1. The Anatomy of the Spine

2. The bones of the spine

3. Vertebral Column: Bones
Column of 33 small bones called VERTEBRAE
Begin at the cranium and end at the coccyx
5 Divisions:
Cervical (7)
Thoracic (12)
Lumbar (5)
Sacrum (5 fused)
Coccyx (4 fused)

4. Functions of Vertebral Column
Protection:
it encloses the spinal cord, shielding it from damage
Support:
it carries the weight of the body above the pelvis (below the pelvis, the lower limbs take over)
Axis:
the vertebral column forms the central axis of the body
Movement:
it has roles in both posture and movement

5. The spine is well-designed!
Each division of the spine is characterized by a different vertebral structure
These differences in vertebral structure allow them to perform their main functions
Cervical= Flexibility and movement
Thoracic= Stability and protection
Lumbar= Power; support weight of body
Before looking the differences, we need to look at the general form of a vertebra….

6. Vertebral Structure
While vertebrae have unique regional features, each vertebra has three main parts:
Body (purple)
Vertebral Arch (green)
Processes for muscle attachment (tan)

7. Vertebral Structure Vertebral Body Anterior part of vertebra
Weight-bearing component
Size increases as vertebral column descends

8. Vertebral Structure Vertebral Arch Consists of 2 pedicles and 2 lamina
Forms a hole for spinal cord called the VERTEBRAL FORAMEN
Vertebral Foramen

9. Vertebral Structure
Processes (7 on each): serve as attachment points for muscles and create joints that allow for movement of the spine
Spinous Process
Transverse Process (2)
Superior Facet (2)
Inferior Facet (2)

10. Inferior Facet would be underneath

11. Facet Joint Each vertebra has four facet joints:
one pair that connects to the vertebra above (superior facets)
one pair that connects to the vertebra below (inferior facets)

12. Intervertebral discs and ligaments

13. Intervertebral Disc Location: Between each vertebra of the spine
Structure: Fibrocartilage
Annulus: Tough outer ring
Nucleus: Soft gel/liquid center
Function:
Transmit weight of body and cushion the vertebrae
Allow movement between vertebrae

14. Intervertebral Disc The fluid in the nucleus changes:
absorbed during the night as you lie down
pushed out during the day as you move upright
With age, our discs increasingly lose the ability to reabsorb fluid
become brittle and flatter
this is why we get shorter as we grow older.

15. Supraspinous Ligament
Spinal Ligaments
Major Ligaments
Ligamentum Flavum
Anterior Longitudinal Ligament (ALL)
Posterior Longitudinal Ligament (PLL)
Interspinous Ligament
Supraspinous LIgament
Supraspinous Ligament

16. Spinal Ligaments Ligamentum Flavum
Attaches between the lamina of each vertebra
Limits flexion of the spine

17. Spinal Ligaments Anterior Longitudinal Ligament (ALL)
Thick and strong ligament
Covers the front and sides of vertebral bodies
Runs the whole length of vertebral column
Limits extension of the spine

18. Spinal Ligaments Posterior Longitudinal Ligament (PLL)
Runs the whole length of vertebral column
Covers the back of the vertebral bodies
Helps limit flexion of the spine

19. Spinal Ligaments Interspinous Ligament: Supraspinous Ligament
Connect the lower edge of one spinous process to the upper edge of the next one
Supraspinous Ligament
Connects the tips of the spinous process
Interspinous Ligament
Supraspinous Ligament

20. Spinal cord and spinal nerves

21. Spinal Cord About 18 inches long and is the thickness of your thumb
Runs within the protective vertebral foramen
Starts at the brainstem and ends at the 1st lumbar vertebra
Then the cord fibers separate into the cauda equina and continue down through the spinal canal to your tailbone before branching off to your legs and feet

22. Spinal Cord
Covered with the same three protective membranes as the brain, called meninges.
Inner membrane = pia mater
Middle membrane = arachnoid mater
Outer membrane = dura mater

23. Spinal Cord
Function: information super-highway, relaying messages between the brain and the body
The brain sends motor messages to the limbs and body through the spinal cord allowing for movement.
The limbs and body send sensory messages to the brain through the spinal cord about what we feel and touch.

24. Spinal Cord
Sometimes the spinal cord can react without sending information to the brain.
These special pathways, called spinal reflexes, are designed to immediately protect our body from harm.

25. Spinal Cord
Any damage to the spinal cord can result in a loss of sensory and motor function below the level of injury.

26. Spinal Nerves
Thirty-one pairs of spinal nerves branch off the spinal cord
Act as “telephone lines,” carrying messages back and forth between your body and spinal cord to control sensation and movement
Numbered according to the vertebrae above which it exits the spinal canal

27. Spinal Nerves
The spinal nerves innervate specific areas and form a striped pattern across the body called dermatomes
Used to diagnose the location of a spinal problem based on the area of pain or muscle weakness

28. Spinal Nerves Nerves in the cervical spine branch out into your arms
This is a neck injury can lead to pain radiating down your arms
Nerves in the thoracic branch out into the middle of the body
Nerves in the lumbar spine branch out into the legs
This is why a low back injury can lead to pain radiating down your legs

29. Range of Motion of Spine

30. Muscles of the spine

31. Spinal Muscles: Deep
Closest to the spine is a network of three types of short muscles that help hold the vertebrae together.
intertransverse muscles:
assist with lateral bending
in between transverse processes
interspinal muscles:
assist flexion and extension
In between spinous processes
rotator muscles:
assist rotation
Connect transverse process to spinous process of vertebra above

32. Spinal Muscles: Deep Multifidus Function = spine stability
Connect transverse process to sides of the spinous processes two to four vertebrae above
Entire length of spine

33. Spinal Muscles: Superficial
Erector Spinae: One on either side of spine
3 Parts
Spinalis
Longissimus
Iliocostalis
Function:
Spine extension
(when both sides contract)
Lateral bending
(when only one side contracts)

34. Spinal Muscles: Abdominal
Rectus Abdominis
Flex spine
External Oblique
Flex and rotate spine
Internal Oblique
Transverse Abdominis
Stabilize pelvis

35. Spinal Muscles: Cervical

36. Spinal Muscles: Cervical
Sternocleidomastoid
Functions:
Flex neck
Rotate neck
Laterally bend neck

37. Spinal Muscles: Cervical
Scalenes (Anterior, Middle, and Posterior Parts)
Function: Lateral bending of neck

38. Spinal Muscles: Cervical