MUSCULAR SYSTEM KATHERINE ROWLAND

FINAL PROJECT

2ND BLOCK

JANUARY 14, 2015

INTRODUCTION

• The muscular system is responsible for the movement of the body. The muscles are attached to the bones of the skeletal system. There are about 650 muscles that make up about half of a person’s body weight. Muscle tissue is found inside of the heart, digestive organs, and blood vessels. There are three types of muscle tissue: Visceral, cardiac, and skeletal.

VISCERAL MUSCLE

• Visceral muscle is found in the stomach, intestines, and blood vessels. Visceral is the weakest of the three muscles. It makes organs contract to move substances through the organ. The visceral muscle is controlled by the unconscious part of the brain, it is known as involuntary muscle. “Smooth muscle” is often used to describe visceral muscle because of the very smooth surface

CARDIAC MUSCLE

• Cardiac muscle is found only in the heart, it is responsible for pumping blood throughout the body. Cardiac muscles tissue cannot be controlled consciously, so it is an involuntary muscle. While other muscles get signals from the brain the cardiac muscle stimulates itself to contract. The natural pacemaker of the heart is made with cardiac muscle that stimulates other cardiac muscle cells to contract. Because of its self-simulation, cardiac muscle is considered autorhythmic or intrinsically controlled.

SKELETAL MUSCLE

• Skeletal muscle is the only voluntary muscle tissue in the human body. Every physical action that a person consciously performs requires skeletal muscle. Things like speaking, walking, and writing require skeletal muscle. The function of the skeletal muscle is to contract and to move parts of the body closer to the bone that the muscle is attached to. Most skeletal muscles are attached to two boned across a joint, so the muscle serves to move parts of those bones closer to each other.

SKELETAL MUSCLES CONT’D

• Most skeletal muscles are attached through tendons. Tendons are tough bands of dense regular connective tissue whose strong collagen fibers firmly attach muscle to bones. Tendons are under extreme stress when muscles pull on them, so they are very strong and are woven into the coverings of both muscles and bones.

• Muscles move by shortening their length, pulling on tendons, and moving bones closer to each other. One of the bones is pulled towards the other bone, which remains stationary. The place on the stationary bone that is connected by the tendon to the muscle is called the origin. The place on the moving bone that is connected to the muscle by the tendons is called the insertion. The belly of the muscle is the fleshy part of the muscle between the tendons that does the actual contraction

MUSCLE METABOLISM

• Muscles use aerobic respiration when we call on them to produce a low to moderate level of force. Aerobic respiration requires oxygen to produce about 36-38 ATP molecules from a molecule of glucose. Aerobic respiration is very efficient, and can continue as long as a muscle receives adequate amounts of oxygen and glucose to keep contracting. When we use muscles to produce a high level of force, they become so tightly contracted that oxygen carrying blood cannot enter the muscle..

• This condition causes the muscle to create energy using lactic acid fermentation, a form of anaerobic respiration. Anaerobic respiration is much less efficient than aerobic respiration—only 2 ATP are produced for each molecule of glucose. Muscles quickly tire as they burn through their energy reserves under anaerobic respiration

MUSCLE METABOLISM CONT’D

• To keep muscles working for a longer period of time, muscle fibers contain several important energy molecules. Myoglobin, a red pigment found in muscles, contains iron and stores oxygen in a manner similar to hemoglobin in the blood. The oxygen from myoglobin allows muscles to continue aerobic respiration in the absence of oxygen. Another chemical that helps to keep muscles working is creatine phosphate. Muscles use energy in the form of ATP, converting ATP to ADP to release its energy.

• Creatine phosphate donates its phosphate group to ADP to turn it back into ATP in order to provide extra energy to the muscle. Finally, muscle fibers contain energy-storing glycogen, a large macromolecule made of many linked glucoses. Active muscles break glucoses off of glycogen molecules to provide an internal fuel supply.

MUSCLE FATIGUE

• When muscles run out of energy during either aerobic or anaerobic respiration, the muscle quickly tires and loses its ability to contract. This condition is known as muscle fatigue. A fatigued muscle contains very little or no oxygen, glucose or ATP, but instead has many waste products from respiration, like lactic acid and ADP. The body must take in extra oxygen after exertion to replace the oxygen that was stored in myoglobin in the muscle fiber as well as to power the aerobic respiration that will rebuild the energy supplies inside of the cell.

• Oxygen debt (or recovery oxygen uptake) is the name for the extra oxygen that the body must take in to restore the muscle cells to their resting state. This explains why you feel out of breath for a few minutes after a strenuous activity—your body is trying to restore itself to its normal state.

MUSCLE SHAPES

• Muscles are further classified by their shape, size and direction, according to the NIH. The deltoids, or shoulder muscles, have a triangular shape. The serratus muscle, which originates on the surface of the second to ninth ribs at the side of the chest, and runs along the entire anterior length of the scapula (shoulder blades), has a distinctive sawlike shape. The rhomboid major, which attaches the scapula to the spinal column, is a diamond shape.

MUSCLE FIBERS

• The direction in which the muscle fibers run can be used to identify a muscle. In the abdominal region, there are several sets of wide, flat muscles, according to the NIH. The muscles whose fibers run straight up and down are the rectus abdominis, the ones running transversely (left to right) are the transverse abdominis and the ones running at an angle are the obliques. As any one who exercises knows, obliques are among the hardest muscles to develop to achieve "six-pack" abs.

MUSCLE FUNCTION IDENTIFICATION

• Muscles also can be identified by their function. The flexor group of the forearm flexes the wrist and the fingers. The supinator is a muscle that allows you to roll your wrist over to face palm up. Adductor muscles in the legs adduct, or pull together, the limbs, according to the NIH.

DISTAL MUSCULAR DYSTROPHY (DD)

• First described in 1902, DD is a class of muscular dystrophies that primarily affect distal muscles, which are those of the lower arms, hands, lower legs and feet. Muscular dystrophies in general are a group of genetic, degenerative diseases primarily affecting voluntary muscles.

• Symptoms: Distal muscular dystrophy can lead to weakness and wasting of muscles of the hands, forearms and lower legs

• Causes: DD is caused by a mutation in any of at least eight genes that affect proteins necessary to the function of muscles. It can be inherited in an autosomal dominant or recessive pattern.

• Below is a calf autopsy of someone that had DD

DUCHENNE MUSCULAR DYSTROPHY (DMD)

• Duchenne muscular dystrophy (DMD), muscle-wasting disease, affects only children, such as muscular dystrophy. There are other diseases that non-genetic muscle disease. This is achieved gradually and not caused by genetics. The disease can be caused by the immune system, a kind of hormonal imbalance or even a disorder caused by the consumption of drugs.

CONCLUSION

• This project was very informative. I relearned a lot of what I had learned in seventh grade but this project also allowed me to add information. I liked to learn about the diseases because it made me more aware of the possible diseases that anyone could have. I enjoyed the simplicity of this project. It was easy but informative as well. The pictures are what I really enjoyed picking out because it was what I had a say about. Instead of typing the facts. For some of the facts I referred back to my notes so I am glad that I kept up with those. If I could change anything about this I would change how many slides of information there were. Make less of those and more picture slides.

This is all a lie

CITATIONS

• http://www.innerbody.com/image/musfov.html

• http://www.livescience.com/26854-muscular-

system-facts-functions-diseases.html