muscles of the body

what are the muscle attachments

• Skeletal muscle is wrapped with layers of connective tissue
  – Epimysium
  – Perimysium
  – Endomysium

•  At the ends of each muscle, all of the connective tissue merge to form a tendon which attaches the muscle to a bone

• Tendons usually are cord-like in appearance but sometimes they are flat aponeuroses

• Every muscle has one insertion point and one origin point.
  - Insertion: The bone that moves
  -Origin: The bone that doesn’t move.

what are the actions of skeletal muscles

1) Agonist (prime mover): a muscle that produces a specific movement when it contracts.
– Ex/ the biceps brachii is an agonist that causes flexion of the elbow joint.

2)  Synergist: a muscle that has the same action as the agonist.
– Ex/ The brachialis also causes flexion at the elbow.

3) Antagonist: a muscle whose action opposes that of an agonist.
– Ex/ The triceps brachii is be an antagonist to the biceps
brachii.
4) Fixator: a muscle that prevents movement of bone to help agonist work effectively.
– Ex/ The rotator cuff stabilizes the shoulder for the biceps
brachii.

what are the size naming of skeletal muscles

—Major (large) – pectoralis major
– Maximus (largest) -- gluteus maximus
– Minor (small) – pectoralis minor
– Minimus (smallest) – gluteus minimus
– Longus (long) – abductor pollicis longus
– Longissimus (longest) – longissimus thoracis
– Brevis (short) – adductor brevis

what are the shape naming of skeletal muscles

– Rhomboideus (rhomboidal) – rhomboideus major
– Trapezius (trapezoidal) – trapezius
– Teres (round, cylindrical) – pronator teres
– Deltoid (triangular) – deltoid
– Quadratus (four-sided) –quadratus lumborum

what are the location names of SM

– Capitis (head) – splenius capitis
– Cervicis (neck) – semispinalis cervicis
– Pectoralis (chest) – pectoralis major
– Thoracis (thorax) – spinalis thoracis
– Intercostals (between ribs) – external intercostals
– Abdominis (abdomen) –rectus abdominis

what are more location names of SM

– Lumborum (lower back) – quadratus lumborum
– Femoris ( femur or thigh) – quadriceps femoris
– Fibularis ( fibula) – fibulars longus
– Brachii (arm) – biceps brachii
– Carpi (wrist) – flexor carpi ulnaris
– Digiti (finger or toe) – extensor digiti minimi

– Digitorum (fingers or toes) – flexor digitorum
longus
– Pollicis (thumb) – oppones policis
– Indicis (index finger) – extensor indicis
– Hallucis (great toe) – abductor hallucis
– Superficialis (superficial) – flexor digitorum
superficialialis
– Profundus (deep) – flexor digitorum profundus

number of heads SM 

-Biceps (two heads) – biceps femoris
– Triceps (three heads) – triceps brachii
– Quadriceps (four heads) – quadriceps femoris

orientation of SM

– Rectus (straight) – rectus abdominis
– Transversus (transverse) – transversus abdominis
– Oblique (slanted) – external abdominal oblique

action of SM

-Adductor pollicis (adduct pollex)
– Abdutor digiti minimi (abduct digits)
– Flexor carpi radialis (flex wrist)
– Extensor carpi radialis (extend wrist)
– Pronator teres (pronate forearm)
– Supinator (supinate forearm)
– Levator scapulae (elevate scapula)

what are axial muscles 

have both their origins and insertions on parts of the axial skeleton
• Functions
– Support the head and spinal column
– Facial expression, chewing and swallowing
– Breathing
– Support and protect the abdominal and pelvic
organs

explain frontalis, orbicularis oculi, orbicularis oris, zygomaticus major/minor,

frontalis: Muscle of the scalp
• Functions
– Wrinkles skin of forehead and raises eyebrows
– Move scalp back and forth

orbicularis oculi: Circular muscle of the eye
• Functions
– Close the eyes
– Blinking
– Winking
– Squinting

orbicularis oris: Circular muscle
of the lips
• Functions
– Close the lips
– Purse lips for kissing and whistling

zygomaticus major/minor:

-“smiling muscles”
• Both muscles
have origin on
zygomatic bone
• Function
– Pull on corner of
lips to create
smile

explain temporalis, masseter, digastric and mylohyoid

temporalis:

Has origin on temporal lines of parietal bone
• Inserts on coronoid process of mandible
• Functions: close the jaw

masseter: Has origin on zygomatic arch
• Inserts on coronoid process and angle of mandible
• Function: close the jaw

digastric: Two belly muscle under the chin
• Origin
– Body of mandible (ant belly)
– Mastoid process (post belly)
• Insertion: hyoid bone
• Functions
– Opens mouth(depress mandible)
– Elevates hyoid bone during swallowing and speech

mylohyoid: Forms floor of mouth
• Functions
– Elevates floor of mouth

explain sternocleidomatoid and scalenes

sternocleidomastoid: Muscle of anterior neck
• Origin on manubrium and clavicle
• Inserts on mastoid process
• Functions
– Bilaterally action is to pull head straight forward and down (neck flexion)
– Unilateral action is to rotate head to opposite side

scalenes: Three part muscle
– Anterior scalene
– Middle scalene
– Posterior scalene
• Origin on transverse process of cervical vertebrae
• Inserts on ribs 1-2
• Functions
– Bilateral action flexes neck
– Elevate ribs if spine is fixed

explain biceps brachii, brachialis, coracobrachialis, triceps brachii,

biceps brachii:

Fusiform muscle on front of humerus
• Has two heads (“biceps”)
• Origin
– Long head: superior margin of glenoid cavity
– Short head: coracoid process
• Insertion: radial tuberosity and bicipital aponeurosis
• Function
– Rapid or forceful supination of forearm
– Synergist in elbow flexion

Brachialis: Sits deep to biceps brachii
• Origin: anterior surface of distal humerus
• Insertion: Coronoid process and tuberosity of ulna
• Functions
– Primer mover of elbow flexion

coracobrachialis: Sits medial to biceps brachii
• Origin: Coracoid process of scapula
• Insertion: Medial surface of shaft of humerus
• Functions
– Flex and adduct shoulder

triceps brachii: Muscle on the posterior aspect of humerus
• Three heads (“triceps”)
• Origin
– Long head: inferior margin of glenoid cavity
– Lateral head: posterior surface of proximal humerus
– Medial head: posterior surface of shaft of humerus
• Insertion: Olecranon
• Functions
– Extends elbow
– Long head: extends and adducts humerus

explain pronator teres, flexor carpi radialis, palmaris longus, flexor carpi ulnaris, flexor digitorum superficialis, flexor digitorum profundus, and flexor pollicis longus

pronator teres: Located at proximal end of forearm
• Origin: coronoid process of ulna and humerus near medial epicondyle
• Insertion: lateral surface of shaft of radius
• Functions
– Pronates forearm

flexor carpi radialis: Runs along intermediate aspect of forearm
• Origin: medial epicondyle of humerus
• Insertion: metacarpals II-III
• Functions
– Flexes wrist
– Abducts the wrist

palmaris longus: This muscle is weakly developed sometimes absent
• Origin: medial epicondyle of humerus
• Insertion: palmaraponeurosis and flexor retinaculum
• Functions
– Anchors skin and fascia of palm
– Weak wrist flexor

flexor carpi ulnaris: Runs along ulna
• Origin: medial epicondyle of humerus
• Insertion: carpals (pisiform, hamate) and metacarpal V
• Functions
– Flexes wrist
– Adduct wris

flexor digitorum superficialis: Deep to flexor carpi muscles
• Origin: medial epicondyle of humerus, coronoid process
• Insertion: Middle phalanges II-V
• Functions
– Flexes wrist, metacarpophalangeal (MCP) , and proximal interphalangeal (PIP) joints

flexor digitorum profundus: Deep to flexor digitorum superficialis
• Origin: proximal portion of ulna, coronoid process
• Insertion: Distal phalanges II-V
• Functions
– Flexes wrist, metacarpophalangeal, and both interphalangeal joints of II-V (PIP and DIP)

flexor pollicis longus: Deep muscle of lateral forearm
• Origin: radius
• Insertion: distal phalanx I (pollex)
• Functions
– Flexes phalanges of thumb