Lecture 7: Axial Skeleton Part 1 Flashcards
how many bones are in the human skeleton?
206
the skeleton can be divided into?
axial skeleton and appendicular skeleton
axial skeleton is?
80 bones and generally the bones that run from the head to bottom of the vertebral column
appendicular skeleton is?
126 bones and is made of the bones of the limbs plus the girdles that attach limbs to axial skeleton
what are the 5 types of bones and what are their features?
1) long bones: longer than they are wide and are curved to distribute shock more evenly
2) short bones: almost as long as they are wide
3) flat bones: thin plates of compact bone
4)sesamoid bones: small bones that develop in areas of high mechanical stress
5) irregular bones: irregularly shaped or distributed
functions of the skull?
- protects the brain
- serves as point of attachment for facial muscles
- forms portions of orbits
- includes auditory ossicles
how many cranial bones are there?
8 cranial bones including: frontal, parietal (2), temporal(2), ethmoid, sphenoid, occipital
frontal bone?
forms the forehead at the anterior of the skull
- supraorbital foramen: provides passage for the supraorbital artery and nerve
ethmoid bone?
- medial portion of the orbits
what are the surface markings? - crista galli: triangular process and the membrane that seperates the2 halves of the brain attach here
- cribriform plate contains the olfactory foramina which provides passage for sensory structures required for smell
- perpendicular plate: forms superior part of the nasal septum
sphenoid bone?
- keystone of the cranial floor
- contains the optic foramen: allows passage for the opthalmic artery and optic nerve
temporal bone?
- forms the lateral and inferior portions of the cranium
what are the surface markings? - mandibular fossa: articulates with condylar process
- styloid process: attachment for neck and tongue muscles
- mastoid process: point of attachment for neck muscles
- external auditory meatus: forms ear canal and sends sound waves to ossicles
occipital bone?
forms posterior and inferior portion of the skull
- occipital condyle: forms joints with atlas
- foramen magnum: provides passage for the spinal cord to connect with the brain
parietal bone?
forms the superior and lateral portions of the skull
how many facial bones and which ones?
mandible, maxilla, palatine, lacrimal, zygomatic, vomer, nasal, inferior nasal conchae
mandible?
- lower jaw
- only moveable bone of the skull
- condylar process: articulates with mandibular fossa
maxilla?
- forms upper jaw
- infraorbital foramen: provides passage for infraorbital blood vessels and nerve
hard palate?
most of the hard palate is the palatine process and the rest is palatine bones
- the hard palate seperates the oral cavity from the nasal cavity
palatine bones?
posterior portion of the hard palate
zygomatic bones?
forms anterior portion of the cheekbones
vomer?
forms the inferior portion of the nasal septum
inferior nasal conchae?
form lateral walls of nasal cavity, swirls air around nasal passages and has increasing chance of trapping airborne invaders
nasal bones?
forms bridge of the nose where glasses sit
lacrimal bones?
smallest of the facial bones
what are the 7 bones that form orbits?
maxilla, frontal, zygomatic, lacrimal, palatine, ethmoid, sphenoid
function of fontanels?
facilitates passage of newborn head through birth canal during labour
sutures and what they connect?
sagittal sutures: connects the parietal bones together
coronal suture connects the frontal bone to the parietal bone
lamboid suture: parietal and occipital
squamous suture: parietal and temporal
hyoid bone?
special bone that doesnt articulate with any other bone
muscles of the tongue attach to the hyoid bone
functions of the vertebral column?
- supports and moves the skull
-protects the spinal cord - provides points of attachment for muscles of the back and abdomen
