Transcript Biology 210 - Rock Hill High School

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
Skeletal Muscle Cells
Smooth Muscle Cells
Cardiac Muscle Cells
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


Epimysium


the groups of muscles fibers
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.
Connective Tissue Components


Endomysium
Perimysium



Fascicles
Epimysium
Tendon
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.
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.
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

a fibrous connective tissue which encloses
certain tendons. Have a lining of synovial
membrane which allows easy movement of the
tendon.
 Deep

Sheath
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.

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.
Size and Shape of Fibers
 Size:
varies from large to small
 Shape: 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 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
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.
Pelvis
Femur
Attachment of Muscles-Origin

Origin


The point of attachment
that does not move
during muscle
contraction.
Pelvis
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
Muscle Actions-Prime Mover
A
muscle or group
of muscles which
directly performs a
specific movement.

Flexion of
forearmBiceps
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 forearmT. brachii
is anatagonist
Muscle Actions-Synergists
 contract
at the same
time as the prime
movers;
 they complement the
prime movers.

Flexion of
forearmbrachialis is
synergist
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


L = Load: Weight – resistance


a point around which the rigid bar
rotates
something that is moved
P = Pull - Muscle contraction

force producing the movement
Naming of Muscles
 Location
 Function
- named for what they do
 Shape - 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
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


Oblique


rectus refers to up and
down
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.