1. Muscle Names & Movement
October 27, 2016

2. Rules of Muscle Movement
All muscles have at least two points of attachment.
The origin is attached to the less movable bone
The insertion is attached to the more moveable bone.
Muscles can only contract / pull. They cannot push.
During contraction, the muscle insertion moves toward the origin.
interactive animation!
If muscles can’t push, how do we do the opposite movement?
How do we extend the arm?

3. Rules of Muscle Movement
All muscles have at least two points of attachment.
The origin is attached to the less movable bone
The insertion is attached to the more moveable bone.
Muscles can only contract / pull. They cannot push.
During contraction, the muscle insertion moves toward the origin.
interactive animation!
Different muscles – called antagonists – do the opposite movement.
Example: biceps flexes the elbow while the triceps extends the muscle.

4. Movements
Flexion – a movement that decreases the angle between two bones, bringing them closer together.
Extension – a movement that increases the angle between two bones, putting them farther apart.
Hyperextension – extension of a joint beyond its normal range of motion
For each, challenge the students to identify as many different examples as possible … and act them out.
Flexion of arm is going up above head

5. Movements
abduction – movement of a limb away from the midline of the body.
adduction – movement of a limb towards the midline of the body
For each, challenge the students to identify as many different examples as possible … and act them out.

6. Movements rotation – movement of a bone raround its longitudinal axis
circumduction – the proximal end of a limb is stationary while the distal end moves in a circle
For each, challenge the students to identify as many different examples as possible … and act them out.

7. Movements of the foot
dorsiflexion – lifting the foot so that its superior surface approaches the shin
plantar flexion – pointing the toes
inversion – turning sole medially
eversion – turning sole laterally
For each, challenge the students to identify as many different examples as possible … and act them out.

8. Movements of radius and ulna
supination – turning the palm so that it faces anteriorly
mnemonic: cupping a bowl of soup in your palm
pronation– turning the palm so that it faces posteriorly
Pronation and supination are used as synonyms (almost) for eversion and inversion in foot, too

9. Movements Contest time!
Get bonus points for (correct) unique responses!
Contest time!
Work with a partner to come up with as many ways to do each of the following movements as possible:
Flexion
Extension
Hyperextension
Abduction
Adduction
circumduction
Make this a contest! 1 pt for each correct, 2 pts for each one no one else go!

10. Types of Muscles
Name
Definition
Example
Prime Mover
Muscle that has major responsibility for a certain motion
Brachialis is prime mover for elbow flexion
Antagonist
Muscle that reverses/opposes a motion
Triceps is the antagonist for elbow flexion
Synergist
Muscles that assist movement by also producing the motion or stabilizing joints and reducing unwanted movements
Biceps brachii and brachioradialis are synergists for elbow flexion
Fixator
A type of synergist that stabilizes the origin of the prime mover, so that only the insertion moves
Rotator cuff muscles are fixators of elbow flexion
Rotator cuff muscles are found around scapula
Note: Muscles often have different roles for different motions. For example, a prime mover for one motion is usually the antagonist for the opposite motion.

11. Muscles of the anterior face and neck
Name
Location
Action(s)
Masseter
Superficial cheek muscle
Close jaw
Orbicularis oculi
Around eye
Closes eye
Orbicularis oris
Around mouth
Purses lips (kisses)
Sternocleidomastoid
Mastoid process of temporal bone to sternum & clavicle
Flexes neck & rotates head
Temporalis
Over temporal bone
No muscle diagrams this year!!
But you need to know general location and actions …
Whoop!

12. Muscles of respiration
Name
Location
Action(s)
diaphragm
Dome-shaped muscle between thoracic and abdominal cavities
Major muscle for breathing – contraction increases size of thoracic cavity for inspiration; relaxation decreases size of thoracic cavity for expiration
external intercostals
Under ribcage
Elevates ribs to increase size of thoracic cavity for inspiration
internal intercostals
Deep to external intercostals, under ribcage
Depresses ribs for forced expiration

13. Muscles of abdominal wall
Name
Location
Action(s)
Obliques (internal and external)
Diagonal (oblique) fibers crossing from sides to center of abdomen
Flexes, laterally flexes, or rotates vertebral column
Rectus abdominus
Straight up and down (rectus)in middle of abdomen
Flexes vertebral column
Transverse abdominis flexes or laterally flexes vertebral column and compresses abdominal cavity

14. Muscles that move the humerus
Name
Location
Action(s)
Latissimus dorsi
Mid back (wrapping around to humerus)
Prime mover of humerus extension (swimmer’s muscle), also adducts, & medially rotates arm
Pectoralis major
chest
Primer mover of humerus flexion humerus, also adducts and medially rotates arm
Triceps brachii
Posterior of humerus
Extends & adducts humerus
Biceps brachii
Anterior of humerus
Flexes humerus
Rotator cuffs
Secure humerus to glenoid cavity
Stabilize joint, rotates, abducts, adducts
Rotator cuffs: subscapularis, supraspinatus, infraspinatus, teres minor
Flexion of arm is lifting above head, extension is down, hyper extension is behind

15. Muscles that move the forearm
Name
Location
Action(s)
Brachialis
Anterior and lateral to humerus, posterior to biceps brachii
Prime mover of forearm
Biceps brachii
Anterior to humerus
Primer mover of humerus flexion humerus, also adducts and medially rotates arm
Triceps brachii
Posterior to humerus
Extends & adducts humerus
Rotator cuffs: subscapularis, supraspinatus, infraspinatus, teres minor
Flexion of arm is lifting above head, extension is down, hyper extension is behind
Fun Fact: Biceps curls should really be called brachialis curls!

16. Muscles that move the thigh
Name
Location
Action(s)
Gluteus maximus
Buttocks
Prime mover of thigh extension, also lateral rotation
Iliopsoas
Anterior hip and thigh
Prime mover of thigh flexion
Gluteus maximus is one of the strongest muscles of the body
Fun Fact:
Iliopsoas is combination of psoas and iliacus

17. Muscles that move the lower leg
Name
Location
Action(s)
Quadriceps
Anterior thigh, superior to knee
Extends lower leg and flexes thigh
hamstrings
Posterior thigh, superior to knee
Flexes leg and extends thigh
Quadriceps (four headed) group contains four distinct muscles: rectus femoris, vastus intermedius, vastus lateralis, vastus medialis
Hamstrings contains biceps femoris, semimembranosus, and semitendinosus

18. Practice
On your note card, write the name of 3 muscles and their actions. Quiz each other on the muscle names and movements in the “congo line”. If your partner can’t guess the movement, act it out for them.

19. Closure What were our objectives, and what did you learn about them.
How does what we did today address our statement of Inquiry, TOK connection, or Learner profile trait?