Deep back and spinal cord week 2

Question 1

What are some causes of back pain?

Answer 1

1. muscle strain
2. inverveterbral disc herniation
3. arthritis
4. skeletal abnormalities (scoliosos, stenosis, spondyloisthesis (vertebrae not in proper alignment)
5. compression fractures from osteporosis

Question 2

What are 4 useful landmarks for palpation of the back?

Answer 2

1. cervicothoracic junction/vertebral prominens C7
2. spine of the scapula: at level of T3
3. inferior angle of the scapula: at level of T7
4. 12th rib: at level of T12
5. ileac crest: at level of L4

Question 3

Identify the parts of a vertebra.

Answer 3

Question 4

How many cervical vertebrae are there? What are the names of C1 and C2? What is special about C7? What is special about all of the cervical vertebrae? How does their size compare to other vertebrae?

Answer 4

1. there are 7 cervical vertebrae
2. C1: atlas (allows you to shake your head yes)

C2: axis (allows you to shake your head no)

4. C7 has a long easily palpable spinous process and is so referred to as vertebra prominens
5. cervical vertebrae have foramina in their transverse processes to allow for arterial blood supply to the brain. if have unstable C-spine fracture, can compromise blood supply to the brain
6. cervical vertebrae are the smallest. size increases as you go down the spine to compensate for increase load bearing

Question 5

Identify the landmarks of this vertebra. What kind of vertebra is it?

Answer 5

cervical

Question 6

How many thoracic vertebrae are there? What is different about the thoracic vertebrae as it pertains to interactions with bones outside of the spine? What is different about thier spinous processes?

Answer 6

1. 12 thoracic vertebra
2. T1-T10 have costal facets for articulation with ribs on their transverse processes
3. spinous processes are long and slope posteriorly and inferiorly to cover the vertebral body of the vertebra below.

Question 7

Identify the parts of this vertebra. What type of vertebra is it?

Answer 7

thoracic

Question 8

How does the size of vertebral foramen change as you move inferiouly along the length of the spinal cord and what is the reason for the change?

Answer 8

The size vertebral formen decreases to match the decreasing diameter of the spinal cord.

Question 9

How many lumbar vertebrae are there? How does their size compare to other vertebrae?

Answer 9

1. there are 5 lumbar vertebrae
2. they have the largest vertebral bodies to accommodate increasing stress imposed by gravity and body weight

Question 10

Identify the landmarks of this vertebra. What kind of vertebra is it?

Answer 10

lumbar

Question 11

What are special features of the atlas vertebra? What is the atlas vertebra?

Answer 11

atlas is C1. it articulates with the skull and allows us to nod “yes”. it has no spinous process and no body. it has a facet for dens, a specialized process on C2.

Question 12

What are special features of the axis vertebra? What is the axis vertebra?

Answer 12

axis is C2. it has a specialized process called the dens (aka odontoid process). the articulation btwn the axis and the axis allows us to shake our heads no. it is the strongest cervical vertebra and supports the weight of the head

remeber which comes first by alphabet: atlas before axis

Question 13

Identify the landmarks of this vertebra. Which vertebra is it?

Answer 13

C2/axis

Question 14

Identify the landmarks of this vertebra. Which vertebra is it?

Answer 14

C1/atlas

note: posterior tubercle is a rudimentary spinous process.

Question 15

Identify the ligaments in this picture. What is special about the circled area?

Answer 15

This area is not held in by ligaments. Most intervertebral slips happen posteriorly and laterally in this region. Is problematic bc spinal nerves emerge in this area

Question 16

The spinal cord extends from the ____ ____ to the level btwn what vertebrae?

Answer 16

foramen magnum (large opening in the base of the skull through which the spinal cord exits the cranial vault) to the level of about L1/L2

Question 17

How many pairs of spinal nerves are there in the spinal cord? Where do they emerge in relation to their correspondingly numbered vertebrae?

Answer 17

31 paris

8 cervical

12 thoracic

5 lumbar

5 sacral

1 coccygeal

spinal nerve pairs C1-C7 exit above their correspondingly numbered vertebrae. spinal nerve pairs from C8 on down exit below their correspondingly numbered vertebra

Question 18

The spinal cord passes through ____ foramen. Spinal nerves pass through ____ foramen.

Answer 18

1. vertebral
2. intervertebral (btwn adjacent pedicles)

Question 19

List the 3 layers of meninges in order of appearance when looking at the spinal cord from the outside. What kind of tissue are the meninges?

Answer 19

1. dura mater
2. arachnoid. in lab, cannot be separated from dura mater
3. pia mater. directly attached to spinal cord. in lab, cannot be separated from spinal cord
4. the meninges are connective tissue

Question 20

What are the 3 spaces btwn the meninges and what is in those spaces? Where is CSF contained?

Answer 20

epidural space: outside of the dura mater. contains fat and plexus of veins and is where anesthetic is injected in epidural. subdural space: btwn dura mater and arachnoid. subarachnoid space: btwn arachnoid and pia mater and is where CSF is contained

Question 21

What is the cauda equina? What creates the cauda equina? What spinal nerve pairs in the cauda equina have to travel the least and the farthest distances to exit the spinal cord?

Answer 21

1. collection of dorsal and ventral roots of lumbar, sacral, and coccygeal nerves passing inferiorly to reach exit points from intervertebral formina
2. because the spinal cord stops above L1/L2
3. the L1/L2 spinal nerve pair has the shortest distance to travel (still has to travel inferiorly to exit). sacral spinal nerves have to travel the farthest. this drop down of spinal nerves creates the cauda equina

Question 22

conus medullaris

Answer 22

distal cone shaped end of the spinal cord

Question 23

What is the filum terminale? What is it composed of?

Answer 23

1. connective tissue that anchors the spinal cord from the conus medullaris to the coccyx
2. part pia mater and part dura mater

Question 24

What are denticulate ligaments? Where are they located?

Answer 24

bilateral anchors in the spinal cord that extend from the pia mater to the dura mater. lie btwn ventral and dorsal rootlets and attach in opposite direction of rootlets. contain 21 pairs of “teeth” attach to the dura mater and anchor the spinal cord

Question 25

Arterial supply to the spinal cord includes longitudinally oriented vessels and segmental spinal arteries. Discuss arteries in these categories and how they gain access to the spinal cord. Also, talk about venous drainage from the spinal cord.

Answer 25

1. longitudinally oriented vessels: orginate in the cranial cavity and descend longitudinally along length of spinal cord. includes one anterior spinal artery and 2 posterior spinal arteries

segmental spinal arteries: feeder arteries that gain access to the spinal cord through the intervertebral foramina at each level. arise primarily from vertebral arteries and deep cervical arteries in the neck, posterior intercostal arteries in the thorax, and lumbar arteries in the abdomen

2. venous drainage: longitudinal channels of veins drain into an extensive internal vertebral plexus of veins found in the epidural space

Question 26

What are motions of the spine? What actions do intrinsic back muscles (deep back) tend to have?

Answer 26

extension/flexion

lateral flextion

rotation

intrinsic/deep back are postural muscles. tend to extend and when some work on their own, can do lateral flexion

note: abdominal muscles cause flexion!

Question 27

The intrinsic back muscles extend from the ___ to the ___ and are innervated by segmental branches of _____ rami of spinal nerves.

Answer 27

extend from pelvis to skull

innervated by dorsal rami of spinal nerves

Question 28

The intrinsic back muscles can be divided into superficial, intermediate, and deep layers (not to be confused with superficial and intermediate layers of extrinsic muscles). What muscles are in these groups and what are their general actions?

Answer 28

1. superifical group: includes splenius muscles which extend and rotate the head and neck
2. intermediate layer includes erector spina which extend and rotate the vertebral column
3. deep group:

transversospinales group: span btwn spinous and transverse processes of adjacent vertebrae. act as postural muscles adjoining adjacent vertebrae to allow mor effect movement of the vertebral column as a whole

suboccipital muscles: span btwn first and second cervical vertebrae and the sull. are small muscles that contribute to extension and rotation of the head

Question 29

What are the origins, insertions, actions, and innervations of the splenius muscles (splenius capitus and splenius cervicus-superficial layer of intrinsic muscles)? Where are they found?

Answer 29

splenius capitus:

origin: lower half of ligamentum nuchae, spinous processes of C7-T3
insertion: posterior lateral skull

splenius cervicus:

origin: spinous processes of T3-T6
insertion: transverse processes of C1-C2
actions: when these muscles act bilaterally, extend the cervical spine and head. when acting unilaterally, cause ipsilateral rotation and side bending
innervation: dorsal rami of spinal nerves

these are the superficial layer of the intrinsic back muscles. they are deep to the trapezius and rhomboids but superficial to the superior aspects of erector spinae muscles

Question 30

Identify the muscles in this picture. What group of intrinsic back muscles do they belong to?

Answer 30

superficial layer

Question 31

What are the origins of the intermediate layer of intrinsic back muscles (erector spinae-I Like Spaghetti=ilocostalis, longissimus, spinalis)? insertions? actions? innervations?

Answer 31

the erector spinae muscles have the same origin: posterior ileac crest, posterior sacrum, spinous processes of vertebrae all along the spinal column

insertion of iliocostalis: angles of ribs and transverse processes of cervical vertebrae

insertion of longissimus: posterior lateral ribs, transverse processes of thoracic and cervical vertebrae, lateral skull

insertion of spinalis: spinous processes of throacic and cervical vertebrae

actions: when acting bilaterally, extend the spine. when acting unilaterally, laterally flex the vertebral column to the same side
innervartions: dorsal rami of spinal nerves

Question 32

Identify the muscles in this picture. What are these muscles called collectively? What layer of the intrinsic muscles are they?

Answer 32

1. erector spinae
2. intermediate

Question 33

What are the origins, insertions, innervations, and actions of the muscles in the transversopinales group of the deep layer of intrinsic back muscles? (semispinalis, multifidus, long rotators, short rotators)

Answer 33

the semispinalis capitus, multifidus, long rotators, and short rotators all orginiate on transverse processes of vertebrae.

semispinalis capitus insertion (span 4-6 vertebrae btwn attachments): spinous proceses of vertebrae. the capitus portion of this muscle attaches to the skull (capitus=cap=head)

the multifidus (span 2-4 vertebrae btwn attachments), long rotators (span 2 vertebrae btwn attachments), and short rotators (attach to adjacent vertebrae) all insert on spinous processes of vertebrae.

function: extend, contralaterally rotate, and stabilize the vertebral column

all of these muscles are innervated by dorsal rami of spinal nerves

Question 34

Identify the muscles in this picture. To what group of muscles do they belong?

Answer 34

transversospinales muscles. in deep group of intrinsic muscles

Question 35

What are the origins, insertions, actions, and innervations of the suboccipital muscles (in deep layer group of intrinsic back muscles). includes rectus capitus posterior major, rectus capitus posterior minor, obliquus capitus superior, and obliquus capitus inferior

Answer 35

rectus capitus posterior major origin: spinous process of C2. insertion: posterior-lateral skull

rectus capitus posterior minor origin: posterior tubercle of C1. insertion: medial skull

when these muscles act bilaterally, they extend the head. when acting unilaterally, they cause ipsilateral rotation of the head

obliquus capitus superior origin: transverse process of C1. insertion: posterior-lateral skull. action: extension of the head and contralateral rotation

obliquus capitus inferior origin: spinous process of C2. insertion: transverse porcess of C1. action: when acting bilaterally, extension of the head. when acting unilaterall, cause ipsilateral rotation of the head

are innervated by the dorsal ramus of C1, the suboccipital nerve. comes through the triangle

note: the greater occipital nerve (dorsal ramus of C2) emerges below the triangle and courses over muscles to supply skin of the back of the head and scalp

Question 36

Identify the muscles in this picture. What group are these muscles a part of?

Answer 36

suboccipital muscles group of deep layer of intrinsic muscles

Question 37

Identify the landmarks. What embryonic structure does the portion labeled 2 come from?

Answer 37

notocord