4.1: Anatomy of the Skeleton- Overview & Axial Skeleton Flashcards
Identify anatomical structures of the skeletal system, including bones and ligaments and describe their function
Skeletal Functions
(SPAMS)
1. Storage of minerals (esp. Calcium)
2. Protection of internal organs
3. Attachment ( muscles, tendons, ligaments)
4. Movement (appendicular skeleton)
5. Support against gravity (heavy bones of the legs)
Bone Types
F- Flat
I- Irregular
L- Long
S- Short
S- Sesamoid
Flat Bones
-Protect Internal Organs
Long Bones
- Support Weight
- Facilitate Movement
Short Bones
- are cubed shaped
- enable movement
Irregular Bones
- have complex shapes
- some designed for movement
- some designed for protection
Sesamoid Bones
- Reinforce tendons
Bone Landmarks
distinct markings, ridges, grooves, or holes found on each bone
Foramen
Fissure
Canal
- openings in bone to allow for nerves, blood supply, or a passageway
Sinus
- hollow chamber in bone, usually filled with air
- helps reduce weight
Process, ramus
- elevations in bone
Trochanter
Tuberosity
Tubercle
Crest
Line
Spine
- processes or projections for tendon or ligament attachment
Head, neck, condyle, trochlea, facet
- processes designed for articulation with adjacent bones
Fossa, sulcus
- depressions in bone
- a “dip” in bone
skull
formed by 22 bones
- the cranium (8 bones)
- facial bones (14 bones)
cranium
- protects the brains
- composed of eight bones fitted tightly together in adults
fontanelles
- “soft spots.”
- allow the bones of the skull to compress during childbirth
- expand to accommodate a rapidly growing infant brain
- begin to close around two months but may last up to two years
frontal bone
(one bone)
- forms the forehead
parietal bones
(two, paired bones)
- extend to the sides
occipital bone
- curves to form the base of the skull
temporal bone
- below the much larger parietal bones
- each one has an opening that leads to the middle ear
sphenoid bone
- completes the sides of the skull
- contributes to the floors and walls of the eye sockets
- lie inside the skull
ethmoid bone
- lies in front of the sphenoid
- part of the orbital wall
- a component of the nasal septum
- lie inside the skull
foramen magnum
- large opening in the occipital bone
- through which the spinal cord passes to become the brain stem
sinuses
- the bones of the cranium contain air spaces lined by mucous membrane
- reduce the weight of the skull
- give a resonant sound to the voice
- mastoid sinuses (2) drain into the middle ear
mastoiditis
- an inflammation of the mastoid sinuses
- a condition that can lead to deafness
- usually found in children younger than 2 yrs
sinusitis
- “sinus infection”
- soft tissues inside the sinuses become inflamed
- caused by a virus, bacteria, fungi or allergy
foramina
- allows for passage for blood vessels, nerves, and the spinal cord
carotid canal
- an opening of the temporal bone for the internal carotid artery
external acoustic meatus
- opening to the middle ear
- located within the temporal bone
- transmission of sound
number of facial bones
fourteen
mandible
- lower jaw
- the only movable portion of the skull
maxillae
- the upper jaw
- forms the anterior portion of the hard palate
- contains the infraorbital foramen
zygomatic bones
- cheekbone prominences
nasal bones
- form the bridge of the nose
palatine bones
- make up the posterior portion of the hard palate
- floor of the nasal cavity
lacrimal bone
- thin, scale-like bone lies between an ethmoid bone and a maxillary bone
vomer
- thin, flat bone
- joins with the perpendicular plate of the ethmoid to form the nasal septum
inferior nasal conchae
- bones located inferiorly to the middle conchae
middle and superior nasal conchae
- formed from the grooves of the ethmoid bone
- swirl the air as it is breathed in through the nasal passages
- helping to warm and humidify the air before it enters the lower respiratory system
vertebral column
- extends from the skull to the pelvis
- four curvatures that provide more resilience and strength in an upright posture than a straight column could
- seven cervical vertebrae (C1-C7)
- twelve thoracic vertebrae (T1-T12)
- five lumbar vertebrae (L1-L5)
- one sacrum
- one coccyx
spinous processes
- located on the dorsal side of the vertebrae
- can be palpated as bony projections along the midline of the neck and back
Define palpate
to examined externally by touch
vertebral body
- the anterior portion of the vertebrae
- most surface area
articular facets
- allow adjacent vertebrae to articulate with each other
cervical vertebra
- a long spinous process with a bifid tip that splits into two parts posteriorly (except for C1)
- bodies are small
- vertebral foramen are large
transverse processes
- have transverse foramina
- passage of the vertebral arteries and veins
thoracic vertebra
- a long, thin spinous process inferiorly
- vertebral bodies are medium-sized with facets for rib articulations
- transverse processes have costal facets for rib articulations
lumbar vertebra
- spinous process: shorter, broader and points posteriorly
- vertebral bodies: largest, enabling it to support the weight of the head, neck, trunk, and upper limbs
- transverse processes: shorter and have no costal facets
- vertebral foramen: smallest and triangular-shaped
sacrum
- comprised of five fused bones at the base of the spine: widest portion & articulates with the L5 vertebra above it
- provide attachment sites for many ligaments and tendons
coccyx
- comprised of four to five fused vertebrae
- begin to fuse by around age 25
- provide attachment sites for many ligaments and tendons
ribs
- twelve pairs
- all connect directly to the thoracic vertebrae posteriorly
- Ribs 1-7 connect directly to the sternum
- Ribs 8-10 connect to the sternum indirectly via shafts of cartilage to the sternum
“floating ribs”
- lower two pairs of ribs (ribs 11 and 12)
- they do not attach to the sternum
