lab two: osteology - the axial skeleton Flashcards
how many bones do humans have at birth?
300 bones
how many bones do we have as adults?
206-213 bones
what are the two major categories of the skeletal system?
axial skeleton and appendicular skeleton
axial skeleton
consists of 80 bones
appendicular skeleton
consists of 126 bones
what are the five major functions of the skeletal system?
support, movement, protection, storage of minerals, and production of blood cells
what are the major bones of the cranium?
frontal, parietal, temporal, occipital, sphenoid, ethmoid, maxilla, and mandible
bones of the adult skeleton are compromised of what two basic kinds of osseous tissue that differ in their texture?
compact bone and spongy bone
compact bone
looks smooth and homogeneous
spongy bone
composed of small trabeculae (tiny beams and struts) of bone and lots of open spaces
what are the different classifications of bone based on their gross anatomy?
long, short, flat, sesamoid, and irregular
long bones
longer than they are wide and generally consist of a shaft with heads at either end
long bones are primarily composed of _____
compact bone
short bones
roughly cube-shaped and contain more spongy bone than compact bone
ex: carpals
flat bones
generally flattened along a major aspect of their geometry, but can be curved with two wafer-like layers of compact bone between a layer of spongy bone
ex: sternum
examples of flat bone that are curved
ribs and occipital bone
irregular bones
do not fit into the other categories due to their irregular morphology
ex: vertebra
bones are encapsulated in a _____
periosteum
periosteum
tough, fibrous membrane that covers the compact bone surface and appears shiny and glossy
the periosteum is made up of what two layers?
an outer fibrous layer and an inner cellular layer
outer fibrous layer of periosteum
layer where muscle tendons and bone ligaments attach
inner cellular layer of periosteum
layer that produces the osteoblasts
osteoblasts
needed for bone growth; are eventually embedded in the bone matrix they produce and become osteocytes
osteocytes
maintain bone tissue
diaphysis
a long, central shaft found in long bones
proximal epiphysis
on the end of the long bone closest to the trunk of the body
distal epiphysis
on the end of the long bone furthest away from the trunk of the body
wherever an epiphysis articulates with another bone, a layer of _____ covers the epiphysis
hyaline cartilage (articular cartilage)
the wall of the diaphysis is made of what?
compact bone
the interior of the diaphysis is hollow, forming a space called the _____
marrow (medullary) cavity
the vast majority of the medullary cavities in the long bone of adults contains a high concentration of lipids called _____
yellow marrow
endosteum
a membrane that lines the marrow cavity
metaphysis
located between the diaphysis and either epiphysis
the epiphyseal line forms in place of the _____
epiphyseal plate
what does the formation of the epiphyseal line indicate?
bone has transitioned from the juvenile stage to the adult stage
when does bone growth stop?
when cartilage of the epiphyseal plate disappears and is replaced by the bone (epiphyseal line)
epiphyseal line
bony remnant of the growth plate
flat bones are thin bones with no _____
marrow cavity
flat bones are made of a layer of _____ bone between superficial layers of _____ bone
spongy; compact
the compact bone layers collectively called the _____ of the bone and individually called the external and internal _____ are thick in order to provide strength for the bone
cortex; tables
the spongy bone between the tables is called the _____
diploe
the diploe is filled with _____
red marrow
red marrow
a type of loose connective tissue made up of stem cells from which all blood cells arise
bone markings
reveal where bones form joints with other bones, where muscles, tendons, and ligaments were attached, and where blood vessels and nerves pass
what are the two categories of bone markings?
projections and depression
projections
processes that grow out from the bone and serve as sites of muscle attachment or help form joints
depressions
indentations or openings in the bone that often serve as conduits for nerves and blood vessels
projections that are sites of muscle and ligament attachment
tuberosity, crest, trochanter, line, tubercle, epicondyle, spine, process
surfaces that form joints
head, facet, condyle, ramus
depressions and openings
foramen, groove, fissure, notch, fossa, meatus, sinus
tuberosity
large rounded projection
crest
narrow ridge of a bone; usually prominent
trochanter
very large, blunt, irregularly shaped process
line
narrow ridge of bone; less prominent than a crest
tubercle
small rounded projection or process
epicondyle
raised area on or above a condyle
spine
sharp, slender, often pointed projection
process
any bony prominence
head
body expansion carried on a narrow neck
facet
smooth, nearly flat articular surface
condyle
rounded articular projection, often articulates with a corresponding fossa
ramus
arm-like bar of bone
foramen
round or oval opening through a bone
groove
furrow
fissure
narrow, slit-like opening
notch
indentation at the edge of a structure
fossa
shallow basin-like depression in a bone, often serving as an articular surface
meatus
canal-like passageway
sinus
bone cavity, filled with air and lined with mucous membrane
what passes through the olfactory foramina of the cribriform plate?
olfactory nerve I
what passes through the optic canal?
optic nerve II
what passes through the superior orbital fissure?
oculomotor nerve III, trochlear nerve IV, trigeminal nerve I, and abducens nerve VI
what passes through the foramen rotundum?
trigeminal nerve V
what passes through the foramen ovale?
trigeminal nerve V
what passes through the foramen lacerum?
no structure passes through because it is covered by a membrane in adults
what passes through the foramen spinosum?
middle meningeal artery
what passes through the carotid canal?
internal carotid artery
what passes through the internal auditory meatus?
facial nerve VII, vestibulocochlear nerve VIII
what passes through the jugular foramen?
internal jugular vein, glossopharyngeal nerve IX, vagus nerve X, and spinal accessory nerve XI
what passes through the hypoglossal canal?
hypoglossal nerve XII
what passes through the supraorbital foramen?
supraorbital artery and nerve
what passes through the inferior orbital fissure?
zygomatic nerve and blood vessels
what passes through the infraorbital foramen?
infraorbital nerve
what passes through the mental foramen?
blood vessels and trigeminal nerve V
what passes through the foramen magnum?
spinal cord
what passes through the stylomastoid foramen?
facial nerve VII
what passes through the mandibular foramen?
alveolar nerve
what passes through the transverse foramen of cervical vertebrae?
vertebral arteries
what passes through the costal groove
neurovascular bundle
mnemonic for cranial nerves:
Oh, Oh, Oh, To Touch And Feel Very Good Velvet AH
I. olfactory nerve
II. optic nerve
III. oculomotor nerve
IV. trochlear nerve
V. trigeminal nerve
VI. abducens nerve
VII. facial nerve
VIII. vestibulocochlear nerve
IX. glossopharyngeal nerve
X. vagus nerve
XI. spinal accessory nerve
XII. hypoglossal nerve
hyoid bone
unique in that it does not articulate with any other bone; rather, many muscles originate or insert into it
what are the five types of vertebrae?
cervical, thoracic, lumbar, sacral, and coccygeal
how many vertebrae are cervical?
seven
how many vertebrae are thoracic?
twelve
how many vertebrae are lumbar?
five
cervical, thoracic, and lumbar vertebrae are all _____
unfused
cervical vertebrae
articulations are not as confined, allowing for a wide range of motion in the head and neck
cervical vertebrae have a _____ spinous process and a _____ foramen
bifid; transverse
the transverse foramina in cervical vertebrae transmit the vertebral arteries, do what?
form the basilar artery and deliver blood to the brain
thoracic vertebrae
articulate with the ribs, limiting flexion in the thorax
the articular processes of thoracic vertebrae are directed anterior and posterior, causing what?
decreased flexion and extension of the thorax
lumbar vertebrae
articular processes are directed medially and laterally, limiting rotation in the lower spine
cauda equina
at L1, the spinal cord proper stops and becomes hanging “roots”
where is a spinal tap performed?
between L3 and L4 in order to avoid hitting the spinal cord
sacrum
made up of five fused vertebrae
sacral foramina
transmit blood vessels and spinal nerves to the lower body
coccyx
the tail bone; made up of four fused vertebrae
what are the four natural curvatures of the spinal cord?
cervical, thoracic, lumbar, and sacral
when determining which articular process is superior and which is inferior, it is based on their position on the _____, NOT their position in the _____
vertebra; joint
cervical vertebrae key features
kidney bean shaped body and horizontal spinous process with a bifid spine in cervical vertebrae 3-6
the hyoid bone does not actually articulate with the _____
cervical vertebrae
atlas
the first cervical vertebra (C1)
what makes the atlas different from other cervical vertebrae?
it has no body, a large vertebral foramen, it articulates with the skull, and has no spinous process
axis
the second cervical vertebra (C2); articulates with the atlas
what is the primary function of the axis?
to provide the atlas with a pivot point for when the head is turned laterally and medially
dens
fits up inside the atlas to form the atlanto-axial joint, which allows rotation of the head
_____ vertebrae are the largest vertebrae in the human body
lumbar
sacrum
is specialized to provide a stable anchoring point for the bones of the pelvic girdle
coccyx
serves as an attachment point for several ligaments and muscles of the pelvic floor
thoracic cage
compromised of the sternum and twelve pairs of ribs
the twelve pairs of ribs articulate with the thoracic vertebrae _____
posteriorly
ten of the pairs of ribs connect to the sternum _____ to enclose the thoracic organs in a protective cage
anteriorly
sternum
flat bone
what three bony elements make up the sternum?
manubrium, sternal body, xiphoid process
manubrium
articulates with the sternal body at the sternal angle and articulates with the clavicle at the clavicular notch
xiphoid process
the attachment site for several muscles and is made up of hyaline cartilage until late adulthood, when it completely ossifies
why are people advised not to perform CPR without proper training?
poor technique could lead to snapping off the xiphoid process and thus puncturing a lung
costal cartilage
attaches the ribs to the sternum and is somewhat flexible allowing for expansion of the rib cage during inhalation
ribs are classified according to how they articulate with the _____
sternum
true ribs
first seven pairs; their costal cartilage attaches directly to the sternum
false ribs
rib pairs 8-12; their costal cartilage does not connect to the sternum directly
floating ribs
rib pairs 11 and 12; a subset of false ribs that do not articulate with the sternum and serve little use other than protection of the kidneys
each rib has a _____ with two articular facets for articulating with the costal facets of the thoracic vertebrae
head
tubercle of rib
articulates with the transverse costal facet of the corresponding vertebra
costal groove
runs on the inferior border of the inner face of all ribs and carries a neurovascular bundle
neurovascular bundle
vein, artery, and nerve
where are injections or intrusions made between ribs?
on the superior border of the inferior rib
what should doctors or nurses avoid hitting when making injections?
the neurovascular bundle: hitting this area would cause tremendous pain for the patient
