Unit 1 Lecture 6: Myology and Movement Flashcards
Muscles
use ATP to generate force
stimulation to generate force can come from nerves, intrinsic system regulation, hormones, etc.
responsible for body movements
contain myofilaments (i.e. actin & myosin) which interact to produce tension
3 Types of Muscle Tissue:
1) Skeletal (voluntary, striated)
2) Cardiac (involuntary, striated)
3) Smooth (involuntary, nonstriated)
Actin and myosin are responsible for striation
Functions of Muscle Tissue:
1) Producing Body Movement – including moving substances within the body (e.g. peristalsis); changing the size of certain structures (e.g. pupil of eye)
2) Maintaining Posture
3) Stabilizing Joints
4) Generating Heat (thermogenesis)
Macroscopic Structure of Skeletal Muscle
1) Skeletal Muscle Fibers
2) Blood Vessels (artery, capillaries, and veins)
3) Nerve Fibers
4) Connective Tissue
Connective Tissue Sheaths Associated with a Skeletal Muscle:
1) Endomysium
2) Perimysium
3) Epimysium
Muscle Tissue:
Macroscopic Structure
Most skeletal muscles cross at least one joint and are usually attached to the articulating bones that form the joint.
When a muscle contracts and shortens, it pulls one of the articulating bones towards the other; so one bone remains relatively stationary, while the other moves.
Origin
the muscle’s attachment to the immovable (or less movable) bone
Can be a Direct or Indirect Attachment
Insertion
the muscle’s attachment to the moveable bone
Can be a Direct or Indirect Attachment
Direct Attachments
the epimysium of the muscle is fused to the periosteum of the bone
Indirect Attachments
the muscle’s connective tissue wrappings extend beyond the muscle as either a tendon or an aponeurosis, which will attach to the bone
aponeurosis
a sheet of pearly-white fibrous tissue that takes the place of a tendon in sheetlike muscles having a wide area of attachment.
Aponeuroses (plural of aponeurosis: απο, “away” or “of”, and νευρον, “sinew”) are layers of flat broad tendons.
4 General Types of Movements
at Synovial Joints:
1) Gliding Movement or Translation
2) Angular Movement:
Includes Flexion, Extension, Abduction, Adduction, and Circumduction.
3) Rotation
4) Special Movements*:
Includes Dorsiflexion, Plantar Flexion, Supination, Pronation, Inversion, Eversion, Protraction, Retraction, Elevation, Depression, and Opposition
*There are other movements that apply to specific joints or don’t fit into the categories first 3 categories; these are called special movements.
Gliding or Translation
Intercarpal Joints
Angular Movements:
Flexion
Decrease in the angle between 2 body parts
Lift entire arm up
Kicking heel backwards
Trend: to curl in toward the bellybutton
Angular Movements:
Extension
Increases the angle between 2 body parts
Opposite of flexion
Pressing entire arm back posteriorly
Swinging leg up anteriorly
Trend: movement toward dorsal