.
Virus
VIRUSES
A Virus is a small particle that contains proteins and heredity material (DNA or RNA), but is not alive.
Viruses are cell specific meaning they can only infect a cell if the capsid of the virus can fit into a receptor site in the host cell membrane. You can think of it as a lock and key, the virus has one of several thousand possible keys that may fit the lock on the surface of the cell membrane.
Name of Disease Symptoms Causative Agent
Small Pox Flu-like at first, fever, rash, in the form of pustules,
round mouth spreading to the entire body Variola major
Polio Fever, headache, sore throat, and sometime paralysis Paralytre poliolelitis
Chicken Pox Fever, itchy open sores forming a rash on the skin Varcilla zosier
Measles Fever, cough, running nose, conjunctivitis of the eye
followed by a itchy skin rash Morbillivirus paramyxovirus
Warts A rough tumor on the skin that resembles a
cold blister Human papilomarvirus
Viral diseases are often prevented using a vaccine.
A Virus is a small particle that contains proteins and heredity material (DNA or RNA), but is not alive.
- The virus is surrounded by a protein coat, or capsid
- A virus particle can not eat, metabolize food and can only reproduce inside a cell.
- Outside the cell, the virus particle does nothing and remains inactive.
Viruses are cell specific meaning they can only infect a cell if the capsid of the virus can fit into a receptor site in the host cell membrane. You can think of it as a lock and key, the virus has one of several thousand possible keys that may fit the lock on the surface of the cell membrane.
- Once the virus inserts its heredity information into the cell, the protein coat falls away and the heredity material then uses the cell’s machinery to make more viral particles.
- The cell then dies and disintegrates releasing more viruses’ particles into the organism body.
Name of Disease Symptoms Causative Agent
Small Pox Flu-like at first, fever, rash, in the form of pustules,
round mouth spreading to the entire body Variola major
Polio Fever, headache, sore throat, and sometime paralysis Paralytre poliolelitis
Chicken Pox Fever, itchy open sores forming a rash on the skin Varcilla zosier
Measles Fever, cough, running nose, conjunctivitis of the eye
followed by a itchy skin rash Morbillivirus paramyxovirus
Warts A rough tumor on the skin that resembles a
cold blister Human papilomarvirus
Viral diseases are often prevented using a vaccine.
- A vaccine is a weakened or dead viral particles suspended in solution. The solution is then injected into the body where the organisms own immune system develops antibodies that are capable of fighting off the disease
Fungi
FUNGI
Fungi are decomposers that live in moist environments.
Normally fungi are kept under control by the human immune systems.
Things like pH of the skin, fatty acid content of skin cells and cell cycle time can affect the incidence of fungal infections.
The spores of virulent fungi strains are inhaled during respiration. These spores become trapped in the lungs or sinus cavity where they can grow, breaking down tissue and causing disease.
Include: ringworm, athlete’s foot, yeast infections, histoplasmosis, aspergillous or nail fungus.
Fungi are decomposers that live in moist environments.
- Fungi-like bacteria can be found in many habitats.
- Fungi can also be found living on the human body.
- Several types of fungi commonly inhibit the skin, hair follicle or nail.
Normally fungi are kept under control by the human immune systems.
- Sometimes these organisms can cause diseases in humans by infecting the layers of the skin or nails.
Things like pH of the skin, fatty acid content of skin cells and cell cycle time can affect the incidence of fungal infections.
The spores of virulent fungi strains are inhaled during respiration. These spores become trapped in the lungs or sinus cavity where they can grow, breaking down tissue and causing disease.
Include: ringworm, athlete’s foot, yeast infections, histoplasmosis, aspergillous or nail fungus.
- These diseases are often treated by applying a fungicide to the infection site.
Protists
PROTISTS
Protists are unicellular or colonial organisms
Many animal-like and fungus-like protests can cause human diseases including African sleeping sickness, amoebic dysentery, Chagas ’ disease, malaria and yellow fever.
Some protists require an animal intermediate, such as a mosquito, to enter the body
Sometimes protists enter the body through the digestive tract from contaminated food or water.
Protists are unicellular or colonial organisms
Many animal-like and fungus-like protests can cause human diseases including African sleeping sickness, amoebic dysentery, Chagas ’ disease, malaria and yellow fever.
Some protists require an animal intermediate, such as a mosquito, to enter the body
Sometimes protists enter the body through the digestive tract from contaminated food or water.
Parasites
PARASITES
A parasite is any organism that benefits by living in another organism (host).
Parasites can be unicellular protists or multicellular invertebrates.
Some human parasites include: Mites, head lice, tapeworms, round worms, pin worms. Loa Loa, liver flukes, ticks, fleas, Wuchereria bancrofti.
Parasites are often treated by the administration of specialized pesticides, a toxic chemical, designed to kill the offending parasite.
Serious parasitic infection can cause death.
A parasite is any organism that benefits by living in another organism (host).
- The parasite usually causes harm to the host.
- Often the association between parasite and its host can continue over along period of time, where the host slowly becomes weakened but does not die.
Parasites can be unicellular protists or multicellular invertebrates.
Some human parasites include: Mites, head lice, tapeworms, round worms, pin worms. Loa Loa, liver flukes, ticks, fleas, Wuchereria bancrofti.
Parasites are often treated by the administration of specialized pesticides, a toxic chemical, designed to kill the offending parasite.
Serious parasitic infection can cause death.
Other Disease Causing Agents
TOXINS
A toxin is a chemical poison that causes harm to tissues in an organism.
Most organisms have a natural pathway used to eliminate these “naturally” produced toxins.
Sometimes toxins found naturally are ingested and can become harmful. Arsenic, found in ground water, in India is a toxin and serious threat to human health in the Ganges region of India.
A toxin can weaken an organism making it susceptible to other diseases caused by microorganisms.
Some toxins are naturally expelled from organism through metabolism and excretion.
Sometimes toxins are stored in fats or deposited in hair or nail growth and can remain inside the organism for a long period of time.
Some toxins, like ricin, are lethal in very small quantities; just one milligram of ricin will kill a healthy adult human.
Humans come into contact with natural and ma made toxins everyday. It is how the human body reacts to these toxins that ultimately determine the appearance of a disease.
GENETICS
Sometimes genes can influence the incidence of disease.
A non-communicable disease is a disease that can not be easily passed from one person to another through close proximity or contact. Examples include: high blood pressure, diabetes, cystic fibrous, PKU, and hemophilia.
A family history of high blood pressure would make it more likely that you will develop high blood pressure because you and your family have similar genes.
A toxin is a chemical poison that causes harm to tissues in an organism.
- A toxin can be produced by a microorganism like a bacteria or be a by-product of metabolic processes (such as carbon dioxide).
- Carbon dioxide, released during respiration, is considered a toxin to cells.
Most organisms have a natural pathway used to eliminate these “naturally” produced toxins.
Sometimes toxins found naturally are ingested and can become harmful. Arsenic, found in ground water, in India is a toxin and serious threat to human health in the Ganges region of India.
- Toxins can be man-made as chemical by-products produced through manufacturing pesticides and herbicides
A toxin can weaken an organism making it susceptible to other diseases caused by microorganisms.
Some toxins are naturally expelled from organism through metabolism and excretion.
Sometimes toxins are stored in fats or deposited in hair or nail growth and can remain inside the organism for a long period of time.
Some toxins, like ricin, are lethal in very small quantities; just one milligram of ricin will kill a healthy adult human.
Humans come into contact with natural and ma made toxins everyday. It is how the human body reacts to these toxins that ultimately determine the appearance of a disease.
GENETICS
Sometimes genes can influence the incidence of disease.
- Genes are passed from parents to offspring.
- Sometimes the genes you inherit from your parents can make you more likely to develop a non-communicable disease.
A non-communicable disease is a disease that can not be easily passed from one person to another through close proximity or contact. Examples include: high blood pressure, diabetes, cystic fibrous, PKU, and hemophilia.
A family history of high blood pressure would make it more likely that you will develop high blood pressure because you and your family have similar genes.
- It’s a combination of your genes and the food you eat that ultimately determines the appearance of the disease.
Immune Response
IMMUNE RESPONSE
When a pathogen gets past the skin, mucus membranes and stomach to enter the body an inflammation response is triggered.
Histamine causes capillaries to expand and blood flow to increase, which causes inflammation (swelling) in the damaged area.
Specialized white blood cells capable of breaking down pathogens travel to the site,
Sometime the inflammation response affects the entire body by producing a fever, an increase in overall body temperature. It is through that the increase in temperature creates an environment unsuitable for pathogen growth.
The breakdown of pathogen signals a foreign substance is present in the body.
There are some white blood cells that are activated by the presence of antigens to destroy disease fighting cells and produce antibodies.
When antibodies are formed against antigens, the immune response is completed and immunity is developed.
Active immunity is acquired when immune response is activated in the body.
Passive immunity us when antibodies are introduced into the body.
The immune system helps with the maintenance or homeostasis by removing pathogens from the body.
When a pathogen gets past the skin, mucus membranes and stomach to enter the body an inflammation response is triggered.
- A pathogen may enter through a cut. The damaged cells release several chemical, one of which is histamine.
Histamine causes capillaries to expand and blood flow to increase, which causes inflammation (swelling) in the damaged area.
- The purpose of the inflammation is to localize the infection and allow the body to destroy the pathogen and repair the damaged tissue.
Specialized white blood cells capable of breaking down pathogens travel to the site,
Sometime the inflammation response affects the entire body by producing a fever, an increase in overall body temperature. It is through that the increase in temperature creates an environment unsuitable for pathogen growth.
- A fever may also increase the production of disease fighting cells.
The breakdown of pathogen signals a foreign substance is present in the body.
- The foreign substance is called the antigen.
- An antigen can be a virus, bacteria, toxin or pieces of foreign substances.
There are some white blood cells that are activated by the presence of antigens to destroy disease fighting cells and produce antibodies.
- Antibodies are proteins created by white blood cells in response to an antigen.
- The antibody and the antigen bind so that the negative effects of the antigen are blocked.
- Antibodies are specific to one antigen.
- A measles antibody will only combine with a measles antigen, not a chicken pox antigen.
When antibodies are formed against antigens, the immune response is completed and immunity is developed.
- Immunity is the ability to resist disease.
Active immunity is acquired when immune response is activated in the body.
- This type of immunity to a disease is long term, explaining why some diseases are contracted once in a lifetime.
Passive immunity us when antibodies are introduced into the body.
- This type of immunity occurs when a mother transfers antibodies to an infant through breast-feeding.
- Passive immunity is short term.
The immune system helps with the maintenance or homeostasis by removing pathogens from the body.
- Pathogens are disease-causing organisms and interfere with cellular functions. If cellular function is disrupted, so is homeostasis.
- One homeostasis mechanism activated to help remove a pathogen is a fever.
- Pathogen enters the body - histamine is released (fluid builds up, blood flow increase, white blood cells are signaled) - white blood cells travel to the site to digest the pathogen - digestion or pathogen signals presence of antigen - antibodies form against antigens- immunity develops.
Nutrition
NUTRITION
If an organism is in good health it is more likely to fight off diseases and remain healthy.
Nutrients are substances needed by organisms to carry out life functions.
Nutrient Source Used by body
Vitamin K Green leafy vegetables, parsley, dairy
products, eggs, soy, avocados, kiwi Blood coagulation,bone
metabolism(deposition and use of calcium)
Vitamin C Citrus, tomatoes, cantaloupe, broccoli,
rose hips, strawberries, kiwi, spinach, red peppers To fight infections and hemorrhaging, helps
with the development of bones and teeth,
maintains healthy gums, helps prevent
scars, helps with the absorption of essential
elements needed to carry oxygen in the blood.
Vitamin D Milk, soy, cereals Regulates the calcium and phosphorus levels in
the blood promoting re-absorption of calcium in
the kidneys, bone metabolism, inhibits parathyroid
hormone secretion, promotes immune system
function, and tumor activity.
Calcium Green leafy vegetables, broccoli, and
dairy products For blood clotting, contracting and relaxing of
muscles, maintaining proper heart rate and blood pressure.
Sodium Table salt, milk, spinach, seafood Regulation of blood and body fluids, transmitting nerve
impulses, proper heart activity, metabolic function.
Iron Red meat, green leafy vegetables, beans,
mushroom Part of the hemoglobin molecule, helps to get oxygen to
all cells in the body.
Carbohydrates Bread, pasta, rice Storage and transport of energy, cellular structural
components, function of immune system, blood clotting.
Proteins Meats, legumes Source of nitrogen and other essential amino acids
necessary for protein synthesis, source of energy.
Fats Oils, butter, avocado, fish Digestion, absorption and transport of some vitamins (A, D, E,
K), maintaining healthy skin and hair, insulating body
temperature, energy stores for the body, buffer against many
diseases, proper brain function.
Receiving proper nutrition throughout ones lifetime can greatly improve overall human health.
The list below lists ways individuals can live a healthy life and ensure they are receiving proper nutrition each day.
Making healthy choices and receiving proper health care can increase you life expectantly and quality of life.
If an organism is in good health it is more likely to fight off diseases and remain healthy.
- People who make healthy life choices throughout their lives are healthier and often avoid chronic or age related diseases like diabetes, arthritis, cancer or heart disease.
Nutrients are substances needed by organisms to carry out life functions.
- Nutrients include things like carbohydrates, fats, proteins, nucleic acids, vitamins and trace minerals.
Nutrient Source Used by body
Vitamin K Green leafy vegetables, parsley, dairy
products, eggs, soy, avocados, kiwi Blood coagulation,bone
metabolism(deposition and use of calcium)
Vitamin C Citrus, tomatoes, cantaloupe, broccoli,
rose hips, strawberries, kiwi, spinach, red peppers To fight infections and hemorrhaging, helps
with the development of bones and teeth,
maintains healthy gums, helps prevent
scars, helps with the absorption of essential
elements needed to carry oxygen in the blood.
Vitamin D Milk, soy, cereals Regulates the calcium and phosphorus levels in
the blood promoting re-absorption of calcium in
the kidneys, bone metabolism, inhibits parathyroid
hormone secretion, promotes immune system
function, and tumor activity.
Calcium Green leafy vegetables, broccoli, and
dairy products For blood clotting, contracting and relaxing of
muscles, maintaining proper heart rate and blood pressure.
Sodium Table salt, milk, spinach, seafood Regulation of blood and body fluids, transmitting nerve
impulses, proper heart activity, metabolic function.
Iron Red meat, green leafy vegetables, beans,
mushroom Part of the hemoglobin molecule, helps to get oxygen to
all cells in the body.
Carbohydrates Bread, pasta, rice Storage and transport of energy, cellular structural
components, function of immune system, blood clotting.
Proteins Meats, legumes Source of nitrogen and other essential amino acids
necessary for protein synthesis, source of energy.
Fats Oils, butter, avocado, fish Digestion, absorption and transport of some vitamins (A, D, E,
K), maintaining healthy skin and hair, insulating body
temperature, energy stores for the body, buffer against many
diseases, proper brain function.
Receiving proper nutrition throughout ones lifetime can greatly improve overall human health.
- If your body has the proper nutrients available it is more able to eliminate toxins, fight parasites and microbial attacks.
The list below lists ways individuals can live a healthy life and ensure they are receiving proper nutrition each day.
- Eat a healthy diet consisting of fruits, vegetables, whole grains, and meats low in saturated fat. Be sure to eat a rainbow of colors each day.
- Eliminate foods high in saturate fats, trans fats, artificial sweeteners and preservative. Limit intake of sweets. Typically the more processed the food the less healthy it becomes.
- Eat slowly and stop when you are full.
- Drink plenty of water and eliminate soft drinks.
- Limit consumption of alcohol. Alcohol abuse can lead to alcohol poisoning, coma paralysis, liver disease, heart disease and emotional disorders.
- Don’t smoke or use tobacco. Tobacco users have a significantly higher rate of cancer, heart disease, tooth decay, chronic bronchitis and emphysema.
- Get regular exercise. Exercise helps maintain body weight, increases blood and lymph circulation, increases flexibility, increases immunity, strengthens bones, relieves stress and decreases depression.
- Get enough sleep.
- Limit stress. Find ways to relieve stress each day such as moderate exercise, reading or participating in a hobby.
- Wear your seatbelt and proactive defense driving techniques.
- Avoid all illegal drugs – JUST SAY NO!
Making healthy choices and receiving proper health care can increase you life expectantly and quality of life.
- A lifetime of bad nutrition, drug use, tobacco use or alcohol abuse will significantly increase your chances of disease or early death.