Download - Muscles
Muscles
Direction of Muscle Fibers
Fig. 11-1
Sites of Muscle Attachment
• _________ attach bone to bone. ________ attach muscle to bone.Ligaments Tendons
. . or cartilage or connective tissue.
• Origin = stationary point of muscle attachment
• Insertion = mobile point of muscle attachment
• Belly = fleshy part of the muscle
• Aponeurosis = large, flat tendon
Special Tendons
Galea aponeurotica
Coordination of Muscle Action
Agonist (prime mover) – a muscle whose contraction is chiefly responsible for a particular movement Synergist – assist the agonist; may provide additional pull near the insertion or may stabilize the point of origin Antagonist – contraction opposes the action of the agonist
e.g. Biceps brachii and Triceps brachii are antagonists
Muscles Work as LeversLever = a rigid structure that moves on a fixed point, or fulcrum, when a force is applied to it. This force overcomes resistance.
Components of a Lever System
• Applied Force = muscle contraction • Lever = bone• Fulcrum = joint• Resistance = weight of body parts, gravity, objects
point of attachment
F
AF
R
Classes of Levers(determined by position of fulcrum)
First Class Lever - fulcrum lies between the AF & resistance
e.g. hyperextension of neck (Fig 11-2a)
Classes of LeversSecond Class Lever – resistance lies between AF & fulcrum
e.g. plantar flexion (Fig 11-2b)
Classes of LeversThird Class Lever – AF lies between resistance & fulcrum
e.g. flexion of elbow (Fig 11-2c)
Naming of Muscles
• Orientation of muscle fibers- Rectus (straight)- Transverse (horizontal)- Oblique (angled)
• Body region (review Fig 1-6)
- Brachialis - Gluteus
Naming of Muscles
• Relative position- External / Internus- Superficialis (superficial) / Profundus (deep) - Supra / Infra
• Size- Maximus / Minimus- Major / Minor- Longus (long) / Brevis (short)
Naming of Muscles
• Shape - Deltoid (triangle; D)
- Trapezius (trapezoid)
• Number of origins (heads)- Biceps- Triceps- Quadriceps
Naming of Muscles
• Location of origin & insertion - Coracobrachialis- Iliotibial tract
• Action- Abductor / Adductor- Pronator / Supinator- Flexor / Extensor
Head & Neck
Platysma
insertion
origin
What is its action? ___________________depresses mandible
Head & Neck
Digastric muscle
Neck muscles
1. Digastric 5. Sternohyoid 6. Sternothyroid
Neck Muscles
Chest, Shoulder, & Back
Chest, Shoulder, & Back
Chest, Shoulder, & Back
Chest, Shoulder, & Back
Arm Muscles
Orbicularis oris
TrapeziusSCM
Pectoralis major
Serratus anterior
Deltoid
Biceps brachii
BrachioradialisPronator teres
Flexor carpi radialisFlexor carpi ulnaris
Arm Muscles
Coracobrachialis
Brachialis
Pronator teresFlexor carpi radialis
Palmarus longusFlexor carpi ulnaris
Arm MusclesSemispinalis capitus
SCM
Splenius capitus
Levator scapulaeTrapezius
Triceps brachii
Deltoid
InfraspinatusTeres minor
Teres major
Arm Muscles
Triceps brachii
Aconeus
Extensor carpi radialis longus
Extensor carpi radialis brevis
Extensor carpi ulnaris
Extensor digitorum
Trunk & Abdominal Muscles
External abdominalobliques
Serratus anterior
Linea alba
Trunk & Abdominal Muscles
External intercostals
Rectus abdominis
Internal abdominal obliques
Trunk & Abdominal Muscles
Serratus anterior
External intercostals
Rectus abdominis
Linea alba
Transverse abdominis
External oblique
Internal oblique
Trunk & Abdominal Muscles
Linea alba
Trunk & Abdominal Muscles
Internal intercostals
Trunk & Abdominal Muscles
Diaphragm
Central tendonof diaphragm
Trunk & Abdominal Muscles
Erector Spinae (sacrospinalis)
Origin: transverse & spinous process of C, T, and L
Insertion: same as origin
Action: extends the spine
Trunk & Abdominal Muscles
Quadratus lumborum
Origin: Iliac crest
Insertion: transverse processes upper L (1 -4)
Action: flexes spine
Hips, Buttocks, & Groin
Tensor Fascia Latae
Origin: iliac crest of the illium
Insertion: iliotibial tract
Action: flexes & abducts the thigh
Hips, Buttocks, & Groin
Iliopsoas - Iliacus
Origin: iliac crest
Insertion: lesser trochanter of femur
Iliopsoas – psoas major
Origin: transverse processes of L
Insertion: lesser trochanter of femur
Action of both iliopsoas: flexes thigh
Hips, Buttocks, & Groin
Inguinal ligament
Hips, Buttocks, & Groin
Gluteus Maximus
Origin: gluteal line of illium
Insertion: gluteal tuberosity of femur
Action: extends and laterally rotates thigh
Gluteus Medius
Origin: outer surface of the illium
Insertion: greater trochanter of femur
Action: abducts and medially rotates thigh
Leg Muscles
IT tract
Tensor fasciae latae
Sartorius
Quadriceps
Rectus femoris
Vastus lateralis
Vastus medialis
Leg Muscles
Vastus lateralis
Vastus medialis
Vastus intermedius
Adductor longus
Adductor magnus
Leg Muscles
Gracilis
Leg Muscles
Biceps femoris(long head)
Biceps femoris(short head)
Semitendonosis
Semimembranosis
Adductor magnus Gracilis
Leg Muscles
Fibularis longus
Tibialis anterior
Soleus
Extensor digitorum longus
Leg Muscles
Tibialis anterior
Fibularis longus
Extensor digitorum longus
Soleus
Gastrocnemius
Leg Muscles
Gatrocnemius
Calcaneal tendon
Leg Muscles
Tibialis posterior
Flexor digitorum longus