Mosquito Diseases

Mosquito Diseases

Mosquito Diseases

Malaria

• Malaria is the most well-known mosquito-transmitted illness. 
• Malaria is spread by a particular type of mosquito (the infected Anopheles mosquito) found only in certain parts of the world. 
• People living in, or visiting, those places can reduce the risk of malaria by taking antimalarial tablets, and taking measures to avoid being bitten.

Dengue fever

• The mosquitoes that transmit dengue fever breed in containers that hold water, and bite during the day, not mainly at dusk or evening like other types of mosquito. 
• People infected with the virus may have no symptoms, but others may experience high fever, severe headache, muscle and joint pain, rash and extreme fatigue. 
• In rare cases, dengue fever can be severe and even fatal (dengue haemorrhagic fever). 
• It is important to seek immediate medical advice if you suspect you have dengue fever.
• There is no vaccine against dengue fever, so mosquito prevention measures are essential. The mosquito responsible (the infected Aedes mosquito) is found in many tropical and subtropical areas. 

Japanese encephalitis

• Japanese encephalitis is an infection of the brain caused by a virus that is spread by infected mosquitoes. 
• The mosquitoes become infected after biting pigs infected with the virus. Japanese encephalitis occurs in parts of Asia and Papua New Guinea. 
• There have also been cases in north Queensland in Australia. 
• Most infected people have no symptoms, but a small proportion may have severe symptoms, including headaches, high fever, convulsions and coma. 
• There is no treatment, but a vaccine is available to protect against the infection in people travelling to, or resident in, areas where the virus is found.

Ross River virus infection

• Occurring widely in Australia, the Ross River virus is spread from animals to humans by several different types of mosquitoes.
• Although many people infected with this virus have no symptoms or only slight symptoms, other people may have a fever, joint pain and swelling and a rash. 
• There is no specific treatment but medicines may be taken to help relieve the symptoms.

Barmah Forest virus infection

• The Barmah Forest virus is also widespread in Australia and causes a similar illness to Ross River virus infection but the symptoms usually last for a shorter length of time.
• The virus is spread from animals to humans by mosquitoes. 
• Again, there is no specific treatment for this infection, but medicines may be taken to help manage the symptoms.

Murray Valley encephalitis

• Murray Valley encephalitis is a very rare disease involving swelling of the brain tissue. 
• The disease is caused by infection with a virus that is spread by the bite of infected mosquitoes. 
• The mosquito responsible is found throughout Australia and breeds in surface pools of water. Water birds, such as herons, are a natural reservoir of the virus. 
• Most people infected with the Murray Valley encephalitis virus do not develop symptoms, but others may have high fever, severe headache, neck stiffness, irritability, seizures (or fits), and drowsiness. 
• Immediate medical advice should be sought for these symptoms.

Yellow fever

• Yellow fever occurs in areas such as Africa and South America, and is spread by infectedAedes and Haemogogus mosquitoes. 
• It can be spread by mosquitoes in jungle/rural areas as well as urban areas. 
• Yellow fever causes a flu-like illness, but some people develop a more severe form which can be life threatening. 
• The ‘yellow’ relates to jaundice which occurs as part of the severe illness. No specific treatment is available other than supportive measures.
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• For prevention, however, yellow fever vaccination is available and involves a single injection. The vaccine becomes effective after 10 days, and should last for 10 years.
• Yellow fever vaccine can only be given in approved vaccination centres, and some countries will require a certificate of vaccination below allowing you to enter. 
• Ask your travel medicine clinic to advise on whether this vaccine is recommended for your trip.

Reducing the risk of mosquito bites

Because there is no specific treatment for many of the mosquito-borne diseases, and few vaccines or medicines available to prevent them, the best protection is to avoid mosquito bites. 

Measures to avoid being bitten by mosquitoes include:

• Trying to stay indoors at dusk (when most mosquitoes do their biting)
• wearing light-coloured, long-sleeved shirts, long trousers and covered shoes at this time of the day (but note, dengue-carrying mosquitoes also bite during the day)
• using effective insect repellents (eg, DEET) when outdoors
• choosing accommodation that has air-conditioning or insect screens on rooms (otherwise, sleeping under a mosquito bed net, preferably pre-soaked in permethrin)
• using insect sprays inside
• if applicable, removing outside containers that hold water where mosquitoes might breed.

Brain Tumors and causes

Brain Tumors

Definition:

• A brain tumor is a mass formed by an overgrowth of abnormal cells. Something triggers a single cell's genes to change, causing it to divide out of control. 
• If a tumor originates in the brain, the brain's coverings, or its nerves, it's known as a primary brain tumor. 
• Most brain tumors in children are primary tumors. In adults, most brain tumors are metastatic or secondary tumors, meaning the cancer has spread to the brain from the breast, lung, or other part of the body.
•  Nearly 1 in 4 people with cancer will get a secondary brain tumor. 
• Historically, the prognosis for patients with these tumors was bleak; people were expected to survive only several weeks after diagnosis. 
• More aggressive surgical treatments, innovative radiation approaches, and new approaches to chemotherapy and other drugs now allow survival with a good quality of life that is measured in several months to years.
• Brain tumors are often classified as benign or malignant. 
• Truly benign tumors are composed of noncancerous cells that don't invade brain or other tissues. A malignant brain tumormay contain benign-appearing cells that invade normal tissue or contain cancerous cells either from the brain or other body cancers. The latter are typically life-threatening tumors, as they can spread throughout the brain or to the spinal cord. (Brain cancer rarely spreads outside the central nervous system).
• Even some benign tumors can be life-threatening. Because the brain and spinal cord are housed within bony structures that can't expand—the skull and spinal column—tumors made of benign cells can grow large enough to put pressure on sensitive areas of the brain, impair function, and lead to coma and death.
• Brain tumors are grouped by their location within the brain and the type of brain cells where the cancer began. 
• The most common primary brain tumors in adults are pituitary tumors, meningiomas, and glioblastomas. 
• The most common primary brain tumors in children aremedulloblastomas, astrocytomas, ependymomas, and brain stem gliomas.
•  The chance of recovery and choice of treatment depend on the type of brain tumor and the patient's general state of health.

This section provides more detail on:

1. Need-to-know anatomy
2. Causes
3. Risk factors
4. Types of tumors

Need-to-know anatomy

The brain is divided into three main parts: the cerebrum, the cerebellum, and the brain stem. The cerebrum is the largest part of the brain and is responsible for most higher-level brain functions, including language, consciousness, emotions, integration of sensory stimuli, and some motor functions. The second-largest structure in the brain is the cerebellum. Located under the cerebrum at the back of the brain (just above the back of the neck), this portion of the brain governs coordination, balance, and some other aspects of movement.

Finally, the brain stem, the smallest part, attaches the brain to the spinal cord and head and includes the midbrain, pons, and medulla oblongata. It is among the most "primitive" parts of the brain and controls many of the body functions that occur automatically, including heartbeat, blood pressure, and wakefulness.

Each part of the brain breaks down into smaller regions that control various body functions and behaviors.

Protected by the skull and three thin membranes called meninges, the brain floats and is cushioned by cerebrospinal fluid. This watery liquid flows between the meninges and other spaces called ventricles.

A network of nerves made up of nerve cells, or neurons, transmits signals from the brain to other parts of the body. A different group of brain cells, called glial cells, serves as support for the neurons-feeding them, insulating them, clearing dead neurons away. The most common primary brain tumors, called gliomas, begin in glial cells or their stem cells.

Causes

It is usually impossible to determine the cause of a brain tumor in any given individual. A brain tumor begins when certain genes on the chromosomes of a cell no longer function properly. These genes normally regulate how often the cell divides (or if it divides at all) and repair other genes. A defective gene might then be programmed to tell a damaged cell to self destruct.

Some people might be born with partial defects in one or more of these genes, and environmental factors (such as radiation and chemicals) might lead to further damage. In other people, environmental factors might be the only cause of damage to the gene function.

Once a cell is dividing too rapidly and can't check its own growth, it can grow into a tumor. If a tumor cell begins to grow, the body's immune system should detect the abnormal cell and kill it. Many tumors, however, produce substances that block the immune system from recognizing the abnormal tumor cells. Over time, the tumor cells overpower all of the body's defenses against their growth.

Risk Factors

1. Scientists have linked several factors with an increased risk of developing a primary brain tumor. Nevertheless, most people who have these risk factors do not develop brain tumors, and many of those who do get brain tumors have none of the risk factors. These factors include the following:
2. Males are more likely to get brain tumors than females. Meningiomas, however, are more common in females.
3. Caucasians tend to get more brain tumors than do people of other races.
4. Having a family member with a glioma may mean you are slightly more likely to develop the disease.
5. If you've been exposed to radiation—working in the nuclear industry, for example—you may have an increased risk of developing a brain tumor. Also, people who have received radiation therapy to the head may have an increased risk of developing meningiomas later in life.
6. Pathologists and embalmers who work with formaldehyde have a greater risk of developing brain cancer. But scientists have not found a link with other workers who are exposed to formaldehyde. Workers who make plastics may be exposed to vinyl chloride, which may increase the risk of brain tumors. Textile and plastic workers may be exposed to acrylonitrile, which could also increase the chance of brain cancer.
7. Scientists are researching whether cellphone use is a risk factor, but so far studies have not found convincing evidence of an increased risk of brain tumors among cellphone users. Researchers are also investigating if head injuries are a risk factor, but so far, studies have not shown an increased incidence of brain tumors.

Types of tumors

• A tumor that begins in the brain or adjacent tissue is called a primary brain tumor. These are named for the type of cells in which they begin. For instance, tumors that start in the glial cells are called gliomas.
•  A secondary brain tumor, which has spread from another part of the body, has the same kind of abnormal cells and the same name as the primary cancer.
• Common benign primary brain tumors include those of the lining of the skull (meningiomas), those of the nerves (schwannomas), and those of the pituitary gland (pituitary adenomas). However, benign brain tumors can become malignant and, once removed, can also grow back unless nearly every tumor cell was destroyed or removed during treatment.
• With few exceptions, most primary brain tumors involving the brain tissue (gliomas) are cancerous. These cancers can range from slow-growing, noninvasive tumors (low-grade tumors) to rapidly growing, highly destructive tumors (high-grade tumors) , such asglioblastomas. (Grading is based on the tumor's tendency to spread as well as its growth rate). In the past, low-grade tumors were often referred to as being benign. It is now widely recognized that even these low-grade tumors are rarely cured and usually change into higher-grade tumors over time.
• Brain tumors in children often arise from tissues that are different from those most commonly affected in adults. Common pediatric tumors include tumors of primitive cells that have not matured into adult cell types (primitive neuroectodermal tumors or PNETs) , tumors of the lining of the brain's fluid sacs (ependymomas), and benign tumors of the supporting cells of the brain (juvenile astrocytomas).

Gliomas

Gliomas are the most common primary brain tumors. There are a number of types, distinguished by the type of cells they affect; some are slow growing, and some grow quickly and are difficult to treat. Mixed gliomas are brain tumors that occur in more than one type of brain cell.

This section provides more information on these types of gliomas:

1. Astrocytomas
2. Ependymomas
3. Oligodendrogliomas
4. Brain stem gliomas

Astrocytomas

Astrocytomas make up nearly 60 percent of all tumors. They resemble astrocytes (star-shaped cells that help feed neurons by drawing nutrients from blood vessels) and arise either from astrocytes or from their stem cells. 

Ependymomas

Ependymomas begin in the ependymal cells that line the cavities and passageways of the brain (ventricles) and spinal cord. 

They most often occur in the cerebellum or brain stem. About 85 percent of ependymomas are low grade.

Well-differentiated ependymomas have cells that look like normal cells and grow slowly.Anaplastic ependymomas grow more quickly than well-differentiated ependymal tumors.Ependymoblastomas are rare cancers that usually occur in children. They may grow very quickly.

Low-grade ependymomas  grow slowly and usually do not spread to the spine or other areas of the brain. They often can be successfully treated with surgery. High-grade tumors tend to grow more quickly and to invade surrounding tissue. Treatment of these tumors is less successful, and they often recur. In some cases, cells from ependymomas "break off" from the tumor and spread to the spine through the cerebrospinal fluid. This process is called CSF seeding.

Ependymomas are relatively uncommon, accounting for about 6 percent of all tumors affecting the central nervous system. Ependymomas that occur in the brain are more common in children, and ependymomas that begin in the central canal of the spinal cord are more common in adults. Ependymomas are the third-most-common brain tumor in children, occurring most often between the ages of 1 and 5. In adults, ependymomas most often occur between the ages of 30 and 35.

Oligodendrogliomas

Oligodendrogliomas begin in the oligodendrocytes (or their stem cells), cells that make a fatty substance called myelin that provides support and nourishment for the neurons, or cells that transmit nerve impulses. Oligodendrogliomas usually occur in the cerebrum. Most are slow-growing, low-grade tumors that spread into surrounding brain tissue and often cause seizures. They account for 10 to 20 percent of all primary brain tumors, and they occur mostly in middle-aged adults. More rare are anaplastic oligodendrogliomas, which grow quickly and invade nearby tissue.

Brain stem gliomas

Brain stem gliomas are located in the brain stem, which attaches the cerebrum to the rest of the head and spinal cord. Most brain stem gliomas occur in the pons and are called pontine gliomas. The pons (Latin for " bridge " ) is a band of nerve fibers linking the medulla oblongata and cerebellum to the upper portions of the brain. Brain stem gliomas rarely spread to other areas of the brain or to the spinal cord. Approximately three fourths of patients with brain stem gliomas are younger than 20. In the United States, brain stem gliomas make up about 2 percent of all brain tumors in adults and about 10 percent to 15 percent of all childhood brain tumors. Treatment of brain stem gliomas in the midbrain or medulla is generally more successful than gliomas affecting the pons.

Other types of tumors

Medulloblastomas begin in the lower part of the brain. This type of cancer may spread to the spine or to other parts of the body. Medulloblastomas are considered to be primitive neuroectodermal tumors or PNETs because they contain nervous system cells that did not develop properly at a very early stage of life. Although they can affect people of any age, 75 percent of all cases occur in children. About 1 in 5 childhood brain tumors is a medulloblastoma, with 350 new cases diagnosed each year in the United States.

Pineal region tumors are found in or around the pineal gland, a small structure located near the center of the brain that produces melatonin. There are many types of pineal region tumors, and they can be slow growing (pineocytomas) or fast growing (pineoblastomas).

Germ cell tumors arise from primitive cells that normally develop into the testicles and ovaries but also can occur in other parts of the body, including the brain. There are different kinds of germ cell tumors, including germinomas, embryonal carcinomas, choriocarcinomas, and teratomas.

Craniopharyngiomas are tumors that occur near the pituitary gland, which is responsible for many body functions, such as growth, metabolism, and reproduction. These are most common in children.

Meningiomas are slow-growing tumors in the meninges, or membranes covering the brain. They are usually benign but can be difficult to remove through surgery and can recur. They generally do not recur if they are completely removed. Meningiomas most often occur as single tumors but can occur as multiple growths. Malignant meningiomas are rare tumors that grow more quickly than other meningiomas. Meningiomas account for 15 percent to 20 percent of all primary brain tumors. They most often occur in people between the ages of 40 and 60. They are more common in women than in men and are rare in children.

Choroid plexus tumors start in the choroid plexus, tissue located in the brain's ventricles. The choroid plexus makes the fluid that fills the ventricles and surrounds the brain and spinal cord. Tumors of the choroid plexus can grow slowly (choroid plexus papilloma) or more rapidly (anaplastic choroid plexus papilloma) . The rapidly growing tumors are more likely to spread to other places in the brain and to the spinal cord.

Schwannomas are tumors that originate in the schwann cells of nerves. Vestibular schwannomas (also known as acoustic neuromas) are tumors of the nerve that controls balance and hearing in the inner ear. The tumor occurs most often in adults.

Childhood supratentorial primitive neuroectodermal tumors occur in the upper part of the brain. Sometimes called cerebral neuroblastomas, they can spread to other parts of the brain and spinal cord.

Mental Illness Or Mental Disorder

Mental Illness Or Mental Disorder 

• Mental illness or mental disorder is a condition that affects thoughts, feelings or behaviors of someone who is strong enough to make social integration problematic, or cause personal suffering.
• Psychosis (psychotic disorder) is a mental disorder that is most severe, leading to personality change and experience.
• While most people don’t know and don’t understand the feelings you’re experiencing psychotic neurotics.
• Psychotic hallucinates or hearing voices delusions, and in fact lost to developed in the meantime.
• Bipolar affective disorder, also called manic-depressive disorder, causes a change between periods of mania and depression, and can accelerate and worsen because of the next issue (the dismantling of relations), lost jobs, money issues, addiction. With increasing age the depression phase became more frequent and longer, so that increases the risk of suicide. Disposition of genetic and biological factors associated with environmental factors thought to be the cause.

Symptoms of mental illness

The following is a list of examples of symptoms of mental disorder

• Antisocial behavior and deterioration relationships;
• Mood disorders;
• Personality disorder;
• Cognitive and perceptual difficulties, hallucinations and altered perception of reality;

There are many different conditions that are recognized as mental illnesses. The more common types include:

Anxiety disorders: People with anxiety disorders respond to certain objects or situations with fear and dread, as well as with physical signs of anxiety or nervousness, such as a rapid heartbeat and sweating. An anxiety disorder is diagnosed if the person's response is not appropriate for the situation, if the person cannot control the response, or if the anxiety interferes with normal functioning. Anxiety disorders include generalized anxiety disorder, post-traumatic stress disorder (PTSD), obsessive-compulsive disorder (OCD), panic disorder, social anxiety disorder, and specific phobias.

Mood disorders: These disorders, also called affective disorders, involve persistent feelings of sadness or periods of feeling overly happy, or fluctuations from extreme happiness to extreme sadness. The most common mood disorders are depression, mania, and bipolar disorder.

Psychotic disorders: Psychotic disorders involve distorted awareness and thinking. Two of the most common symptoms of psychotic disorders are hallucinations -- the experience of images or sounds that are not real, such as hearing voices -- and delusions, which are false beliefs that the ill person accepts as true, despite evidence to the contrary. Schizophrenia is an example of a psychotic disorder.

Eating disorders: Eating disorders involve extreme emotions, attitudes, and behaviors involving weight and food. Anorexia nervosa, bulimia nervosa and binge eating disorder are the most common eating disorders.

Impulse control and addiction disorders: People with impulse control disorders are unable to resist urges, or impulses, to perform acts that could be harmful to themselves or others. Pyromania (starting fires), kleptomania (stealing), and compulsive gambling are examples of impulse control disorders. Alcohol and drugs are common objects of addictions. Often, people with these disorders become so involved with the objects of their addiction that they begin to ignore responsibilities and relationships.

Personality disorders: People with personality disorders have extreme and inflexible personality traits that are distressing to the person and/or cause problems in work, school, or social relationships. In addition, the person's patterns of thinking and behavior significantly differ from the expectations of society and are so rigid that they interfere with the person's normal functioning. Examples include antisocial personality disorder, obsessive-compulsive personality disorder, and paranoid personality disorder.

Other, less common types of mental illnesses include:

Resources for Military Families

Although all families face stress, military families face a unique set of stressors that can negatively affect their health and well-being.  The Department of Defense, Department of Veterans Affairs, and individual branches of the military provide a variety of online resources to help families navigate these challenges. 

Adjustment disorder: Adjustment disorder occurs when a person develops emotional or behavioral symptoms in response to a stressful event or situation. The stressors may include natural disasters, such as an earthquake or tornado; events or crises, such as a car accident or the diagnosis of a major illness; or interpersonal problems, such as a divorce, death of a loved one, loss of a job, or a problem with substance abuse. Adjustment disorder usually begins within three months of the event or situation and ends within six months after the stressor stops or is eliminated.

Dissociative disorders: People with these disorders suffer severe disturbances or changes in memory, consciousness, identity, and general awareness of themselves and their surroundings. These disorders usually are associated with overwhelming stress, which may be the result of traumatic events, accidents, or disasters that may be experienced or witnessed by the individual. Dissociative identity disorder, formerly called multiple personality disorder, or "split personality," and depersonalization disorder are examples of dissociative disorders.

Factitious disorders: Factitious disorders are conditions in which physical and/or emotional symptoms are created in order to place the individual in the role of a patient or a person in need of help.

Sexual and gender disorders: These include disorders that affect sexual desire, performance, and behavior. Sexual dysfunction, gender identity disorder, and the paraphilias are examples of sexual and gender disorders.

Somatoform disorders: A person with a somatoform disorder, formerly known as psychosomatic disorder, experiences physical symptoms of an illness, even though a doctor can find no medical cause for the symptoms.

Tic disorders: People with tic disorders make sounds or display body movements that are repeated, quick, sudden, and/or uncontrollable. Tourette's syndrome is an example of a tic disorder.

Prevention

People with serious mental disorders and lack of knowledge about their own care needs, can be given treatment.

Treatment takes place in a closed psychiatric ward.
After the crime as a measure of improvement and security.

According to the laws of each accommodation (mental health law), shaped differently depending on the country is a Federal (called houses) as accommodation.

Various ways to prevent it is to support children’s mental health, parenting skills competencies encourage children’s development and use of prevention strategies, especially for children at risk .

Including known risk factors for mental illness that involves a parent is a parent rejection, lack of parental warmth, high hostility, harsh discipline, the negative effect of high maternal, parental favoritism, anxious childrearing, dysfunctional behavior modeling and drug abuse, and child abuse.

Human Cell

Human Cell

• Cell is the smallest part of living beings. The body is made up of millions of tiny cells. These are the building blocks of the body. A single is too small to be seen with a naked eye.
• A microscope is needed to see the single cell. There are different kinds of cell. Cells differ in their shapes and functions. For example, skin cells, muscles are made up of muscle cells, bones, teeth, and mails are made up of different jobs. Cell wall, cell membrane, nucleus and cytoplasm are the basic parts of the cell.

Types of Human Cell:
Red Blood Cells: These are blood cells which form most of the part of our blood. These cells carry food and oxygen to other body parts to sustain life.
Liver Cells: Liver cells perform many functions like like glucose breakdown and protein and carbohydrate synthesis. They are found in liver which is one of the major organs of human body.

Brain and Nerve Cells:Brain controls the functioning of all the organs of the body. The brain and nerve cells create an electronic impulse for sending messages from brain to organs and vise versa.

Chief Cells:These types of cells are found in stomach and they produce gastric juices for the break down of food to make it usable for the different cells of the body and to supply energy.

Kidney Cells: These are purifying cells which are in two kidneys of the human body. These cells extract toxic chemicals from human blood and excrete it out of the body through urine.

Skin Cells

Epithelial cells, or skin cells, divide and reproduce much more quickly than some other types of cells. Skin cells form a protective barrier between delicate organs and the outside world.

Not only do skin cells provide a means to contain all the various inner workings of the human body, but they also help to regulate body temperature, and to keep out infection.

Skin cells are square in shape and flat.

Human skin itself is composed of layers of cells: the epidermis, the dermis, and the hypodermis. The epidermis is the outermost, visible layer of skin which provides waterproof protection against foreign substances. The dermis, the layer beneath the epidermis, is a thick layer of tissue which contains glands, nerve endings, hair follicles, and blood vessels.

Muscle Cells

 

Human muscles contain hundreds of thousands of muscle cells and each muscle cell performs a function specific to the type of muscle of which it is a part. Individual muscle cells, or muscle fibers, are composed of myofibrils - cylindrical structures which contain both thick and thin filaments.

The overlapping of these filaments creates cellular units called sarcomeres and when muscle fibers and sarcomeres are grouped together, they form what are called fascicles.

These bundles, or fascicles, are then grouped together to form human muscle.

There are three different types of muscles within the human body: skeletal, cardiac, and smooth muscle. Skeletal muscle is anchored to bone by tendons and can be used to facilitate motion. Cardiac muscle is similar in structure to skeletal muscle, but is only present in the heart.

Smooth muscle, also called involuntary muscle, makes up the walls of organs and other bodily structures like the esophagus and blood vessels.

Nerve Cells

Nerve cells, or neurons, are electrically charged cells that transmit information between different parts of the body by means of electrical and chemical signals.

Neurons make up the body's nervous system, which includes the brain and spinal cord by forming networks of nerve cells through which signals, or synapses, can be sent.

There are several specific types of neurons including the sensory neurons and motor neurons.

Sensory neurons respond to stimuli affecting the cells of sensory organs, like the eyes, and then send signals to the brain.

Motor neurons transmit signals from the brain and spinal cord to other parts of the body to affect the glands and to stimulate muscle contractions which facilitate movement.

Stem Cells

Stem cells are known for their self-renewing properties and for their capacity to differentiate into many specialized cell types.

Recent scientific developments have led to the manipulation of stem cells to produce viable tissues through the means of cell culture. Stem cells are found in high concentration in amniotic fluid, umbilical cord blood, and bone marrow.

These cells can be used to treat leukemia and may, in the future, provide insight into a cure for Parkinson's disease, spinal cord injuries, and other types of cancer.

Gametes

Gametes, or sex cells, exist in two varieties within the body: sperm and eggs. These cells are formed by the process of meiosis within the ovaries and testes.

The union of these two types of cells initiates the process of reproduction and the formation of a new individual.

Both male (sperm) and female (egg) sex cells contain genetic material (called DNA) and the combination of the genetic material results in an individual genetically different from the parents.

How Cells Work Together in the Human Body

Although there are many different types of cells in the human body and their uses are all very different, every cell works together with every other cell to make the body function.

All cells in the human body are encased in a cell membrane which not only protects the contents of the cell but also contains receptors which help to identify one cell to another.

The different cells in the human body perform different functions, each one essential to the overall health of the body.

Some cells produce substances which the body needs to survive - substances like insulin - and others are bound together to create bones, muscles, and organs. Nerve cells allow for communication between all the different parts of the body and help to regulate its many functions.

If the function of even one type of cell is interrupted, the entire body can be affected. Though they may be small, cells are what make up the human body and what make it work.

From nerve cells and muscle cells to stem cells and sex cells, there are myriad types of cells in the human body and their uses are just as variegated.

No one type of cell is more important than the other, because without all of the different types of cells the human body would not be able to function.

It is because of the hundreds of different types of cells working together that our lungs are able to take in oxygen and that our brain can communicate with the different parts of our body. Cells are the fundamental units that make up the human body and they are extremely important.

Facts of cells

1.     Cells are too small to be seen without magnification.

Cells range in size from 1 to 100 micrometers. The study of cells, also called cell biology, would not have been possible without the invention of the microscope. With the advance microscopes of today such as the Scanning Electron Microscope and Transmission Electron Microscope, cell biologists are able to obtain detailed images of the smallest of cell structures.

2. There are two primary types of cells.

Eukaryotic and prokaryotic cells are the two main types of cells. Eukaryotic cells are called so because they have a true nucleus. Animals, plants, fungi and protists are examples of organisms that are composed of eukaryotic cells. Prokaryotes include bacteria and archaeans. 

3. Prokaryotic single-celled organisms were the earliest and most primitive forms of life on earth.

Prokaryotes can live in environments that would be deadly to most other organisms. They are able to live and thrive in various extreme habitats.Archaeans for example, live in areas such as hydrothermal vents, hot springs, swamps, wetlands, and even animal intestines.

4. There are more bacterial cells in the body than human cells.
Scientists have estimated that about 95% of all the cells in the body are bacteria. The vast majority of these microbes can be found within the digetive tract.

5. Cells contain genetic material.

Cells contain DNA (deoxyribonucleic acid), the genetic information necessary for directing cellular activities. DNA is a type of molecule known as a nucleic acid. In prokaryotic cells, the single bacterial DNA molecule is not separated from the rest of the cell but coiled up in a region of the cytoplasm called the nucleoid region. In eukaryotic cells, DNA molecules are located within the cell's nucleus. DNA and proteins are the major components of chromosomes. Human cells contain 23 pairs of chromosomes (for a total of 46). There are 22 pairs of autosomes (non-sex chromosomes) and one pair of sex chromosomes. The X and Y sex chromosomes determine gender.

6. Cells contain structures called organelles which carry out specific functions.

Organelles have a wide range of responsibilities within a cell that include everything from providing energy to producing hormones and enzymes. Eukaryotic cells contain several types of organelles, while prokaryotic cells contain a few organelles (ribosomes) and none that are bound by a membrane. There are also differences between the kinds of organelles found within different eukaryotic cell types. Plant cells for example, contain structures such as a cell wall and chloroplasts that are not found in animal cells. Other examples of organelles include:

·         Nucleus

·         Mitochondria

·         Endoplasmic Reticulum

·         Golgi Complex

·         Ribosomes

7. Different types of cells reproduce through different methods.

Most prokaryotic cells reproduce by a process called binary fission. This is a type of cloning process in which two identical cells are derived from a single cell. Eukaryotic organisms have a similar type of reproductive method known as mitosis. Some eukaryotes also have the ability to reproduce sexually, which involves the fusion of sex cells or gametes. Gametes are produced by a process called meiosis.

8. Groups of similar cells form tissues.
Tissues are groups of cells with both a shared structure and function. Cells that make up animal tissues are sometimes woven together with extracellular fibers and are occasionally held together by a sticky substance that coats the cells. Different types of tissues can also be arranged together to form organs. Groups of organs can in turn form organ systems.

9. Cells have varying life spans.
Cells within the human body have different life spans based on the type and function of the cell. They can live anywhere from a few days to a year. Certain cells of the digestive tract live for only a few days, while some immune system cells can live for up to six weeks. Pancreatic cells can live for as long as a year.

10. Cells commit suicide.
When a cell becomes damaged or undergoes some type of infection, it will self destruct by a process called apoptosis. Apoptosis works to ensure proper development and to keep the body's natural process of mitosis in check. A cell's inability to undergo apoptosis can result in the development of cancer.