Bio 3

Question 1

What is the origin of the Masseter muscle?

Answer 1

Zygomatic arch

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

Question 2

What is the insertion point of the Temporalis muscle?

Answer 2

Coronoid process of mandible

The Temporalis elevates and retracts the mandible and is supplied 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).

Question 4

What is the nerve supply for the Supraspinatus muscle?

Answer 4

Suprascapular nerve (C5–C6)

The Supraspinatus abducts the arm for the first 15°.

Question 5

What is the action of the Infraspinatus muscle?

Answer 5

Laterally rotates arm

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

Question 6

What is the blood supply for the Teres Minor muscle?

Answer 6

Circumflex scapular artery

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

Question 7

What is the origin of the Deltoid muscle?

Answer 7

Lateral third of clavicle, acromion, spine of scapula

The Deltoid abducts, flexes, and extends the arm.

Question 8

What is the action of the Biceps Brachii muscle?

Answer 8

Flexes elbow, supinates forearm

It is innervated by the musculocutaneous nerve (C5–C7).

Question 9

What is the insertion of the Triceps Brachii muscle?

Answer 9

Olecranon process of ulna

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

Question 10

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

Answer 10

Radial artery

It flexes and abducts the wrist and is innervated by the median nerve (C6–C7).

Question 11

What is the action of the Pectoralis Major muscle?

Answer 11

Adducts and medially rotates arm

It is innervated by medial and lateral pectoral nerves (C5–T1).

Question 12

What is the origin of the Latissimus Dorsi muscle?

Answer 12

Spinous processes T7–L5, thoracolumbar fascia, iliac crest

The Latissimus Dorsi extends, adducts, and medially rotates the arm.

Question 13

What is the nerve supply for the Trapezius muscle?

Answer 13

Spinal accessory nerve (CN XI), C3–C4

The Trapezius elevates, retracts, and rotates the scapula.

Question 14

What is the action of the Rhomboid Major muscle?

Answer 14

Retracts and rotates scapula

It is innervated by the dorsal scapular nerve (C4–C5).

Question 15

What is the insertion of the Rectus Abdominis muscle?

Answer 15

Xiphoid process and costal cartilages (5–7)

The Rectus Abdominis flexes the vertebral column.

Question 16

What is the origin of the Gluteus Maximus muscle?

Answer 16

Ilium, sacrum, coccyx

The Gluteus Maximus extends and laterally rotates the thigh.

Question 17

What is the action of the Gluteus Medius muscle?

Answer 17

Abducts and medially rotates thigh

It is innervated by the superior gluteal nerve (L4–S1).

Question 18

What is the blood supply for the Rectus Femoris muscle?

Answer 18

Lateral circumflex femoral artery

The Rectus Femoris extends the leg and flexes the thigh.

Question 19

What is the nerve supply for the Biceps Femoris muscle?

Answer 19

Sciatic nerve (L5–S2)

The Biceps Femoris flexes the leg and extends the thigh.

Question 20

What is the action of the Gastrocnemius muscle?

Answer 20

Plantar flexes foot and flexes knee

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

Question 21

What is the insertion of the Soleus muscle?

Answer 21

Calcaneus via Achilles tendon

The Soleus plantar flexes the foot.

Question 22

What is the origin of the Tibialis Anterior muscle?

Answer 22

Lateral condyle and upper tibia

The Tibialis Anterior dorsiflexes and inverts the foot.