Muscles of the Anterior Neck and Muscles of the Anterior Neck and Throat: SuprahyoidThroat: Suprahyoid

Four deep throat muscles Four deep throat muscles Form the floor of the oral cavityForm the floor of the oral cavity Anchor the tongueAnchor the tongue Elevate the hyoidElevate the hyoid Move the larynx superiorly during swallowingMove the larynx superiorly during swallowing

Muscles of the Anterior Neck and Muscles of the Anterior Neck and Throat: SuprahyoidThroat: Suprahyoid

Figure 10.8a

Muscles of the Anterior Neck and Muscles of the Anterior Neck and Throat: InfrahyoidThroat: Infrahyoid

Straplike muscles that depress the hyoid and Straplike muscles that depress the hyoid and larynx during swallowing and speakinglarynx during swallowing and speaking

Muscles of the Anterior Neck and Muscles of the Anterior Neck and Throat: InfrahyoidThroat: Infrahyoid

Figure 10.8b

Muscles of the Neck: Head Muscles of the Neck: Head MovementsMovements

Major head flexor is the sternocleidomastoidMajor head flexor is the sternocleidomastoid Synergists to head flexion are the suprahyoid Synergists to head flexion are the suprahyoid

and infrahyoidand infrahyoid Lateral head movements are accomplished by Lateral head movements are accomplished by

the sternocleidomastoid and scalene musclesthe sternocleidomastoid and scalene muscles Head extension is accomplished by the deep Head extension is accomplished by the deep

splenius muscles and aided by the superficial splenius muscles and aided by the superficial trapeziustrapezius

Muscles of the Neck: Head Muscles of the Neck: Head MovementsMovements

Figure 10.9a

Muscles of the Neck: Head Muscles of the Neck: Head MovementsMovements

Figure 10.9b

Trunk Movements: Deep Back Trunk Movements: Deep Back MusclesMuscles

The prime mover of back extension is the erector The prime mover of back extension is the erector spinaespinae

Erector spinae, or sacrospinalis, muscles consist Erector spinae, or sacrospinalis, muscles consist of three columns on each side of the vertebrae – of three columns on each side of the vertebrae – iliocostalis, longissimus, and spinalisiliocostalis, longissimus, and spinalis

Lateral bending of the back is accomplished by Lateral bending of the back is accomplished by unilateral contraction of these musclesunilateral contraction of these muscles

Other deep back extensors include the Other deep back extensors include the semispinalis muscles and the quadratus lumborumsemispinalis muscles and the quadratus lumborum

Trunk Movements: Deep Back Trunk Movements: Deep Back MusclesMuscles

Figure 10.9d

Figure 10.9c

Trunk Movements: Short Trunk Movements: Short MusclesMuscles

Four short muscles extend from one vertebra to anotherFour short muscles extend from one vertebra to another These muscles are synergists in extension and rotation of the These muscles are synergists in extension and rotation of the

spinespine

Muscles of Respiration: External Muscles of Respiration: External IntercostalsIntercostals

The primary function of The primary function of deep thoracic muscles deep thoracic muscles is to promote is to promote movement for breathingmovement for breathing

External intercostals – External intercostals – more superficial layer more superficial layer that lifts the rib cage that lifts the rib cage and increases thoracic and increases thoracic volume to allow volume to allow inspirationinspiration

Figure 10.10a

Muscles of Respiration: Internal Muscles of Respiration: Internal IntercostalsIntercostals

Internal intercostals – Internal intercostals – deeper layer that aids deeper layer that aids in forced expirationin forced expiration

Diaphragm – most Diaphragm – most important muscle in important muscle in inspirationinspiration

Figure 10.10a

Muscles of Respiration: The Muscles of Respiration: The DiaphragmDiaphragm

Figure 10.10b

Muscles of the Abdominal WallMuscles of the Abdominal Wall The abdominal wall is composed of four The abdominal wall is composed of four

paired muscles (internal and external obliques, paired muscles (internal and external obliques, transversus abdominis, and rectus abdominis), transversus abdominis, and rectus abdominis), their fasciae, and their aponeurosestheir fasciae, and their aponeuroses

Fascicles of these muscles run at right and Fascicles of these muscles run at right and oblique angles to one another, giving the oblique angles to one another, giving the abdominal wall added strengthabdominal wall added strength

Muscles of the Abdominal WallMuscles of the Abdominal Wall In addition to forming the abdominal wall, In addition to forming the abdominal wall,

these muscles:these muscles: Are involved with lateral flexion and rotation of Are involved with lateral flexion and rotation of

the trunkthe trunk Help promote urination, defecation, childbirth, Help promote urination, defecation, childbirth,

vomiting, coughing, and screamingvomiting, coughing, and screaming

Muscles of the Abdominal WallMuscles of the Abdominal Wall

Figure 10.11a

Muscles of the Abdominal WallMuscles of the Abdominal Wall

Figure 10.11b

Muscles of the Abdominal WallMuscles of the Abdominal Wall

Figure 10.11c

Muscles of the Pelvic Floor Muscles of the Pelvic Floor (Pelvic Diaphragm)(Pelvic Diaphragm)

The pelvic diaphragm is composed of two The pelvic diaphragm is composed of two paired muscles – levator ani and coccygeuspaired muscles – levator ani and coccygeus

These muscles: These muscles: Close the inferior outlet of the pelvisClose the inferior outlet of the pelvis Support the pelvic floorSupport the pelvic floor Elevate the pelvic floor to help release feces Elevate the pelvic floor to help release feces Resist increased intra-abdominal pressure Resist increased intra-abdominal pressure

Muscles of the Pelvic Floor: Pelvic Muscles of the Pelvic Floor: Pelvic DiaphragmDiaphragm

Figure 10.12a

Muscles Inferior to the Pelvic Muscles Inferior to the Pelvic FloorFloor

Two sphincter muscles allow voluntary control Two sphincter muscles allow voluntary control of urination (sphincter urethrae) and of urination (sphincter urethrae) and defecation (external anal sphincter)defecation (external anal sphincter)

The ischiocavernosus and bulbospongiosus The ischiocavernosus and bulbospongiosus assist in erection of the penis and clitorisassist in erection of the penis and clitoris

Muscles of the Pelvic FloorMuscles of the Pelvic Floor

Figure 10.12b

Muscles of the Pelvic FloorMuscles of the Pelvic Floor

Figure 10.12c

Extrinsic Shoulder MusclesExtrinsic Shoulder Muscles Muscles of the thoraxMuscles of the thorax

Anterior: pectoralis major, pectoralis minor, Anterior: pectoralis major, pectoralis minor, serratus anterior, and subclavius serratus anterior, and subclavius

Posterior: latissimus dorsi, trapezius muscles, Posterior: latissimus dorsi, trapezius muscles, levator scapulae, and rhomboids levator scapulae, and rhomboids

These muscles are involved with the movements of These muscles are involved with the movements of the scapula including elevation, depression, the scapula including elevation, depression, rotation, and lateral and medial movementsrotation, and lateral and medial movements

Prime movers of shoulder elevation are the Prime movers of shoulder elevation are the trapezius and levator scapulaetrapezius and levator scapulae

Extrinsic Shoulder MusclesExtrinsic Shoulder Muscles

Figure 10.13a

Extrinsic Shoulder MusclesExtrinsic Shoulder Muscles

Figure 10.13b