Anatomy of Back, Spine and Spinal Cord Flashcards
What do the dimples at the bottom of the back indicate the position of?
Posterior superior iliac spines
What may ‘low back pain’ be due to?
Erector spinae strain
Where do extrinsic back muscles attach to?
Pectoral girdle
What are the rhomboids responsible for?
Retraction of the scapulae - pull the scapulae medially
What are extrinsic back muscles responsible for?
Movement of the upper limb
What do intrinsic back muscles act to do? (2)
Maintain posture
Move spine
Name the 2 groups of intrinsic back muscles and mention which ones are superficial and deep.
Erector spinae (superficial) Transversospinalis (deep)
What are the erector spinae muscles?
3 VERTICAL muscles groups located lateral to the spine
What do the erector spinae muscles attach to inferiorly?
SACRUM + ILIAC CREST via a common tendon
Name the 3 erector spinae muscles (from lateral to medial).
Iliocostalis
Longissimus
Spinalis
Where does the illiocostalis muscle attach to?
A rib
Where does the longissimus attach to?
A transverse process
Where does the spinals attach to?
A spinous process
think ‘s’ for spinous process
Where is the transversospinalis muscle located?
Between a transverse and spinous process of each vertebrae
Outline the nerve supply to the intrinsic back muscles.
Segmental - myotome
Posterior rami branches - cervical, thoracic, lumbar
Name the muscles of the anterolateral abdominal wall starting from superficial to deep.
Extrinsic oblique
Intrinsic oblique
Transvers abdominas
What muscles flex the spine?
Psoas major
Rectus abdominas
What muscles EXTEND the spine?
Erector spinae
Transversospinalis
Erector spinae muscles contract bilaterally. What happens if they contract unilaterally?
Lateral flexion
How many vertebrae are there?
33
How many cervical vertebrae are there?
7
How many thoracic vertebrae are there?
12
How many lumbar vertebrae are there?
5
How many sacral vertebrae are there?
5 - fused to form 1
How many coccygeal vertebrae are there?
5 - fused to form 1
What happens to vertebrae as you go from superior to inferior?
They get larger as you bear more weight
They then get smaller again as weight is transferred to the hips
Primary curvatures are…
Concave anteriorly
Secondary curvatures are…
Concave posteriorly
What may pregnancy lead to?
An exaggerated lumbar lordosis
What does the pedicle connect?
The arch to the body behind it
What does the lamina do?
Connect the transverse process to the spinous process
What do spinous processes provide?
A site for muscle and ligament attachment
What do the superior and inferior articular processes facilitate?
Mobility with adjacent spinal vertebra via synovial facet joints
What type of joint is found in vertebrae? Where is it found?
Synovial FACET joints
Between articular processes of adjacent joints
What is the function of the vertebral arch and what does it consist of?
Protect the spinal cord
2 x lamina
2 x pedicle
What does the vertebral foramina allow?
The spinal cord to pass through
Where do intervertebral foramen form? What do they allow?
Between adjacent vertebrae
Allow spinal nerves to pass through
What do spinal nerves become once they pass through the intervertebral foramen?
Anterior or posterior rami
What can the facet joints be affected by?
Arthritis
Where are intervertebral discs found?
Between bodies of adjacent vertebrae
Where in the spine is there no IVD’s?
C1-C2
Sacral and coccyx when fused
What are IVD’s important for?
Weight and strength
What are IVD’s made of?
Fibrous cartilage which will never ossify
Name the outer and inner part of IVD’s.
Annulus fibrosus (OUT) Nucleus pulposus (IN)
What does the ligamentum flavum connect?
Adjacent laminae, posterior to the spinal cord
The ligamentum flavum is LONG
FALSE
Short
Describe the posterior longitudinal ligament. State its function.
Narrow + weak
Prevent over-flexion of the spine
Describe the anterior longitudinal ligament. State its function.
Broad + thick
Prevents over-extension of the spine
What does the supraspinous ligament do?
Connects the ends of all the spinous processes
What does the interspinous ligament do?
Connects superior and inferior surfaces of adjacent spinous processes
What are the common typical features of cervical vertebrae?
Transverse foramen
Bifid spinous process
What does the transverse foramen transmit?
Vertebral arteries
What vertebrae does not have a body or spinous process?
C1
What vertebral level has an odontoid process?
C2
What is the first palpable spinous process in most people?
C7
Where are atlanto-occipital joints located?
Between the occipital condyles
What type of joints are atlanto-occipital joints?
Synovial joints with a loose capsule
What movements do the atlanto-occipital joints facilitate?
Flexion and extension of the neck
‘YES’ joint
What is the main movement of atlanto-axial joints?
Rotation
What does the caudal equina consist of?
Spinal roots of L2-C1
What does the sacral hiatus form due to?
Non fusion of the 2 parts of the sacrum
In caudal anaesthesia, where is local anaesthesia injected into?
Sacral hiatus
What is caudal anaesthesia used for?
To anaesthetise the sacral spinal nerve roots of the caudal equina
At what level does the spinal cord begin and end?
Begins at foramen magnum (C1) via the medulla and continues to L1/L2 to the conus medullaris
What is laminectomy used to access?
Spinal canal, posterior exposure of the spinal cord and/or spinal roots
What is laminectomy used for? Give examples.
Relieving pressure on the spinal cord or nerve roots
Tumour
Herniated disc
Bone hypertrophy
What does laminectomy involve?
Removal of one or more spinous process and the adjacent lamina
