The Muscular System AP Fall 2016 IV Muscle

The Muscular System A&P Fall 2016

IV. Muscle Movements, Types and Names A. Type of Body Movements 1. Muscles connect to bones at no less than 2 points a. Origin- attached to an immovable or less movable bone i. A muscle may have more than one origin b. Insertion- attached to a moveable bone i. When a muscle contracts , the insertion moves closer to the origin

2. Common Body Movements a. *Make flashcards of these movement names and definitions* There are 13 terms and definitions Scissors and Paper are available

• Flexion- brings two bones closer together • Extension- moves two bones farther apart • Rotation- moves bones around longitudinal plane • Abduction- moving limb away from midline • Adduction- moving limb toward midline • Circumduction- limb moves in a circle

Dorsiflexion- lifting foot toward shin Plantar Flexion- pointing toes Inversion- turn the foot toward the midline Eversion- turn the foot away from midline Supination- palm is out, radius & ulna are parallel • Pronation- palm in in, radius crosses ulna • Opposition- thumb touching the tips of other fingers (on the same hand) • • •

B. Naming Skeletal Muscles 1. Direction of the muscle fiber a. Direction based of midline OR long axis of a limb bone b. “Rectus” means fiber run parallel to line i. Ex. Rectus Abdominus c. “Oblique” means fiber run at a slant i. External Oblique

2. Relative size of the muscle a. “Maximus” = largest i. Ex. Gluteus Maximus b. “Minimus” = smallest c. “Longus” = long

3. Location of the muscle a. location means the bone with which it is associated i. Ex. Temporalis & Frontalis

4. Number of origins a. Muscles with the term “cep” b. Prefix refers to number of origins i. Ex. Bicep (has 2 origins)

5. Location of the origin and insertion a. Both the origin bone and insertion bone are in the name i. Ex. Sternocleidomastoid ii. Origins: Sternum (Sterno) & Clavicle (Cleido) iii. Insertion: Mastoid process of temporal bone

6. Shape of the muscle a. Some muscles have a distinct shape i. Ex. Deltoid (means triangle)

7. Action of the muscle a. Name includes “Body Movement Terms” i. Ex. Flexor or Extensor

C. Arrangement of Fascicles 1. Circular a. facicles arranged in concentric circles b. surround exterior body openings i. Ex. Eyes, mouth, etc ii. Openings close when muscle contracts

2. Convergent a. Fascicles converge toward a single insertion tendon b. Produces triangular or fan shaped muscles i. Ex. Pectoralis major

3. Parallel a. fascicles run parallel to the long axis of the muscle b. creates a strap-like muscle i. Ex. sartorius

4. Fusiform a. Modification of parallel arrangement b. gives spindle-shaped muscles i. Ex. Bicep Brachii

5. Pennate a. means “feather” b. short muscles attach obliquely to a central tendon c. 3 subcategories i. Unipennate- inserts on one side of the tendon ii. Bipennate- Inserts into opposite sides of the tendon iii. Multipennate- Inserts into multiple sides of the tendon

V. Gross Anatomy of Skeletal Muscles A. Head and Neck Muscles 1. Facial Muscles Name Origin Insertion Action(s) a. Frontalis Cranial aponeurosis Skin of eyebrows Raises eyebrows b. Orbicularis Oculi Frontal bone & maxilla Blinks & closes eye c. Orbicularis Oris Mandible & maxilla Skin & muscle around mouth Closes & protrudes lips d. Buccinator Maxilla & mandible Orbicularis oris near molars Compresses cheek, holds food between teeth during chewing e. Zygomaticus Zygomatic bone Tissue around eyes Skin & muscle Raises corner of mouth at corner of lips

Frontalis

Orbicularis Oculi

Orbicularis Oris

Buccinator

Zygomaticus

2. Chewing Muscles Name a. Masseter Origin Insertion Action(s) Temporal Mandible Bone Closes Jaw b. Temporali Temporal Mandible s Bone Closes Jaw

Masseter

Temporalis

3. Neck Muscles Name Origin a. Sternocleido- Sternum & mastoid Clavicle b. Platysma Insertion Action(s) Temporal Bone (Mastoid Process) Flexes neck; laterally rotates head Tenses skin of neck (as in shaving) Connective Tissue tissue around covering of mouth superior chest muscles

Sternocleidomastoid

Platysma

B. Trunk Muscles 1. Anterior Muscles Name a. Pectoralis Major Origin Sternum, clavicle & 1 st-6 th ribs b. Rectus Abdominus Pubis c. External Oblique Lower 8 ribs Insertion Proximal humerus Action(s) Adducts & flexes humerus Sternum & Flexes 5 th-7 th ribs vertebral column Iliac crest Flexes & rotates vertebral column

Pectoralis Major

Rectus Abdominis

External Oblique

2. Posterior Muscles Name Origin Insertion Action(s) a. Trapezius Occipital bone & all cervical & thoracic vertebrae Scapular spine Raises, & clavicle retracts & rotates scapula b. Latissimus Dorsi Lower spine & iliac crest Proximal humerus Extends & adducts humerus c. Erector Spinae Iliac crests, ribs 312, & vertebrae Ribs, thoracic & cervical vertebrae Extends & laterally flexes spine d. Quadratus Lumborum Iliac crest, lumbar fascia Transverse processes of upper lumbar vertebrae Flexes spine laterally; extends spine e. Deltoid Scapular spine & clavicle Humerus Abducts humerus

Trapezius

Latissimus Dorsi

Erector Spinae

Quadratus Lumborum

Deltoid

C. Muscles of the Upper Limb 1. Muscles of the Humerus that act on the Forearm Name Origin Insertion Action(s) a. Biceps Brachii Scapula of shoulder girdle Proximal radius Flexes elbow and supinates forearm b. Brachialis Distal humerus Proximal ulna Flexes elbow c. Triceps Brachii Shoulder girdle & proximal humerus Ulna Extends elbow

Biceps Brachii

Brachialis

Triceps Brachii

2. Muscles of the forearm that act on the wrist and hand Name Origin Insertion Action(s) a. Flexor carpi radialis Distal humerus 2 nd & 3 rd metacarpals Flexes wrist & abducts hand b. Flexor carpi ulnaris Distal humerus & posterior ulna Carpals of wrist & 5 th metacarpal Flexes wrist & adducts hand c. Flexor digitorum superficialis Distal humerus, ulna Middle & radius phalanges of the 2 nd-5 th fingers d. Extensor carpi radialis Humerus Base of 2 nd & 3 rd Metacarpals Extends wrist & abducts hand e. Extensor digitorum Distal phalanges of 2 nd-5 th figners Extends fingers Distal humerus Flexes wrist & fingers

Flexor carpi radialis

Flexor Carpi Unlaris

Flexor Digitorum Superficialis

Extensor carpi radialis

Extensor Digitorum

D. Muscles of the lower limb 1. Muscles causing movement at the hip joint Name a. Gluteus Maximus Origin Sacrum & Ilium Insertion Proximal Femur Action(s) Extends hip (when forceful extension is required) b. Gluteus Medius Ilium Proximal Femur c. Iliopsoas Ilium & Lumbar vertebrae Femur Abducts thigh; steadies pelvis during walking Flexes hip d. Adductor Muscles Pelvis Proximal Femur Adduct & medially rotate thigh

Gluteus Maximus

Gluteus Medius

Iliopsoas

Adductor Muscles

2. Muscles causing movement at the knee joint Name Origin Insertion Action(s) a. Hamstring Group (Semitendinosus, Semimembranosus, Biceps Femoris) Ischial Tuberosity Proximal Tibia Flex knee & extend hip b. Sartorius Ilium Proximal Tibia Flexes thigh on hip c. Quadriceps Group (Vastus Medialis, Intermedius, & Lateralis; Rectus Femoris Vasti: Femur Tibial tuberosity All extend via patellar knee; Rectus ligament Femoris also flexes hip on thigh Rectus: Pelvis

Hamstring Group

Sartorius

Quadriceps Group

3. Muscles causing movement at the ankle & foot Name Origin Insertion Action(s) a. Tibialis Anterior Proximal Tibia 1 st tarsal & 1 st Dorsiflexes & metatarsal of inverts foot b. Extensor Digitorum Longus c. Fibularis Muscles Proximal Tibia Distal toes 2 -5 Extends toes & Fibula d. Gastrocnemius Distal Femur e. Soleus Metatarsals of Plantar flex & foot evert foot Calcaneus Proximal Tibia Calcaneus & Fibula Plantar flexes foor & flexes knee Plantar flexes foot

Tibialis Anterior

Extensor Digitorum Longus

Fibularis Muscles

Gastrocnemius

Soleus