Chapter 7: The Axial Skeleton Flashcards
how many bones are in the axial skeleton
80
how many cranial bones
8
how many facial bones
14
how many auditory bones
6
how many bones of the vertabral column
26
function of the cranial bones
protect the brain and provide large areas for muscle to attach for movement
the function of facial bones
form the face and protect and support the entrances to the digestive and respiratory system
function of the thorax
- protects the organs of the thoracic and superior abdominal cavities
- supports the bones of the shoulder girdle and upper limbs
functions of the vertebral column
- form the skeleton of the trunk of the body with the ribs and the sternum
- provides flexible movement
- encloses and protects the spinal cord
- supports the head
- provides the attachment of rib, pelvic girdle and back muscles
how many bones does the skull contain
22
the structures that form the nasal septum
the perpendicular plate of the ethmoid bone, the vomer, and septal cartilage
define foramina
openings for blood vessels, nerves and ligaments
define sutures
fiberous joints composed of very short coninuous connective tissue that unites wavy edges of the skull bones. during youth, sutures (fontanels) permit the skull bones to grow. in adults, connective tissue in the sutures is replaced by bone tissue to form solid bonry joints called synostoses. sutures are immovable joints (synarthroses)
true formina
completely surronded by bone
false formina
not completely surronded by bone- ligament completes the ring
what lies under the occiptal bone?
cerebellum
what does the temporal bone house
aditory cavity
what is a process
a projection off a bone
what is the largest cranial fossa?
the posterior cranial fossa
what does the posterior cranial fossa house?
cerebellum, pons, mendulla oblongata
what does the anterior cranial fossa house?
the frontal lobes
what does the middle cranial fossa house?
temporal lobes, cerebral hemishperes and the pituitary gland
how is the hyoid bone attached
- doesnt atriculate with anyother bone
- suspended from the styloid process for the temporal bone by ligaments and muscles
what is the function of the hyloid bone
- supports the tounge
- provides and attachment site for muscles of the tongue, neck and pharynx
The roof of your mouth (hard palate) is formed by which two bones?
palatine and maxilla
Which bone contains the external auditory meatus?
temporal
Which two bones contribute to forming the nasal septum?
vomer and ethmoid
The ___________ is a rounded projection that serves as an attachment point for several neck muscles.
mastoid
This cranial bone is shaped like a butterfly.
sphenoid
What vital structure is protected by the sella turcica portion of the sphenoid bone?
pituitary
The ________ bone connects to all other cranial bones, thus giving it the nickname “keystone”.
sphenoid
Olfactory nerves travel through small holes in which bone?
ethmoid
What structure(s) make up the nasal septum?
- vomer
- ethmoid
- septal cartilage
These paired bones are the smallest bones of the face.
lacrimal
Dentist inject anesthetics into the mental nerve , near this structure.
mental foramen
The auditory ossicles and the _________ are the only freely moving bones in your skull.
mandible
What is the relation of the hyoid bone to the larynx?
it lies above the larnyx
the number of cervical vertebrea
7
the number of thoraxic vertebrea
12
the number of lumbar vertebrea
5
the number of fused vertebrea that make up the scacrum
5
the number of fused coccygeal vertebrae that make up the coccyx
4
which curves of the adult vertebral column are concave (relative to the anterior side of the body)
- thoracic
- sacral
which curves of the adult vertebral column are convex (relative to the anterior side of the body)
- cervical
- lumbar
what are the functions of the curves in the vertebral column
The curves of the vertebral column increase its strength, help maintain balance in the upright position, absorb shocks during walking, and help protect the vertebrae from fracture.
what are primary curves
-thoracic and sacral
what are secondary curves
- cervical and lumbar
- cervical is formed about 3 months after birth when the baby begins to hold it’s head up
- lumbar is formed when the child begins to sit, stand and walk
- the curves are fully developed by the age of 10
describe the structure of the inter vertebral disk
- fibrous outter ring made of fibrocartilage called annulus fibrous
- nucleus pulposus- inner soft, pulpy substance
scoliosis
a lateral bending of the vertebral column, usually in the thoracic region
kyphosis
is an increase in the thoracic curve of the vertebral column
lordosis
sometimes called hollow or sway back, is an increase in the lumbar curve of the vertebral column
What are the functions of the vertebral and intervertebral foramina?
The vertebral foramina enclose the spinal cord; the intervertebral foramina provide spaces for spinal nerves to exit the vertebral column.
name the seven processes on a typical vertebrea
- transverse processes (x2)
- spinous processes (x1)
- inferior articuar processes
- supirior articular processes
the yes bone is the?
atlas (C1)
the no bone is the?
axis (C2)
the superior articular faucets articulate with which part of the scull?
the occipital condials forming the atlanto-occipital joints
what makes cervical vertebrae different from other thoracic vertebrae?
- smaller bodies (less weight to support)
- their transverse processes each contain transverse foramen through which a vertebral artery and it’s vein as well as nerve fibre pass.
- the spinous processes of C2 through C6 are bifid (their tips branch off into two small projections)
- largest vertebral foramen- houses the vertebral enlargment of the spinal cord
the vertebral notch creates what?
creates a false vertebral foramen
thoracic vertebrae can be identified by:
- COSTAL FACETS
- form synovial joints with the tubricals of the ribs - Movements of the thoracic region are limited by thin intervertebral discs and by the attachment of the ribs to the sternum.
what are the distingishing features of the lumbar vertebrae
- spinous process is short and blunt
- transverse process is large and blunt
- large intervertebral dick and body
how would you determine the rib # if you knew the vertebrae #?
the number of the inferior vertebrae (ie. attached to T2 and T3 = rib number 3)
what ligament conects the lamina between two vertebrae
ligamentum flavum
what ligament runs all the way down the spinal column and stops the vertebrae from fish tailing?
supraspinous ligament
which ligament attaches one spinous process to another?
interpinous ligament
which ligament covers the anterior body of the vertebrae and prevents hyper extension?
anterior longitudinal ligament
the posterior longitudinal ligament does what where?
- prevents hyper flexion
- lines the anterior side of the vertebral cannal
which ribs of the sternum articulate dirrectly or indirrectly to the sternum
2-10
what are the two main joints on the sternum?
the sternoclavicular joint (attach to the clavical at the suprasternal notches)
- sternocoastal joints (with the costal cartalge of the ribs)
when does the xiphoid process turn from hyaline cartalage to bone?
not until the age of 40
How does a rib articulate with a thoracic vertebra?
The facet on the head of a rib fits into a facet on the body of a vertebra, and the articular part of the tubercle of a rib articulates with the facet of the transverse process of a vertebra
which ribs are “true” ribs?
1-7
which ribs are “false’ ribs?
8-10
which ribs are floating?
11 and 12
the sternal angle (joint between the manubrium and the body) creates what kind of joint?
hinge joint
what makes the first rib unique?
The superior surface of the first rib has two shallow grooves, one for the subclavian vein and one for the subclavian artery and inferior trunk of the brachial plexus.
the procces of sacral vertabrae fusion usually comes by age?
30
true or false? the maxilla and the mandible articulate
false
the skeleton of the thorax:
- is formed by 12 pairs of ribs, costal cartilage, the sternum, 12 thoracic vertebra
- protects the internal chest organs as well as the liver
- is narrower at the superior end
- aids in supporting the bones of the shoulder girdle
