BNG-345: Lecture 13 The Spine Anatomy Test on Friday

Learning Objectives Identify and describe the main regions of the spine Identify the components of the vertebrae Identify and describe the function of the components of the discs Identify the main muscles of the spine Identify the ligaments of the spine

Vertebral Column Consists of 33 vertebrae Upper 24 are articulating and separated by intervertebral discs The lower 9 are fused 5 at sacrum 4 at coccyx

Vertebrae A vertebrae consists of 2 parts: An anterior part known at the vertebral body A posterior part known as the vertebral arch encloses the vertebral foramen

Vertebral Arch Formed by a pair of pedicles and a pair of lamina These support 7 processes

Intervertebral Foramen

Curves of Vertebral Column

Cervical Curve Convex forward Starts at 2 nd cervical vertebra and ends at 2 nd thoracic vertebra

Thoracic Curve Concave forward Starts at 2 nd thoracic vertebra and ends at 12 th thoracic vertebra Most prominent point corresponds to spinous process of 7 th vertebra

Kyphotic Curve The thoracic curve is also known as the kyphotic curve

Lumbar Curve Convex forward Starts at middle of last thoracic vertebra and ends at sacrovertebral angle Convexity of lower 3 vertebrae much greater than upper 2

Lumbar Curve More prominent in females Curve also known as lordotic curve

Sacral Curve Concave downward and forward Begins at sacrovertebral articulation and ends at coccyx point

Regions and Vertebrae Shape

Cervical Spine C1 and C2 allow the head all its movement Most mammals have 7 cervical vertebrae regardless of neck length

Atlas and Axis

Thoracic Spine Transverse processes have surfaces to articulate with ribs Can rotate some, but ribs prevent much flexion

Lumbar Spine

Sacral Spine

Intervertebral Discs Located between adjacent vertebrae Forms a fibrocartilaginous joint that allows slight movement between vertebrae Acts as a ligament Shock absorber

Disc Structure & Function

Muscles Spinal muscles attach themselves to many different vertebrae, arms, legs, head, rib cage, and pelvis Movements of spine include flexion, extension, lateral bending

Erector Spinae Most important extensor muscle group Returns column to its erect position It originates at many locations Subdivisions blend in lower back giving good lumbar strength

Flexion Muscles Located in cervical and lumbar region Rectus abdominis and internal and external oblique contribute to spinal movement

Trunk Flexion Muscles

Multifidus Long muscle with fibers that extends from one vertebral process to spinous process of a vertebra several levels above Helps with extension and rotation

Ligaments

Learning Objectives Identify and describe the main regions of the spine Identify the components of the vertebrae Identify and describe the function of the components of the discs Identify the main muscles of the spine Identify the ligaments of the spine