GROSS ANATOMY OF MUSCLE

GROSS ANATOMY OF MUSCLE

BODY MOVEMENTS

• MUSCLES ARE ATTACHED TO BONE OR CONNECTIVE TISSUE AT NO LESS THAN 2 POINTS

• ORIGIN – ATTACHED TO THE IMMOVABLE OR LESS MOVABLE BONE

• INSERTION – ATTACHED TO THE MOVABLE BONE

• DURING CONTRACTION THE INSERTION MOVES TOWARD THE ORIGIN

TYPES OF BODY MOVEMENTS

• FLEXION –DECREASES ANGLE BETWEEN BONES

• EXTENSION –INCREASES ANGLE BETWEEN BONES

• HYPEREXTENSION –GREATER THAN 180 DEGREES

• http://www.zoology.ubc.ca/~biomania/tutorial/mvmt/mv02.htm

• ABDUCTION –MOVE AWAY FROM THE MIDLINE

• ADDUCTION –MOVE TOWARD MIDLINE


• ROTATION –MOVEMENT OF BONE AROUND A LONGITUDINAL AXIS

• CIRCUMDUCTION –PROXIMAL END STATIONARY WHILE DISTAL END MOVES IN A CIRCLE


• PRONATION – MOVING HAND FROM ANTERIOR TO POSTERIOR POSITION (RADIUS OVER ULNA)

• SUPINATION – HAND FROM POSTERIOR TO ANTERIOR (RADIUS AND ULNA PARALLEL)

• INVERSION – SOLE OF FOOT TURNED MEDIALLY

• EVERSION – SOLE OF FOOT TURNED LATERALLY

• DORSIFLEXION –INSTEP OF FOOT MOVED UP TOWARD SHIN (STANDING ON HEELS)

• PLANTAR FLEX –TOES POINTED DOWNWARD

CRITERIA FOR NAMING MUSCLES

• DIRECTION OF MUSCLE FIBERS– RECTUS –

STRAIGHT– OBLIQUE -

DIAGONALLY

• RELATIVE SIZE– MAXIMUS –

LARGEST– MINIMUS –

SMALLEST– LONGUS – LONGEST– BREVIUS - SHORT

• LOCATION –ASSOCIATION WITH BONE– FRONTALIS– TEMPORALIS

• NUMBER OF ORIGINS– BICEPS – 2 – TRICEPS – 3– QUADRACEPS - 4

• LOCATION OF ORIGIN & INSERTION- STERNOCLEIDOMASTOID

- ORIGIN ON STERNUM & CLAVICLE AND INSERTS ON MASTOID PROCESS

• SHAPE OF MUSCLE– Deltoid – triangular– Trapezius

• ACTION OF MUSCLE– Adductor– Abductor– Extensor– Flexor

HEAD & FACIAL MUSCLES

• Frontalis – covers frontal bone; raises eyebrows & wrinkles forehead

• Temporalis – fan shaped; covers temporal bone; chewing muscle

• Orbicularis Oculi – circular muscle around the eye; close, squint, blink & wink eye

• Orbicularis Oris – circular muscle around mouth; kissing muscle; closes mouth & protrudes lips

http://www.gwc.maricopa.edu/class/bio201/head/head1b.htm

• Buccinator – runs horizontally across the cheek; flattens cheek & holds food in place while chewing

• Zygomaticus – group of muscles that extending from corner of mouth to cheekbone; raises corners of mouth upward; smiling muscle

• Masseter – covers the angle of mandible; closes jaw by elevating mandible

http://www.gwc.maricopa.edu/class/bio201/head/head1b.htm

Neck & Trunk Muscles• Platysma – single sheet - like muscle

covering anterolateral neck; superficial to sternocleidomastoid; pulls the corners of mouth inferior

• Sternocleidomastoid – 2 headed muscle (sternum & clavicle); heads fuse as they insert into mastoid process; bend head to shoulder & bows head

• Pectoralis Major – superficial upper chest muscle; adducts & flexes the arm

• Intercostal muscles –deep muscles between the ribs

• Raise rib cage for inhaling & depresses rib cage for exhaling

• 2 sets – internal & external

• Rectus Abdominis – paired muscles; most superficial of abs; flexes vertebral column, compressed abdomen during defecation & childbirth

• External Obliques – paired muscles on lateral wall of abdomen; flex & rotate vertebral column

• Internal Obliques – deep to external; flex & rotate vertebral column

• Transversus Abdominis – deepest layer; runs horizontal; compress abdominal contents

A

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• Trapezius – diamond or kite shaped; extends neck & adducts scapula

• Latissimus dorsi – covers lower back; extends & adducts humerus

• Erector Spinae – composed of 3 columns– Longissimus– Iliocostalis– Spinalis

– http://www.gwc.maricopa.edu/class/bio201/muscle/musc14.htm

• 1. iliocostalis

• 2. longissimus• 3. spinalis

MUSCLES OF ARM

• Deltoid – triangular; forms rounded part of shoulder; arm abduction

• Biceps brachii – anterior upper arm; 2 heads on shoulder girdle; inserts into radial tuberosity; supinates & flexes arm

• Triceps brachii – posterior upper arm; 3 heads on shoulder girdle& humerus; inserts into ulna; extension of arm

• Flexor carpi radialis – flexes wrist & abducts hand

• Flexor carpi ulnaris – flexes wrist & adducts hand

• Flexor digitorum superficialis – flexes wrist & fingers

f. digitorum

• Extensor carpi radialis – extends wrist & abducts hand ; 2 – longus & brevius

• Extensor digitorum - extends wrist & fingers

• Extensor carpi ulnaris – extends & adducts wrist

• Brachioradialis – flexes forearm

e.c.radialisbrevius

e.c. radialis longus e.c. ulnaris

e. digitorumbrachioradialis

MUSCLES OF THE LEG

• Gluteus maximus – largest; extends & rotates thigh laterally; sciatic nerve present

• Gluteus medius – abducts & rotates thigh medially

• Gluteus minimus – deep to medius; abducts & rotates thigh laterally

• Iliopsoas – fusion of 2 muscles – psoasmajor & iliacus; runs from ilium to lesser trochanter; flexes hip; prevents falling backwards

• Adductor muscles – compose medial thigh; adduct thigh (press together)– A. longus– A. magnus– A. brevius

• Pectineus – crosses under sartorius; adducts & rotates thigh laterally

• Sartorius – most superficial; runs diagonally across thigh; weak thigh flexor

• Gracilis – innermost thigh muscle; flexes & adducts thigh

– http://www.gwc.maricopa.edu/class/bio201/muscle/leg1.htm

Quadriceps

• Rector femoris – straight fibers; origin on iliac crest; flexes thigh & extends leg

• Vastus lateralis – “large lateral”• Vastus medialis – “large medial”• Vastus intermedialis – “large middle”; deep

to rector femoris*Extend leg; origin on femur & join to patellar

ligament

HAMSTRING GROUP

• Biceps Femoris – flexes leg & extends thigh

• Semitendinosus – “1/2 tendon”; flexes leg & extends thigh

• Semimembranosus – “1/2 membrane”; flexes leg & extends thigh

1 & 2 - Long & Short heads of Bicep Femoris3 – semitendinosus4 - semimembranosus

• Gastrocnemius – originates at base of femur & inserts into calcaneous via Achilles tendon; plantar flexion

• Soleus – deep &inferior to gastrocnemius; plantar flexion

• Tibialis Anterior – superficial muscle of the anterior lower leg; inversion & dorsiflexion

• Peroneus muscles – lateral lower leg; eversion & plantar flexion; 3 – longus, brevius, tertius

Drill & Practice Sites

• http://media.pearsoncmg.com/bc/bc_marieb_ehap_8/activities/index.html

• http://www.wiley.com/college/apcentral/anatomydrill/

• http://www.mhhe.com/biosci/esp/2002_general/Esp/default.htm

• http://highered.mcgraw-hill.com/sites/0072919329/student_view0/chapter9/labeling_exercises.html#

GROSS ANATOMY OF MUSCLE

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