MSK L7.1 Vertebral Column

Question 1

Functions of Vertebral Column

Answer 1

Question 2

Divisions of Vertebral Column

Answer 2

🦴 Vertebral Column Breakdown

Total vertebrae = 33 (approx)
Split into regions:

Cervical (neck) – 7
👉 "Wake up at 7"

Thoracic (upper back/ribs) – 12
👉 "Lunch at 12"

Lumbar (lower back) – 5
👉 "Go home at 5"

Sacral – 5 (fused into 1 bone)

Coccyx (tailbone) – 3–4 (fused)

🧩 Movement vs. Fusion

24 single (movable) vertebrae
→ Cervical, thoracic, and lumbar

8–9 fused vertebrae
→ Sacrum + coccyx

Question 3

Explain how the structure of the vertebral column supports the transmission of body weight to the lower limbs.

Answer 3

1) Spine shape curved, balances body’s weight centrally
2) Lower vertebrae are bigger because they take more pressure
3) Sacrum fused into one strong bone, wider and curved forward (concave), helps pass body weight into pelvis and legs

Question 4

Describe the difference between primary and secondary curvatures of the vertebral column.

Answer 4

Question 5

Role of Vertebra

Answer 5

1. Protects spinal cord
2. Creates a tunnel (canal) for spinal cord to run through

Question 6

Where does the spinal cord end in adults?
Explain what the cauda equina is and where spinal nerves exit in relation to vertebrae.
How do spinal nerves exit?

Answer 6

In adults, the spinal cord ends at vertebral level L1

Below that, the nerves keep going down inside the spinal canal like a horse’s tail — this is called the cauda equina

Spinal nerves exit BELOW their vertebra number.
EXCEPT in the cervical region:

Cervical nerves exit ABOVE their vertebra

    e.g., C1 nerve exits above C1 vertebra

⚠️ Clinical Tip: Disc prolapse

A slipped (prolapsed) disc often presses on the nerve below the affected disc

Example: A disc between L4-L5 affects the L5 nerve, not L4

Question 7

Structure of a Typical Vertebra
What is the largest part of the vertebra?

Answer 7

Vertebral body.
Largest part of vertebra
* Weight bearing part of vertebra
* Major site of contact between adjacent vertebra
* Articular surface covered with hyaline cartilage
(cartilaginous joint)
* Linked to adjacent vertebral bodies by IV discs
* Size increases from superior to inferior

Question 8

Processes Vertebral Arch

Answer 8

Question 9

Typical Cervical Vertebra

Answer 9

Question 10

Atypical Cervical Vertebra

Answer 10

Question 11

Atypical Cervical Vertebrae Summary

Answer 11

Question 12

Atypical Cervical Vertebra

Answer 12

C7 EASILY FELT

Question 13

AP VIEW OF CERVICAL SPINE*

Answer 13

Question 14

Lateral View of Cervical Spine

Answer 14

Question 15

Nerves in Cervical Region

Answer 15

🧠 Mnemonic:

“7 vertebrae, 8 nerves — C8 breaks the rule”

📘 Exam Question Example:

Q: How many cervical spinal nerves are there, and where does C8 exit?
A: There are 8 cervical nerves. C8 exits below the C7 vertebra.

Question 16

Fractures of the Cervical Spine

Answer 16

“Hyperextension” means bending the head too far backwards.

“Unstable”

The break means the top of the spine (skull + C1) is no longer held firmly in place.

It can slide or move, and that’s dangerous because it might press on the spinal cord.

📌 In short:

Hangman’s Fracture = Back part of C2 breaks from head bending too far back, making the spine unstable.

Question 17

Cervical Spine Whiplash Injury

Answer 17

🧠 Simple Terms:

Hyperextension = Head goes too far back

Hyperflexion = Head goes too far forward

Whiplash = combo of both = injury to neck

Question 18

Cervical vs Thoracic vs Lumbar Vertebra

Answer 18

Question 19

How many vervebra are are fused in sacrum?
How many in coccyx?

Answer 19

Question 20

Intervertebral Discs
1) What keeps them turgid?
2) What are the two regions they are made of?

Answer 20

Make up 25% of the vertebral column’s length

High water content keeps them turgid (plump and strong)

Shrink with age

Made of two regions:

Nucleus Pulposus (central)

Annulus Fibrosus (outer ring)

Question 21

What is the function of IV discs?

Answer 21

Shock absorbers.
IV discs are very strong in axial compression. They are built to handle the weight of your body pushing down through your spine

Question 23

What are the major ligaments of the spinal column?

Answer 23

🔗 Major Ligaments of the Spine
1️⃣ Anterior Longitudinal Ligament

Strongest spinal ligament

Runs along front of vertebral bodies

Prevents hyperextension (bending too far backward)

2️⃣ Posterior Longitudinal Ligament

Weaker than anterior

Runs along back of vertebral bodies (inside vertebral canal)

Prevents hyperflexion (bending too far forward)

Prevents posterior disc prolapse

Question 24

What are the 4 additional ligaments of the spinal column?

Answer 24