Muscles Flashcards
Actions
Are movement resulting from the contraction of a muscle or group of muscles
Prime movers
Are the most efficient muscles for a particular action
Agonist
Contracts to cause an action
Antagonist
Opposes or counters the agonist
Synergist
Aid in agonist
Fixators
Stabilize the origin of an agonist
(Facial expression)
Frontalis
Anterior part of epicarnius, & serves to elevate the eyebrows
(Facial expression)
Occipitalis
Posterior part of epicranius, it dread scalp posteriorly
(Facial expressions)
Orbicularis oculi
Closes eye, squinting
(Facial expressions)
Orbicularis Oris
Closes mouth, purses lips
(Facial expressions)
Zygomaticus
Elevates corner of mouth
(Facial expressions)
Risorius
Draws corner of mouth laterally
(Muscles of mastication)
Buccinator
Compressed cheek, holds food b/t teeth
(Muscles of mastication)
Medial/lateral pterygoids
Grinding of teeth; medial pterygoid elevates mandible while lateral pterygoid protracts jaw
(Muscles of mastication)
Temporalis
Elevates jaw
(Muscles of mastication)
Masseter
O & I
Elevates jaw
Origin: zygomatic arch; maxilla
Insert: angle, ramus of mandible
(Muscles of the neck)
Sternocleidomastoid
O & I️
Bilaterally: cervical flexion; unilaterally: cervical rotation to opposite side
O: manubrium, medial clavicle
I: mastoid process (part of temporal bone)
(Muscles of the neck)
Platysma
Depresses mandible
(Muscles of the neck)
Scalenes
Flex & slightly rotates the neck
(Muscles of thorax acting on the scapula)
Trapezius
Upper portion: elevates scapula; middle portion: adducts scapula
Lower portion: depresses scapula
(Muscles of thorax acting on the scapula)
Pectoralis minor
O & I️
Abducts scapula
O: clavicle, sternum, ribs 1-6
I️: intertubercular sulcus Of humerus
(Muscles of thorax acting on the scapula)
Serratus anterior
Abducts scapula
(Muscles of thorax acting on the scapula)
Rhomboids
Adduct scapula
(Muscles of thorax participating in respiration)
Intercostals
Respiration
(externals: inspiration contracts)
(Internals: expiration relaxes)
(Muscles of thorax participating in respiration)
Diaphragm
Inspiration
(Muscles of the shoulder)
Rotator Cuff
SITS: Supraspinatus Infraspinatus Teres Subscapularis
Arise from scapula
(Muscles of the shoulder)
Supraspinatus
Abducts humerus
(Muscles of the shoulder)
Infraspinatus
Laterally rotates humerus
(Muscles of the shoulder)
Teres Minor
Laterally rotates humerus; rotator cuff
(Muscles of the shoulder)
Teres Major
Adducts, extends, medially rotates humerus
(Muscles of the shoulder)
Subscapularis
Medially rotates humerus
(Muscles of the shoulder)
Pectoralis major
Adducts, medially rotates humerus
(Muscles of the shoulder)
Deltoid
Abducts humerus
(Muscles of the shoulder)
Latissimus dorsi
Adducts, extends, medially rotates humerus
(Muscles of the upper extremity (arm & forearm))
Triceps brachii
Elbow extension
(Muscles of the upper extremity (arm & forearm))
Biceps brachii
O & I
Elbow flexion, supinates forearm
O: caracoid process, supraglenoid tubercle of scapula
I: radial tuberosity
(Muscles of the upper extremity (arm & forearm))
Pronator teres
Pronates forearm
(Muscles of the upper extremity (arm & forearm))
Flexor carpi radialis
Wrist flexion
(Muscles of the upper extremity (arm & forearm))
Extensor carpi radialis longus
Wrist extension
(Muscles of the upper extremity (arm & forearm))
Supinator
Supinates forearm
(Muscles of the back)
Erector spinae
Extends vertebral column
(Muscles of the abdomen)
Rectus abdominus
Trunk flexion
(Muscles of the abdomen)
Internal/External obliques
Trunk rotation & lateral flexion; bilaterally, assists in flexion
(Muscles of the abdomen)
Transverse abdominus
Abdominal compression
(Muscles acting on the hip)
Iliopsoas
(Ilicus + Psoas major)
Hip flexion
(Muscles acting on the hip)
Gluteus Maximus
O & I
Hip extension
O: dorsal ilium, sacrum, coccyx
I️: Gluteal tuberosity of femur
(Muscles acting on the hip)
Gluteus medius
Hip abduction
(Muscles acting on the hip)
Tensor fascia latae
Hip abduction
(Muscles acting on the hip)
Adductor magnus
Hip adduction
(Muscles acting on the hip)
Gracilis
Hip adduction
(Muscles acting on the hip)
Sartorius
Hip & knee flexion, laterally rotates femur
O:anterior superior iliac spine (ASIS)
I️: medial proximal tibia
(Muscles acting on the hip)
Rectus femoris
O & I
Hip flexion, knee extension
O:anterior inferior iliac spine (AIIS)
I️: tibial tuberosity, patella
(Muscles acting on the hip)
Hamstrings
Hip extension; knee flexion
(Muscles of the lower extremity)
Quadriceps
Knee extension, hip flexion
4 in group consisting:
- Rectus femoris
- Vastus lateralis
- Vastus medialis
- Vastus intermedius
(Muscles of the lower extremity)
Hamstrings
Knee flexion, hip extension 3 consisting in groups 1. Biceps femoris (lateral) 2. SemiTendinosus (medial; more superficial) 3. Semimembranosus (most medial)
All extends thigh; flexes leg
2&3 Semi’s medially rotates leg
1 Biceos f. Laterally rotates leg
(Muscles of the lower extremity)
Tibialis anterior
Dorsiflexion
(Muscles of the lower extremity)
Gastrocnemius
O & I️
Plantar flexion
O: medial & lateral femoral condyles
I️: calcaneus
(Muscles of the lower extremity)
Soleus
Plantar flexion
Muscle origins & insertions
Origin: doesn’t move; stable; fix end
Insertion: moving; immobile end