Summary Muscle and Muscle Tissue

Muscle and Muscle Tissue
SKELETAL MUSCLE ANATOMY  Circular (orbicularis oris muscle)
 Convergent (pectoralis muscle)
Functions of the Muscular System
 Multipennate (deltoid muscle)
 Movement of the body  Parallel (bicepts brachii muscle)
 Maintenance of posture  Unipennate (extensor digitorum
 Respiration muscle)
 Production of body heat  Bipennate (rectus femoris muscle)
 Communication
Skeletal Muscles
 Constriction and support of organs ad
vessels  Muscle terminology
 Contraction of the heart  Origin or head: muscle end
 Nutrient stores attached to more stationary of
two bones
Types of Movement
 Insertion: muscle end attached
 Angular movements to bone with greatest movement
 Flexion and extension  Belly: largest portion of muscle
(decrease angle of joint / between origin and insertion
straightening angle)  Tendons: attached muscle to
 Abduction and adduction bones
(toward mid-line / away from  Skeletal muscle pairs
body)  Agonist: muscle that causes
 Circumduction action when it contracts
 Rotation  Antagonist: muscle working in
 Left and right opposition to agonist
 Lateral  Synergists: muscle that work
 Pronation and supination together to cause a movement



 Movement of the body result from
muscle contraction
 Skeletal muscle: 40% of body
weight



Types of Skeletal Muscle
The shapes of muscles are determined by the
way the fascicles are aligned

Levers, Forces, Fulcrums and
Resistance
Muscles, tendons, joints and bones act
together as lever systems to move either
parts or whole body
 Muscle contractions

,  Pull or generate force by Walls of hollow organs, blood
relative positions vessels, eye, gland, skin
 Lever: rigid shaft or bone  Some functions: propel urine,
 Fulcrum: pivot point or joint mix food in digestive tract,
 Weight or resistance (force of dilating / constricting pupils,
gravity either in form of weight regulating blood flow
of body parts or weight of object  In some locations, autorhythmic
being lifted, pulled or pushed)  Controlled involuntarily by
endocrine and automatic
General Proprieties of Muscle
nervous system
 Contractility: ability of a muscle to  Cardiac
shorten with force  Heart: major source of
 Excitability: capability of a muscle to movement of blood
respond to a stimulus (from nerves)
 Extensibility: muscle can be stretched
to normal resting length and beyond to Individual skeletal muscle consists
limited degree of:
 Elasticity: ability of muscle to recoil to
original resting length after stretched  Skeletal Muscle Tissue
 Nervous Tissue
Types of Muscle Contractions  Connective Tissue
 Isotonic – change in muscle length,  Adipose Tissue
no change in tension
 E.g. lifting arm white holding
heavy weight (movement
involved)  Autorhythmic
 Isometric – change in muscle tension,  Controlled involuntarily by
no change in length endocrine and autonomic
 E.g. holding something up, nervous system
maintaining posture (no
Connective Tissue
movement involved)
 Fascia
 Dense sheet of irregular
connective tissue that surrounds
muscles
 Epimysium
 The outermost layer
 Separates 10 – 100 muscle fibres
into bundles called fascicles
 Perimysium
 Surrounds a fasciculus (also
called fascicle)
Types of Muscle Tissue  Endomysium
 Separates individual muscle
 Skeletal fibres from one another
 Responsible for locomotion,  Tendon
facial expressions, posture,  Cord that attaches a muscle to a
respiratory movements, other bone
types of body movement
 Voluntary Myoblasts and Muscle Fibres
 Smooth