Major Muscles of the Human Body

Question 1

Neck

1. Sternocleidomastiod

Answer 1

Origin: sternum and clavicle

Insertion: mastoid process

Function: flexes the head from side to side and rotates the neck

Question 2

Deep Vertebral Column
— Erector Spinae Group
1. Spinalis
(most medial)

Answer 2

Origin: cervical and thoracic vertebrae

Insertion: cervical and thoracic vertebrae

Function: extends and laterally flexes the spine

Question 3

Deep Vertebral Column
- Erector Spinae Group
2. Longissimus
(more lateral than spinalis)

Answer 3

Origin: cervical, thoracic and lumbar vertebrae

Insertion: mastoid process, cervical and thoracic vertebrae

Function: extends and laterally flexes the spine and head

Question 4

Deep Vertebral Column
- Erector Spinae Group
3. Iliocostalis
(most lateral)

Answer 4

Origin: sacrum, lumbar vertebrae and the ribs

Insertion: ribs and the cervical vertebrae

Function: extends and laterally flexes the spine

Question 5

Thoracic Cage

1. Diaphragm

Answer 5

Origin: sternum, the ribs and the lumbar vertebrae

Insertion: central tendon

Function: increases volume of the ribs and decreases pressure in the thoracic cavity, thus drawing in air

Question 6

Thoracic Cage

2. Internal Intercostals

Answer 6

Origin: inferior aspect of all ribs

Insertion: superior aspects of all the ribs

Function: elevation and depression of ribs

Question 7

Abdomen

1. Rectus Abdominis

Answer 7

Origin: pubic crest

Insertion: xiphoid process and the inferior ribs

Function: flexes the trunk

Question 8

Abdomen

2. External Obliques

Answer 8

Origin: lower 8 ribs

Insertion: iliac crest and pubis

Function: flexes and rotates vertebral column and compress abdomen

Question 9

Upper Limbs

1. Pectoralis Major

Answer 9

Origin: clavicle, lower sternum and first to sixth ribs

Insertion: intertubercular groove

Function: internal rotation, adduction and flexion of the arm

Question 10

Upper Limbs

2. Latissimus Dorsi

Answer 10

Origin: lumbar vertebrae, half of the thoracic vertebrae, iliac crest and sacrum

Insertion: intertubercular groove of the humerus

Function: adducts, extends and internally rotates

Question 11

Rotator Cuff

1. Supraspinatus

Answer 11

Origin: supraspinous fossa of scapula

Insertion: greater tubercle of the humerus

Function: stabilizes the shoulder joint and abducts the shoulder

Question 12

Rotator Cuff

2.Infraspinatus

Answer 12

Origin: infraspinous fossa

Insertion: greater tubercle of the humerus

Function: stabilizes the shoulder joint and laterally rotates the shoulder

Question 13

Rotator Cuff

3. Teres Minor

Answer 13

Origin: lateral border of the scapula

Insertion: greater tubercle of the humerus

Function: stabilizes the shoulder joint and laterally rotates the shoulder

Question 14

Rotator Cuff

4. Subscapularis

Answer 14

Origin: subscapular fossa of scapula

Insertion: lesser tubercle of the humerus

Function: rotates the humerus medially and stabilizes the shoulder

Question 15

Scapula

1. Trapezius

Answer 15

Origin: base of the occipital bone, cervical and thoracic vertebrae

Insertion: spine of the scapula, the acromion process and the clavicle

Function: scapular elevation, adduction/retraction, upward rotation, depression and the extension of the neck

Question 16

Scapula

2. Rhomboid Major and Minor

Answer 16

Origin: - major T2-T5 - minor C7-T1

Insertion: lower medial border of the scapula

Function: elevates scapula and rotates scapula downward

Question 17

Scapula

3. Levator Scapulae

Answer 17

Origin: C1-C4

Insertion: medial border of scapula

Function: elevates the scapula and rotates the scapula downward

Question 18

Scapula

4. Pectoralis Minor

Answer 18

Origin: third rib to fifth rib

Insertion: corocoid process of the scapula

Function: elevates the ribs, depresses and protracts the scapula

Question 19

Scapula

5. Deltoid

Answer 19

Origin: the clavicle, acromion and the spine of the scapula

Insertion: deltoid tuberosity of the scapula

Function: - anterior medially rotates - lateral abducts the arm - posterior extends and laterally rotates the arm

Question 20

6. Teres Major

Answer 20

Origin: inferior lateral border of the scapula

Insertion: intertubercular groove of the humerus

Function: medially rotates, adducts and extends the humerus at the arm

Question 21

Flexors and Extensors

1. Biceps Brachii

Answer 21

Origin: - short coracoid process - long supraglenoid tubercle

Insertion: radial tuberosity

Function: supinates forearm and flexes the elbow

Question 22

Flexors and Extensors

2. Brachialis

Answer 22

Origin: lower anterior surface of the humerus

Insertion: coranoid process of ulna

Function: flexes the elbow

Question 23

Flexors and Extensors

3. Triceps Brachii

Answer 23

Origin: - lateral, posterior aspect of humerus - long, infraglenoid tubercle of scapula - medial, posterior aspect of humerus

Insertion: olecranon process of ulna

Function: extensor of the arm

Question 24

Flexors and Extensors

4. Brachioradialis

Answer 24

Origin: lateral epicondyle of humerus

Insertion: styloid process of the radius

Function: flexes the elbow and plays the biggest part when arm is pronated

Question 25

1. Pronator Teres

Answer 25

Origin: medial epicondyle of humerus and coronoid process of the ulna

Insertion: mid-lateral surface of radius

Function: Pronates arm and flexes elbow

Question 26

2. Supinator

Answer 26

Origin: lateral epicondyle of humerus

Insertion: anterior and lateral aspects of radious

Function: supinates the arm