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

What are the two characteristics of the muscles of the vertebral column?

Permit movement of the spine and stabilize spine when moving limbs

What are prevertebral muscles responsible for?

Flexing the spine and pulling it to one side

Sternocleidomastoid

muscle that goes from sternum and clavicle to mastoid process on temporal bone, allows neck to bend laterally to one side

External oblique

Oblique abdominal muscle on the top of the side of the waist, flexes the waist

Internal oblique

Oblique abdominal muscle internal to the external oblique, flexes the waist

Transversus abdominus

Muscle that goes across the abdomen laterally

Rectus abdominus

Muscles that form si

Quadratus lumborum

four part muscle that flexes the waist

Iliopsoas

Two muscles, the psoas that goes from the lumbar to the femur, and the iliacus, that is in the ilium of the hip

Why is the iliopsoas called the switch hitter?

It flexes and extends the waist

What are post vertebral muscles responsible for?

Extension of the spine, and can pull spine to one side

Splenius

From the occipital bone to spine, it extends the neck and moves the head up

What are the three muscles of the erector spinae?

Spinalis dorsi, longissimus dorsi, and Iliocostalis dorsi

Trapezius

Shoulder muscle with three parts that is responsible for moving shoulders toward midline and shrugging shoulders

What are the three parts of the trapezium?

Clavotrapezius, spinotrapezius, and acromiotrapezius

Rhomboideus

Muscle in the shape of a rhombus, pulls shoulders toward midline

Serratus Anterior

Serrated muscles that connect to the ribs and the scapula, it pulls the shoulder downward toward the ribs

What does abduct mean?

Moves back

Deltoid

Muscle that abducts the arm, connects to the humerus as well as the clavicle, spine, and scapula

Supraspinatus

Abducts the arm, as a synergist with the deltoid

What does supinate mean

Roll to make it face up

Biceps Brachii

Originates on scapula, inserts to the radius, flexes forearm and supinates hand

Brachialis

Originates at the distal head of the humerus, inserts to coronoid process of ulna, and flexes the forearm as a synergist with the Biceps

Brachioradialis

Originates at distal end of the humerus, inserts to styloid process of radius, and flexes the forearm

Triceps Brachii

Three heads, the long head originates at scapula, while lateral and medial heads originate at the humerus, inserts to olecranon process of the ulna, extends forearm as an antagonist of the biceps

Flexor Carpi radialis

Flexes and abducts the hand

Palmaris Longus

Flexes middle three fingers in the hand

Flexor Carpi ulnaris

Flexes the little finger of the hand

Pronator Teres

Pronates the hand

Extensor Carpi Radialis

Extends the thumb into a ‘thumbs up’

Extensor Carpi Ulnaris

Extends little finger

Thennar Eminence

The thumb muscle that makes it opposable, important for gripping and grasping.

Levator Ani

Originates at the pubic arches and inserts into the coccyx bone, supports the pelvic organs

Bulbocavernosus

Constricts vaginal opening

Tensor Fascia Lata

Originates in the iliac crests, inserts into the tibia, abducts the thigh

Gluteus Maximus

Forms the mass of the buttocks, essentia for running and walking, extends and rotates the thigh laterally

Quadriceps Femoris

Originates in the femur, inserts into the knee, it extends the lower leg

Rectus Femoris

Located on the mid portion of the thigh

Vastus Lateralis

Commonly used for IM injection

Vastus Medialis

One of the heads of the quadrices

Vastus Intermedius

Located just below rectus femoris, but is difficult to separate from the other three parts of the quads.

Sartorius

Strap like muscle that extends diagonally across the anterior aspect of the thigh, pulls the entire thigh towards the hip.

Gracilis

Dancer’s muscle, appears very broad in the cat, a part of the adductor group.

Biceps Femoris

One of the hamstring muscles

Semiteninosus

One of the hamstring muscles

Semimembranosus

One of the hamstring muscles

Plantar Flexion

Pointing toes or fingers

Dorsiflexion

Extending toes or fingers back toward the forearm or lower leg

Tibialis Anterior

Shin splints muscle

Extensor Digitorum Longus

Located on the lateral aspects of the leg

Gastrocnemius

posterior heads of the calf

Soleus

Deep head of the calf

Flexor Digitorum Longus

Deep muscle located on the posteromedial aspect of the leg

Peroneus Longus

Everts the foot, plantar flexes the foot