Axial Skeleton Flashcards
What are the 4 functional roles of the axial skeleton?
- Support and protective framework for internal organs
- Skull houses special sensory organs
- Vertebral column/ ribs provide attachment for muscles moving head, neck, trunk and limbs
- Thoracic cage performs movements during respiration
What are the two major divisions of the skull?
Neocranium (houses brain)
Viscerocranium (houses mandible and sensory organs)
What are the 4 major bones of the skull from anterior to posterior?
- Frontal bone
- Parietal bone
- Occipital bone
- Temporal bone
What are the bones that lie somewhat in your cheek?
Zygomatic bone and the sphenoid bone
What bone is a major component of the nose and is pneumatized?
Ethmoid bone
What bone holds the lacrimal gland (tears)?
Lacrimal bone
What is the bone called where your glasses sit?
Nasal bone
What are the two bones that hold the upper and lower teeth respectively?
Maxilla (upper teeth)
Mandible (lower teeth)
What are the three sutures in the brain you can see from a lateral view?
- Coronal suture (between frontal and parietal)
- Lambdoid suture (between occipital and parietal)
- Squamous suture (between temporal and parietal)
What are two “holes” that lie in the orbit of the skull?
- Supraorbital fissure- in back wall, cranial nerve 3/4/6 pass through here and move eyeball
- Optic canal- cranial nerve 2 (optic nerve) passes here to bring sensory info from retina to the brain
What is the suture that divides the 2 halves of the parietal bone?
Sagittal suture
What two bones are connected to the back of the maxilla and you can only see from inferior view?
Palatine bone- connected to back of maxilla
Vomer- base of the backside of wall, contributes to septum with the ethmoid bone
What is the bone that forms the joint with the first cervical vertebra?
Occipital condyle (forms atlas)
What are the three openings at the cranial base?
Foramen magnum (largest)
Carotid canal- bony canal inside temporal bone
Jugular foramen- venous return of brain exits through here
What does the sphenoid bone look like? What is its internal structure and what does it house?
Butterfly
Pneumatized
Houses the pituitary gland (connected to the brain)
What are three structures contained within the temporal bone?
Mastoid process
Mandibular fossa- concave depression where temporomandibular joint forms
External acoustic meatus- rounded bony canal connected to external ear with 3 ossicles
What are the 4 structures contained within the mandible? What joint is formed at the 4th structure?
- Body
- Ramus
- Coronoid process (temporalis muscle attaches)
- Mandibular condyle (joint surface)
- Temporomandibular joint
What are the 4 skull cavities and paranasal air sinuses?
- Cranial cavity (brain)
- Orbit (eye)
- Nasal cavity (drainage for air sinuses)
- Oral cavity (tongue)
What is the difference between an infant skull and an adult one?
Infant skulls have no cranial sutures, they have Fontanelle which is fibrous material connecting flat bones of skull and eventually become sutures. Allows babies head to mold to fit through the birth canal, look like conehead but goes back to normal eventually
What are the different divisions of the vertebral column and how many vertebrae are in each?
- Cervical (7)
- Thoracic (12)
- Lumbar (5)
- Sacral (5)
- Coccygeal (4)
What are primary and secondary curvatures of the spine? What is the purpose of the curves?
- Primary- in thoracic and sacral, posteriorly convex
- Secondary- in cervical and lumbar, anteriorly convex
To align head with lumbar vertebrae and hip joint, show where weight is distributed
What are the 6 structures on the each vertebra?
- Vertebral body
- Pedicle
- Transverse process
- Spinous process
- Articular process
- Vertebral foramen
What are the two different joints in the vertebral column?
- Intervertebral joint- intervertebral disc attached btwn two adjacent vertebrae (secondary cartilaginous, permanent)
- Zygapophyseal joint- joint between two adjacent articular processes (synovial joints)
Vertebral canal in between these
What are the two parts of the vertebral body?
- Annulus fibrosus
- Nucleus pulposus (what escapes during hernatied disc)
What foramen is housed in the cervical vertebrae?
Transverse foramen- allow passage of vertebral artery going up to supply the brain
What are C1 and C2 referred to as?
C1- Atlas
C2- Axis
What are the two joints that are around C1 and C2?
Atlanto-occipital joint- synovial joint between occipital condyle and C1 (allows flexion of head up and down)
Atlanto-axial joint- synovial joint between C1 and C2 (allows head to turn side to side)
What is the joint associated with the thoracic vertebrae?
Costovertebral joint- two synovial joints between thoracic vertebra and associated rib (allow ribs to move slightly during respiration)
What are two structures associated with the ribs?
Sternum
Costal cartilage
What differentiates lumbar vertebra from others?
More elongated because they have to hold more weight
what is all 5 sacral verts called?
Sacrum
