SM_221a: Functional Anatomy of the Back

Question 1

Components of the vertebral column are _____, _____, and _____

Answer 1

Components of the vertebral column are vertebrae, intervertebral discs, and ligaments/muscles

(having vertebrae and intervertebral discs separate allows for flexibility/mobility/shock absorption)

Question 2

There are ____ cervical vertebrae

Answer 2

There are 7 cervical vertebrae

Question 3

There are ____ thoracic vertebrae

Answer 3

There are 12 thoracic vertebrae

Question 4

There are ____ lumbar vertebrae

Answer 4

There are 5 lumbar vertebrae

Question 5

There are ____ sacral vertebrae

Answer 5

There are 5 sacral vertebrae

(fused together)

Question 6

Cervical and lumbar spine exhibit ______

Answer 6

Cervical and lumbar spine exhibit lordosis

(convex - i.e. facing anterior)

Question 7

Thoracic and sacral spine exhibit ______

Answer 7

Thoracic and sacral spine exhibit kyphosis

(concave - i.e. facing posterior)

Question 8

The spine of a newborn exhibits ______

Answer 8

The spine of a newborn exhibits kyphosis

(concave - i.e. facing posterior)

Question 9

Scoliosis is abnormal _____ curvature of the spine

Answer 9

Scoliosis is abnormal lateral curvature of the spine

Question 10

The body of a vertebrae faces ______, while the arch faces ______

Answer 10

The body of a vertebrae faces anteriorly, while the arch faces posteriorly

Question 11

Describe the parts of the vertebral arch

Answer 11

Parts of the vertebral arch

• Pedicles connect arch to body
• Lamina extend the pedicles
• Vertebral foramen is where spinal cord is
• Spinous process attaches to muscle
• Articular processes are where two vertebrae on top of each other articulate

Question 12

Cervical vertebrae are distinguished by the presence of a _____

Answer 12

Cervical vertebrae are distinguished by the presence of a transverse foramen

(also vertebral foramen is large b/c spinal cord is larger)

Question 13

Thoracic vertebrae are distinguished by the presence of _____

(vertebral foramen smaller than cervical, spinous processes are larger b/c of attachment to muscles)

Answer 13

Thoracic vertebrae are distinguished by the presence of rib articular facets

(articulate with ribs)

Question 14

Lumbar vertebrae are distinguished by their _____

Answer 14

Lumbar vertebrae are distinguished by their large bodies

Question 15

_____ emerging at the facet joint are implicated in neck and back pain

Answer 15

Osteophytes emerging at the facet joint are implicated in neck and back pain

(also movements at loose articulations can impinge on spinal cord or nerves)

Question 16

Intervertebral foramina are where ______ emerge from

Answer 16

Intervertebral foramina are where spinal nerves emerge from

Question 17

Describe ligaments of the vertebral column

Answer 17

Ligaments of the vertebral column

• Anterior longitudinal ligament: links all vertebrae anteriorly
• Posterior longitudinal ligament: links all vertebrae posteriorly
• Ligamentum flava: links arches of vertebrae together
• Supraspinous ligament: links spines of vertebrae together

(whiplash disrupts these ligaments)

Question 18

Functions of the intervertebral disc are to _____ and _____

Answer 18

Functions of the intervertebral disc are to act as a shock absorber and mediate movement between vertebral bodies

Question 19

Intervertebral discs are composed of an outer _____ and inner _____

Answer 19

Intervertebral discs are composed of an outer annulus fibrosis and inner nucleus pulposus

Question 20

Herniated discs lead to functional deficit or pain because _____

Answer 20

Herniated discs lead to functional deficit or pain because the nucleus pulposus cannot be contained by the damaged annulus fibrosis, compressing the spinal nerve located in the intervertebral foramen

Question 21

Extrinsic muscles of the back come from the ______

Answer 21

Extrinsic muscles of the back come from the hypomere

Question 22

Extrinsic muscles of the back are innervated by ______

Answer 22

Extrinsic muscles of the back are innervated by anterior (ventral) rami

Question 23

Extrinsic muscles of the back attach to ______

Answer 23

Extrinsic muscles of the back attach to limbs

(except serratus posterior)

Question 24

Extrinsic muscles of the back move _____

Answer 24

Extrinsic muscles of the back move limbs

Question 25

Intrinsic muscles of the back come from the ______

Answer 25

Intrinsic muscles of the back come from the epimere

Question 26

Intrinsic muscles of the back are innervated by _____

Answer 26

Intrinsic muscles of the back are innervated by posterior (dorsal) rami

Question 27

Intrinsic muscles of the back attach to the ______

Answer 27

Intrinsic muscles of the back attach to the vertebral column

Question 28

Intrinsic muscles of the back move the _____

Answer 28

Intrinsic muscles of the back move the vertebral column

Question 29

Myotome of the somite divides into the _____ and _____

Answer 29

Myotome of the somite divides into the hypomere and epimere

Question 30

Describe characteristics of the extrinsic muscles of the back

Answer 30

Extrinsic muscles of the bacl

• Come from hypomere
• Innervated by the anterior (ventral) rami
• Attach to limbs except serratus posterior
• Move limbs

Question 31

Name the major extrinsic muscles of the back

Answer 31

Major extrinsic muscles of the back

• Trapezius
• Latissimus dorsi
• Levator scapulae
• Rhomboids
• Serratus posterior

Question 32

Trapezius functions to _____

Answer 32

Trapezius functions to rotate and retract the scapula

Question 33

Trapezius is unique among extrinsic muscles of the back because it ______

Answer 33

Trapezius is unique among extrinsic muscles of the back because it is innervated by the spinal accessory nerve (cranial nerve XI), not an anterior ramus

Question 34

Latissimus dorsi functions to _____

Answer 34

Latissimus dorsi functions to extend and adduct the arm

Question 35

Latissimus dorsi is innervated by the _____

Answer 35

Latissimus dorsi is innervated by the posterior cord brahcial plexus (subcapsular nerves)

Question 36

Levator scapulae functions to _____

Answer 36

Levator scapulae functions to elevate the scapula

Question 37

Rhomboids function to _____

Answer 37

Rhomboids function to retract the scapula

Question 38

Functions of the serratus posterior superior and serratus posterior inferior are _____

Answer 38

Functions of the serratus posterior superior and serratus posterior inferior are unknown

Question 39

Describe characteristics of the intrinsic muscles of the back

Answer 39

Intrinsic muscles of the back

• Come from epimere
• Innervated by posterior (dorsal) rami
• Attach to vertebral column
• Move vertebral column: extension, lateral bending, rotation

Question 40

Name the intrinsic muscles of the back

Answer 40

Intrinsic muscles of the back

• Splenius: capitis and cervicis
• Erector spinae: spinalis, longissimus, iliocostalis
• Transversospinalis: semispinalis, rotatores, multifidus

Question 41

Splenius includes the _____ and _____

Answer 41

Splenius includes the splenius capitis and splenius cervicis

Question 42

Splenius functions in _____, _____, and _____

Answer 42

Splenius functions in extension, ipsilateral rotation, and lateral bending

Question 43

Erector spinae includes the _____, _____, and _____

Answer 43

Erector spinae includes the spinalis, longissimus, and iliocostalis

Question 44

Erector spinae functions in _____, _____, and _____

Answer 44

Erector spinae functions in extension, lateral bending, and ipsilateral rotation

Question 45

Transversospinalis includes the _____, _____, and _____

Answer 45

Transversospinalis includes the semispinalis, rotatores, and mutlifidus

Question 46

Transversospinalis functions in _____, _____, and _____

Answer 46

Transversospinalis functions in contralateral rotation, extension, and lateral rotation

Question 47

This is a _____ vertebra

Answer 47

This is a thoracic vertebra

(articulates with rib)