Chapter 7 Axial Skeleton Flashcards
- Typically ___ bones in the adult skeleton
- Skeletal system is divided into two parts:
- -
- -
- Typically 206 bones in the adult skeleton
- Skeletal system is divided into two parts:
A. Axial skeleton: Skull, vertebral column, and thoracic cage
B. Appendicular skeleton: Shoulder and hip bones and those of the upper and lower extremities
Skull Bones
Skull is composed of ….
Many bones have passageways for….
Skull is composed of cranial and facial bones
Many bones have passageways for blood vessels and nerves
Cranial bones: __ bones that surround and enclose the brain
- -____
- -____
Cranial bones: 8 bones that surround and enclose the brain
- -Unpaired: ethmoid, frontal, occipital, and sphenoid bones
- -Paired: parietal and temporal bones
Facial bones: ___bones that form the face and have no brain contact
two types
—
—
Facial bones: 14 bones that form the face and have no brain contact
- Unpaired: vomer and mandible bones
- Paired: maxillae, nasal, lacrimal, zygomatic, palatine, and inferior nasal conchae bones
Sutures
- _____ between skull bones
- It is common for some individuals to have….
- During adulthood sutures start to….
- Immovable joints between skull bones
- It is common for some individuals to have small sutural bones
- During adulthood sutures start to disappear as bones fuse
Four major sutures:
- 4.
Four major sutures:
- Coronal suture: Junction between frontal and parietal bones
- Lambdoid suture: Junction between occipital and parietal bones
- Sagittal suture: Junction between parietal bones
- Squamous suture: Junction between temporal and parietal bones
Bones of the Cranium
- The eight bones of the cranium protect the brain
1. ___: skullcap, roof of cranium - –Made of….
2. ____: floor - —Made of parts of….
The eight bones of the cranium protect the brain
Calvaria: skullcap, roof of cranium
Made of parietal bones and parts of frontal and occipital bones
Base of cranium: floor
Made of parts of ethmoid, sphenoid, occipital and temporal bones
Cranial Fossa
A fossa is a…
The floor of the cranial cavity contains three cranial fossae:
A fossa is a depression in a bone
The floor of the cranial cavity contains three cranial fossae:
- Anterior cranial fossa
- Middle cranial fossa
- Posterior cranial fossa
Bones of the face
__ facial bones give shape to the face,
Form part of the ___ and ___ cavities
Support ____
Serve as attachment sites for muscles of …
Fourteen facial bones give shape to the face,
Form part of the orbital and nasal cavities
Support teeth
Serve as attachment sites for muscles of expression and chewing
Nasal Complex
- Bones and cartilages forming the ___ & ___around them
- Superior border:
- Inferior border:
- Lateral walls:
- Bones and cartilages forming the nasal cavities and sinuses around them
- Superior border: Cribriform plate of ethmoid, parts of frontal and sphenoid
- Inferior border: Maxillae and palatine bones
- Lateral walls: Ethmoid, maxillae, inferior nasal conchae, palatine bones, and lacrimal bones
Paranasal Sinuses
- ____ in skull bones around nasal cavity
a. ___ ____ humidifies and warms inhaled air
b. __ ____
c. Resonant chambers for….
- Air-filled spaces in skull bones around nasal cavity
a. Mucous lining humidifies and warms inhaled air
b. Lightens skull
c. Resonant chambers for sound production while speaking
- Air-filled spaces in skull bones around nasal cavity
Orbital Complex
- The orbits are _____ cavities in skull that hold and protect the __
a. Consist of multiple bones
b. Also contain…
- The orbits are bony cavities in skull that hold and protect the eyes
a. Consist of multiple bones
b. Also contain muscles that move the eyes
Roof of orbit: Floor: Medial wall: Lateral wall: Posterior wall:
Roof of orbit: Frontal bone and lesser wing of sphenoid bone
Floor: Mainly the maxilla bone
Medial wall: Maxilla, lacrimal, and ethmoid bones
Lateral wall: Zygomatic, greater wing of sphenoid, and frontal bones
Posterior wall: Mainly the sphenoid bone
Bones Associated with the skull
2
Auditory ossicles
hyoid
Auditory ossicles: Three tiny bones in ___ part of each ____ bone are for hearing:
3
Auditory ossicles: Three tiny bones in petrous part of each temporal bone are for hearing:
Malleus
Incus
Stapes
- Hyoid bone: Located between the ___ & ___
- Does not ___ with another bone
- Attachment site for…
- Hyoid bone: Located between the mandible and larynx
- Does not articulate with another bone
- Attachment site for tongue and muscles of larynx used in swallowing
Aging of the Skull
-Infant cranial bones are connected by flexible areas of dense regular connective tissue called ___
Major fontanelles: 1. 2. 3. 4.
Infant cranial bones are connected by flexible areas of dense regular connective tissue called fontanelles
Major fontanelles:
- Mastoid fontanelle
- Sphenoidal fontanelle
- Posterior fontanelle
- Anterior fontanelle
Vertebral column is composed of __ bones
24 individual vertebrae
Cervical vertebrae:
Thoracic vertebrae:
Lumbar vertebrae:
Two inferior bones are fusions of several vertebrae
Sacrum:
Coccyx:
Vertebral column is composed of 26 bones
24 individual vertebrae
- -Cervical vertebrae: Seven bones of the neck
- -Thoracic vertebrae: Twelve bones that help form the superior region of the back and articulate with the ribs
- -Lumbar vertebrae: Five bones that help form the inferior, concave region of the back
Two inferior bones are fusions of several vertebrae
- -Sacrum: Five fused vertebrae
- -Coccyx: Four fused vertebrae forming the “tailbone”
Four spinal curvatures present in adult:
Primary curves appear in fetal development
- __ & ___ curvatures
Secondary curves appear at 3-4 months of age
- -___ and ___ curvatures
- -Help shift trunk’s weight over ___
Four spinal curvatures present in adult:
- Cervical curvature
- Thoracic curvature
- Lumbar curvature
- Sacral curvature
Primary curves appear in fetal development
–Thoracic and sacral curvatures
Secondary curves appear at 3-4 months of age
- -Cervical and lumbar curvatures
- -Help shift trunk’s weight over the legs
Most vertebrae have the following features:
Body: weight bearing region
Vertebral arch: attaches to body to form …
- –___: feet of the arch
- –___: posterior extensions of the arch
Jutting processes
- –Spinous processes project ___
- –Transverse processes project ____
- -____ – join to vertebra above
- —____ – join to vertebra below
Most vertebrae have the following features:
Body: weight bearing region
Vertebral arch: attaches to body to form vertebral foramen
- —Pedicles: feet of the arch
- —Laminae: posterior extensions of the arch
Jutting processes
- –Spinous processes project posteriorly
- –Transverse processes project laterally
- –Superior articular process – join to vertebra above
- –Inferior articular process – join to vertebra below
Sacrum: triangular bone forming posterior wall of pelvic cavity
- ___: points ___; base is broad superior surface
- Transverse ridges mark…
- __ __ is continuation of vertebral canal
- —__ __ in inferior opening - __ and __ allow nerves to exit
- Has an auricular surface at _____
Sacrum: triangular bone forming posterior wall of pelvic cavity
- Apex: points inferiorly; base is broad superior surface
- Transverse ridges mark fusion points of the five vertebrae
- Sacral canal is continuation of vertebral canal
- — Sacral hiatus in inferior opening - Anterior and posterior sacral foramina allow nerves to exit
- Has an auricular surface at sacroiliac joint
Coccyx: fusion of ____ small vertebrae
- Attachment site for __ & ___
- ___ ____ are the laminae of the first coccygeal vertebrae
Coccyx: fusion of four small vertebrae
- Attachment site for ligaments and muscles
- Coccygeal cornua are the laminae of the first coccygeal vertebrae
Thoracic Cage
Bony frame around chest composed of: - - - Protects ....., and other thoracic organs
Bony frame around chest composed of:
- Thoracic vertebrae posteriorly
- Ribs laterally
- Sternum anteriorly
Protects heart, lungs, trachea, esophagus, and other thoracic organs
Sternum
The “breastbone” in anterior midline
Composed of three parts:
The “breastbone” in anterior midline
Composed of three parts:
Manubrium
Body
Xiphoid process
Ribs
__ pairs
Articulate posteriorly with ____
True ribs: Ribs 1-7; articulate anteriorly with..
False ribs: Ribs 8-12; their costal cartilages do not attach directly to the ____
—-Floating ribs: False ribs (pairs 11 and 12) that do not…
-12 pairs
Articulate posteriorly with thoracic vertebrae
True ribs: Ribs 1-7; articulate anteriorly with the sternum via costal cartilages
False ribs: Ribs 8-12; their costal cartilages do not attach directly to the sternum
—-Floating ribs: False ribs (pairs 11 and 12) that do not articulate with the sternum
Development of the axial skeleton
Most bones form from ____ (endochondral ossification)
Flat skull bones develop from ___ (intramembranous ossification)
Sternum develops from…
Most bones form from cartilage (endochondral ossification)
Flat skull bones develop from mesenchyme (intramembranous ossification)
Sternum develops from cartilaginous sternal bars that fuse medially
