AXIAL: Axial Skeleton and its Bone Markings Flashcards
What are the 5 main types of bones found in the Axial Skeleton?
- Skull (Calvarium & Facial)
- Auditory Ossicles
- Hyoid Bone
- Vertebrae
- Thoracic Cage
How many bones are found in the skull?
22
How many bones are found in the auditory ossicles?
6
How many bones are there in the hyoid bone
1
How many bones are found in an adult vertebrae?
26
Why? because sacrum fuses into one as well as coccyx fuses into one:
* C1-C7
* T1-T12
* L1-L5
* 1 Sacrum
* 1 Coccyx
How many bones are found in an infant vertebrae?
33
Why?
* C1-C7
* T1-T12
* L1-L5
* 5 Sacral bones
* 4 Coccyx bones
How many bones are in the thoracic cage?
25
Why?
* 12 pairs of true and false ribs
* 1 sternum
What is the total number of axial bones found in an adult axial skeleton?
80
These are important since they allow for identification of bones and bony pieces, as well as they help bones interact with other bones and tissues.
Bone markings
What are the 3 types of bone markings?
- Articulating
- Non-articulating
- Depressions and openings
An articulating bone marking that is mostly found in long bones and has an enlarged end.
Head
An articulating bone marking that is rounded or pointed ; has a smooth rounded articular surface
Condyle
An articulating bone marking that has a smooth flattened surface
Facet
A bone marking that attaches itself to another bone structure
Articulating
A bone marking that serves as an attachment for nerves, blood vessels, and muscles
Non-articulating
A non-articulating bone marking that has a knob-like process which is usually larger than a tubercle ; an enlargement
Tuberosity
A non-articulating bone marking that serves as a prominent projection on a bone (ex.: jawline)
Process
A non-articulating bone marking that has a prominent ridge or elongated projection; a curvature.
Crest
A non-articulating bone marking that is a small rounded projection or process; site of muscle and ligament attachment
Tubercle
A non-articulating bone marking that is embedded on the bone surface ; narrow bridge of bone and less prominent than a crest
Line
These are sites allowing the passage of soft tissue (nerves, blood vessels, ligaments, tendons) or formation of joints
Depressions and openings
This is an opening / hole ; allows passageway of blood vessels and nerves
Foramen
This is where articulating bone markings attaches itself
Fossa
Tunnel-like opening (ex.: ears)
Meatus
A cleft-like structure
Fissure
A cavity within a bone, most likely from the skull ; filled with air and lined with mucous membrane
Sinus
