1. The Muscular System
Chapter 10

2. Understanding Muscles
Pull never push
Attach to skeleton via tendons or muscles via aponeurosis
Attachment points
Origin: end attaches to a stationary bone; doesn’t move
Insertion: end attaches to a moving bone; moves
Contractions shorten muscles

3. Functional Groups Agonist (prime movers) Antagonist Synergist Fixators
Prime responsibility for causing a movement
Antagonist
Oppose/reverse movement
Regulate agonist by adding resistance
Synergist
Assist prime mover
Add extra force or reduce undesirable movement
Fixators
Immobilize bone or muscle origin
Not mutually exclusive

4. Naming Muscles Location Shape Size Direction of fibers & fasicles
Bone or region associated w/
Brachii and femoris
Shape
Deltoid and trapezius
Size
Maximus, minimus, longus
Direction of fibers & fasicles
Rectus, oblique, transversus
Number of origins
Biceps and triceps
Location of attachment
Points of origin & insertion
Sternocleidomastoid
Action
Flexor , extensor, supinator

5. Fasicle Arrangement Determines range of mov’t & power Types Parallel
Parallel to long axis
Pennate
Short & attach obliquely to an insertion tendon
Uni-, bi-, or multi
Convergent
Broad origin converges to an insertion
Circular
Concentric rings around external openings
Contractions close

6. Lever Systems
A lever is a rigid bar moving on a fixed point (fulcrum) when force is applied (effort) to move resistance (load)
Bones = levers, joints = fulcrums, muscle contract = effort at insertion, load = bone and everything else
Mechanical advantage (power lever)
Effort farther from load then fulcrum
Little effort needed
Force gained for speed and stability
E.g. car jack
Mechanical disadvantage (speed lever)
Effort nearer load then fulcrum
Force lost for speed and range
E.g. shovel

7. Classes of Levers First Second Third Uncommon in body Always advantage
Most skeletal muscles
Always disadvantage

8. Learning Muscles Need to know Studying Names of major muscles
Functions/actions of muscles
Table 10.1
Location
Studying
Learn names
Look for clues in names from existing knowledge
Draw and or act out
Identify on models or self

9. Muscles to Know Facial expression Scapula Humerus Mastication
Frontalis
Orbicularis oculi & oris
Zygomaticus major
Buccinator
Platysma
Extrinsic eye
Superior, inferior, medial, lateral rectus
Superior & inferior oblique
Mastication
Masseter
Temporalis
Pterygoid
Moving head & deep to back
Sternocleidomastoid
Capitis group
Erector spinae group
Abdominal wall
Rectus abdominis
External & internal oblique
Transverse abdominis
Scapula
Trapezius
Serratus anterior
Pectoralis minor
Levator scapula
Rhomboids major & minor
Humerus
Pectoralis major
Latissimus dorsi
Deltoid
Supraspinatus
Infraspinatus
Subscapularis
Teres major
Forearm
Brachialis
Brachioradialis
Biceps & triceps brachii
Supinator
Pronator teres

10. Muscles to Know (cont.) Wrist Fingers Thumb Breathing Pelvic floor
Flexor carpi radialis & ulnaris
Extensor carpi radialis & ulnaris
Fingers
Flexor digitorum superficialis & profundus
Extensor digitorum
Thumb
Extensor pollicis longus & brevis
Abductor pollicis longus & brevis
Breathing
Diphragm
External & internal intercostals
Pelvic floor
Coccygeus group
Levator ani
External anal sphincter
Femur at hip
Illiacus & psoas major (Iliopsoas)
Gluteus maximus, medius, & minimus
Adductor group
Thigh
Gracilis
Sartorius
Leg at knee
Quadriceps femoris
Rectus femoris
Vastus intermedius, lateralis, and medialis
Hamstrings
Semitendinosus
Semimembranosus
Biceps femoris

11. Muscles to Know (cont.) Foot at ankle Toes Gastrocnemius Soleus
Tibialis anterior & posterior
Fibularus group (peroneus muscles)
Toes
Flexor & extensor digitorum longus
Flexor & extensor hallucis longus