Asher Coffman Chapter 6 Myology

How many muscles are in the body?

650

What are the two general characteristics of muscles?

They are excitable and contractable

What does excitablility mean?

they are able to generate electrical impulses called action potentials

What does contractility mean?

The ability to shorten in length

What are the only two cells in the body that exhibit excitability?

Muscle and nerve cells

What are the three functions of the muscles?

Voluntary movement, maintenance of body posture, and heat production

What is the tendon of origin commonly called?

the head or ceps

What does the tendon of origin connect to?

the less movable structure

What is the tendon of insertion commonly called?

the tail

What does the tendon of insertion connect to?

the more movable structure

What are the three layers of fascia?

Epimysium, perimysium, and endomysium

What does a somatic motor unit consist of?

A somatic motor neuron and all the muscles it innervates

What are proprioceptors?

Receptors that let you feel touch

What is an agonist?

the prime mover or muscle that causes the desired action

What is a synergist muscle?

A muscle that helps the agonist

What is an antagonist muscle?

A muscle that does the opposite of the agonist

What is a fixator or stabilizer?

A muscle that stabilizes body position

What are the characteristics of muscles that are used in maximal training?

Wider diameter, anaerobic muscles, and whiter color

What are characteristics of muscles that are used in submaximal training?

Thinner diameter, more aerobic, and darker in color

Frontalis

Raises eyebrows and wrinkles forehead

Orbicularis oculi

Closes the eyelids

Orbicularis oris

Puckers the lips

Buccinator

Compresses the cheeks, as when blowing

Platysma

pulls lower lip and jaw downwards

Zygomaticus

smiling and raising corners of the mouth

Superior Rectus

Elevates eye

Inferior Rectus

Depresses eye

Medial Rectus

Rotates eye medially

Lateral Rectus

Rotates eye laterally

Temporalis

Elevates mandible, and thus closes the jaw

Masseter

Synergist with the temporalis, helps elevate mandible

Genioglossus

Sticks out tongue

Styloglossus

Pulls tongue back in

What are the general characteristics of facial muscles?

Superficial cutaneous muscles, insert into overlying skin, all innervated by the facial nerve

What nerve innervates the facial muscles?

Facial nerve, cranial nerve #7

What is the action of the frontalis?

Raises eyebrows and wrinkles forehead

What muscle closes the eyelids?

Orbicularis oculi

What muscle is responsible for squinting, winking, blinking?

Orbicularis Oculi

What muscle puckers the lips?

Orbicularis oris

What muscle compresses the cheeks?

Buccinator

What muscle pulls the lower lip downward?

Platysma

What is Bell’s Palsy

Asymmetry of facial features, facial muscles are flaccid on one side of the face

How many muscles move the eye?

6

What muscles elevate the mandible?

Temporalis and masseter

What nerve innervates the tongue?

Hypoglossal nerve, cranial nerve #11