o rganization of s keletal m uscle. s keletal m uscle o rganization connective tissue coverings...
TRANSCRIPT
ORGANIZATION OF SKELETAL MUSCLE
SKELETAL MUSCLE ORGANIZATION Connective Tissue Coverings
Skeletal muscles are attached to tendons which attach the muscle to bone
Belly: Thicker part of muscleEpimysium: connective tissue layer that
covers the muscleSeparates muscles from other structures/organs
Perimysium: Layer underneath the epimysiumSeparates muscles into individual bundles
Endomysium: Layer underneath the perimysium Surrounds each individual muscle fiber
SKELETAL MUSCLE ORGANIZATION
MICRO-ANATOMY OF MUSCLE TISSUE
SKELETAL MUSCLE BUNDLE (COVERED BY EPIMYSIUM) MANY MUSCLE FASCICLES (COVERED BY PERIMYSIUM) MANY MUSCLE FIBERS (COVERED BY ENDOMYSIUM) MANY MYOFIBRILS MANY SARCOMERES MANY ACTIN AND MYOSIN FILAMENTS
STRUCTURE OF A SKELETAL MUSCLE FIBER
Individual Muscle Fiber consists of: (outside to inside) Outside of muscle fiber
1. Sarcolemma: cell membrane of muscle fiber2. Sarcoplasm: cytoplasm of muscle fiber3. Transverse Tubules or T-Tubules:
connections from the sarcolemma to interior of muscle fiber for connection
Inside muscle fiber
1. Myofibrils: proteins that run the length of each fiber, surrounded by Sarcoplasmic Reticulum
1. S. R. stores Ca2+ ions which dictates muscle contraction
STRUCTURE OF A SKELETAL MUSCLE FIBER
Myofibril Components: Several Sarcomeres
made up of:Actin: Thin Filaments, bundles with globular sections that fit into the binding sites on actin
Myosin: Thick Filaments, has binding sites to which actin attaches to during contraction
MUSCLE CONTRACTION
T-tubules are stimulated from the nervous system
T-tubules release Ca2+ ions The thin filaments/actin then are pulled
along the thick filaments/myosin in place of where the Ca2+ ions were
http://www.youtube.com/watch?v=Ae0UYxqj3cM
RIGOR MORTIS
After death, ion pumps stop functioning calcium builds up in the sarcoplasm causing a fixed muscular contraction
MUSCLE PAIN
Soreness after a workout Stretching the muscle tissue farther
than usualSmall microscopic tears to an individual
muscle fiberSkeletal muscle tissue is multinucleated + many neuromuscular junctions you mind sends signals when you are injured
SKELETAL MUSCLE IDENTIFICATION Muscular system can be divided into 2
groups:1. Axial Muscles (60 %)2. Appendicular Muscles (40%)
NEUROMUSCULAR JUNCTION
Each skeletal muscle is controlled by a nerve cell called a motor neuron Where the motor neuron and muscle fiber
meet = Neuromuscular Junction
AXIAL MUSCLES
Muscles that position the head, spinal column, and move the rib cage.
Divided into 4 groups based on location and function:1. Muscles of the head and neck2. Muscles of the vertebral column3. Oblique and rectus muscles4. Muscles of the pelvic
AXIAL MUSCLES
Muscles of the SkullOrbicularis orisOrbicularis OculiNasalisZygomaticus
MajorZygomaticus
MinorFrontalis
AXIAL MUSCLES Muscles of the Skull continued…
PlatysmaBuccinatorTemporalisOccipitalisMasseter*Sternocleidomastoid*
Sternomastoid on cats
AXIAL MUSCLES Muscles of the Back
Trapezius*Clavotrapezius on cats
Latissimus Dorsi*
AXIAL MUSCLES Muscles of the Oblique
Pectoralis major*Serratus Anterior*
Serratus ventralis on cats
Rectus Abdominis*External abdominal
oblique*
Day 2
APPENDICULAR MUSCLES
Muscles that support the pectoral and pelvic girdles, and the limbs.
Separated into 2 major groups:1. Muscles of shoulders and upper
limbs2. Muscles of pelvis and lower limbs
APPENDICULAR MUSCLES
Muscles of Pectoral girdle:Pectoralis major*Deltoid*
Clavodeltoid on catLatissimus Dorsi
APPENDICULAR MUSCLES
Muscles that move the arm:Deltoid*
Clavodeltoid on catSupraspinatus*SubscapularisInfraspinatus*Pectoralis major*Latissimus dorsi*
APPENDICULAR MUSCLES Muscles of the arm:
Biceps brachii*Triceps brachii*Brachialis*Brachioradialis*
APPENDICULAR MUSCLES Muscles of the arm:
Flexor carpi ulnaris*Flexor carpii
radialis*Palmaris longus*Extensor carpi
radialis*Extensor carpi
ulnaris*
APPENDICULAR MUSCLES
Muscles of the Pelvic Girdle: Gluteus maximus* Gluteus medius*
APPENDICULAR MUSCLES Muscles that move the lower limb:
The “Quad”:Rectus femoris*Vastus Medialis *Vastus Lateralis*
Sartorius*Biceps femorisSemitendinosus*
APPENDICULAR MUSCLES
Muscles of the lower limb:Gastrocnemius*Soleus*Tibialis posterior*Tibialis anteriorCalcaneal tendon
APPENDICULAR MUSCLES Muscles of the lower limb:
Gastrocnemius*Soleus*Tibialis posterior*Tibialis anteriorCalcaneal tendon*