Periodic Table of Elements and Chemistry Mitosis: An Interactive Animation This animation demonstrates the stages of mitosis in an animal cell. Use the control buttons along the bottom to run the complete animation. Click on any intermediate stage (for example, Anaphase), and see a representative still frame. Interphase: Cells may appear inactive during this stage, but they are quite the opposite. Prophase: During this first mitotic stage, the nucleolus fades and chromatin (replicated DNA and associated proteins) condenses into chromosomes. Prometaphase: In this stage the nuclear envelope breaks down so there is no longer a recognizable nucleus. Metaphase: Tension applied by the spindle fibers aligns all chromosomes in one plane at the center of the cell. Anaphase: Spindle fibers shorten, the kinetochores separate, and the chromatids (daughter chromosomes) are pulled apart and begin moving to the cell poles. Telophase: The daughter chromosomes arrive at the poles and the spindle fibers that have pulled them apart disappear.
Skeletal System – Posterior (Back) View [Continued from above] . . . calcium, iron, and energy in the form of fat. Finally, the skeleton grows throughout childhood and provides a framework for the rest of the body to grow along with it. Skeletal System Anatomy The skeletal system in an adult body is made up of 206 individual bones. SkullHyoidAuditory ossiclesRibsSternumVertebral column The appendicular skeleton is made up of 126 bones in the folowing regions: Upper limbsLower limbsPelvic girdlePectoral (shoulder) girdle SkullThe skull is composed of 22 bones that are fused together except for the mandible. The bones of the superior portion of the skull are known as the cranium and protect the brain from damage. Hyoid and Auditory OssiclesThe hyoid is a small, U-shaped bone found just inferior to the mandible. The malleus, incus, and stapes—known collectively as the auditory ossicles—are the smallest bones in the body. VertebraeTwenty-six vertebrae form the vertebral column of the human body. Long. Skeletal System Physiology
Interval Training: Good Exercise For All Ages Muscular System - Muscles of the Human Body [Continued from above] . . . Muscle TypesThere are three types of muscle tissue: Visceral, cardiac, and skeletal. Visceral Muscle. Visceral muscle is found inside of organs like the stomach, intestines, and blood vessels. The weakest of all muscle tissues, visceral muscle makes organs contract to move substances through the organ. Gross Anatomy of a Skeletal MuscleMost skeletal muscles are attached to two bones through tendons. Muscles move by shortening their length, pulling on tendons, and moving bones closer to each other. Names of Skeletal MusclesSkeletal muscles are named based on many different factors, including their location, origin and insertion, number of origins, shape, size, direction, and function. Location. Groups Action in Skeletal MuscleSkeletal muscles rarely work by themselves to achieve movements in the body. In addition to the agonist/antagonist pairing, other muscles work to support the movements of the agonist. The sarcolemma is the cell membrane of muscle fibers.
Spinal Cord Injury (SCI): Fact Sheet - Traumatic Brain Injury - Injury Center Spinal cord injury (SCI) is an important contributing factor to morbidity and mortality in the United States. Overview Spinal cord injury may occur following damage to the spinal column. The spinal column comprises 31 bones called vertebrae: 7 cervical vertebrae (neck), 12 thoracic vertebrae (upper and middle back), 5 lumbar vertebrae (lower back), 5 sacral vertebrae (sacrum), and 2 fused coccygeal vertebrae (coccyx). Each vertebra comprises a vertebral body and a vertebral arch, which form an enclosed opening (or vertebral foramen). The spinal cord, the central bundle of nerves extending from the brain and branching peripherally, is responsible for transmitting signals between the brain and the rest of the body. Occurrence About 200,000 people are currently living with SCI in the United States.2,14 Annually, 15 to 40 new cases per million people—or 12,000 to 20,000 new patients—are estimated to occur.2,3,9,11 Alcohol has been found to play a major factor in 25% of spinal cord injuries.1
Concussions on the Rise for Young Athletes Study Shows Many Traumatic Brain Injuries Occur Among Bicycle Riders and Football Players Why do I need to register or sign in for WebMD to save? We will provide you with a dropdown of all your saved articles when you are registered and signed in. Oct. 6, 2011 -- There was about a 60% increase in the estimated number of concussions and other traumatic brain injuries (TBI) seen among young athletes during the past decade, according to the CDC. In 2001, there were an estimated 153,375 traumatic brain injuries among people from birth to age 19. Many of these injuries occurred among bicyclers, football players, and children in playgrounds. Exactly why we are seeing this uptick is not known, but "I believe this is, at least, in part due to increased awareness," says study researcher Julie Gilchrist, MD. "We are hoping that awareness has gotten up to the point that parents, teachers, and coaches recognize the signs and symptoms of concussion and make sure that children are evaluated," she says.