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Question 1

What is the origin of the Masseter muscle?

Answer 1

Zygomatic arch

The Masseter muscle elevates the mandible and is innervated by the mandibular branch of the trigeminal nerve (CN V3).

Question 2

What is the insertion of the Temporalis muscle?

Answer 2

Coronoid process of mandible

The Temporalis muscle elevates and retracts the mandible and is innervated by deep temporal branches of CN V3.

Question 3

What action does the Sternocleidomastoid muscle perform when acting unilaterally?

Answer 3

Rotates head to opposite side

Bilaterally, it flexes the neck and is innervated by the spinal accessory nerve (CN XI), C2–C3.

Question 4

What is the action of the Supraspinatus muscle?

Answer 4

Abducts arm (first 15°)

The Supraspinatus is innervated by the suprascapular nerve (C5–C6).

Question 5

What is the nerve supply for the Infraspinatus muscle?

Answer 5

Suprascapular nerve (C5–C6)

The Infraspinatus muscle laterally rotates the arm.

Question 6

What is the origin of the Teres Minor muscle?

Answer 6

Lateral border of scapula

The Teres Minor laterally rotates the arm and is innervated by the axillary nerve (C5–C6).

Question 7

What is the action of the Subscapularis muscle?

Answer 7

Medially rotates arm

The Subscapularis is innervated by the upper and lower subscapular nerves (C5–C6).

Question 8

What is the insertion of the Deltoid muscle?

Answer 8

Deltoid tuberosity of humerus

The Deltoid muscle abducts, flexes, and extends the arm and is innervated by the axillary nerve (C5–C6).

Question 9

What is the action of the Biceps Brachii muscle?

Answer 9

Flexes elbow, supinates forearm

The Biceps Brachii is innervated by the musculocutaneous nerve (C5–C7).

Question 10

What is the origin of the Triceps Brachii muscle?

Answer 10

Long head: infraglenoid tubercle; Lateral and medial heads: posterior humerus

The Triceps Brachii extends the elbow and is innervated by the radial nerve (C6–C8).

Question 11

What is the action of the Brachioradialis muscle?

Answer 11

Flexes forearm at elbow

The Brachioradialis is innervated by the radial nerve (C5–C7).

Question 12

What is the nerve supply for the Flexor Carpi Radialis muscle?

Answer 12

Median nerve (C6–C7)

The Flexor Carpi Radialis flexes and abducts the wrist.

Question 13

What is the origin of the Pectoralis Major muscle?

Answer 13

Clavicle, sternum, and costal cartilages (1–6)

The Pectoralis Major adducts and medially rotates the arm and is innervated by medial and lateral pectoral nerves (C5–T1).

Question 14

What is the action of the Latissimus Dorsi muscle?

Answer 14

Extends, adducts, and medially rotates arm

The Latissimus Dorsi is innervated by the thoracodorsal nerve (C6–C8).

Question 15

What is the insertion of the Trapezius muscle?

Answer 15

Lateral clavicle, acromion, spine of scapula

The Trapezius elevates, retracts, and rotates the scapula and is innervated by the spinal accessory nerve (CN XI), C3–C4.

Question 16

What is the action of the Rhomboid Major muscle?

Answer 16

Retracts and rotates scapula

The Rhomboid Major is innervated by the dorsal scapular nerve (C4–C5).

Question 17

What is the origin of the Rectus Abdominis muscle?

Answer 17

Pubic crest and symphysis

The Rectus Abdominis flexes the vertebral column and is innervated by intercostal nerves (T7–T12).

Question 18

What is the action of the Gluteus Maximus muscle?

Answer 18

Extends and laterally rotates thigh

The Gluteus Maximus is innervated by the inferior gluteal nerve (L5–S2).

Question 19

What is the insertion of the Gluteus Medius muscle?

Answer 19

Greater trochanter of femur

The Gluteus Medius abducts and medially rotates the thigh and is innervated by the superior gluteal nerve (L4–S1).

Question 20

What is the action of the Tensor Fasciae Latae muscle?

Answer 20

Abducts and medially rotates thigh

The Tensor Fasciae Latae is innervated by the superior gluteal nerve (L4–S1).

Question 21

What is the origin of the Rectus Femoris muscle?

Answer 21

Anterior inferior iliac spine

The Rectus Femoris extends the leg and flexes the thigh and is innervated by the femoral nerve (L2–L4).

Question 22

What is the action of the Biceps Femoris muscle?

Answer 22

Flexes leg and extends thigh

The Biceps Femoris is innervated by the sciatic nerve (L5–S2).

Question 23

What is the insertion of the Gastrocnemius muscle?

Answer 23

Calcaneus via Achilles tendon

The Gastrocnemius plantar flexes the foot and flexes the knee and is innervated by the tibial nerve (S1–S2).

Question 24

What is the action of the Soleus muscle?

Answer 24

Plantar flexes foot

The Soleus is innervated by the tibial nerve (S1–S2).

Question 25

What is the **origin** of the **Tibialis Anterior** muscle?

Answer 25

Lateral condyle and upper tibia ## Footnote The Tibialis Anterior dorsiflexes and inverts the foot and is innervated by the deep fibular (peroneal) nerve (L4–L5).