5.1: Anatomy of the Muscular System

Question 1

What is conscious control?

Answer 1

Ability to move muscles at own will

Question 2

Define peripheral nerves.

Answer 2

• Nerves outside of the brain and spinal cord
• they send messages to and from the brain

Question 3

What constitutes the central nervous system?

Answer 3

Brain and spinal cord

Question 4

What are motor actions?

Answer 4

• Message FROM the central nervous system
• TO a muscle

Question 5

What are sensory actions?

Answer 5

• Message FROM the external environment
• TO a central nervous system

Question 6

What is the function of tendons?

Answer 6

Connect skeletal muscle to bone; flexible, can bend at joints, cushion against sudden movement

Question 7

What do ligaments connect?

Answer 7

Bone to bone; stabilize joints

Question 8

What is the origin in muscle anatomy?

Answer 8

• the bony site of attachment that is stationary during the movement
• the “fixed” point

Question 9

Define insertion in muscle contraction.

Answer 9

Place that is MOVED during a muscle contraction

Question 10

What is the action of a muscle?

Answer 10

The EFFECT produced by the muscle’s contraction

Question 11

What does innervation refer to?

Answer 11

The peripheral nerve that supplies a muscle with a message from the brain

Question 12

What is the action of the orbicularis oculi?

Answer 12

Eye closure

Innervation: facial nerve (CN VII)

Question 13

What action does the orbicularis oris perform?

Answer 13

Mouth closure; closes lips, protrudes lips forward, presses lips against teeth

Innervation: facial nerve (CN VII)

Question 14

What is the function of the zygomaticus major?

Answer 14

Pull corners of lips upward

Innervation: facial nerve (CN VII)

Question 15

What is the action of the risorius?

Answer 15

Pulls the corners of the mouth posteriorly (grin or grimace)

Innervation: facial nerve (CN VII)

Question 16

What does the occipitofrontalis do?

Answer 16

Raises eyebrows

Innervation: facial nerve (CN VII)

Question 17

What is the action of the buccinator?

Answer 17

Compress cheeks

Innervation: facial nerve (CN VII)

Question 18

What action does the masseter perform?

Answer 18

Jaw closure

Innervation: trigeminal nerve (CN V, mandibular branch)

Question 19

What is the action of the temporalis?

Answer 19

Elevates mandible, closes jaw

Innervation: trigeminal nerve (CN V, mandibular branch)

Question 20

Define lateral flexion.

Answer 20

Side bending of the neck; side flexion

Question 21

What is neck flexion?

Answer 21

Action of moving chin towards the sternum

Question 22

What does bilaterally mean?

Answer 22

Both sides

Question 23

What does unilaterally refer to?

Answer 23

One side

Question 24

What is the origin of the semispinalis capitis?

Answer 24

Articular processes of inferior cervical & transverse process of superior thoracic vertebrae

Question 25

What is the insertion of the semispinalis capitis?

Answer 25

Occipital bone

Question 26

What is the action of the sternocleidomastoid?

Answer 26

Bilateral: neck flexion; Unilateral: turns face to opposite side ## Footnote Origin: sternal end of clavicle and manubrium; Innervation: accessory nerve (CN XI)

Question 27

What is the action of the splenius capitis?

Answer 27

Bilateral extend head; Unilateral laterally flexes neck to same side ## Footnote Origin: spinous process/ligaments of inferior cervical vertebrae; Innervation: cervical spinal nerves

Question 28

What does the longissimus cervicis do?

Answer 28

Bilateral extend head; Unilateral laterally flexes neck to same side ## Footnote Origin: transverse processes of superior thoracic vertebrae; Innervation: cervical and thoracic spinal nerves

Question 29

What is the origin of longissimus thoracis?

Answer 29

Transverse process of all thoracic and lumbar vertebrae

Question 30

What is the action of the thyrohyoid?

Answer 30

Elevates thyroid, depresses hyoid bone ## Footnote Origin: thyroid cartilage of larynx; Innervation: hypoglossal nerve

Question 31

What is the action of the scalenes?

Answer 31

Elevates ribs 1 & 2 ## Footnote Origin: transverse processes of C2-C7; Innervation: cervical spinal nerves

Question 32

Define spine flexion.

Answer 32

Forward bending the trunk; 'cat' stretch

Question 33

What is spine extension?

Answer 33

Backward bending the trunk; 'cow' stretch

Question 34

What is the medial column of erector spinae?

Answer 34

Spinalis ## Footnote Made up of three divisions (spinalis thoracis, spinalis cervicis, and spinalis capitis)

Question 35

What is the intermediate column of erector spinae?

Answer 35

Longissimus ## Footnote Made up of three divisions (longissimus thoracis, longissimus cervicis, longissimus capitis)

Question 36

What is the lateral column of erector spinae?

Answer 36

Iliocostalis ## Footnote Made up of three divisions (iliocostalis lumborum, iliocostalis thoracis, iliocostalis cervicis)

Question 37

What is the origin of the rectus abdominis?

Answer 37

Pubic crest, pubic symphysis

Question 38

What is the action of the external oblique?

Answer 38

Bilateral: flexion of the spine, compress the abdomen; Unilateral: flexes trunk to same side, rotates to opposite side ## Footnote Origin: sternum, ribs (5-12); Innervation: lower intercostal, ilioinguinal nerves

Question 39

What does the internal oblique do?

Answer 39

Compresses abdomen, depresses ribs, flexes spine ## Footnote Origin: iliac crest, lumbodorsal fascia; Innervation: lower intercostal, ilioinguinal nerves

Question 40

What is the action of the transverse abdominis?

Answer 40

Compression of abdomen ## Footnote Origin: lateral inguinal ligament, inner iliac crest; Innervation: first lumbar nerve (T7-L1), iliohypogastric (T12-L1), ilioinguinal (T12-L1)

Question 41

What is the origin of the diaphragm?

Answer 41

Cartilage of ribs 7-12, xiphoid process, lumbar vertebrae

Question 42

What is the action of the internal intercostals?

Answer 42

Depresses ribs (forced expiration) ## Footnote Origin: superior border of ribs 2-12; Innervation: intercostal nerves

Question 43

What is the function of the external intercostals?

Answer 43

Elevates ribs (normal inspiration) ## Footnote Origin: lower border of ribs 1-11; Innervation: intercostal nerves