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 at least 2 points

• Origin• Attachment to immoveable bone

• Insertion• Attachment to 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

Have out:Muscular Sys. notes Pt 1Mr. Muscle ManPick up:Same colored pencil as yesterday’sMuscle Tissue Comparison wkstMuscle diagramsWeb of Life article & questionnaire (EC)

Agenda:1. Continue Muscular System

- Finish coloring muscle worksheets- Continue with types of muscle tissue notes

Anatomy Fun Fact:There are muscle cells in the longest body muscle (Sartorius) which are more than a foot in length.

Homework:1. Rubber bones Lab

(3I) – Tues, 11/172. Muscles Quiz #1 –

Wed, 11/183. Muscles Quiz #2 –

Mon, 11/23

Learning Goal: I will be able to describe the structure & function of the Muscular System.

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

Superficial Muscles: PosteriorIdentify (by number) & color-code (all the same color) the following Posterior Muscles:-Adductor group-Gluteus maximus-Gastrocnemius

Per. 4 start - Tues

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!

Have out your Muscle Tissue Comparison checklist…

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

Involuntary controlled by autonomic nervous system

Skeletal muscle (aka striped or striated muscle)

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 an intercalated disc

• Involuntary• Contractions happen

slowly • Found only in 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

EXAMPLEElbow joint flexed

Flexor muscles contractedExtensor muscles re laxed

Elbow joint extendedExtensor m uscles contracted

Flexor muscles relaxed

biceps

triceps

Section through arm

Flexorm uscles

Extensor m uscles

HumerusBone

Closing ActivityComparing 3 Muscles Tissues wkst• Work INDIVIDUALLY on the wkst using the notes we

just discussed!

Per. 1 start - Wed

Week #6 (11/17-11/21) Warm Up – Wed, 11/18:- Review Quiz #1 Muscle Group

Turn in:NothingPick up:Comparing the 3 muscles tissues wkst 4 colored pencilsMuscle Worksheets

Agenda:1. Muscles Quiz #12. Identify Muscle Quiz #2 Muscles3. Notes: Finish Types of Muscle Tissue4. Microscope Activity: Types of Muscle Tissue

Anatomy Fun Fact:Muscles in the middle of the ear are the smallest muscles present in the human body.

Homework:1. Muscles Quiz

#2 – Mon, 11/23

Learning Goal: I will be able to describe the structure & function of the Muscular System.

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: AnteriorIdentify (by number) & color-code (all the same color) the following Anterior Muscles:-Sternocleidomastoid-Biceps brachii-Deltoid-Vastus lateralis-Transverse abdominis

Superficial Muscles: PosteriorIdentify (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

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 bellyFascicles

Muscle fibers

Myofibrils

Per. 1 - The end