The skeleton 1 Flashcards
What are the 2 divisions of the skeleton, what are the structures that make it up and what is their function?
Axial
- skull, vertebral column, rib cage
- protects CNS and organs in the thorax
Appendicular
- bones of upper and lower limbs, pectoral/pelvic girdles
- attach limbs to axial skeleton and facilitates movement
How many bones are in the body and what percentage of it takes?
206
- 20%
Skull - how many sets of bone makes up the skull, what are the types and what is it unified by?
2 sets (cranial and facial)
- flat bones (except mandible - only moveable part of the head)
- united by sutures
Cranium - What is the difference between the cranial vault and cranial base?
CV (calvaria) - superior, lateral, and posterior aspects of the skull and forehead
CB - anterior, middle, and posterior cranial fossae
Cranium - what is it function, the 3 distinct areas and what does it provide a site for?
- surround and protect brain and organs of hearing and balance
- 3 bony ridges: anterior fossa (highest - frontal), middle fossa (temporal), and posterior fossa (lowest - cerebellum, medulla oblongata, pons)
- site of attachment for head and neck muscles
Cranium: frontal bone - what is the function of the frontal sinus on the lateral to glabella?
on left and right to light the skull
Cranium - What are the 8 bones of the cranium and what is the function of its curvatures?
- parietal (2)
- ethmoid
- sphenoid
- temporal (2)
- occipital
- frontal
- make them self-bracing (support weight of head and impact)
Facial bones - how many bones make up the face and what are the sensory cavities?
14
- contain the cavities for the sensory organs of sight, small, and taste
Cranium: frontal bone - What does the frontal bone form and what does it articulate?
roof of the orbits and anterior cranial fossa
- paired parietal bones posteriorly
Cranium - frontal bone: what is the supraorbital margins, supraorbital foramen and glabella area?
SOM - ridge above eye socket (protection)
SOF - small hole above orbit for BV and NF for forehead
GA - bone between brows
Cranium - parietal bones: what does it form?
superior and lateral aspects of the skull
- form the bulk of cranial vault
Cranium - parietal bones: what are the 4 articulations of the parietal bones with the frontal, occipital and temporal bones?
Sagittal sutures: parietal bones meet in the midline of the skull
Coronal sutures: parietal bones meet the frontal bone anteriorly
Lambdoid suture: marking the junction between the parietal bones in the occipital bones posteriorly
Squamosal sutures: found on each side of the skull where parietal bone meets the temporal bones
Cranium - occipital bone: what is it, what does it form and what does it articulates?
single bone at the base of the skull
- posterior aspects of skull and walls of the posterior cranial fossa
- anteriorly with 2 parietal and 2 temporal and the sphenoid bone
Cranium - occipital (structure): what is the foramen magnum, occipital condyles, and external occipital protuberance?
FM - large hole at base that is a passage for continuation of the brain as spinal cord
OC - on each side of the FM which articulates with the first cervical vertebrae (nodding and rotation of head)
OP - projection at back of skull - more prominent in males - attachment point for muscles and ligaments of neck
Cranium - temporal bones: what is it made of and what are the 3 different regions?
form inferior and lateral aspects of skull and parts of the cranial floor
- Squamous: flat and thin; forms sides
- Tympanic: ear canal; good for hearing
- Petrous: dense; houses organs for hearing and balance
Cranium - temporal bones: what is the squamous region?
flattened
- zygomatic process to cheekbone (zygomatic bone)
- mandibular fossa receives condyle of mandible
- Temporal mandibular joint
Cranium - temporal bones: what is the tympanic region?
- surrounds the external auditory meatus styloid process points inferiorly
- sound transmission into head
Cranium - temporal bones: what is the petrous region and what are the 2 processes?
on external temporal bone forming some of cranial base and houses middle/inner ear cavities
- contains organs for hearing and balance
- Mastoid process: major attachment site for neck muscles (head movement and posture)
- Styloid process: attachment area for muscles of the tongue and some neck muscles - swallowing and speech
Cranium - sphenoid bone: what does the central body contains and what are the 3 pairs of processes?
sphenoid sinuses
- greater wings (laterally from sphenoid - forms parts or orbits and internal cranial fossa)
- lesser wings (horizontally forms part of orbits and internal cranial fossa)
- pterygoid processes (muscles for movement of jaw)
Cranium - sphenoid bone: what is the shape and location, and contribute to?
bate shaped
- base of middle cranial fossa
- contributes to the base of anterior cranial fossa
Cranium - sphenoid bone: what is keystone bone and what are the articulations?
another name for the sphenoid bone because it connects with almost every bone in the cranium
- frontal
- parietal
- temporal
- occipital
- ethmoid
Cranium - sphenoid bone: what is the difference between the optic foramina (canals), superior orbital fissures, Sella turcica?
OF - for optic nerves (pass from eyes to brain)
SOF - between greater and lesser wings (for eye movement)
ST - houses pit gland
Cranium - ethmoid bone: where does it lie?
deep between orbits and nasal cavities
Cranium - ethmoid bone: what is the difference between cribriform plate, perpendicular plate and crista galli?
CP - forms roof of nasal cavity and floor of anterior cranial fossa; tiny holes for olfactory nerves
PP - projects inferiorly to contribute to nasal septum
CG - projects superior to attach to dura mater of brain