1 / 10

The Muscular System

The Muscular System. Skeletal Muscle Muscle anatomy Muscle contraction. The Muscular System. Pectoralis major • Draws arm forward and toward the body. Serratus anterior • Helps raise arm • Contributes to pushes • Draws shoulder blade forward. Biceps brachii • Bends forearm at elbow.

kenyon-valencia
Download Presentation

The Muscular System

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. The Muscular System • Skeletal Muscle • Muscle anatomy • Muscle contraction

  2. The Muscular System Pectoralis major • Draws arm forwardand toward the body Serratus anterior • Helps raise arm • Contributes to pushes • Draws shoulder blade forward Biceps brachii • Bends forearm at elbow Rectus abdominus • Compresses abdomen • Bends backbone • Compresses chest cavity External oblique • Lateral rotation of trunk • Compresses abdomen Adductor longus • Flexes thigh • Rotates thigh laterally • Draws thigh toward body Sartorius • Bends thigh at hip • Bends lower leg at knee • Rotates thigh outward Quadriceps group • Flexes thigh at hips • Extends leg at knee Tibialis anterior • Flexes foot toward knee Figure 6.2 (1 of 2)

  3. The Muscular System Deltoid • Raises arm Trapezius • Lifts shoulder blade • Braces shoulder • Draws head back Triceps brachi • Straightens forearm at elbow Latissimus dorsi • Rotates and draws arm backward and toward body Gluteus maximus • Extends thigh • Rotates thigh laterally Hamstring group • Draws thigh backward • Bends knee Gastrocnemius • Bends lower leg at knee • Bends foot away from knee Achilles tendon • Connects gastrocnemius muscle to heel Figure 6.2 (2 of 2)

  4. Muscle Structure Muscle bundle (fascicle) surrounded by connective tissue (fascia) Whole muscle • Fascicles: bundles; CT covering on each one • Muscle fibers: muscle cells Single muscle cell (fiber) Tendon Bone Figure 6.3

  5. Skeletal Muscle Contractile Unit Figure 6.5a–b

  6. Nerve Activation of Individual Muscle Cells Figure 6.6

  7. Calcium Initiates the Sliding Filament Mechanism Figure 6.7

  8. Mechanism of Muscle Contraction Figure 6.8

  9. Muscle Relaxation • Nerve activation ends, contraction ends • Calcium pumped back into sarcoplasmic reticulum • Calcium removed from troponin • Myosin binding site covered • No calcium = no cross-bridges

  10. Energy Required for Muscle Activity • Principle source of energy: ATP • ATP is replenished by a variety of means • Creatine phosphate • Stored glycogen • Aerobic metabolism of glucose, fatty acids, and other high-energy molecules

More Related