Study Guide: Axial Muscles

An entire skeletal muscle is covered by a coarse sheath called

Muscles that are arranged like the feathers in a plume are described as

An aponeurosis is

Antagonists are muscles that

A fixed point about which a rod moves is called a

In first-class levers, the

The origin of a muscle is the point of attachment that moves when the muscle contracts.

Skeletal muscles usually act in groups rather than individually.

Prime mover and agonist are synonymous.

The optimum angle of pull of a muscle is generally parallel to the long axis of the bone.

Tipping the head back, as in looking up at the sky, is an example of the function of a first-class lever.

Shape: [blank_start]deltoid[blank_end] Location: [blank_start]brachialis[blank_end] Points of attachment: [blank_start]sternocleidomastoid[blank_end] Number of heads: [blank_start]quadriceps[blank_end] Size of muscle: [blank_start]gluteus maximus[blank_end] Function: [blank_start]adductor[blank_end] Direction of fibers: [blank_start]rectus[blank_end]

[blank_start]Corrugator supercilii[blank_end]: wrinkling the forehead vertically [blank_start]Pterygoids[blank_end]: grating the teeth during mastication [blank_start]Buccinator[blank_end]: kissing [blank_start]Epicranius[blank_end]: raising the eyebrows [blank_start]Sternocleidomastoid[blank_end]: flexing the head [blank_start]Orbicularis oculi[blank_end]: closing the eyes

Label the following diagram

The external oblique compresses the abdomen.

The rectus abdominis flexes the trunk.

The levator ani closes the anal canal.

The external intercostals elevate the ribs.

The coccygeus muscles and levator ani form most of the pelvic floor.

The muscles of the anterior and lateral abdominal wall are arranged in 3 layers.

Label the following diagram: Muscles of the Thorax

Label the following diagram: Muscles of the trunk and abdominal

[blank_start]Semispinalis capitis[blank_end]: bends head and neck laterally [blank_start]External intercostals[blank_end]: elevates ribs [blank_start]Diaphragm[blank_end]: enlarges thorax [blank_start]Sternocleidomastoid[blank_end]: "prayer" muscle [blank_start]Internal oblique[blank_end]: provides important postural function [blank_start]Rectus abdominis[blank_end]: flexes trunk [blank_start]Quadratus lumborum[blank_end]: depresses last rib [blank_start]Erector spinal group[blank_end]: extends vertebral column [blank_start]Levator ani[blank_end]: helps from the floor of the pelvic cavity [blank_start]Zygomaticus major[blank_end]: assists in laughing

Fascicles are bound together into bundles by a tough connective tissue envelope called the [blank_start]perimysium[blank_end].

[blank_start]Convergent[blank_end] muscles have fascicles that radiate out from a small to a wider point of attachment, much like the blades in a fan.

The prime mover is also known as the [blank_start]agonist[blank_end].

When a muscle shortens, the central body portion called the [blank_start]belly[blank_end] contracts.

Lever systems have four component parts: a lever, a fulcrum, a load and a [blank_start]force[blank_end] / [blank_start]pull[blank_end].

During [blank_start]inspiration[blank_end] the diaphragm flattens.

The muscular pelvic floor filling the diamond-shaped outlet is called the [blank_start]perineum[blank_end].

A [blank_start]lever[blank_end] is any rigid bar free to turn about a fixed point called its fulcrum.

The deltoid is so-named because of its descriptive [blank_start]shape[blank_end].

The powerful muscles that either elevate or retract the mandible are the [blank_start]masseter[blank_end] and the [blank_start]temporalis[blank_end].