Ch. 8 Axial Skeleton Flashcards
Axial skeleton (3)
- 80 bones that make up midline of the body
- support and protect the organs of the head, neck, chest, and pelvis
- provide attachment sites for the muscles that move the head, neck, and trunk
Appendicular skeleton (2)
- 126 bones that make up the extremities
- attach the extremities to the trunk
Bones of the axial skeleton (4)
- skull (cranium and facial bones)
- hyoid bone
- vertebral column (cervical, thoracic, and lumbar vertebrae, scrum, and coccyx)
- rib cage (sternum and ribs)
Cranium bones
house and protect the brain
Facial bones
attachment sites for the muscles of chewing and facial expressions
Hyoid bone
- does not articulate with any other bones of the skeleton
- attachment site for the muscles of the tongue and throat
Paranasal sinuses (4)
- air-filled cavities within frontal bone, sphenoid bone, ethmoid bone, and maxillary bone
- lined by mucous membrane
- connect directly with nasal cavity
- echo chambers in the production of speech
Vertebral column (5)
- vertical series of bones stacked on each other
- protects the spinal cord
- serves as an attachment site for the back muscles
- superior end: articulates with occipital bone
- distal end: sacrum articulates with pelvic bones
Cervical vertebrae (2)
- 7 vertebrae
- form neck region
Atlas (C1) (3)
- 1st cervical vertebra
- articulates with occipital condyles of the skull
- allows up and down movement of the skull
Axis (C2) (2)
- 2nd cervical vertebra
- allows left and right rotation of the atlas and skull
Thoracic vertebrae (3)
- 12 vertebrae
- form chest region
- articulate with the ribs to form rib cage
Intervertebral disc (2)
- composed of fibrocartilage
- shock absorber between vertebrae
Lumbar vertebrae (2)
- 5 vertebrae
- form the lower back region
Sacrum (2)
- 5 fused vertebrae
- articulates with pelvic bones to form pelvic girdle
Coccyx (3)
- 3-4 rudimentary vertebrae
- fused together
- also called tailbone
Pedicle of vertebra (2)
- anterior portion of vertebral arch
- between body and transverse process
Lamina of vertebra (2)
- posterior portion of vertebral arch
- between spinous process and transverse process
Vertebral arch (2)
- “sides” of the vertebra
- formed by fusion of pedicle and lamina
Spinous process of vertebra (3)
- single posterior projection
- backbone of vertebrae
- attachment point for tendons and ligaments
Body of vertebra (3)
- centrally located
- round in outline
- site of attachment of intervertebral discs
Vertebral foramen (2)
- opening formed by body and vertebral arch
- houses spinal cord
Transverse process (2)
- each vertebra has a left and right lateral projection
- attachment point for tendons and ligaments
Superior articular facet (2)
- each vertebra has a left and right facet
- articulates with inferior articular facet of vertebra above it
Superior costal facet (thoracic vertebra) (2)
- superior lateral side of body
- articulates with head of ribs
Transverse costal facet (thoracic vertebra) (2)
- transverse process
- articulates with tubercle of ribs
Inferior costal facet (thoracic vertebra) (2)
- inferior lateral side of the body
- articles with head of ribs
Intervertebral notch (lumbar vertebra) (3)
- found on all vertebrae
- below pedicle
- nerves and blood vessels to and from spinal cord pass through these spaces
Inferior articular facet (lumbar vertebra) (2)
- found on all vertebrae
- articulates with superior facet of the vertebra below it
Rib cage bones
articulate with one another to form a flexible, protective cage around the organs of the thoracic cavity
Rib cage structures (4)
- thoracic vertebrae
- ribs
- sternum
- costal cartilages
Ribs 1-7 (2)
- connect to sternum via costal cartilages
- true ribs or vertebrosternal ribs
Ribs 8-10 (2)
- connect to sternum via shared cartilage
- false ribs
Ribs 11-12 (3)
- do not connect to sternum
- part of false ribs
- floating ribs
Sternum (3)
- flat bone
- forms interior midline of the rib cage
- breast bone
Fetal skull (2)
- flexible connective tissue
- fontanelles: anterior, posterior, mastoid, and sphenoidal
Fontanelles (2)
- where multiple bones meet
- largest areas of connective tissue
