Download Skeletal Muscle Functions

Skeletal Muscle Functions
• Produce movement
• Maintain posture
• Stabilize joints
• Generate heat
Muscles & Body Movements
• Movement is attained due to a muscle moving an attached bone
• Muscles are attached to
points
• Origin
• Attachment to
• Insertion
• Attachment to
at least 2
immoveable bone
movable bone
Types of Muscles
• Prime mover—muscle with major responsibility for a
certain movement
• Antagonist—muscle that opposes or reverses a prime
mover
• Synergist—muscle that aids a prime mover in a
movement & helps prevent rotation
• Fixator—stabilizes origin of a prime mover
Naming Skeletal Muscles
• By direction of muscle fibers
• Examples
• Rectus (straight)
• Transverse (horizontal)
• Oblique (angle)
• By relative size of the muscle
• Examples
• Maximus (largest)
• Minimus (smallest)
• Longus (longest)
• By location of the muscle
• Examples
• Temporalis (temporal bone)
• Occipitalis (occipital bone)
• By number of origins
• Examples
• Triceps (3 heads)
• Biceps (2 heads)
• Quadriceps (4 muscles in
group)
Naming Skeletal Muscles
• By location of the muscle’s origin
& insertion
• Example
• Sternocleidomastoid (on the
sternum)
• By action of the muscle
– Examples
• Flexor (flexes a bone)
• Extensor (extends a bone)
• Abductor (abducts a limb)
• Adductor (adducts a limb)
• By shape of the muscle
• Examples
• Deltoid (triangular)
• Trapezius (trapezoid)
Week #6 (11/16-11/20)
Warm Up – Mon, 11/16:
- Check for Latin Flash Cards
Anatomy Fun Fact:
There are muscle cells in the longest
body muscle (Sartorius) which are
more than a foot in length.
Have out:
Muscular Sys. notes Pt 1
Mr. Muscle Man
Pick up:
Same colored pencil as
yesterday’s
Muscle Tissue Comparison
wkst
Muscle diagrams
Web of Life article &
questionnaire (EC)
Homework:
Agenda:
1.
Continue Muscular System
-
Finish coloring muscle worksheets
Continue with types of muscle tissue notes
Learning Goal: I will be able to describe the structure &
function of the Muscular System.
1.
2.
3.
Rubber bones Lab (3I)
– Tues, 11/17
Muscles Quiz #1 –
Wed, 11/18
Muscles Quiz #2 –
Mon, 11/23
Superficial Muscles:
Anterior
Identify (by number)
& color-code (all the
same color) the
following Anterior
Muscles:
-Orbicularis oris
-Pectoralis major
-External oblique
-Adductor group
-Vastus medialis
Per. 4 start - Tues
Superficial
Muscles:
Posterior
Identify (by number) &
color-code (all the same
color) the following
Posterior Muscles:
-Adductor group
-Gluteus maximus
-Gastrocnemius
Naming Skeletal Muscles Review
• Identify 1 skeletal muscle we have learned that is
named for…
• Its relative size?
• Gluteus maximus
• Its location on the body?
• Latissimus dorsi
• Its shape?
• Orbicularis oris
• The number of origins?
• Biceps brachii
• The direction of muscle fibers?
• External obliques
3!
The Muscular System
• Muscles are responsible for all types of body
movement
• 3 muscle types are found in the body
– Skeletal muscle
• Attached to bone & skin
• Produce movement, stabilize joints, provide
posture & generate heat
– Cardiac muscle
• Walls of the heart
• Protect the heart & produce contractions of the
heart walls
– Smooth muscle
• Walls of hollow visceral (i.e, stomach) organs
(except heart)
• Protect organs & produce slow contractions
Comparison of Skeletal, Cardiac & Smooth
Muscles
Characteristics of Muscles
• All muscles share some terminology
– myo & mys refer to “muscle”
– sarco refers to “flesh”
• Skeletal & smooth muscle cells are elongated (muscle cell = muscle
fiber)
• Contraction of muscles is due to the movement (pulling together) of
microfilaments (micro = “small”; fila = “thread”)
Cardiac muscle
Smooth muscle
Skeletal muscle
(aka striped or
striated muscle)
Involuntary
controlled by
autonomic
nervous system
Voluntary
controlled by
somatic nervous
system
Smooth Muscle Characteristics
•
•
•
•
Lacks striations
Spindle-shaped cells
Single nucleus
Involuntary—no conscious
control
• Contractions happen very slowly
• Found mainly in the walls of
hollow organs
• Stomach, urinary bladder,
respiratory passages
Cardiac Muscle Characteristics
•
•
•
•
Striations
Usually has a single nucleus
Branching cells
Joined to another
muscle cell at
disc
• Involuntary
• Contractions
slowly
• Found only in
an intercalated
happen
the heart
Skeletal Muscle Characteristics
• Most are attached by tendons to bones
• Cells are multinucleated
• Striated—have visible banding
• Voluntary—subject to conscious control
• Contractions happen slow to fast
• Muscles are either contracted or relaxed
• Contracted the muscle exerts
pulling force =
muscle shortens
• Since muscles can only pull
(not push),
they work in pairs
(antagonistic muscles)
• Example: Biceps & Triceps
• Muscle that bends joint is called the flexor muscle
• Muscle that straightens joint is called the extensor muscle
EXAMPLE
Elbow joint flexed
Flexor muscles contracted
Extensor muscles relaxed
Elbow joint extended
Extensor muscles contracted
Flexor muscles relaxed
Section through arm
Flexor
muscles
biceps
Humerus
Bone
Extensor
muscles
triceps
Per. 1 start - Wed
Closing Activity
Comparing 3 Muscles Tissues wkst
• Work INDIVIDUALLY on the wkst using the notes we
just discussed!
Week #6 (11/17-11/21)
Warm Up – Wed, 11/18:
- Review Quiz #1 Muscle Group
Anatomy Fun Fact:
Muscles in the middle of
the ear are the smallest
muscles present in the
human body.
Turn in:
Nothing
Pick up:
Comparing the 3
muscles tissues wkst
4 colored pencils
Muscle Worksheets
Agenda:
1.
2.
3.
4.
Muscles Quiz #1
Identify Muscle Quiz #2 Muscles
Notes: Finish Types of Muscle Tissue
Microscope Activity: Types of Muscle Tissue
Learning Goal: I will be able to describe the structure &
function of the Muscular System.
Homework:
1.
Muscles Quiz #2
– Mon, 11/23
Muscles to Identify Quiz #1
• Pick up 1 colored pencil (ALL
muscles will be color-code with 1
color).
• QUIETLY take the quiz & turn it in
to the Hmwk Bin when finished.
• Take out Mr. Muscles, your other
muscle diagrams & flashcards for
your next set of muscles (Quiz
#2)!
Superficial Muscles:
Anterior
Identify (by number) &
color-code (all the same
color) the following
Anterior Muscles:
-Sternocleidomastoid
-Biceps brachii
-Deltoid
-Vastus lateralis
-Transverse
abdominis
Superficial
Muscles:
Posterior
Identify (by number) &
color-code (all the same
color) the following
Posterior Muscles:
-Latissimus dorsi
-Deltoid
-Semitendinosus
Connective Tissue Wrappings &
Attachments of Skeletal Muscle
• Tendons—cord-like
structures
• Mostly collagen fibers
• Attach muscle belly to bone
Figure 6.1
Connective Tissue Wrappings &
Attachments of Skeletal Muscle
• Cells are surrounded & bundled by connective tissue
• Fascia—tough connective tissue, outside of the epimysium of the
muscle belly, that creates a 3-D web around every muscle
Figure 6.1
Connective Tissue Wrappings &
Attachments of Skeletal Muscle
• Cells are surrounded &
bundled by connective tissue
• Epimysium—covers the entire
skeletal muscle (muscle belly)
Figure 6.1
Connective Tissue Wrappings &
Attachments of Skeletal Muscle
• Cells are surrounded &
bundled by connective tissue
• Perimysium—wraps around a
fascicle (bundle) of muscle
fibers
Figure 6.1
Connective Tissue Wrappings &
Attachments of Skeletal Muscle
• Cells are surrounded &
bundled by connective tissue
• Endomysium—encloses a
single muscle fiber
Figure 6.1
Microscopic Anatomy of Skeletal
Muscle
• Sarcolemma—specialized
plasma membrane that
surrounds a myofibril
• Myofibrils—long organelles
inside muscle cell
Per. 1 - The end
REVIEW of SKELETAL MUSCLE STRUCTURE:
Play Doh Model Challenge
• Using the 4 colors of modeling clay, develop a mini
replica of skeletal muscle, including…
•
•
•
•
1 muscle belly
At least 3 fascicles
At least 3 muscle fibers within each fascicle
At least 3 myofibrils within each muscle fiber
Muscle belly
Fascicles
Muscle fibers
Myofibrils