Human Anatomy Lecture 8: Vertebral Column (1st Year) PDF

Academic year 2023-2024 ‫فرع جراحة الفم والوجه والفكين‬ ‫كلية طب االسنان‬ 1st year Human Anatomy Lecture 8...

Academic year 2023-2024 ‫فرع جراحة الفم والوجه والفكين‬ ‫كلية طب االسنان‬ 1st year Human Anatomy Lecture 8 Vertebral Column By:Dr.Nada hashim AL Jassim Snell R.S. Clinical Anatomy by regions, 9th Edition, Lippincott Williams & Wilkins, [2012 For more detailed instructions, any question, cases need help please post to the telegram group of the session  Vertebral Column (Spine) Extends from the skull, which it supports, to the pelvis, where it transmits the weight of the body to the lower limbs The spine is formed from 26 irregular bones connected and reinforced by ligaments in such a way that a flexible curved structure results  Before birth, the spine consists of 33 separated bones called vertebrae, but 9 of these eventually fuse in to 2 composite bones Of the remaining 24 single bones: 7 vertebrae of the neck (cervical vertebrae) 12 thoracic vertebrae 5 lumbar vertebrae supporting the lower back  Intervertebral disks Cushion the vertebrae and absorb shocks - In a young person, the disks have a high water content - As a person ages, the water content of the disks decreases, and the disks become harder and less compressible - Drying of the disks, along with a weakening of the ligaments of the vertebral column predisposes older people to herniated (slipped disks ) or(disk prolaps) Vertebral foramin  Spinal Curvatures Functions: 1. The disks and the S- shaped structure of the vertebral column work together to prevent shock to the head when we walk or run 2. They also make the body trunk flexible  Spinal Curvatures Primary curvatures: The curvatures that are present when we are born. e.g. The spinal curvatures in the thoracic and sacral (lower spine) regions Secondary curvatures: The curvatures that are present after we are born. e.g. The cervical (neck) curvature  Vertebrae Structure Body or Centrum: Disk like, weight- bearing part of the vertebra facing anteriorly in the vertebral column Vertebra Foremen: Canal through which the spinal cord passes  Vertebrae Structure Spinous process: Single projection arising from the posterior aspect of the vertebrae Transverse processes: Two lateral projections from the body Vertebrae Structure Superior and inferior articular processes: Paired projections lateral to the vertebral foramen, allowing a vertebra to form joints with adjacent vertebrae  Cervical Vertebrae The 7 cervical vertebrae (C1-C7) form the neck region of the spine. The first 2 vertebrae are different because they perform functions not shared by the other cervical vertebrae Cervical Vertebrae C1 The 7 cervical vertebrae (C1-C7) form the neck region of the spine. C1 is called the atlas. It has no body, and large depressions on the surface where the skull sits. It articulates with the occipital condyles, and allows you to nod “yes”  Cervical Vertebrae C2 C2 is called the axis, and acts as a pivot point for rotation of the atlas and the skull. It has a large process called the odontoid process, which sticks into the atlas. The joint between C1 and C2 allows us to rotate the head from side to side “no” Cervical Vertebrae C3-C7 The C3 through C7 vertebrae are typical vertebrae with some features that will identify them as cervical vertebrae: They are the smallest and lightest vertebrae They have short spinous processes that are divided in two  Cervical Vertebrae C3-C7 They have foramen in their transverse processes – this is what one can use to identify these vertebrae as cervical vertebrae; The foramina are where the vertebral arteries run through Superior and lateral views of the cervical vertebrae  Thoracic Vertebrae The 12 thoracic vertebrae (T1-T12) are all typical Thoracic Vertebrae T1-T12 Their bodies are heart- shaped They have long spinous processes that point sharply downward From the side, thoracic vertebrae look like giraffe’s head, this is what one can use to identify these vertebrae as thoracic vertebrae  Lumbar Vertebrae The 5 lumbar vertebrae are the sturdiest of the vertebrae since most of the stress on the vertebral column occurs in the lumbar region Lumbar vertebrae L1-L5 Their bodies are massive and block like From the side, a lumbar vertebrae look like a moose head – this is what one can use to identify these vertebrae as lumbar vertebrae  Sacrum The sacrum forms the posterior wall of the pelvis The vertebrae canal continues inside the sacrum as the sacral canal  Sacrum The sacrum is formed by the fusion of 5 vertebrae Superiorly, it articulates with L5 Inferiorly, it articulates with the coccyx (tail bone)  Coccyx The coccyx is formed by the fusion of 3 to 5 small, irregularly shaped vertebrae It is the human “tailbone”, a remnant of the tail that other vertebrate animals have THANK YOU