Lecture 8/9 Spine Anatomy Flashcards
Exam 2
Which portion of the spinal cord is wider?
The top of the cord is wider than the bottom because the cord is larger at the neck than lower back, so less info is sent through the lower part of the cord
The C-spine has a ______ spinous process
Bifid
- C2-C5 is bifid
- C6 is bifid half the time
- C7 has a single spinous process
The C-spine vertebrae have extra openings or foremen called ______. What are they for?
Transverse foramen - run vertebral arteries (2/4 blood supplies for brain/brain stem)
What 3 things are different about the vertebra of the C-spine?
Transverse foramen, bifid spinous process, and the atlas (C1)/ axis (C2)
Transverse foramen are located where?
C1-C7
The spinal nerves in the neck are located in the ______ of the transverse process
Spinal nerve sulcus
The _____ is the connection between the skull and C1
atlas
The _____ is the connection between the C1 and C2
axis
What is C1 named after?
Named from the mythical god that had the weight of the world on his shoulders
The biggest difference between Atlas and the other neck vertebra is that there is
no vertebral body on C1 - doesn’t have a lot of weight that it supports so doesn’t need bulky body
What is the structure on C1 that is there instead of the vertebral body?
Anterior arch
What does the anterior arch do?
Allows rotational axis between C1 and C2; how C1 and C2 fit together
What are the specialized structures on the anterior arch of C1? What do they do?
Anterior tubercle - front nub
Facet for dens - posterior joint/cartilage where C2 articulates with C1
What does C1 have instead of a spinous process?
posterior tubercle
What is different about C1 than the other neck vertebrae?
Anterior arch instead of vertebral body
Posterior tubercle instead of a spinous process
Which structures does the base of the skull sit in?
Superior articular facets/processes
What is the opening of the base of the skull? What is it for?
Foramen magnum - where the spinal cord comes out and neck ligaments
What are the 2 projections on the skull that fit into C1?
Occipital condyles - fit into superior articular facets of C1
Which ligaments connect the top of the spine in the opening of the foramen magnum?
Atlantooccipital Ligaments - anterior and posterior
How are Atlantooccipital ligaments named?
Ligament connects to the occipital bone in the skull and the other part of the ligament connects to C1 (atlas) in the arch
What allows us to nod our heads yes?
Occipital condyles from the skull sitting in superior articular processes of C1
- pivot point
What is the structure on C2 that isn’t found anywhere else? What is its function?
Dens - bony projection on posterior C2
Connection point for the rear or anterior arch of C1
Which structure on C2 rubs up against the anterior arch of C1?
Anterior articular facet - cartilage coating on dens
Differentiate between the roles of the anterior and posterior articular facets of C2
Anterior - cartilage on dens that rubs against the anterior arch of C1
Posterior - cartilage on dens where ligaments wrap around at the top of the neck and make sure it’s a solid connection
The anterior of the dens connects to the _______ side of the anterior arch of C1
posterior
What allows side-to-side movement of the head?
The dens (C2) connection to the anterior arch of C1
Where do the spinal ligaments run?
Run from sacrum or pelvis to base of skull
Which ligament runs the entire front of the spine? What is it anterior to?
Anterior longitudinal - anterior to vertebral bodies
- Runs down to the coccyx
Which ligament runs the entire back of the spine? What is it posterior to?
Posterior longitudinal - posterior to vertebral bodies
Which ligament links the transverse processes together?
Intertransverse
Which ligament sits above/on top of the spinous processes?
Supraspinous - continues down the spine to front of pelvis
Which ligament sits in between spinous processes? What does it do?
Interspinous - connects the vast bulk of the spinous processes together; covers up more area than supra-spinous ligament
Which ligament connects the rest of the anterior arches together at each vertebral level?
Ligamenta Flava
What is special about ligamenta flava? Why is this helpful?
- More stretchy/elasticity than other ligaments
- Other ligaments more fibrous, made from collagen
- Looks yellow, other ligaments look white
- Figure out how deep you are with the needle based on feel
If you’re trying to hit the ligamenta flava with a needle, how do you need to approach it? Why?
- Most people have incomplete fusion of 2 sides of the ligament - If approaching needle midline, won’t hit different feeling
- Can’t use the marker of the ligament feeling different if the ligament is not fused - need to take lateral approach to avoid missing ligament
Which ligament is the expanded, fan-like ligament in the back of the neck? What is it an extension of?
Nuchal ligament - extension of interspinous ligaments
What is the nub marker on the back/top of the neck?
External occipital protuberance - on back of occipital bone where big fan-shaped nuchal ligament is connected to the occipital bone
Why shouldn’t you hit someone in the back of the neck?
You can break the ligaments
What is the pad in between the intervertebral bodies?
Intervertebral disc - where the weight is resting
What can you see in the MRI?
Nuchal ligament
Dens - longer than other vertebral bodies
Connection of dens to rear anterior arch of C1
What is the bump in the base of the neck called?
Vertebral prominens
What is the vertebral prominens from?
C7: Textbooks say the spinous process of C7 (last cervical vertebra) because C7 is large
T1: Schmidt says it looks like the T1 spinous process is bigger than C7
What is the opening underneath the spinous process and lamina called?
Interlaminar Foramen: The more you lean forward, the larger this foramen becomes
What is unique about the curvature of the T-spine?
Spinous processes angled steep - makes midline difficult to access with a needle
How many vertebrae are in the thorax?
12
What gives the thorax spine more stability?
Extra things connecting to spine in this area makes this area of the spine extra strong, more stability → very robust
- T-spine injuries are rare (bad car wreck) - usually in neck or lower back
What are the T-spine vertebrae connected to?
12 Ribs
Where do the ribs connect to the vertebra?
2 spots:
Costal facets (front) - ribs connect to the body of the vertebra; inferior and superior
Transverse processes (back)
Which ribs are connected to T-1?
Rib pair 1; continues down to 12
What makes the 11th and 12th rib pairs different?
Floating ribs: have limited numbers of connections to the last 2 thoracic vertebrae - one little area (not connected to sternum)
- Easier to displace/move out of position with trauma
What are the 3 parts of sternum?
manubirum, body, xiphoid process
How do the ribs connect to the sternum?
Costal cartilage - allows for flexibility, less susceptible to crush injuries
Differentiate between true and false ribs and their locations
- True ribs - direct connection to sternum; first 7 ribs
- False ribs - indirect connection to the sternum through earlier piece of cartilage (costal cartilage) that connected rib 7 directly to sternum; ribs 8, 9, 10
What are the unique structures of the T-spine vertebrae?
Downward-facing spinous processes and costal facets (inferior and superior)
Explain how ribs are connected to vertebrae
Rib 7: connects to the inferior costal facet of T-6 and the superior costal facet of T-7 as well as the transverse process of T7
Costal tubercle connects to the transverse process
Head of rib attaches to the costal facets
Projection where rib comes into contact with transverse process
Costal Tubercle - comes off neck of rib
Most ribs are attached to __ vertebra at the body and __ vertebra at the transverse process
2 (inferior and superior facets), 1
The shape of the vertebral bodies of the T-spine
Heart-shaped
Which side of the vertebral body is flat in the T-spine? Why?
Left side flat d/t aorta sitting next to vertebral bodies, right side more curved
Inferior articular process of L5 connects to the __________ in sacrum
superior articular process
Describe the bodies and spinous processes of the L-spine
Bodies - hefty, supports a lot of weight
Spinous Processes - closer to angled straight back/posterior
- Can access spine midline
- Have the patient lean forward to open up spaces
What are the openings in between pedicles of neighboring vertebra? What is their role?
Intervertebral foramen - superior and inferior vertebral notches
- where spinal nerves can exit the spine
When do the sacral vertebra fuse?
14-15 years old
How many vertebra are in the sacrum?
1 - started as 5 that fused together
_______ indicate the locations where the sacral bones fused together
transverse lines
At the top of the sacrum ______ connects to the ______ of the L spine
Superior articular processes connect to inferior articular processes of the L-spine
The body of L5 rests on top of the sacrum called the _____
promontory - weight supporting structure on top of the sacrum
What is the structure that holds the spinal nerves and roots in the sacrum similar to the vertebral foramen?
Sacral canal - fusion of the vertebral foramen
What are the openings in the front and back of the sacrum for the spinal nerves to exit? How many do we have?
Anterior and Posterior Sacral Foramina - 8
What is the structure that includes the remnants of the spinal processes from fusing together in the sacrum?
Median Sacral Crest
What are the structures formed from the fusion of the superior/inferior articular processes in the sacrum called? Where are they located?
Intermediate (Medial) Sacral Crest - slightly off to the side off midline, located in between medial and lateral sacral crests
What are the structures formed from the fusion of the transverse processes in the sacrum?
Lateral Sacral Crest
_______ is the opening at the base of sacrum where coccygeal nerves can exit base of sacrum
Sacral hiatus - Ligaments that continue all the way down to coccyx also pass through
_____ are raised ridges on either side of sacral hiatus
Sacral Cornu (Horn)
How to the coccygeal vertebra fuse?
Fusion of last 3 vertebrae, 1 stays by itself → 2 coccygeal vertebrae as adults
If you want to administer a drug directly to the sacral canal, how would you do it?
Through the sacral foramina
What is the most superior part of the pelvis?
The iliac crest
Where is the iliac crest located in relation to vertebral height? Why is this important?
L4 - marker for epidurals
What is the marker on the lower back that you can see when people where low-rise pants?
Posterior superior iliac spines
Why is the posterior superior iliac spine an important marker? How is it located?
Markers to try to estimate access to the S2 posterior sacral foramina
Locate posterior superior iliac spine → drop down 1 cm → 1 cm midline → good approach for opening
Would you rather attempt to hit S1 or S2 sacral foramina with a needle? Why?
S2
Don’t want to access S1 because the opening for S1 is difficult to hit straight up because the opening opens more to the side than to the back; S2 faces back more, easier to hit
What is the palpable marker below the posterior superior iliac spines?
Posterior inferior iliac spines - hardly ever used but has to mention it in class
Why would you want to do a spinal at the sacral level?
If you want to shut down the pain sensation in the pelvis
What connects the anterior superior iliac spine and pubic tubercle?
Inguinal ligament - should be able to palpate, if not see it
_______ is a rounded bony projection located on the lateral end of the pubic crest
Pubic tubercle
If you have a lot of extra weight, it might fold over this ligament that is usually pretty identifiable even in people with high BMI
Inguinal ligament
The _________ ligament connects transverse process of L4-L5 with top of pelvis
Iliolumbar - illio = pelvic
The _______ is the piece of cartilage that joins the two hip bones and the pelvis in the front
Pubic symphysis
What are the 6 spinal ligaments?
- Anterior longitudinal
- Posterior longitudinal
- Ligamenta Flava
- Interspinous
- Intertransverse
- Supraspinous
What are the 5 sacral ligaments?
- Inguinal ligament
- Anterior longitudinal
- Iliolumbar ligament
- Pubic symphysis
- Supraspinous ligament
What are the 2 sets of hips?
- Lower set of hips: top of femur (greater trochanter), wide spot of legs
- Upper set of hips - top of pelvis
Where is the umbilicus located in relation to the vertebra?
In between L3 and L4 - Not a good marker because of extra weight, rely on bony markers in the back
What is the top of the femur called?
Greater trochanter
______ serve as cushion between vertebra
Intervertebral Disks
- designed to be resilent
The _______ is the fibrous housing filled with gel center of the intervertebral disks
Nucleus pulposus
The fibers that wrap around the nucleus pulposus are called the _____
Anulus fibrosus
The ______ cartilage sandwiches the tops and bottoms of vertebral bodies
Hyaline
What is the pattern of the anulus fibrosis? What is the purpose?
Criss-crossing cartilage in front of spine - makes very strong
More in front than back
- back cartilage runs in a uniform direction instead of crossing fibers
- back is more likely to have herniated discs
How does disc herniation occur?
Loss of inner gel from nucleus pulposus if outer anulus fiber has any weak spots; part of nucleus pulpous leaks out and puts pressure on spinal nerves
Schmidt believes that 80% of back problems could be fixed with _____ and _____
PT (stretching) and lifestyle changes (strengthening)
- Lower back - hamstrings tight will make muscles rigid/contracted → tension on the back of spine → compresses openings
- Hamstring stretches help decrease lower back problems
- People are too lazy to do it regularly
Why are herniated discs so painful?
Incredibly painful because less space for spinal nerve → squeezes spinal nerves
- always posterior because weaker than front
What are the solutions to fix a herniated disc?
Discectomy, fusion of vertebra, and laminectomy
What is a discectomy?
removal of the part of disc that causes problems (not that invasive, very painful)
What is fusion of the vertebra? How does it work? What is the catch?
Stabilizes the spine to prevent pulposus from getting pushed out when moving out; have to access from the front of the patient (very invasive)
- Rods screwed into body of vertebra to stabilize
- Extra stress on vertebra above and below fusion
- 6-7 years down the road - mess up these discs and have to fuse more → extra stress on levels above and below, etc.
- Reduces shock absorber of spine
Who do you want doing a back surgery on you?
Want neurosurgeon to do it - not orthopedic
What is a laminectomy? What’s the catch?
Removes the part of the bone that is putting pressure on the spinal nerve (lamina); creates more space so the spinal nerve is not pushed on as much
- The less invasive, the more likely to be the lasting solution
- Removing the entire lamina would hurt the integrity of the vertebra
