Chapter 11:The Muscular System

**insertion**

The moveable end of the muscle that attaches to the bone being pulled is called the muscle’s

**origin**

The end of the muscle attached to a fixed (stabilized) bone is called the

**prime mover**, or **agonist**.

Although a number of muscles may be involved in an action, the principal muscle involved is called the

**antagonist**

A muscle with the opposite action of the prime mover is called an

**fascicle**

When a group of muscle fibers is “bundled” as a unit within the whole muscle by an additional covering of a connective tissue called perimysium, that bundled group of muscle fibers is called a

**Parallel muscles**

have fascicles that are arranged in the same direction as the long axis of the muscle.

**fusiform**

When a parallel muscle has a central, large belly that is spindle-shaped, meaning it tapers as it extends to its origin and insertion, it sometimes is called

**sphincters**

**Circular** muscles are also called

**convergent**

When a muscle has a widespread expansion over a sizable area, but then the fascicles come to a single, common attachment point, the muscle is called

**Pennate muscles**

(penna = “feathers”) blend into a tendon that runs through the central region of the muscle for its whole length, somewhat like the quill of a feather with the muscle arranged similar to the feathers.

**unipennate** muscle

In a **__** , the fascicles are located on one side of the tendon.

**bipennate**

A **_** muscle has fascicles on both sides of the tendon.

**orbicularis oris**

is a circular muscle that moves the lips, and the orbicularis oculi is a circular muscle that closes the eye. 

**occipitofrontalis**

muscle moves up the scalp and eyebrows.

**epicranial aponeurosis**

Instead, the two bellies are connected by a broad tendon called the

**extrinsic eye muscles**

The movement of the eyeball is under the control of the **__**

**mastication**

In anatomical terminology, chewing is called

**masseter muscle**

is the main muscle used for chewing because it elevates the mandible (lower jaw) to close the mouth

**temporalis** muscle

which retracts the mandible.

**medial pterygoid** and **lateral pterygoid**

muscles provide assistance in chewing and moving food within the mouth.

**genioglossus**

(genio = “chin”) originates on the mandible and allows the tongue to move downward and forward.

**styloglossus**

originates on the styloid bone, and allows upward and backward motion.

**palatoglossus**

originates on the soft palate to elevate the back of the tongue

**hyoglossus**

originates on the hyoid bone to move the tongue downward and flatten it.

**infrahyoid muscles**

are located inferiorly.

**stylohyoid**

The**_**muscle moves the hyoid bone posteriorly, elevating the larynx,

**mylohyoid**

muscle lifts it and helps press the tongue to the top of the mouth.

**geniohyoid**

depresses the mandible in addition to raising and pulling the hyoid bone anteriorly.

**omohyoid**

The **_** muscle, which has superior and inferior bellies, depresses the hyoid bone in conjunction with the **sternohyoid** and **thyrohyoid** muscles.

**sternocleidomastoid**

The major muscle that laterally flexes and rotates the head is the

**splenius**

The _ muscles originate at the midline and run laterally and superiorly to their insertions

**splenius capitis**

the __ inserts onto the head region, and the splenius cervicis extends onto the cervical region.

**erector spinae group**

The **___** forms the majority of the muscle mass of the back and it is the primary extensor of the vertebral column.

l**ongissimus cervicis**

 the _ associated with the cervical region

**longissimus thoracis**

the_ , associated with the thoracic region

**spinalis capitis**

(head region)

**spinalis cervicis**

(cervical region)

**spinalis thoracis**

 (thoracic region)

**multifidus**

The _ muscle of the lumbar region helps extend and laterally flex the vertebral column.

**external oblique**

The_ , closest to the surface, extend inferiorly and medially, in the direction of sliding one’s four fingers into pants pockets.

 **internal oblique**

extending superiorly and medially, the direction the thumbs usually go when the other fingers are in the pants pocket.

 **transversus abdominis**

is arranged transversely around the abdomen, similar to the front of a belt on a pair of pants.

**linea alba**

is a white, fibrous band that is made of the bilateral **rectus sheaths** that join at the anterior midline of the body.

**tendinous intersections**

Each muscle is segmented by three transverse bands of collagen fibers called the

**intercostal muscles**

which span each of the intercostal spaces.

**external intercostal**

muscles aid in inspiration of air during breathing because when they contract, they raise the rib cage, which expands it.

 **internal intercostal**

muscles, just under the externals, are used for expiration because they draw the ribs together to constrict the rib cage

**innermost intercostal**

muscles are the deepest, and they act as synergists for the action of the internal intercostals.

**pelvic diaphragm**

spanning anteriorly to posteriorly from the pubis to the coccyx, comprises the levator ani and the ischiococcygeus.

**perineum**

is the diamond-shaped space between the pubic symphysis (anteriorly)

**urogenital triangle**

which includes the external genitals.

**anal triangle**

which contains the anus.

**anterior muscles**

the **subclavius, pectoralis minor, and serratus anterior.**

 **posterior muscles**

 the **trapezius, rhomboid major, and rhomboid minor.**

**pectoralis major**

is thick and fan-shaped, covering much of the superior portion of the anterior thorax.

**deltoid**

the thick muscle that creates the rounded lines of the shoulder is the major abductor of the arm, but it also facilitates flexing and medial rotation, as well as extension and lateral rotation.

**subscapularis**

originates on the anterior scapula and medially rotates the arm.

**brachioradialis**

can flex the forearm quickly or help lift a load slowly.

**anterior compartment of the arm**

These muscles and their associated blood vessels and nerves form the **___** (anterior flexor compartment of the arm).

**extrinsic muscles of the hand**.

The forearm is the origin of the

**deep anterior compartment**

produces flexion and bends fingers to make a fist.

**deep posterior compartment of the forearm**

(deep posterior extensor compartment of the forearm) originate on the radius and ulna.

**retinacula**

Fibrous bands called **_** sheath the tendons at the wrist.

**flexor retinaculum**

extends over the palmar surface of the hand

**extensor retinaculum**

extends over the dorsal surface of the hand.

**hypothenar**

The **_** muscles are on the medial aspect of the palm, and the intermediate muscles are midpalmar.

 **thenar eminence**

the rounded contour of the base of the thumb, and all act on the thumb.

**hypothenar eminence**

the rounded contour of the little finger, and as such, they all act on the little finger.

**gluteus medius**

deep to the gluteus maximus is the

**gluteus minimus**

deep to the gluteus medius is the

**tensor fascia lata**

is a thick, squarish muscle in the superior aspect of the lateral thigh.

**medial compartment of the thigh**

The muscles in the **____** are responsible for adducting the femur at the hip

**anterior compartment of the thigh**

The muscles of the **____** flex the thigh and extend the leg.

**rectus femoris**

is on the anterior aspect of the thigh

**astus lateralis**

is on the lateral aspect of the thigh

 **vastus medialis**

is on the medial aspect of the thigh

**vastus intermedius**

is between the vastus lateralis and vastus medialis and deep to the rectus femoris.

**sartorius**

is a band-like muscle that extends from the anterior superior iliac spine to the medial side of the proximal tibia.

**hamstring group**

The three long muscles on the back of the knee are the

**fibularis tertius**

a small muscle that originates on the anterior surface of the fibula, is associated with the extensor digitorum longus and sometimes fused to it, but is not present in all people.

**superior extensor retinaculum**

Thick bands of connective tissue called the **__** (transverse ligament of the ankle)

**inferior extensor retinaculum**

hold the tendons of these muscles in place during dorsiflexion.