Ch.9 Gross Anatomy of Skeletal Muscles
Retinacula
bands of deep fascia, which hold tendons of muscles of forearm, blood vessels, and nerves close to wrist
Abdominal Wall Muscles fascicle orientation
Fascicles of these muscles run at right and oblique angles to one another, giving the abdominal wall added strength
Rectus sheath
Fibrous sheath surrounding rectus abdominis Formed by aponeurosis of the oblique muscles and connecting them to linea alba
External intercostals
more superficial layer that lifts the rib cage and increases thoracic volume to allow inspiration
Major head flexor
sternocleidomastoid
How muscles are named
location, size, origin and insertion, shape, orientation of fasciculi, number of heads, function
Levator Scapulae and Rhomboid: ACTION
A-scapular elevation Rhomboid major and minor
SUPRASPINATUS ACTION
ABDUCTS ARM; HOLDS HEAD OF HUMERUS IN PLACE
Abdominal Wall Muscles actions
Aid in functions such as forced expirations (coughing and screaming), vomiting, defecation, urination, and childbirth
Cutaneous muscles: Primary location in Animals and Humans
Animals have cutaneous muscles all over the trunk that allow skin to twitch (remove irritants); Humans have cutaneous muscles primarily on the face and neck
Abdominal Wall Muscles movements
Are involved with lateral flexion and rotation of the trunk
Internal intercostal muscles
Between the ribs Fibers running at right angle to the external intercostal Depress the rib cage during expiration
External intercostal Muscles
Between the ribs Fibers running downward toward the sternum Elevate ribs for inspiration
Forearm flexion
Brachialis and Biceps brachii are the chief forearm flexors The Brachioradialis acts as a synergist and helps stabilize the elbow
Muscles of the Shoulder Girdle Association
Closely associated with muscles that move the arm
Muscles of the Shoulder Girdle Connections and Movements
Connect the scapula to nearby bones and move the scapula upward, downward, forward, and backward
Tendinous intersections
Cross rectus abdominis and at three or more locations and muscles appear segmented
POSTERIOR FOREARM & HAND EXTENSORS
Extensor carpi radialis longus Extensor carpi ulnaris Extensor digitorum
Flexion and extension of the elbow
Flexion and extension of the elbow
ANTERIOR FOREARM & HAND FLEXORS
Flexor carpi radialis Flexor carpi ulnaris Palmaris longus Flexor digitorum
LINEA ALBA
From the xiphoid process through the navel to the pelvis
Muscles of Mastication
Mainly deal with the movement of the mandible: Temporalis and masseter muscles elevate the mandible; Gravity opens the jaw
Thoracic Muscles
Mainly involved in the process of breathing Diaphragm External intercostals Internal intercostals
Cutaneous muscles: Insertions
Insertions are into the skin, causing movement of the facial skin, lips, and eyelids;
TERES MINOR ACTION
LATERALLY ROTATES AND ADDUCTS ARM
INFRASPINATUS ACTION
LATERALLY ROTATES ARM; HOLDS HEAD OF HUMERUS IN PLACE
SUBSCAPULARIS ACTION
MEDIALLY ROTATES AREM; HOLDS HEAD OF HUMERUS IN PLACE
Forearm Movements
Movements at the elbow Flexion: biceps brachii, brachioradialis, and brachialis Extension: triceps brachii Supination and pronation
WRIST, HAND, AND FINGER MOVEMENT: ANTERIOR
Muscles on anterior surface of forearm: flexion as well as abduction and adduction of the wrist
WRIST, HAND, AND FINGER MOVEMENT: POSTERIOR
Muscles on posterior surface of forearm: extension and abduction
A: Biceps Femoris; A-hip extension, knee flexion
NAME AND ACTION
A: Extensor Digitorum Longus A- extension of toes
NAME AND ACTION
A: Gastrocnemius A- plantarflexion, eversion B: ACHILLES TENDON
NAME AND ACTION
A: Peroneus (Fibularis) Longus A- plantarflexion, eversion
NAME AND ACTION
A: Soleus A- plantarflexion
NAME AND ACTION
A:Tibialis Anterior A- ankle dorsiflexion, inversion
NAME AND ACTION
PSOAS A- hip flexion ANTERIOR
NAME, ACTION, ORIENTATION
A: Tensor fasciae latae; LATERAL ROTATION AND HIP FLEXION B:SARTORIUS; LATERAL ROTATION BOTH ANTERIOR AND MEDIAL GROUP
NAME, ACTION, ORIENTATION, PART OF WHAT GROUP
A: VASTUS LATERALIS B: VASTUS MEDIALIS C: VASTUS INTERMEDIUS A- KNEE EXTENSION ANTERIOR AND MEDIAL QUADRICEPS
NAME, ACTION, ORIENTATION, PART OF WHAT GROUP
Rectus femoris A- hip flexion, knee extension ANTERIOR QUADRICEPS
NAME, ACTION, ORIENTATION, PART OF WHAT GROUP
A: Semimembranosus B: Semitendinosus A- hip extension, knee flexion, medial rotation
NAMES AND ACTION
A: TENSOR FASCIAE LATAE B: SARTORIUS C: PSOAS MINOR D: ILIACUS E: PSOAS MAJOR F: PSOAS (ILIOPSOAS) G: PECTINEUS H: ADDUCTOR LONGUS I: GRACILIS J: ADDUCTOR MAGNUS K: RECTUS FEMORIS L: VASTUS INTERMEDIUS (DEEP TO RECTUS FEMORIS, NOT VISIBLE) M: VASTUS MEDIALIS N: VASTUS LATERALIS O: QUADRICEPS FEMORIS
NAMES AND WHAT VIEW IS THIS?
A: HAMSTRINGS B: SEMITENDINOSUS C: BICEPS FEMORIS D: SEMIMEMBRANOSUS POSTERIOR VIEW
NAMES; WHAT VIEW IS THIS?
Cutaneous muscles: Origins
Origins of facial muscles are on skull bones or fascia;
Cutaneous muscles: Actions
Produce facial expressions; Control openings on face;
Orientation of fasciculi
Rectus (straight); Oblique (at an angle); Transverse (across)
SHOULDER JOINT FUNCTION
Support and stabilize shoulder joint, reinforce the capsule of the shoulder by holding the head of the humerus in the glenoid cavity Secondarily act as synergists and fixators
Forearm extension
The Triceps brachii is the prime mover of forearm extension
Aponeurosis
a very broad tendon, e.g. palmar aponeurosis
Forearm Supination and pronation
are accomplished primarily by forearm muscles
Muscles in the anterior compartment of the leg
cause dorsiflexion, inversion, or eversion of the foot and extension of the toes
Internal intercostals
deeper layer that aids in forced expiration
Intrinsic foot muscles
flex or extend and abduct or adduct the toes
Muscles of the posterior compartment of the leg
flex the leg, plantar flex and invert the foot, and flex the toes
Movement of head and neck caused by neck muscles
flexion, extension, rotation, and lateral flexion
Abdominal Wall Muscles are composed of:
four paired muscles (Internal and External obliques, Transversus abdominis, and Rectus abdominis), their fasciae, and their aponeuroses
Muscles of the lateral compartment of the leg
plantar flex and evert the foot
Head extension is accomplished by
splenius capitis and trapezius muscles
Lateral head movements are accomplished by
the sternocleidomastoid and scalene muscles