Chapter 7: Axial Skeleton Flashcards
How many bones are in the body?
206
How many are in the axial skeleton?
80
How many are in the appendicular skeleton?
126
How many bones are associated with the skull?
29
How many bones are in the thoracic cage?
25
How many bones are in the vertebral column?
26
Skull
- Consists of the cranium and the bones of the face
- Encloses the cranial cavity
What do the facial bones do?
Surround and protect the entrances to the respiratory and digestive tracts
Sutures of the skull
- Lambdoid
- Coronal
- Sagittal
- Squamous
Lambdoid Suture
Attaches/separates the occipital bone from the two parietal bones
Coronal Suture
Attaches the frontal to the two parietal bones
Sagittal Suture
- Located between the two parietal bones
- Extends from the lambdoid to coronal suture
Squamous
The boundary between the temporal and the parietal bone on either side of the skull
Which cranial bones articulate with the sphenoid bone?
All of them
Which cranial bones have sinuses?
- Frontal
- Sphenioid
- Ethmoid
Which facial bone is the largest?
Largest facial bones are in the maxillae
Maxillae
Forms the upper jaw and most of the hard palate
Palatine bones
- Small “L” shaped bones
- Forms the posterior hard palate and floor of the nasal cavity
Nasal bones
- Superior border of external nares
- Forms the bridge of the nose
Vomer
Inferior portion of the nasal septum
Zygomatic bone
Temporal process articulates with zygomatic process of temporal bone
Lacrimal bones
- Smallest bones of the face
- Sit medially in orbit
Mandible
- Only moveable facial bone
- Bone of the lower jaw
Hyoid
- Suspended by stylohyoid ligaments
- Connects from the mastoid process (temporal bone) to the lesser horn (hyoid)
- Supports the larynx
How many bones are in the orbital complex?
7
Nasal complex
Bones that enclose the nasal cavities and paranasal sinuses
What is the function of fontanels?
They permit skulls of infants and children to continue growing
Primary (accommodation) curves
Thoracic and sacral
Secondary (compensation) curves
Lumbar and cervical
Abnormal curvatures in the spine
- Kyphosis
- Lordosis
- Scoliosis
Vertebral anatomy
- Typically has a body and vertebral arch
- Superior and inferior articular processes
- Separated by intervertebral discs
Cervical vertebrae
- Has distinctive shape
- Large relative size of vertebral foramen
- Only vertebra with transverse foramina
- Notched spinous processes
Thoracic vertebrae
- Resembles a giraffe’s face due to slender spinous process
- Heart-shaped body
- Articulations for ribs: superior or inferior costal facets
Lumbar vertebrae
- Resembles a moose head
- Most massive and largest vertebral body area
- Least mobile
- Subjected to great stresses
Sacrum
- Protects reproductive, digestive, and urinary organs
- Articulates with pelvic girdle and fused elements of coccyx
How do you know is a sacrum is male or female?
- More curved = male
- Less curved = female
Thoracic cage
Consists of:
- Thoracic vertebrae
- Ribs
- Sternum
Rib cage
Formed by the ribs and sternum
True ribs
- Ribs 1-7
- Attach to sternum
False ribs
- Ribs 8-12
- Do not attach directly to the sternum
Vertebrochondral ribs
- Ribs 8-10
- Costal cartilage of ribs fuses together and merge with the cartilage of rib 7 before reaching the sternum
Floating ribs
- 11-12
- No connection to sternum
Characteristics of a typical rib
- Has a head, neck, tubercle, and a body
- Costal groove marks pathway of blood returning to the heart
Parts of the sternum
- Manubrium
- Body
- Xiphoid process
Manubrium
Superior region of sternum
Body
Main portion of the sternum
Xiphoid process
Inferior end of sternum
