1 / 10

Muscle Types, Functions, and Microscopic Anatomy Pg. 162 – 167

Muscle Types, Functions, and Microscopic Anatomy Pg. 162 – 167. October 2, 2012. Overall Function of Muscles. Contraction, a.k.a. shortening A unique characteristic that sets it apart from any other body tissue

wesley
Télécharger la présentation

Muscle Types, Functions, and Microscopic Anatomy Pg. 162 – 167

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Muscle Types, Functions, and Microscopic AnatomyPg. 162 – 167 October 2, 2012

  2. Overall Function of Muscles • Contraction, a.k.a. shortening • A unique characteristic that sets it apart from any other body tissue • Muscles are responsible for basically all body movement and can be viewed as the “machines” of the body.

  3. Muscle Structure • Muscles are a tissue made up of many muscle cells • All muscle cells are elongated and are called muscle fibers • Muscle cells, or fibers, are made up of myofilaments • Myofilaments allow a muscle to contract

  4. Muscle Types – Skeletal Muscle • Location: covers the skeleton • Multinucleate • Largest of the muscle fiber types • Striated muscle – fibers appear to be striped • Voluntary • Often activated by reflexes as well • Contracts rapidly with great force, but tires rapidly

  5. Muscle Types – Skeletal Muscle • Bundled in several sets of connective tissue • Endomysium surrounds each muscle fiber (cell) • Perimysium surrounds bundles of fibers (cells) called fascicles • Epimysium surrounds a bundle of fascicles (the whole muscle) • Tendons • Anchor muscle to bone and provides durability

  6. Muscle Types – Smooth Muscle • Location: lining of hollow organs • Uninucleate • No striations • Involuntary • Propels substances along a pathway through the body • Arranged in sheets or layers – usually two, one running lengthwise and one circling the outside • Contraction is slow and sustained

  7. Muscle Types – Cardiac Muscle • Location: heart ONLY • Serves as a pump that propels blood around the body • Uninucleate • Striated • Involuntary • Cardiac muscle cells are connected by intercalated disks, which allow free movement of substances between cells

  8. Muscle Functions • Producing movement • Muscles allow us to move, respond, express emotions, pump blood, move substances through body organs • Maintaining posture • Skeletal muscles can hold us upright despite gravity • Stabilizing joints • Tendons help reinforce and stabilize joints, especially those that are articulated poorly • Generating heat • A by-product of muscle activity – body temperature is 37˚C or 98.6˚F.

  9. Microscopic Anatomy of Skeletal Muscle • Each muscle fiber (cell) is made up of many myofibrils • Myofibrils are made up of units called sarcomeres • Each sarcomere includes myofilaments called actin and myosin • Actin = thin filament • Myosine = thick filament • The myofilaments are arranged in light (I) and dark (A) bands – this is what gives the muscle is striped, or striated, appearance • Light (I) bands have a Z disc • Dark (A) bands have an H zone

More Related