Glossary of terms

Acetylcholine:
A chemical in the brain that acts as a neurotransmitter.

Adult Stem cells:
Cells which are found in human/animal tissue of a developed body, ie after birth. They are specialised to the tissue which they can be found in, and are capable of regeneration to replace specific cells for those that have died or are lost.

Aggregration of a cell:
The clumping together of cells or bacteria which are suspended in a fliud. Aggregation occurs when there is abnormal changes to cellular structure.

Akinesia:
Refers to the inability to move, or absence of the ability to move.

Alleles:
Forms of the same gene with small differences in their sequence of DNA bases. These small differences contribute to each person’s unique physical features.

ALS:
Amyotrophic Lateral Sclerosis (ALS)/ Motor Neurone Disease (MND) is a progressive neurological disorder. The function of a neurone is affected, resulting in an inability to to receives and sends messages from the body to the brain and back to the body. As motor neurones degenerate, they can no longer send impulses to the muscle fibers that normally result in muscle movement, which in turn leads to muscle weakness and wasting.

Amino Acids:
Commonly known as the building blocks of proteins due to the fact that they are made up of small molecules that link together in long chains to form proteins.

ANG (Angiogenin) gene:
The ANG gene provides instructions for making a protein called angiogenin. This angiogenin protein promotes the formation of new blood vessels from pre-existing blood vessels through a process called angiogenesis.

Angiogenesis:
A process which enables angiogenin to stimulate the growth and division of endothelial cells, which line the inside surface of blood vessels, to form new blood vessels. Angiogenesis is important for restoring blood flow after an injury.

Ataxia:
Failure of muscular coordination, irregularity of muscular action – may lead to the loss of balance.

Atom:
A particle of matter that uniquely defines a chemical element. An atom consists of a central nucleus that is usually surrounded by one or more electrons.

Atrophy:
Progressive wasting of muscle.

Axon:
Nerve fibers that are capable of rapidly conducting impulses away from the neurone cell body.

Bulbar muscles:
Muscles in the head and neck that control speech, chewing and swallowing

Bulbar symptoms:
Symptoms involving the impairment of speech and swallowing.

Central Nervous System (CNS):
The brain and spinal cord.

Cell:
A cell is the basic structural and functional unit of all organisms.

Chromosome:
found in the nucleus of a cell, which contains the genes. Chromosomes come in pairs, and a normal human cell contains 46 chromosomes.

Compound:
A material made up of two or more elements.

Dementia:
acquired deterioration in cognitive abilities that impairs activities of daily living.

DNA:
A material found within the cell nucleus and is responsible for carrying genetic information. Each person has their own unique DNA.

DNA Bank:
A project funded by the MND Association that collects and stores samples of DNA from people with MND  and their unaffected carers / family. The bank provides a great resource for investigation into the genetic causes of MND.

Dysarthria:
Impaired speech.

Dysphagia:
Impaired swallowing.

Dyspnea:
Difficulty breathing.

Efferent Nerve:
A nerve that carries impulses away from the central nervous system (CNS). An efferent nerve is the opposite of an afferent nerves that carries impulses toward the CNS.

Element:
Simple substances which can not be decomposed by chemical means.

EMG:
Electromyography, or EMG, is a test used to assess electrical activity of muscles. Muscular movement involves the action of muscles and nerves via the utilisation of an electrical current. In MND the electrical activity of the muscles or nerves is affected. Finding and describing these electrical properties in the muscle or nerve helps confirm a diagnosis.

Enzyme:
A protein that increase the rate of a chemical reaction in the body.

Fasciculations:
Small, involuntary, irregular, visible contractions of individual muscle fibers. Often seen in the legs, arms, shoulders and tongue.

Feeding tubes:
A feeding tube is a medical device used to provide nutrition to patients who cannot obtain adequate daily calorie intake by swallowing. Percutaneous endoscopic gastrostomy (PEG) tubes are most commonly used. Tubes are inserted while the person is sedated and is placed with the aid of an endoscope, to assist in guiding the placement of the tube through the wall of the stomach.

Frontotemporal dementia (FTD):
A disorder characterized by cognitive, behavioral, and sometimes motor abnormalities reflecting degeneration of the brain, anterior frontal and temporal regions, basal ganglia, and motor neurons.

Gene:
A gene is the basic physical and functional unit of heredity, consisting of a segment of DNA arranged in a linear manner along a chromosome. Genes carry out instructions to make molecules called proteins. Every person has two copies of each gene, one of which is inherited from each parent.

Genetic:
Inherited; having to do with information that is passed from parents to offspring through genes in sperm and egg cells.

Hyperreflexia:
Excessive response of muscle reflexes when a stimulus is applied. Overactive and exagerrated reflexes

Idiopathic:
Of unknown cause. Any disease that is of uncertain or unknown origin may be termed idiopathic.

Inherited:
Genetic; having to do with information that is passed from parents to offspring through genes in sperm and egg cells.

Lower motor neruone:
Located in the brain stem and spinal cord, they are responsible for carrying messages to the muscle fibres. Glossary M-P

Major Gene:
A gene that is necessary and sufficient by itself to cause a condition.

Neurofibril:
Any of the long, thin, microscopic fibrils that run through the body of a neuron and extend into the axon and dendrites, giving the neuron support and shape.

Neurofilament:
Any of the long fine threads that make up a neurofibril.

Neurological:
Having to do with the nerves or nervous system.

Neurone:
The basic cellular unit of nervous tissue. Each neurone is composed of a body, an axon and dendrites. The function of a neurone is to act as a messanger for communication from the body to the brain and back to the body.

Neurofibril:
Any of the long, thin, microscopic fibrils that run through the body of a neuron and extend into the axon and dendrites, giving the neuron support and shape.

Neurotransmitter:
Any of the various chemical substances, such as acetylcholine, that transmit nerve impulses across a synapse.
Neurotrophic factors:
A family of protein which induce the survival of neurones.

NIPPV (Non-Invasive Positive Pressure Ventilation):
Can be used to alleviate symptoms of breathlessness when the respiratory muscles become weak. Works through a mask by providing extra air when you breathe in. Most people who use this equipment do so at night because breathing is shallower when you are asleep

Protein:
Fundamental components of all living cells and include many substances, such as enzymes, hormones and antibodies, that are necessary for the proper functioning of an organism. They are compounds containing an amino acid sequence of more than 100 amino acids, at least two of which are different, bound mostly through normal peptide links.

Peptides:
Compounds containing a sequence of 4-100 amino acid units, which are bound through at least one normal peptide link.

Ribonucleic acid (RNA):
A substance found in the cell nucleus which is responsible for regulating which genes are kept active. It serves as the intermediary between genes and the proteins that they code for.

SOD (Superoxide Dismutase):
An enzyme that inactivates excess free radicals, preventing them from damaging cell membranes. Mutations in the first SOD (SOD1) has been linked to familial forms of MND.

Synapse:
The gap across which a nerve impulse passes from an axon terminal to a neuron, a muscle cell, or a gland cell.

Upper motor neurone:
Located in the brain, they send messages to the spine but are unable to leave the central nervous system.