Axial

Axial Skeleton

Includes the bones of the skull, sternum, ribs, vertebrae, sacrum, coccyx, and other associated bones.

Axial Muscles

Muscles that must attach to features of the axial skeleton.

Functions of Axial Muscles

Help position the head, move and position the spinal column, and move the ribcage.

Categories of Axial Muscles

1. Head and neck muscles 2. Vertebral column muscles 3. Rib cage and body wall muscles 4. Pelvic floor muscles.

Muscles of Facial Expression to Know

Occipitofrontalis, orbicularis oculi, orbicularis oris, zygomaticus major and minor, platysma.

Important Neck Muscle

Sternocleidomastoid.

Buccinator Muscle

Located in the cheeks, helps circulate food and generates suction when drinking.

Buccinator "Trumpeter" Muscle

Called so because it distends outward while playing the trumpet.

Extraocular Muscles

Muscles that move the eyeball.

Technical Term for Chewing

Mastication.

Main Chewing Muscles

Masseter, temporalis, and pterygoids.

Tongue Muscles Naming Pattern

Usually have "-glossus" in their names.

Throat Wall Muscles Naming Pattern

Usually have "-pharyngeus" in their names.

Bilateral Contraction

Occurs when paired muscles pull equally on both sides of the body.

Unilateral Contraction

Occurs when one side contracts more than the other side.

Ipsilateral Movement

Movement toward the same side where the contraction occurred.

Contralateral Movement

Movement toward the opposite side from where the contraction occurred.

Suprahyoid Muscles

Muscles located above the hyoid bone: digastric, mylohyoid, stylohyoid.

Infrahyoid Muscles

Muscles located below the hyoid bone: sternohyoid, omohyoid, sternothyroid, thyrohyoid.

Erector Spinae Muscles

Group of three vertical columns of muscle running up and down the back.

Three Erector Spinae Muscles from Lateral to Medial

Iliocostalis, longissimus, spinalis.

Splenius Muscles Location

Found along the back of the neck.

Scalene Muscles Location

Found in the deep anterior and lateral neck.

Main Examples of Intercostal Muscles

External intercostals and internal intercostals.

Functions of External Intercostals

Assist with forced inspiration.

Functions of Internal Intercostals

Assist with forced expiration.

Main Abdominal Wall Muscles

External oblique, internal oblique, rectus abdominis, transversus abdominis.

Diaphragm Function During Inspiration

Contracts and descends to allow the lungs to expand.

Diaphragm Function During Expiration

Relaxes and ascends to allow the lungs to contract.

Weakness of Pelvic Floor Muscles

Can lead to urinary incontinence or urinary leakage.