1. Muscle Movements, Roles, Names, and Gross Anatomy Notes 3
Objectives:
I will be able to:
Identify the different types of body movements.
Describe the different roles of muscles.
Name and locate the major muscles of the human body and state the action of each.

2. Ordinary Body Movements
flexion
extension
hyperextension: extension that greater than 180o
rotation
abduction
adduction
circumduction

3. Special Movements
Certain movements cannot be classified as one of the ordinary body movements and occur at only a few joints, these are called Special Movements.
dorsiflexion: flexing your foot upward at the ankle
plantar flexion: flexing your foot downward at the ankle
inversion: turning the sole of your foot inward
eversion: turning the sole of your foot outward

4. Special Movements
supination: turning the palm upward or rolling outward of the foot
pronation: turning the palm downward or the rolling inward of the foot
opposition: moving the thumb to touch the fingertips

5. Skeletal Muscle Interactions/Roles
prime mover: muscle with the major responsibility for a certain movement
antagonist: muscle that opposes or reverses a prime mover
synergist: muscle that aids a prime mover in a movement and helps prevent rotation
fixator: stabilizes the origin of a prime mover

6. Naming of Skeletal Muscles
Direction of muscle fibers
Example: rectus (straight)
Relative size of the muscle
Example: maximus (largest)
Location of the muscle
Example: many muscles are named for bones (e.g., temporalis)
Number of origins
Example: triceps (three heads)

7. Naming of Skeletal Muscles
Location of muscle’s origin and insertion
Example: sterno (on the sternum)
Shape of the muscle
Example: deltoid (triangular)
Action of the muscle
Example: flexor and extensor (flexes or extends a bone)

8.  What is “opposition” movement?
Which way does your palm turn when pronating?
Touching fingertips to thumb
Downward

9. Arrangement of Fascicles
Muscle fascicle arrangement varies producing different structures and functional properties.
Types of fascicle arrangements:
circular: arranged in concentric rings
convergent: converge toward a single insertion tendon, triangular
parallel: run parallel to the long axis of the muscle
fusiform: modified parallel with a spindle shape
unipennate: fascicles insert into only one side of a tendon
bipennate: fascicles insert into opposite sides of a tendon
multipennate: fascicles insert into multiple sides of a tendon

10. Arrangement of Fascicles

11.  The arrangement of fascicles affects what two things?
Structure and function

12. Head and Neck Muscles Facial Muscles:
Frontalis: covers the frontal bone, allows you to raise your eyebrows
Orbicularis oculi: fibers run in circles around the eyes, allows you to close your eyes, squint, blink, and wink
Orbicularis oris: make up your lips, closes mouth and protrudes the lip
Buccinator: runs horizontally across your cheek, flattens and compresses cheek for whistling and holding food between teeth for chewing
Zygomaticus: runs from the corner of the mouth to the cheekbone, the “smiling” muscle

13. Head and Neck Muscles Neck Muscles:
Masseter: runs from the zygomatic process to the mandible, closes the jaw
Temporalis: fan-shaped over the temporal bone, synergist for the masseter
Neck Muscles:
Platysma: sheet-like covering the anterolateral neck, pulls the corners of the mouth inferiorly producing sad face
Sternocleidomastoid: paired muscles on each side of the neck, flexes the neck downward

14. Head and Neck Muscles

15. Trunk Muscles Anterior Muscles:
Pectoralis major: fan-shaped covering the upper chest, forms the anterior wall of the axilla (armpit), acts to adduct and flex the arm
Intercostals: found between the ribs, assist in raising and depressing the rib cage for breathing
Rectus abdominus: most superficial, paired muscles extending from the pubis to the rib cage, flex the vertebrae, compress the abdomen during defecation and childbirth

16. Trunk Muscles Posterior Muscles:
External oblique: paired superficial muscles of the lateral walls of the abdomen, flex the vertebral column, rotate the trunk, and bend it laterally
Internal oblique: paired deep muscles of the abdomen, run at right angles to the external oblique and have the same functions
Transversus abdominus: deepest muscle of abdominal wall, compresses abdominal contents
Posterior Muscles:
Trapezius: most superficial muscles of the posterior neck and upper trunk, have a diamond shape, elevate, depress, adduct, and stabilize the scapula

17. Trunk Muscles
Latissimus dorsi: two large, flat muscles covering the lower back, assist in the power stroke movement of swimming or striking a blow
Erector spinae: paired, deep muscles of the back, prime mover of back extensions, can cause painful spasms when the back is injured
Quadratus lumborum: fleshy muscles forming part of the posterior abdominal wall, flex the spine laterally, and extend the lumbar spine
Deltoid: triangular, forming the rounded part of your shoulder, prime movers of arm abduction

18. Trunk Muscles

19.  Which muscle group is the prime mover of back extension?
Which muscle of the posterior trunk is the synergist of the pectoralis major muscle in arm abduction?
Erector spinae
Latissimus dorsi

20. Muscles of the Upper Limb
Triceps brachii: located on the posterior side of the humerus, is the prime mover of elbow extension, antagonist of biceps brachii and brachialis
All three anterior muscles of the humerus (bone) cause elbow flexion. From strongest to weakest:
Brachialis: lies deep to the biceps brachii and is a prime mover in elbow flexion, lifts the ulna (forearm bone)
Biceps Brachii: lies below the anterior deltoid and is a prime mover for flexion of the forearm, lifts the radius (forearm bone), best known for bulging when flexing your elbow and forearm
Brachioradialis: weak muscle arises on the lower humerus and aids in elbow flexion and pronation and supination of the forearm

21. Deep Trunk and Arm Muscles

22. 
Which muscle is the antagonist of the biceps brachii when the biceps flexes the elbow?
How is a prime mover different from a synergist?
Triceps brachii
Prime mover is the major muscle responsible for a certain movement, synergist assists the prime mover

23. Muscles of the Lower Limb
Muscles that act on the lower limb cause movement at the hip, knee, and foot joints.
Muscles Causing Movement at the Hip Joint
Gluteus maximus: superficial muscle of the hip forming most of the buttock, a powerful hip extensor involved with climbing stairs and jumping
Gluteus medius: lies beneath the gluteus maximus, a hip abductor that steadies the pelvis during walking, also an injection site
Iliopsoas: a fused muscle (iliacus and psoas major) deep inside the pelvis, a prime mover of hip flexion and keeps the body from falling backward when standing straight
Adductor muscles: muscle mass at the medial side of each thigh, adduct, or press the thighs together

24. Muscles of the Lower Limb
Muscles Causing Movement at the Knee Joint
Hamstring group: muscle mass of the posterior thigh consisting of the biceps femoris, semimembranosus, and the semitendinosus; prime movers of thigh extension and knee flexion
Sartorius: thin, strap-like superficial muscle of the thigh, a synergist that assists with sitting cross-legged
Quadriceps group: muscle mass of the anterior thigh consisting of the rectus femoris, vastus medialis, vastus intermedius, and vastus lateralis; prime movers of knee extension for powerful kicking

25. Muscles of the Lower Limb
Muscles Causing Movement at the Ankle and Foot
Tibialis anterior: superficial muscle of the anterior leg, responsible for dorsiflexion and inversion of the foot
Extensor digitorum longus: lateral to the tibialis anterior, a prime mover of toe extension
Fibularis muscles: lateral to the extensor digitorum longus, consists of the fibularis longus, fibularis brevis, and fibularis tertius; an antagonist to the tibialis anterior, causes plantar flexion and eversion (movement of the sole to the outside) of the foot
Gastrocnemius: a two-bellied muscle of the posterior leg that forms the calf; a prime mover for plantar flexion of the foot
Soleus: located deep to the gastrocnemius, a synergist of the gastrocnemius

26. Pelvis, Hip, and Thigh Muscles

27. Muscles of the Lower Leg

28.  Which muscle group is the antagonist of the hamstring muscles?
What are two good sites for intramuscular injections in adults?
What is the location of the gastrocnemius?
Quadriceps on the anterior thigh
Deltoid and gluteus medius
Posterior leg, forms the calf

29. Superficial Muscles: Anterior

30. Superficial Muscles: Posterior