Biology 210
Chapter 10 Muscles
PowerPoint by John McGill
Based on notes by Beth Wyatt &
PowerPoint by Jack Bagwell
Types of Muscle Cells
Skeletal (Voluntary, Striated) Muscle
Smooth (Involuntary, Smooth) Muscle
these are muscles you control; the ones you
exercise.
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
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Skeletal Muscle Cells
Smooth Muscle Cells
Cardiac Muscle Cells
2
Tissues that Compose Skeletal Muscle
Skeletal muscle tissue
Connective Tissue
Components
Nervous Tissue
Tissues that Compose Skeletal Muscle
Skeletal
muscle tissue
Composed of skeletal muscle fibers, arranged in
fasicles.
Connective Tissue
Components
Will discuss on the next slide
Nervous Tissue
Attached to SMFs
Stimulate muscle contraction.
Connective Tissue Components
Endomysium
a delicate membrane
composed of connective tissue
which covers the individual
skeletal muscle fibers
Perimysium
the tough connective tissue
which binds skeletal muscle
fibers together, I.e. wraps
around fascicles.
Fascicles
the groups of muscles fibers
Epimysium
the whole muscle is covered by
a coarse sheet of connective
tissue
Tendon
The epimysium, perimysium
and endomysium may come
together to form a tendon on
the muscle end, is extension of
periosteum on bone end.
3
Connective Tissue Components
Endomysium
Perimysium
Epimysium
Tendon
Fascicles
Try this to
remember
these:
Every
Paranoid
Friend
Eats
Tomatoes
Endomysium
a delicate membrane composed of connective tissue which
covers the individual skeletal muscle fibers
Perimysium
the tough connective tissue which binds skeletal muscle fibers
together, I.e. wraps around fascicles.
4
Fascicles
The groups of muscles fibers
Formed from perimysium
Epimysium
the whole muscle is covered by a coarse sheet of connective
tissue
Tendon
The epimysium, perimysium and endomysium may come
together to form a tendon on the muscle end, is extension of
periosteum on bone end.
5
Tendon Pictures
Connective Tissue Components continued
Aponeurosis
Also may be formed from the three fibrous
wrappings; may merge with the wrappings of
another muscle.
Tendon
Deep
Sheath
a fibrous connective tissue which encloses
certain tendons. Have a lining of synovial
membrane which allows easy movement of the
tendon.
Fascia
dense fibrous connective tissue; extensions of
this tissue form the epimysium, perimysium, and
endomysium.
Aponeurosis
Also may be formed
from the three fibrous
wrappings
may merge with the
wrappings of another
muscle.
6
Tendon Sheath
a fibrous connective tissue which encloses
certain tendons. Have a lining of synovial
membrane which allows easy movement of
the tendon.
Deep Fascia
dense fibrous
connective tissue;
extensions of this
tissue form the
epimysium,
perimysium,
and endomysium.
Tissues that Compose Skeletal Muscle
Nervous Tissue
Attached to SMFs
Stimulate muscle
contraction.
7
Size and Shape of Fibers
Size:
varies from large to small
Shape: varies
Broad:
Latisimus dorsi
Sartorius
Flat: Latisimus dorsi
Bulky: Gastrocnemius
Long: Sartorius
Circular: Orbicularis oris
Triangular: Deltoid
Narrow:
Shape: Broad
Latisimus dorsi
Shape: Narrow
Sartorius
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Shape: Flat
Latisimus dorsi
Shape: Bulky
Gastrocnemius
Shape: Long
Sartorius
9
Shape: Circular
Orbicularis oris
Shape: Triangular
Deltoid
Fiber Arrangement
Arrangement of SMF within the muscle, varies.
Parallel to long axis
Converge to narrow attachment
Oblique are slanted
Pennate – “think feather pen”
Bipennate
Curved
10
Parallel to long axis
Horizontal:
Transversus
abdominis
Vertical
Rectus abdominis
Converge to narrow attachment
Pectoralis major
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Oblique are slanted
External oblique
Pennate – “think feather pen”
Vastus group
Bipennate
“two feathered”
Rectus femoris
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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.
Pelvis
Femur
Attachment of Muscles-Origin
Origin
The point of attachment
that does not move
during muscle
contraction.
Pelvis
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Attachment of Muscles-Insertion
Insertion – the points of
attachment that does
move when the muscles
contract.
Femur
Attachment of MusclesContraction
Typically, when a
muscle contracts, the
insertion is moved
closer to the origin.
Muscle Actions
Muscles work
together! Some
muscles in a group
contract while other
relax.
Prime mover
Antagonist
Synergists
Fixator muscles
14
Muscle Actions-Prime Mover
A
muscle or group
of muscles which
directly performs a
specific movement.
Flexion of
forearmBiceps
brachii is PM
Muscle Actions-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
Muscle Actions-Synergists
contract
at the same
time as the prime
movers;
they complement the
prime movers.
Flexion of
forearmbrachialis is
synergist
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Muscle Actions- Fixator muscles
usually
serve to stabilize joints. They help
to maintain balance and posture during the
contractions of the prime movers.
ROLE OF MUSCLES, BONES, AND
JOINTS IN MOVEMENT
MECHANISM
Skeletal Muscle Attached to
Bones (by Tendons) With
Joint in Between POA’s
Skeletal Muscle Stimulated
by Nerve Impulse
Skeletal Muscle Contracts,
Pulls on Bone(s), Produces
Movement at a Joint
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
P = Pull - Muscle contraction
something that is moved
force producing the movement
16
Naming of Muscles
Location
Function
- named for what they do
- shape of the muscle
Direction of fibers - orientation of fibers
Number of divisions or heads - connections
Points of attachment - what bones are
attached to OR bone markings
Size - how big is the muscle relative to
other muscles
Shape
Location brachialis - in the arm
Function - named for what they do
Adductor group
move leg toward the
midline
17
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
transversus
slanting
Number of divisions or heads – connections
biceps brachii
18
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.
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