Rutgers Functional Human Anatomy Lec 5 (Axial Skeleton - Head & Vertebral Column & Thoracic Cage)

Function of the axial skeleton

- supports and protects body organ

- protects special sense organs

- attachment sites for muscles

Face (bones)

Vomer, Conchae, Nasal, Maxilla, Mandible, Palatine, Zygomatic, Lacrimal

(virgil can not make my pet zebra laugh)

Cranium (bones)

occipital, parietal, frontal, temporal, ethmoid, sphenoid

( Old people from timbuktu eat spaghetti)

Where does the pituitary gland sit?

sella turcica of the sphenoid bone

Palatine bone

- 2 bones making up the roof of the mouth

- posterior to the palatine process of the maxilla

Nasal bone

- 2 nasal bones articulate with the frontal bone

Inferior Nasal Conchae

- one on each side of the nasal septum attached to the lateral wall of the nasal cavity

Zygomatic bone

- articulate w/ the zygomatic process of the temporal bone (form the zygomatic arch)

- zygomaoicofacial foramen

Lacrimal bone

- found in the medial portion of the orbit of the eye

- lacrimal groove leads to the nasolacrimal canal

vomer

forms inferior portion of the nasal septum

orbits

protects the eye

made up of:

front lobe (roof of orbit)

maxilla bone (floor of orbit)

lacrimal & ethmoid (medial wall of orbit)

Sphenoid ( posterior wall)

Zygomatic (lateral wall)

orbits consist of

- lacrimal gland

- adipose tissue

- muscles that move the eye

- blood vessels

- nerves

nasal complex consists of

- anterior nostrils

- posterior nasal apertures

- Nasal septum (vomer, perpendicular plate of ethmoid)

- Nasal wall (nasal conchae)

Paranasal sinuses in nasal complex

- air-filled chambers that open into the nasal cavity

- frontal sinuses

- sphenoidal sinuses

- maxillary sinuses

- ethmoid air cells

hyoid bone

- suspended by stylohyoid ligaments

- extremely mobile

- serve as points for muscle and ligament attachments

Vertebral column

- 26 bones in adult

- 24 vertebrae (7 cervical, 12 thoracic, 5 lumbar)

- 1 sacrum (5 fused vertebrae)

1 coccyx (3-5 fused vertebrae)

Functional anatomy of the vertebral column

- encloses and protects the spinal cord

- supports the skull

- supports weight of head, neck and trunk

- transfers weight to lower limbs

- helps maintain upright position of the body

Spinal curves

- cervical

- thoracic

- lumbar

- sacral

- help maintain balance along with muscle attachment

Vertebral arch

- forms vertebral foramen

- made of pedicle and laminae

- spinous process project posteriorly

- transverse process project laterally

spina bifida

- malformation of structures making up the vertebral arch where the vertebral arch fails to close completely

articular processes (facet)

superior and inferior articular process, attachment points where a superior facet of the bottom vertebrae attaches to the inferior facet of the superior vertebrae

intervertebral foramina

- vertebrae have articular facets and vertebral canal

- vertebral bodies are separated by intervertebral discs

- resulting in a space called the intervertebral foramina

numbering system of vertebral regions

cervical region (C1 - C7)

thoracic region (T1 - T12)

lumbar region (L1 - L5)

cervical vertebrae

- 7 cervical vertebrae

- supports weight of head

- spinous processes are bifid (v shaped) except for C7

- all have transverse foramina (where transverse process attaches to costal process)

The Atlas

C1

- articulates with occipital condyles of the skull

- does not have a body

- consists of anterior and posterior vertebral arches & tubercles

- superior articular facets

inferior articular facets

- allows head to move in "yes" manner

- largest vertebral foramen of all vertebrae

The Axis

C2

- has dens

- allows head to move in a "no" manner

Vertebral Prominens (C7)

- has a long prominent spinous process

Ligamentum nuchae (C7)

- large elastic ligament

- begins at the vertebral prominens and extends to the external occipital crest of the skull

Thoracic region

- 12 vertebrae

- support the ribs

T1-T8 have superior and inferior costal facets

T9-T12 have only 1 facet

T1-T10 have transverse costal facets

- most spinous processes point inferiorly

Lumbar vertebrae

- 5 vertebrae

- support weight of torso

- vertebral bodies are quite large

- spinous process point posteriorly

Sacrum

- one sacrum but consists of 5 fused vertebrae

coccyx

- consists of 3-5 fused vertebrae

- adult male coccyx points anteriorly

- adult female coccyx points inferiorly

- coccyx consists of the coccygeal cornua

Thoracic Cage Functions

- protection

- attachment site for muscles

types of ribs in thoracic cage

- vertebrosternal (true) ribs (connect to sternum via costal cartilages) 1-7

- vertebrochondral (false) ribs 8-12

- vertebral (floating) ribs 11-12

structure of a rib

head, neck, body, tubercle, angle, costal groove

sternal end - superior and inferior articular facet/interarticular crest

sternum

consist of:

manubrium

body

xiphoid process

jugular notch