Muscular System

Major muscles of the back, shoulder and chest

Muscles of the quadriceps

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3 types of muscle tissues,

Rhomboids

Deltoid

Trapezius

Pectoralis major

Latissimus dorsi

Erector spinae

Extension of the vertebral column

Adduction, extension and medial rotation of the arm. Retraction and depression of shoulder

Elevation, depression and retraction of the scapula

Retraction and depression of the scapula. Fixes the scapula to the thoracic wall

Abduction, extension, lateral rotation, flexion and medial rotation of arm

Adduction, flexion and medial rotation of arm

Major muscles of the upper arm

Triceps brachii

Extension of elbow

Major muscles of the Abdomen

Rectus abdominis

Flexion of vertebral column

External oblique’s

Internal oblique’s

Rotation of vertebral column, compression of abdomen and flexion of vertebral column

Compression of abdomen, flexion of vertebral column and rotation of vertebral column


Major muscles of the hip region

Gluteus medius

Gluteus minimus

Gluteus maximus

Hip flexors

Abduction and medial rotation of leg

Extension and lateral rotation of leg

Abduction and medial rotation of leg

Flexion of femur and vertebral column. Flexion and lateral rotation of leg

Quadriceps


(Rectus femoris, Vastus lateralis, Vastus intermedius, Vastus medialis)

Flexion of the femur and extension of the knee femur

Muscles of the hamstrings

Hamstrings


(Semimembranosus, Semitendinosus, Biceps femoris)

Extension, medial and lateral rotation of leg. Flexion of knee

Muscles of the calves

Gastrocnemius

Plantar flexion of foot and flexion of knee

Soleus



Plantar flexion of foot

Smooth muscle

Skeletal muscle

Cardiac muscle

located in the walls of the heart, appear striated, and are under involuntary control.

located in walls of hollow visceral organs, except the heart, appear spindle-shaped, and are also under involuntary control.

Skeletal muscle fibers occur in muscles which are attached to the skeleton. They are striated in appearance and are under voluntary control.

Body movement terminology

Medial and Lateral Rotation

Muscular System
by Jose Arcos
Per 2

Dorsiflexion and Plantarflexion

Abduction and Adduction

Flexion and Extension

Flexion refers to a movement that decreases the angle between two body parts.

Extension refers to a movement that increases the angle between two body parts.

Abduction is a movement away from the midline – just as abducting someone is to take them away

Adduction is a movement towards the midline. Adduction of the hip squeezes the legs together.

Medial rotation is a rotational movement towards the midline.

Lateral rotation is a rotating movement away from the midline.

Dorsiflexion refers to flexion at the ankle, so that the foot points more superiorly.

Plantarflexion refers extension at the ankle, so that the foot points inferiorly.

Organizational levels of the skeletal muscle

Microscopic level — sarcomere and myofibrils

Cell level — myoblasts and myofibers

Molecular level — actin and myosin

Tissue level — neuromuscular junctions and fascicles

Organ level — major skeletal muscles of the body

Picture

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The sliding filament theory is the explanation for how muscles contract to produce force. The actin and myosin filaments within the sarcomeres of muscle fibres bind to create cross-bridges and slide past one another, creating a contraction. The sliding filament theory explains how these cross-bridges are formed and the subsequent contraction of muscle.

The Sliding Filament Theory