BIO 2O1 Axial Muscles

Question 1

Levator Palpebrae Superioris

Answer 1

A: Elevates upper eyelid

Question 2

Orbicularis Oculi

Answer 2

A: closes eyes, helps tears flow across eye

Question 3

Zygomaticus Major/Minor

Answer 3

A: elevates upper lip

Question 4

Orbicularis Oris

Answer 4

A: closes lips, protrudes lips, uniquely developed in humans for speech

Question 5

Temporalis

Answer 5

A: elevation of the mandible, chewing (mastication)

Question 6

Masseter

Answer 6

A: elevation of the mandible, chewing (mastication)

Question 7

Platysma

Answer 7

A: depression of the mandible

Question 8

Digastric

Answer 8

O: Anterior Belly: Digastric fossa of the mandible
Posterior Belly: Mastoid process of the temporal bone
I: Hyoid bone
A: depression of the mandible (hyoid fixed), elevates hyoid (mandible fixed)

Question 9

Stylohyoid

Answer 9

O: Styloid process of the temporal bone
I: Hyoid bone
A: Elevates/retracts hyoid

Question 10

Mylohyoid

Answer 10

O: Inferior margin of the mandible
I: Hyoid bone
A: Elevates the floor of the mouth in swallowing

Question 11

Sternohyoid

Answer 11

O: Manubrium of sternum, medial end of clavicle
I: Hyoid bone
A: Depression of the hyoid

Question 12

Omohyoid

Answer 12

A: Depression of the hyoid

Question 13

Thyrohyoid

Answer 13

O: Thyroid cartilage of the larynx
I: Hyoid bone
A: Depression of the Hyoid

Question 14

Sternothyroid

Answer 14

O: Manubrium of sternum, costal cartilage
I: Thyroid cartilage of the larynx
A: Depresses the larynx

Question 15

Sternocleidomastoid

Answer 15

O: Manubrium of sternum, medial 1/3 of clavicle
I: Mastoid process of the temporal bone
A: Unilateral action: contralateral; rotation of the head
Bilateral action: flexion of the neck

Question 16

Scalenes

Answer 16

A: Bilateral action: neck flexion, elevation of ribs 1-2 (spine fixed), aid in breathing
Unilateral action: lateral flexion of the neck

Question 17

Semispinalis

Answer 17

A: Unilateral action: contralateral rotation of the neck
Bilateral action: extension of the head and neck

Question 18

External Intercostals

Answer 18

A: Expand the thoracic cavity (aiding in inspiration)

Question 19

Internal Intercostals

Answer 19

A: Depresses and retracts the ribs, compresses thoracic cavity, (aiding in expiration)

Question 20

Diaphragm

Answer 20

A: prime mover of inspiration, contraction aids in childbirth and expulsion of urine and feces

Question 21

Rectus Abdominis

Answer 21

A: flexion of the trunk, stabilizes pelvic region while walking, compresses abdominal viscera

Question 22

External Abdominal Oblique

Answer 22

A: support viscera, stabilizes vertebral column, maintains posture

Question 23

Internal Abdominal Oblique:

Answer 23

A: support viscera, stabilizes the vertebral column, maintains posture
Unilateral action: ipsilateral rotation of the waist

Question 24

Transverse Abdominis

Answer 24

A: compresses abdominal contents, does NOT contribute to vertebral column movements

Question 25

Linea Alba

Answer 25

Li

Question 26

Spinalis

Answer 26

A: unilateral action: lateral flexion of the vertebral column bilateral action: extension of the vertebral column

Question 27

Longissimus

Answer 27

A: depresses the ribs Unilateral action: lateral flexion of vertebral column, contralateral rotation of the head Bilateral action: extension of the vertebral column, extension of the head,

Question 28

Iliocostalis

Answer 28

A: unilateral action: lateral flexion of the vertebral column extension action: of vertebral column; depresses the ribs

Question 29

Serratus Anterior

Answer 29

A: protracts the scapula, prime mover in all forward-reaching and pushing actions, fixes scapula during abduction of the arm

Question 30

Pectoralis Minor

Answer 30

O: Ribs 3-5, and overlying fascia I: Coracoid process of scapula A: protracts the scapula

Question 31

Pectoralis Major

Answer 31

O: Medial 1/2 clavicle, lateral margin of sternum, costal cartilages 1-7, aponeurosis of external oblique I: intertubercular sulcus of humerus A: flexion of the shoulder, adduction of the shoulder, medial rotation of the shoulder

Question 32

Levator Scapulae

Answer 32

A: elevates scapula (cervical vertebrae fixed), lateral flexion of the back (scapula fixed), retracts and braces shoulder

Question 33

Rhomboideus Major

Answer 33

A: retracts scapula

Question 34

Latissimus Dorsi

Answer 34

A: adduction of the shoulder, extension of the shoulder, medial rotation of the shoulder

Question 35

Trapezius

Answer 35

A: stabilizes scapula and shoulder during the arm movements, elevates/depresses shoulder, rotates and retracts scapula

Question 36

Coracobrachialis

Answer 36

O: Coracoid process of scapula I: Medial aspect of humeral shaft A: shoulder flexion, medial rotation of shoulder