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