ANATOMY_part3.1 Flashcards
Parts of the skeletal system
-Bones (skeleton)
– Joints
– Cartilages
– Ligaments
Two subdivisions of the skeleton
– Axial skeleton
– Appendicular skeleton
-Support the body
* Protect soft organs
* Allow movement due to attached skeletal
muscles
* Store minerals and fats
* Blood cell formation
Functions of Bones
The adult skeleton has?
206 bones
Two basic types of bone tissue
Compact bone
Spongy bone
Compact bone
Homogeneous
– Typically longer than they are wide
– Have a shaft with heads at both ends
– Contain mostly compact bone
Long bones
Spongy bone
Small needle-like
pieces of bone
* Many open spaces
– Generally cube-shape
– Contain mostly spongy bone
Short bones
– Thin, and usually curved
– Two thin layers of compact bone surround a
layer of spongy bone
Flat bones
Irregular bones
-_______shape
- Do not fit into other bone classification
categories
– Shaft
– Composed of compact bone
Diaphysis
– Ends of the bone
– Composed mostly of spongy bone
Epiphysis
– Outside covering of the diaphysis
– Fibrous connective tissue membrane
Periosteum
– Secure periosteum to underlying bone
Sharpey’s fibers
– Supply bone cells with nutrients
Arteries
– Covers the external surface of the epiphyses
– Made of hyaline cartilage
– Decreases friction at joint surfaces
Articular cartilage
– Flat plate of hyaline cartilage seen in young,
growing bone
Epiphyseal plate
– Cavity inside of the shaft
– Contains yellow marrow (mostly fat) in adults
– Contains red marrow (for blood cell formation)
in infants
Medullary cavity
– Remnant of the epiphyseal plate
– Seen in adult bones
Epiphyseal line
Surface features of bones
Sites of attachments for muscles, tendons,
and ligaments
– Passages for nerves and blood vessels
Categories of bone markings
Projections or processes—grow out from the
bone surface
– Depressions or cavities—indentations
– A unit of bone containing central canal and
matrix rings
Osteon (Haversian system)
– Opening in the center of an osteon
– Carries blood vessels and nerves
Central (Haversian) canal
– Canal perpendicular to the central canal
– Carries blood vessels and nerves
Perforating (Volkman’s) canal
– Cavities containing bone cells (osteocytes)
– Arranged in concentric rings
Lacunae
– Rings around the central canal
– Sites of lacunae
Lamellae
– Tiny canals
– Radiate from the central canal to lacunae
– Form a transport system connecting all bone
cells to a nutrient supply
Canaliculi
what are the Types of Bone Cells?
Osteocytes
Osteoblasts
Osteoclasts
mature bone cells
Osteocytes
bone-destroying cells
Osteoclasts
bone-forming cells
Osteoblasts
a break in the continuity of a
bone
Fracture
2 Types of bone fractures
Closed (simple) fracture
Open (compound) fracture
broken bone
penetrates through the skin
Open (compound) fracture
break that does not
penetrate the skin
Closed (simple) fracture
Bones are joined by?
sutures
The Axial Skeleton divided into 3 parts are?
– Skull
– Vertebral column
– Bony thorax
Repair of Bone Fractures
-Hematoma (blood-filled swelling) is formed
* Break is splinted by fibrocartilage to form a
callus
* Fibrocartilage callus is replaced by a bony
callus
* Bony callus is remodeled to form a
permanent patch
Two sets of bones
– Cranium
– Facial bones
Hollow portions of bones surrounding the
nasal cavity
Paranasal Sinuses
– Lighten the skull
– Give resonance and amplification to voice
Functions of paranasal sinuses
- The only bone that does not articulate with
another bone - Serves as a moveable base for the tongue
- Aids in swallowing and speech
Hyoid Bone
is large compared to the
infant’s total body length
Fetal Skull
fibrous membranes
connecting the cranial bones
– Allow the brain to grow
– Convert to bone within 24 months after birth
Fontanels
Each vertebrae is given a name according
to its location
Vertebral Column
Nine vertebrae fuse to form two composite
bones called?
– Sacrum
– Coccyx
the spinal curvatures
of the thoracic and sacral regions
* Present from birth
Primary curvatures
the spinal
curvatures of the cervical and lumbar regions
* Develop after birth
Secondary curvatures
Formed by the fusion of five vertebrae
Sacrum
Formed from the fusion of three to five
vertebrae
– “Tailbone,” or remnant of a tail that other
vertebrates have
Coccyx
Forms a cage to protect major organs
* Consists of three parts
Bony Thorax
what are the three parts of Bony Thorax?
– Sternum
– Ribs
– Thoracic vertebrae
