SKELETAL (bones and joints) Flashcards
are bone-building cells. These cells have an extensive endoplasmic reticulum and numerous ribosomes.
Osteoblasts
The hydroxyapatite crystals act as templates that stimulate further hydroxyapatite formation and mineralization of the matrix. The formation of new bone by osteoblasts is called
osteocytes
once the osteoblasts have secreted sufficient bone matrix
osteocytes
Osteocyte cell bodies are housed within the bone matrix in spaces called
lacunae
Osteocyte cell extensions are housed in narrow, long spaces called
canaliculi
are bone-destroying cells. These cells break down bone.
Osteoclasts
Mature bone is called. It is organized into thin, concentric sheets or layers, called lamellae
lamellar bone
consists of interconnecting rods or plates of bone called trabeculae
Spongy bone
The functional unit of compact bone, composed of concentric rings of matrix, which surround a central tunnel and contain osteocytes
Osteon
In cross section, an osteon resembles a circular target; the bull’s-eye of the target is the
central canal
The ends of a long bone are called e
epiphyses
It is the center portion of the bone. It is composed primarily of compact bone tissue, surrounding a hollow center called the medullary cavity.
diaphysis
Within joints, the end of a long bone is covered with hyaline cartilage called
articular cartilage
is located between the epiphysis and the diaphysis
epiphyseal plate
When bone stops growing in length, the epiphyseal plate becomes ossified and is called the
epiphyseal line
is the site of blood cell formation
Red marrow
is mostly adipose tissue.
yellow marrow
is a connective tissue membrane covering the outer surface of a bone
periosteum
is a single cell layer of connective tissue that lines the internal surfaces of all cavities within bones, such as the medullary cavity of the diaphysis and the smaller cavities in spongy and compact bone
endosteum
Skeletal System Functions
- Support
- Protect
- Movement
- Storage
- Blood cell production
bones are longer than they are wide;
examples are upper and lower limb bones.
Long bones
bones are approximately as wide as they
are long; examples are the bones of the wrist and ankle.
short bones
bones have a relatively thin, flattened shape;
examples are bones of the skull and sternum.
flat bones
include the vertebrae and facial
bones, which have shapes that do not fit readily
into the other three categories.
Irregular bones
covers epiphyses
reduces friction
Articular cartilage
site of growth between diaphysis and epiphysis
Epiphyseal plate
center of
diaphysis red or
yellow marrow
Medullary cavity
membrane around
bone’s outer
surface
Periosteum
membrane that
lines medullary
cavity
Endosteum
Bones contain cavities, such as the large
medullary cavity in the diaphysis, as well as
smaller cavities in the epiphyses of long bones
and in the interior of other bones.
Bone Marrow
location of blood forming
cells.
Red marrow
marrow is mostly fat.
Yellow marrow
rings of bone matrix
Lamella
spaces between lamella
Lacunae
tiny canals
transport nutrients
and remove
waste
Canaliculus
center of osteon, contains blood vessels
Central canal
It is located at the epiphyses of long bones
and center of other bones.
- It has trabeculae, which are interconnecting
rods, and spaces that contain marrow. - It has no osteons.
Spongy bone
responsible for the formation of
bone and the repair and remodeling of bone.
Osteoblasts
cells that maintain bone matrix and
form from osteoblast after bone matrix has
surrounded it.
Osteocytes
contribute to bone repair and
remodeling by removing existing bone, called
bone reabsorption.
Osteoclasts
Bone formation that occurs within connective
tissue membranes is called
intramembranous
ossification.
is the formation of bone by
osteoblasts.
Ossification
The process begins in areas called, and the trabeculae radiate out from the
centers.
ossification
centers
Bone formation that occurs inside hyaline
cartilage is called
endochondral ossification.
occurs when
osteoblasts begin to produce bone within
connective tissue.
Intramembranous ossification
Endochondral bone formation is bone formation
within a cartilage model.
Endochondral Ossification
smooth, rounded end
* Example - occipital condyle
Condyle
is composed of the skull, the
vertebral column, and the thoracic cage.
The axial skeleton
The braincase, which encloses the cranial cavity,
consists of how many bones
8
The skull has how many bones?
22
The bony structure of the face has
14 facial bones
Anterior part of cranium
Frontal bone
Posterior portion and floor of cranium
Occipital bones
Sides and roof of cranium
Parietal bones
- Inferior to parietal bones on each side of the cranium
- Temporomandibular joint
Sphenoid bone
- Anterior portion of cranium, including medial
surface of eye orbit and roof of nasal cavity - Nasal conchae
Ethmoid bone
Form upper jaw, anterior portion of hard palate,
part of lateral walls of nasal cavity, floors of eye
orbits
Maxillae
Form posterior portion of hard palate, lateral wall of nasal cavity
Palatine bones
- Cheek bones
- Also form floor and lateral wall of each eye orbit
Zygomatic bones
Medial surfaces of eye orbits
Lacrimal bones
Form bridge of nose
Nasal bones
- In midline of nasal cavity
- Forms nasal septum with the ethmoid bone
Vomer
Attached to lateral walls of nasal cavity
Inferior nasal conchae
- Lower jawbone
- Only movable skull bone
Mandible
Several of the bones associated with the nasal
cavity have large cavities within them, called the
paranasal sinuses which open into the nasal
cavity.
Paranasal Sinuses
The paranasal sinuses are
- Frontal
- Ethmoid
- Sphenoid
- Maxillary
is an unpaired, U-shaped bone
that is not part of the skull and has no direct bony attachment to the skull or any other bones.
-provides an attachment for some
tongue muscles,
-has the unique distinction of
being the only bone in the body that does not
articulate with another bone.
Hyoid Bone
spine, is the central axis of the
skeleton, extending from the base of the skull to slightly past the end of the pelvis.
Vertebral Column
In adults, it usually consists of ___ individual bones, grouped into five regions.
26
The adult vertebral column has four major curvatures:
cervical, thoracic, lumbar and sacrococcygeal
can be classified structurally as fibrous,
cartilaginous, or synovial, according to the major
connective tissue type that binds the bones
together and whether a fluid-filled joint capsule is
present.
Joints
- united by means of cartilage
- subclasses are synchondroses and symphysis
Cartilaginous
- joined by a fluid cavity
- Most joints of the appendicular skeleton
Synovial
- non-movable joint
- Example – skull bone articulations
Synarthrosis
- slightly movable joint
- Example - between vertebrae
Amphiarthrosis
- freely movable joint
- Example - knee, elbow, and wrist articulations
Diarthrosis:
