Introduction to the Muscles

I

Muscles of the Skull and Neck

Muscle FactsA person has about 600 muscles in their

body

Those muscles account for about ½ of a person’s body weight

The heart beats about 3 billion times in the average person’s lifetime

Functions of MusclesMaintain Body Posture

Stabilize Joints

Produce Movement

Generate Heat

MusclesTwo Kinds of Muscles

VoluntaryYou control the muscle when you want it to

move

InvoluntaryMuscles move without you telling it to

3 Types of Muscles Skeletal Muscles

• Also called striated muscles

• Muscles of the arms, legs, etc.

• Voluntary muscles

Skeletal Muscle

Types of MusclesSmooth Muscles

• Muscles of internal organs

• Involuntary muscles

Smooth Muscle

Types of MusclesCardiac Muscles

• Muscles of the heart

• Involuntary muscles

Cardiac Muscles

Three Types of Muscle

Skeletal MusclesSlow-Twitch Muscles

Also called red muscles, because of dense number of capillaries

Carries a lot of oxygen, making them extremely useful for aerobic exercise

Fast-Twitch MusclesCalled white musclesUsed primarily in anaerobic exercise

Muscles During ExerciseSlow-Twitch

MusclesLong, low levels of

exercise Consume a mixture of

fats, protein, and carbohydrates

Consume large amounts of oxygen and produces little lactic acid

Muscles During ExerciseFast-Twitch Muscles

Relies primarily on ATP and glucose for fuel

Consumes very little oxygen, fat, or protein and produces large amounts of lactic acid

Can not be sustained as long as aerobic exercise

Quiz1. Name 1 of the 4 functions of muscle.2. Name a second function of muscle. 3. What is the kind of muscle that works

without you having to tell it to?4. What is the type of muscle that is found

in the heart?5. What is type of skeletal muscle used in

aerobic exercise?

Quiz Answers1. Name 1 of the 4 functions of muscle.2. Name a second function of muscle.

1. Maintain Body Posture2. Stabilize Joints3. Produce Movement4. Generate Heat

3. What is the kind of muscle that works without you having to tell it to?

1. Involuntary4. What is the type of muscle that is found in the heart?

1. Cardiac5. What is type of skeletal muscle used in aerobic exercise?

1. Slow-Twitch Muscle

Structure of the MuscleBelly

Body of the muscleTendons

Ends of the muscles that attach to the boneMuscles are arranged in pairs

One muscle bends the joint, another straightensFlexorsExtensors

Tendons vs Ligaments

Short, bands of fibrous tissues

Connect bone to bone and form a joint

Short, bands of fibrous tissues

Connect muscle to bone and allow a joint to move

Muscle AttachmentOrigin

End of the muscle that is attached to the bone to form stationary attachment

Acts as an anchoring pointInsertion

The point where the muscle is attachedThe movable bone

Muscles of the SkullTemporalis –

anchored at the temple

Masseter – anchored at the cheek bone

These muscles move the lower jaw

Muscles of the NeckSternocleidomastoid

(Neck Cord)Anchored to the

clavicle and top of the sternum

Turns and lifts the headSternomastoid