human muscles. types of muscle cells skeletal (voluntary, striated) muscle these are muscles you...
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Human Muscles
Types of Muscle Cells Skeletal (Voluntary, Striated) Muscle
these are muscles you control; the ones you exercise.
Smooth (Involuntary, Smooth) Muscle these are muscles you cannot control They work the inner parts of the body (viscera)
Cardiac Muscle (Involuntary, striated) myogenic due to interconnections These muscles of the heart do not get tired.
Types of Muscle Cells
Smooth Muscle Cells
Cardiac Muscle Cells
Skeletal Muscle Cells
Tissues in Skeletal Muscles
1. Skeletal muscle tissue
2. Connective Tissue Components
3. Nervous Tissue
Connective Tissue Components
Endomysium Perimysium
Fascicles Epimysium Tendon
Tendon Pictures
Aponeurosis Also may be formed
from the three fibrous wrappings
may merge with the wrappings of another muscle.
Size and Shape of FibersSize: varies from large to smallShape: varies
Broad: Latisimus dorsi Narrow: Sartorius Flat: Latisimus dorsi Bulky: Gastrocnemius Long: Sartorius Circular: Orbicularis oris Triangular: Deltoid
Shape: Broad Latisimus dorsi
Shape: Narrow Sartorius
Shape: Flat Latisimus dorsi
Shape: Bulky Gastrocnemius
Shape: Long Sartorius
Shape: Circular
Orbicularis oris
Shape: Triangular
Deltoid
Fiber ArrangementArrangement of SMF within the muscle, varies.
Parallel to long axis Converge to narrow attachment Oblique are slanted Pennate – “think feather pen” Bipennate Curved
Parallel to long axis
Horizontal: Transversus abdominis
Vertical
Rectus abdominis
Converge to narrow attachment
Pectoralis major
Oblique are slanted
External oblique
Pennate – “think feather pen” Vastus group
Bipennate “two feathered”
Rectus femoris
Curved
Fibers are circular Orbicularus oris
Attachment of Muscles-Joints Most muscles attach
articulating bones across a joint.
Upon contraction of the muscle, one bone remains in a fixed position and the other moves. Femur
Pelvis
Attachment of Muscles-
Origin
Origin The point of attachment that does not move during
muscle contraction.
Pelvis
Attachment of Muscles-
Insertion
Insertion – the point of attachment that does move when the muscles contract.
Femur
Attachment of Muscles-Contraction
Typically, when a muscle contracts, the insertion is moved closer to the origin.
ROLE OF MUSCLES, BONES, AND JOINTS IN MOVEMENT Lever
any rigid bar free to move around a fixed point called a fulcrum
Lever system Rigid bar - a bone
F = Fulcrum - joint a point around which the rigid bar rotates
L = Load: Weight – resistance something that is moved
P = Pull - Muscle contraction force producing the movement
Muscle GroupsMuscles work
together! Some muscles in a group contract while other relax. Prime mover Antagonist Synergists Fixator muscles
Prime MoverA muscle or group
of muscles which directly performs a specific movement. Flexion of
forearmBiceps brachii is PM
Antagonist When actively contracting, they oppose the movement
of the prime mover. They are relaxed when the
prime mover is contracting. Flexion of forearmT. brachii
is anatagonist
Synergistscontract at the same
time as the prime movers;
they complement the prime movers. Flexion of
forearmbrachialis is synergist
Fixator muscles
usually serve to stabilize joints. They help to maintain balance and posture during the contractions of the prime movers.
Naming of MusclesLocationFunction - named for what they doShape - shape of the muscleDirection of fibers - orientation of fibersNumber of divisions or heads - connectionsPoints of attachment - what bones are
attached to OR bone markingsSize - how big is the muscle relative to
other muscles
Location brachialis - in the arm
Function - named for what they do
Adductor group move leg toward the
midline
Shape - shape of the muscle deltoid - triangular
muscle in the shoulder
Direction of fibers - orientation of fibers rectus abdominus
rectus refers to up and down
Oblique slanting
transversus
Number of divisions or heads – connections
biceps brachii
Points of attachment What bones are
attached to OR bone markings
Sternocleidomastoid
Size
how big is the muscle relative to other muscles Gluteus maximus – in human beings, bigger than
gluteus medius and minimus.