axial skeleton Flashcards
how many bones are in the axial skeleton?
80
what does the axial skeleton consist of?
the skull, vertebrae column, thoracic cage
what are the sets of bones in the skull?
the cranial bones and the facial bones
what are the cranial bones?
frontal, parietal, occipital, temporal, sphenoid, ethmoid
what are the facial bones?
mandible, maxillary, zygomatic, nasal, lacrimal, palatine, vomer, inferior nasal conchae
what bones make up the nasal cavity?
ethmoid, palatine, maxillary, inferior nasal conchae
what do the paranasal sinuses do?
they’re air filled mucosa lined spaces that enhance resonance of voice, lighten the skull, and are found in the frontal, sphenoid, ethmoid, and maxillary bones.
what curvatures does the vertebral column have?
two posteriorly convex curvatures on the cervical and lumbar with two posteriorly convex curvatures on the thoracic and sacral as well
how many cervical vertebrae are there?
7, vertebrae of the neck
how many thoracic vertebrae are there?
12, vertebrae of the thoracic cage
how many lumbar vertebrae are there”
5, vertebrae of the lower back
what is the general structure of vertebrae?
body or centrum, vertebral arch, vertebral foramina, intervertebral foramina.
what is the sacrum and coccyx?
5 fused vertebrae that forms the posterior wall of the pelvis, and articulates with L5 superiorly and with auricular surfaces of the hip bones laterally
what does the sternum consist of?
manubrium (top), Body (middle), diploid process (bottom)
which ribs are true ribs?
pairs 1-7 which attach directly to the sternum by individual cartilages
which ribs are false?
pairs 8-12 which attach indirectly to the sternum by joining costal cartilage of rib above
what are floating ribs and which ones are they?
ribs 11-12 which have no attachment to the sternum
what’s the purpose of bone markings?
they’re sites of muscle and ligament attachment, projections that help to form joints, or passageways for veins, arteries, nerves, etc.
what are the different types of cartilage growth?
appositional, interstitial, calcification
what is appositional cartilage growth?
cells secrete matrix against the external face of existing cartilage
what is interstitial cartilage growth?
chondrocytes divide and secrete new matrix, expanding cartilage from within
what is the function of bones?
storage of minerals, creation of RBC, triglyceride storage (energy storage)
what is the microscopic bone structure?
osteons which consist of weight bearing column tubes called lamella, then the central canal which houses blood vessels and nerves.
they also consist of perforating canals, lacunae, and canaliculi.
what is the organic chemical composition of bone?
osteogenic cells, osteoblasts, osteocytes, osteoclasts, and osteoids
what are osteoid?
ground substance made up of proteoglycans and glycoproteins, and collagen fibers
what is the inorganic composition of bone?
hydroxyapatite’s (mineral salts), calcium phosphate crystals, responsible for hardness and resistance to compression
what happens when the parathyroid gland releases PTH?
stimulates osteoclasts to degrade bone matrix and release Ca, which in turn increases blood ca levels
what happens when calcitonin is released?
blood Ca levels rise, parafollicular cells release calcitonin which allows for osteoblasts to deposit calcium salts, decreases blood Ca levels.
what are the responses of mechanical stress?
Wolffs law: a bone grows or remodels in response to forces or demands placed upon it
