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
Cranium - ethmoid bone: what do the lateral masses and medially areas contain?
LM - ethmoid sinuses (part of paranasal –> lightens skull)
M - superior and middle nasal conchae
major cranial sutures - what bones make up the squamous, coronal, sagittal and lambdoid?
SQ - parietal and temporal bones
C - frontal and 2 parietal bones
SG - 2 parietal bones
L - occipital and 2 parietal bones
What is the sutural bones?
tiny irregular bones; can occur within cranial sutures
- varying amounts in everyone
- lambdoid sutures are the most common location
Facial bones - how many bones make up the face and which ones are unpaired (2) and paired (2x6)?
14
UP: mandible and vomer
P: maxillae, zygomatic, nasal, lacrimal, palatine, and inferior conchae
Facial bones - mandible: what is it made of and what is the joint called?
- strongest and largest bone in face
- TMJ joint
Facial bone - mandible: What is the mandibular notch, coronoid process and mandibular condyle?
MN - passage for the masseteric nerve and vessels
CP - temporalis muscle inserts onto the coronoid process
MC - articulates with the temporal bone to form the TMJ
Facial bones: what is the maxillary bones and palatine processes?
fused medially and is a keystone facial bone
PP - project posteriorly forming anterior 2/3 of hard palate
Facial bone - mandible: what is the alveolar margin, mandibular foramina, and mental foramina?
AM - boarder of the alveolar process of the mandible
MF - small opening allowing for BV and NF to pass into mandibular canal
MF - opening that allows the mental nerve and vessels to pass into the face
Facial bone - maxillary bone: what is the incisive fossa, frontal and zygomatic processes and infra orbital foramen?
IF - passage of blood vessels and nerves
F&ZP - forms orbit and cheekbones
IOF - small opening in the upper jawbone that allows blood vessels and nerves to pass through
Facial bones: what is the zygomatic bone, what parts are articulated and what does it contribute to?
cheek bones
- with zygomatic processes of temporal, frontal and maxillary bones
- inferolateral margins of orbit (sockets that have eyes)
Facial bone: what is the nasal bone and how does it fuse, what does it articulate?
2 rectangular bones that fuse medially to form bridge of nose
- frontal bone (superiorly) and maxillary bone (laterally)
Facial bone: what is the lacrimal bone and what is it articulated with?
2 bones in anterior, medial portion of orbit
- frontal and ethmoid bone and the maxillae
Facial bones: What is the palatine bone and what is the vertical plates?
2 L-shaped bones horizontal plates form hard palate
- VP: nasal cavity and orbit
Facial bones: what is the vomer and what does it work with to form nasal septum?
single thin bone forms nasal septum
- perpendicular plate
Orbits: what does it incase and what is it a site for?
- eyes and lacrimal glands
- attachment of eye muscles
Orbit: what is the 7 bones that make up the orbits?
- zygomatic
- frontal
- maxilla
- ethmoid
- lacrimal
- sphenoid
- palatine (orbital process)
Facial bones - what is the inferior nasal conchae and what is its function?
largest of 3 conchae
- forms part of lateral walls of nasal cavity
function: increases SA in nasal passage
- warming, humidification and filtration of inhaled air
Facial bones - what are the parts that make up the ethmoid bone and hard palate?
EB -superior and middle nasal concha
HP - palatine bone and palatine process of maxilla
Hyoid bone - why is it unique, what does it support and what is its function?
- only bone that isn’t articulate with other bone
- supports tongue
- attachment for muscles for swallowing and speech
Paranasal sinuses - what is it and what are the functions?
mucosa-lined, air-filled
- lightens skull and enhance resonance of voice
Paranasal sinuses - what are the 4 types of sinuses?
- frontal
- maxillary
- sphenoid
- ethmoid
Vertebral column: how many bones (name and number)?
33 bones, 24 remain separate (flexible) and 9 fused (sacrum and coccyx)
- 7 cervical
- 12 thoracic
- 5 lumbar
- 5 sacral
- 3/4 coccygeal
What are the 3 main functions of the vertebral column?
- weight-bearing
- anchor for muscles and ligaments
- protection of spinal cord
Vertebral column: what are the 4 curvatures and what is the difference between primary and secondary?
2 posteriorly convex
- thoracic and sacral
- considered primary curves because they are present at birth
2 posteriorly concave
- cervical (lifting head)
- lumbar (walking)
- considered secondary since developed post birth
Vertebral column: supporting elements - what are the 2 main supporting ligaments and what do they prevent orientation wise?
anterior and posterior longitudinal
- anterior prevents hyperextension
- posterior prevent hyperflexion
Vertebral column: supporting element - what is the intervertebral discs and what is the difference between the nucleus pulposus and annulus fibrosus?
cushioning between vertebral bodies - shock absorption and thickest in lumbar/ sacral regions
NP (center) - inner gelatinous nucleus - elasticity and compressibility
AF (periphery) - outer collar of collagen and fibrocartilage that holds together successive vertebrae and resists tension in spine
Vertebral column - what is the difference between the vertebral column and arch?
VC - made of many vertebrae
VA - posterior part of vertebra
Vertebrae - What forms the vertebral canal and what passes through here?
posterior and lateral vertebrae
- spinal cord
- blood vessels
- meninges
Vertebrae - what do pedicles have and what passes through them?
notches on superior and inferior surface
- spinal nerves and blood vessels
Vertebrae - what are the 7 processes that project from each vertebral arch?
- 1 spinous (posteriorly; muscle attachment)
- 2 transverse (laterally; one on each side)
- paired superior and inferior articular (lie vertebrae above and below)
Cervical vertebrae - how many, and what is the difference between C1 and C2 vs. C3-C7?
7
C1 + C2: have unusual structures and no intervertebral disc
C3 - C7: considered cervical typical, spinous shorter, transverse foremen, larger vertebral foremen
Cervical vertebrae - What is the difference between the spinous process, vertebral foramen and transverse process structurally?
SP - short and split at end (except for 7)
VF - large triangle
TP - contains transverse foramen for passage of vertebral artery to brain
Cervical vertebra: Atlas (C1) - what structure does this lack and what does it support?
no body and no spinous process
- supports the skull
Cervical vertebra: Atlas (C1) - what makes up the structure and what is it articulated with?
- posterior and anterior neural arches
- lateral masses with superior and inferior articulate with occipital condyles
Cervical vertebra: Atlas (C1) - What does the occipital condyles allow the head to do?
allows nodding movements of head
Cervical Vertebra: Axis (C2) - what is its structure and how does it project?
more like C3-C7, except for dens or odontoid process
- projects superiorly onto the anterior arch of the atlas
Cervical Vertebra: Axis (C2) - what does its pivoting action allow it to do?
allows rotation of atlas
ex. shaking head no
Thoracic vertebrae - What is it made of and what is it articulated with?
T1 to T12 (increasing in size from first to last)
- with the ribs
Thoracic vertebrae - what is the vertebral foramen and what does the transverse process have?
VF - opening in the vertebrae where the spinal cord passes
TP - facets for articulation with tubercules of ribs (except 11 and 12)
Lumbar vertebrae - How many are there and where are they located?
5 (L1 to L5)
- lower back
Lumbar vertebrae - what is its shape and size and what is the function of the spinous processes?
kidney- shaped, increases in size from top to bottom
- weight bearing and limits hyperextension
Lumbar vertebrae - how is the orientation of the facets unique?
superior faces in and inferior faces out
- this prevents rotations which stabilizes spine
Sacrum and coccyx - what is the sacral vertebrae and what is it articulated with?
starts as 5 separate vertebrae - fuse in adolescents = sacrum
- articulates with coccyx, 5th lumbar and laterally with hip bones
Sacrum and coccyx - what is the coccygeal vertebrae?
tailbone = 3 or 4 fused coccygeal vertebrae
- attachment area for some pelvic ligaments
Thoracic cage - What is it made of, what does it protect, support and provide (attachment wise)?
thoracic vertebrae, ribs, costal cartilage and sternum
- heart, lungs, and major BV
- shoulder girdle and upper limbs
- muscle attachment for back, chest and shoulders
Thoracic cage - What are the 3 bones that are fused together?
Manubrium - articulate with clavicles (via clavicular notch and with rib 1 and 2)
Body - notches for articulation with ribs 2 to 7
Xiphoid process - attachment of some abdominal muscles
Thoracic cage: sternum - what is the difference between the jugular notch, sternal angle, and xiphisternal joint?
JN - indentation you can palpate - disc between T2 and T3 - left common carotid artery from aorta
SA - cartilaginous hinge between manubrium and body of sternum - between T4 and T5
XJ - fusion of sternal body and xiphoid process - opposite T9
Thoracic cage: ribs - How many ribs and what do they attach to?
12/ side
- vertebral column
Thoracic cage: ribs - what is the difference between true ribs and false ribs and how many of each?
TR - vertebrosternal
- ribs 1-7: attached directly to sternum by individual costal cartilages
FR - vertebrochondral
- ribs 8-10: attached indirectly to sternum vis costal cartilage
- ribs 11-12: not attached anteriorly to the sternum
Thoracic cage: ribs - What type of bone is the ribs and what are the 4 components that make it up?
flat bone
- shaft
- head
- neck
- tubercle
Thoracic cage: ribs - what is the difference between the shaft and the head?
S - main portion of rib
- costal groove: passage for intercostal nerves and vessels
H (2 facets) - one articulates the demi-facet on body of same-numbered thoracic vertebra
- other on body of superior vertebra
Thoracic cage: ribs - what is the difference between the neck and the tubercle?
N - narrowed portion of rib that extends between neck and tubercule
T - articulates with transverse process of same-numbered thoracic vertebra
