Anatomy of the back

Question 1

Name the back ligaments

Answer 1

Anterior longitudinal ligament
Posterior Longitudinal ligament
Ligamentum flavum
Ligamentum Nuchae

Question 2

Describe the anterior longitudinal ligament

Answer 2

• Anterior longitudinal ligament attaches to the anterior surface of the body and intervertebral discs. Very broad.

Question 3

Describe the posterior longitudinal ligament

Answer 3

Narrower and cord like as it is not attached to the posterior aspect of the body.
However, it is attached to the posterior aspect of the Intervertebral discs

Question 4

Ligamentum flavum

Answer 4

Multiple elastic ligaments that attaches to the lamina anterior surface of the superior vertebra
and posterior surface of the inferior vertebra. Used to bind adjoining vertebrae.

Question 5

Ligamentum Nuchae

Answer 5

Strong, elastic ligament that attaches to the external occipital protuberance of the skull and the spinous processes of the cervical vertebrae. Forms a sheet-like structure along the midline in the posterior neck.

Question 6

Intervertebral Discs categories and duties

Answer 6

Absorbs shock
- Anulus Fibrosus: made of fibrocartilage called concentric lamellae. Surrounds nucleus pulposus to help it stay in the centre

Nucleus pulposus: squishy, gelatinous structure present in the centre

Question 7

Layers of back muscles

Answer 7

Three layers:

Superficial muscles 2. Intermediate muscles 3. Deep muscles

Question 8

Name the superficial muscles

Answer 8

1. Trapezius
2. Latissimus Dorsi
3. Romboideus Major and minor
4. Levator scapulae

Question 9

Trapezius origin, insertion

Answer 9

Originates at occipital bone, spinous processes and inserts into the scapula and clavicle

Question 10

Latissimus Dorsi

Answer 10

Originates at lower back (spinous processes) and inserts into the anterior part of the humerus

Question 11

Rhomoideus major and minor

Answer 11

Minor is superior. Insertion is the medial aspect of the scapula and originates at spinous processes. Pulls scapula towards V.C.

Question 12

Levator scapulae

Answer 12

Originates in the transverse processes of vertebra and inserts into the medial and superior aspect of the scapula. It elevates the scapula

Question 13

Name and describe the Intermediate muscles

Answer 13

1. Serratus posterior superior: Deep to rhomboideus muscles. Originates at spinous processes, inserts into ribs. Respiratory functions
   
   2. Serratus posterior inferior: Originates at spinous processes, inserts into ribs. Respiratory functions

Question 14

Deep Muscles

Answer 14

1. Erector spinae (group): Originates at V.C. , Sacrum and illiac crest. Classified as extensors. Straightening back and flexed
   
   2. Transversospinalis (group): Deep to erector spinae muscles. Consists of number of smaller muscles that attaches to the transverse and spinous process of the vertebra. Plays a role in extending and rotating V.C.

Question 15

3 Landmarks of the back

Answer 15

Vertebra Prominens: C7 spinous process
Thoracic spinous processes: Can be palpated on the back
Sacral triangle: Base between right and left PSIS (posterior superior illiac spine). Apex = S3

Question 16

Describe shape of spinal canal in different regions

Answer 16

Vertebral canal narrows with age (spinal synosis)
Cervical region - wider canal (due to enlargement)
Thoracic - circular canal
Lumbar - wider canal (due to enlargement)

Question 17

Describe the spinal cord

Answer 17

Begins at foramen magnum at medulla oblongata 
Conus medullaris of the spinal cord terminates between L1/L2 (range: T12 to L3). Important during lumbar puncture 
Cauda Equina (horse tail) - nerve rootlets extending from conus medullaris in the inferior aspect

Question 18

Describe the dorsal root

Answer 18

Carries sensory information to the spinal cord. Contains the dorsal root ganglion, which consists of the cell bodies of the sensory neurons. Divides into a number of rootlets before entering the spinal cord. Surrounded by pia mater.

Question 19

Ventral/Anterior Root

Answer 19

Carries motor information from the spinal cord. Does not contain a ganglion. A number of rootlets arise from the spinal cord before combining to form the ventral root. Surrounded by pia mater.

Question 20

Body of Spinal Nerve

Answer 20

Short, mixed nerve (contain both sensory and motor nerve fibres). Located partly inside the intervertebral foramen and partly outside.

Question 21

Dorsal Ramus

Answer 21

Located outside the intervertebral foramen. Smallest branch of the spinal nerve. Mixed nerve (contains both sensory and motor nerve fibres).

Question 22

Ventral Ramus

Answer 22

Located outside the intervertebral foramen. Largest branch of the spinal nerve. Mixed nerve (contains both sensory and motor nerve fibres).

Question 23

Blood supply of the spinal cord

Answer 23

Anterior spinal artery: single; origin in the cranial cavity as the union of two vessels that arise from the vertebral arteries; courses along the anterior median fissure of the spinal cord

Posterior Spinal arteries (2): : multiple; origin in the cranial cavity from a terminal branch of the vertebral arteries. Extend along the length of the spinal cord to the conus medullaris

Question 24

Meninges of the spinal cord

Answer 24

The dura mater is a tough, fibrous layer, while the arachnoid and pia mater are delicate membranous layers.

Question 25

ligamentum denticulatum

Answer 25

The pia mater attaches to the spinal nerves and therefore extends into the intervertebral foramen. Extending laterally from the spinal cord, the pia mater forms two elongated bands with a notched border called the ligamentum denticulatum that extend to the arachnoid and dura mater to suspend the spinal cord in place

Question 26

periradicular recess

Answer 26

The subarachnoid space extending through the intervertebral foramina and surrounding the spinal nerve roots is called the periradicular recess.

Question 27

Cauda Equina

Answer 27

Formed by numerous roots of the lumbar, sacral and coccygeal spinal nerves
Each root is covered by pia mater
Extends inferiorly from the conus medullaris

Question 28

Filum terminale

Answer 28

strand of pia mater extending from the conus medullaris to the coccyx that helps to suspend the spinal cord in place.

Question 29

Caudal Sac

Answer 29

Formed by arachnoid and dura mater and contains the cauda equina, filum terminale and CSF
Typically terminates at S2
Located inferiorly and is different to the dural/thecal sac, which is the dural sac surrounding the length of the spinal cord

Question 30

Lumbar Cistern

Answer 30

Dilated region of the subarachnoid space located at the cauda equina in the lumbar region

Question 31

Epidural Space

Answer 31

Located in the vertebral canal outside the dural sac, separating the dura mater from the vertebral bodies. Contains:

Epidural fat
Internal vertebral venous plexus
Posterior longitudinal ligament

Question 32

Internal vertebral venous plexus

Answer 32

The internal vertebral venous plexus forms a complex network along the length of the epidural space. The spinal veins drain into this plexus. The basivertebral veins are large veins that drain the vertebral bodies and exit through a foramen in the vertebra, usually posteriorly. These veins will also drain into the internal vertebral venous plexus.

Question 33

Intervertebral Foramen

Answer 33

The intervertebral foramen is located laterally, where the spinal nerves exit the vertebral canal.

Question 34

Periradicular recess

Answer 34

CSF filled space surrounding the posterior spinal roots