Muscle Contraction

Kaylee Hennessey            November 22, 2013       Period A

The Mechanism of Muscle Contraction

Texas A&M University

1 Page

Summary of the Article

The following steps are involved in muscle contraction:

1. Reflexes from the spinal cord or instructions from the brain cause nerve cells to initiate a reaction

2. A motor neuron is activated, and action potential passes out of the spinal cord

3. Action potential is conveyed to a numerous amount of places on the motor unit

4. ACh is released into synaptic clefts on the surface of the muscle fiber

5. ACh causes an action potential on the muscle fiber surface, dragging in separate directions

The Sliding Filament Theory

6. Action potential spreads into the muscle fiber through each transverse tubule

7. Sarcoplasmic reticulum releases calcium ions

8. Calcium ions result in movement of tropomin and tropomyosin on thin filaments. Myosin molecules swivel the filaments, which is the driving force of muscle contraction.

In conclusion, the nervous system plays a large part in the contraction and relaxation of muscles.

Smooth and Skeletal Muscle

Kaylee Hennessey                  November 6, 2013           Period A

Smooth and Skeletal Muscle

Dr. Thomas Caceci

1 page (continuous)

Summary of the Article:

           There are two major classifications of muscle: smooth and striated. Skeletal as well as cardiac muscle fall under the category of striated. Muscles are metabolically dynamic tissues and receive plentiful blood flow.All muscles can be excited, in that they respond to stimuli outside or inside the body. Both neuron stimulation and chemical stimulation affects the response of the cells.  

Skeletal Muscle:

Skeletal muscle is voluntary because it is subject to control by the nervous system. Most movement requires skeletal muscle. 

Skeletal muscle fibers

 Skeletal muscle is made of numerous fibers grouped together. Fibers can be grouped into larger groups, which are then grouped into even larger groups and attached to bones by tendons.

Smooth Muscle:

Smooth muscle is non-striated and found in all organ systems. They are involuntary muscles and help with processes like digestion and sometimes are present in large blood vessels.

Smooth muscle fibers are largest in the center. 

Healthy Skin

Kaylee Hennessey
October 17, 2013
Period A

Skin Care: 5 Tips for Healthy Skin

Mayo Clinic Staff

Mayo Clinic

2011

2 pages

http://www.mayoclinic.com/health/skin-care/SN00003/NSECTIONGROUP=2

Summary of the Article:

     This article provides tips for healthy skin without having to use products or other expensive alternatives. The five key points to help your skin look and be healthy according to the article are:

1. Protect Yourself from the Sun

By using sunscreen or wearing protective clothing, one can protect oneself from wrinkles, age spots, and even skin cancer. 

2. Don't Smoke

Because smoking reduces blood flow, it often makes your skin wrinkle and look older. It also destroys elasticity, contribution to wrinkles.

3. Treat Your Skin Gently

Prolonged showers with hot water, intense soaps, shaving, rough towel drying, and not enough moisture can be damaging to the skin.

4. Eat a Healthy Diet

Fruits, vegetables, whole grains, and lean proteins will all help your skin look and feel healthier. Unhealthy fats as well as processed carbohydrates can cause your skin  to break out in acne.

5. Manage Stress

Stress can trigger acne breakouts. By reducing stress and finding ways to deal with it, one can also reduce acne breakouts and maintain clear skin.

Burns- 10/09/13

Kaylee Hennessey
October 9, 2013
Period A

Burns

 Mayo Clinic Staff
 Mayo Clinic

August 21, 2012.
10 Pages

http://www.mayoclinic.com/health/burns/DS01176

Summary of the Article:

Some burns may be minor, affecting only the Epidermic and Dermic layers of the skin. These are measured in degrees. Burns that require a lot of attention are those that can be caused by chemicals and electricity. These burns often affect the hypodermis in addition to other layers. Third and second degree burns may require immediate medical attention. Although burns can be minor, many are fatal. These burns, fourth degree burns, affect body tissues beyond the skin, like muscles or bones. 

The causes of burns include, but are not limited to:

• Fire
• Chemicals
• Electrical encounters
• Sunlight or excessive exposure to UV rays, and
• Radiation

Serious burns can lead to complications. Some complications include, but are not limited to:

• Infection
• Low body temperature
• Scarring
• Bone and joint problems

Minor burns may heal in a matter of a few weeks with no medical attention. For more serious burns, however; medication, physical therapy, or even surgical procedures are required depending on the severity of the burn.