“Muscles are the body’s ‘flesh.’ They bulge and ripple just under the skin, and are arranged in crisscrossing layers down to the bones. Their job is to contract and pull the bones to which they are anchored. Rarely working alone, they usually contract in groups, moving bones at accurate angles and by precise distances.”

 Movement through the shortening of muscles pulling on bones  Heat from friction of contractions of muscles  Maintaining posture through monitoring position of body parts

 Extensibility: stretches when pulled  Elasticity: returns to original shape after contractions  Excitability: responds to stimuli  Contractility: able to shorten in length

 Striated muscles are also known as Voluntary muscles, since we control their actions at will.  Striated muscles get their name from how they appear under a microscope. If you were to view striated muscles under a microscope it would look like a series of stripes or bands together.  The bands are made up of fibers called actin and myosin. The Z- line, the region between the two fibers, is what makes the muscle functional.  40% of adult body weight  The striated muscles are located in all of the body parts that we can control. (hands, arms, legs, feet)

 Visceral muscle is also called Smooth muscle because of the lack of striations.  Visceral muscles are controlled by the nervous system and hormones. We can not directly control the movement of our visceral muscles.  Visceral muscles are located within organs such as the stomach or lungs. This muscle type produces peristalsis, which are contractions, necessary in the stomach, blood vessels, and the closing of bronchioles.

 The Cardiac muscle is only found in the heart and makes up the muscular tissue around the heart called myocardium  Cardiac muscles contain striations (like skeletal muscles) but are involuntary (like visceral muscles.)  The job of Cardiac muscles is to pump blood from the heart to blood vessels throughout the body

 09LfHQ3M

 Muscular fatigue means that someone cannot exert a sufficient amount of energy in order to flex a muscle  Types › True weakness- substantial › Perceived- the feelings of putting in too much effort in order to complete an easy task › Central Muscle Weakness-throughout the body › Peripheral weakness-specific muscles

 Tetany is the term used when a disease is causing the increase of action potential frequency which leads to the involuntary contraction of muscles  Tetany is only found in voluntary muscles such as the hands, arms, fingers, and legs  Low levels of Calcium in bones will depolarize the ions, making them sensitive and disassociate with the sodium channels. They are not attached to anything and they are sent to the muscles, causing a spasm.

 “The principle states that if a stimulus is strong enough to generate a nerve action potential, the impulse is conducted along the entire neuron at maximum strength, unless conduction is altered by conditions such as toxic materials in cells or fatigue.”  A muscle contraction requires little effort and can be done with minimal stimulus

 Muscular Dystrophy is a genetic disorder that weakens muscles  It is caused by missing information in genes which prevents the formation of necessary protein  While MD is not contagious, the effects of the disease can appear gradually

 Duchenne  Becker  Emery-Dreifuss  Limb-girdle  Facioscapulohumeral  Myotonic  Congenital

 Delayed muscle relaxation  Weakness in voluntary muscles (face, arms, legs) especially the muscles affecting speech and swallowing  Heart abnormalities  Respiratory problems  Frequent falls  Weakness in lower extremities  Difficulty in simple physical actions (standing up. Etc.)

 A main key to diagnosing MD is personal medical history  Tests focusing on muscle/nerve activity and levels of enzymes in the blood can determine the type of MD affecting the person  Muscle biopsies are sometimes necessary to see how muscular fibers are shaped, either extremely large or broken down

 No known cure  Scientists are working on detecting the deformed gene in patients suffering with MD  Scientists are also trying to compose gene and enzyme replacement therapy

 People affected with MD should continually stretch their muscles to avoid the stiffening of the affected muscles  Braces are also applied to make sure tendons do not over flex  Medicine can also me administered to slow down the affects of this disease

 This disease, while affecting everyone, is mostly common in men  1 in 30,000 male births  While the affects of MD can be hidden until adulthood, the disease is in their genes from birth

 Myasthenia Gravis is an autoimmune disease that causes weakness and fatigue in the muscles  Commonly, the muscles affecting the movement of eyelids and facial expressions are involved  The muscles that are mainly affected are overused muscles, but they can improve with rest

 In a person affected with this disease, they produce antibodies that attack the part of the muscle that receives signals from nerves  In regular muscle, the nerve impulse releases acetylcholine. In people affected with this disease, antibodies attack that neurotransmitter

 Drooping eyelids  Difficulty swallowing/breathing  Slurred speech  Lack of facial expression  Failure to move arms and legs  Weak neck  Cannot walk properly  Blurred vision

 Myasthenia Gravis is very hard to diagnose, seeing that weakness is a symptom of many other diseases  Testing muscles and their ability to be repeatedly moved can tell a doctor if this person in fact does have Myasthenia Gravis  Blood test, focusing on the amount of acetylcholine can also be conducted

 Medicine can be administered to help the flow of neurotransmitters  Immunosuppressive drugs can also be taken to reduce the production of antibodies  There is a procedure that can be done to remove abnormal antibodies from blood cells

 This disease is not inherited, seeing that it’s a malformed protein not an autoimmune disorder, so anyone has a chance of getting this disease  Mostly, this disease attacks women under the age of 40 and men over the age of 60  Many young children will get this disease, but it will cure itself over one to two years

 This disease attacks the connective tissue in the body  The body’s repair mechanism forms fibrous tissue to be turned into bone which causes frozen joints after an injury  Ligaments, tendons, and muscles turn into bone  From the womb, the body cannot control bone production

 Malformed/overgrowth of toes  Formation of fibrous knots in neck, back, and shoulders  Inflammation of joints  Stiffness from head to feet  Random tumor-like lumps

 While biopsies can be done, this may cause the bone-product to progress even worse  The appearance of the big toe is definitely a red flag in diagnosing FOP  There is an 80% of a doctor misdiagnosing FOP for another disease because there is such a lack of information

 There is no known cure for FOP…yet

 =p