What does the skeletal system do?
support, store minerals and lipids, blood cell production, protection, leverage
How is a bone classified?
shape or internal tissue organization
How many bones/categories in typical adult skeleton?
206 bones, 6 categories by their individual shape
Long bones?
long and slender, located in the arm, forearms, thigh, leg, palms, soles, fingers, toes
Sutural bones?
small, flat, irregular shaped bones. vary in number, shape, size, and position
Irregular bones?
have complex shapes with short, flat, notched, or ridged surfaces. ex. bones of the pelvis, spinal vertebrae, and several skull bones
Short bones?
small and boxy ex. carpals and tarsals
Sesamoid bones?
general small, flat, and shaped like sesame seed. develop inside tendons, most commonly located near joints at knees, hands, and feet. Individuals may vary in the location and abundance (form in at least 26 locations)
Bone external and internal characteristics?
elevations and projections form where tendons and ligaments attatch. depressions, grooves, and tunnels in bone indicate cites where blood vessels or nerves lie alongside/pentrate bone
Uses for Bone Markings/Surface Features?
determine size, age, sex, and general characteristics
Process
projection or bump
Ramus
extension of a bone making an angle with the rest of the structure
Trochanter
large, rough projection
Tuberosity
smaller, rough projection
Tubercle
small, rounded projection
Crest
prominent ridge
Line
low ridge
Spine
pointed or narrow process
Head
expaned articular end of an epiphysis, separated form the shaft by a neck
Neck
narrow connection between the epiphysis and the diaphysis
Condyle
smooth, rounded process
Trochlea
smooth, grooved articular process shaped like a pulley
Fossa
shallow depression
Sulcus
narrow groove
Foramen
rounded passageway for blood vessels or nerves
Canal
passageway through the substance of a bone
Fissure
elongated cleft
Sinus
chamber within a bone, normally filled with air
Diaphysis
shaft, makes up the bones length. wall consists of a layer of compact bone(dense bone). solid, forms layer called medullary cavity. covered and protected by connective tissue membrance called periosteum,attatched to the bone by Sharpeys fibers
Epiphysis
at end of the long bone. thin layer of spongy bone. open network of struts and plates. covers with cartilage
Epiphyseal line
remnant of epiphyseal plate with growth occurs
Metaphysis
narrow zone connecting the epiphysis and diaphysis
Medullary cavity
central space in bone primarily a storage area for adipose tissue (in infants formation of blood cells and red marrow can be found)
Osteocytes
mature bone cells, cant divide. most abundant. maintains the protein and mineral content of the surrounding matrix and repair damaged bones
What are four cells of the bone?
osteocysts, osteoblasts, osteoprogenitors, osteoclasts
Osteoblasts
produce new bone matrix by osteogenesis, make and release protein, assist in elevating levels, become osteocytes once completely surrounded by bone matrix
Osteoprogenitor
small numbers of mesenchymal cells, squamous stem cells that divide to produce daughter cells,maintain populations of osteroblasts, important in fractures, located in the endosteum
Osteoclasts
giants cells with more than 50 nuclei, remove and recycle bone matrix by secreting enzymes that dissove and release stored minerals
Ossification
process of bone formation by replacing other tissues
Bone Growth Length?
osteoblasts at the shaft end remove cartilage at the same rate as cartilage is forming on the epiphyseal side
Appositional Bone Growth (width/diameter)
osteoblasts in periosteum add bone tissue to the external face of the diaphysis. Osteoclasts in the endosteum remove bone from the inner face of the diaphysis wall
Calcification
deposition of calcium deposits, occurs during ossification
Structure of Compact Bone
Osteon-basic unit, osteocytes in layers around central canal, canal contains blood vessels, canaliculi interconnect the lacunae with one another in central canal
Central canal
parallel to the surface of the bone
Perforating canal
extend perpendicular to the surface
Structure of Spongy Bone
Matrix-forms struts, branch, nutrients reach osteocytes by diffusion
Characteristics /Locations of Spongy Bone
lighter than compact bone, able to withstand stress. In short bones(carpals of wrists),inner layer of flat bones, sesamoid
Bone Composition
matrix consisting of extracellular protein fibers and ground substance. very dense and contains calcium deposits, bone cells inside of lacunae, canaliculi
Remodeling
components of bone keep recycling and renewing, "game" between osetocytes, blasts, and clasts.
Closed Bone Fracture
completely internal, no break of the skin, cant be seen in x-rays, easy to treat
Open Bone Fracture
project through the skin, more dangerous due to possibility of infection
Pott Fracture
occurs in ankle, affects bones of leg
Comminuted Fracture
shatter bone into multiple fragments
Transverse Fracture
break bone shaft across its axis
Displaced/Nondisplaced Fracture
produce new and abnormal bone arrangements, retain normal alignment
Colles Fracture
break in the distal portion of the radius
Greenstick Fracture
only one side of the shaft is bone, and the other is bent
Epiphyseal Fracture
occur where bone matrix is undergoing calcification, can permanently stop growth
Compression Fracture
occur in the vertebrae
Avulsion Fracture
tendon or ligament is injured in such a manner that it pulls off a piece of bone
4 steps 2 repair fracture
1-extensive bleeding 2-internal callus forms network of spongy bone 3-carilage of external callus replaced with bone, dead bones removed 4-swelling over fracture until remodeling ocurrs
Skeleton Parts
axial and appendicular
Axial
forms longitudinal axis of body, 80 bones, 40% of bones in human body, provide framework that supports and protects brain, spinal cord, and organs in the ventral cavities, extensive surface areas for attatchment of muscles, joints have limited movements
Axial includes....
Skull & associated bones, vertebral column, thoracic cage
How many bones in the skull?
22
Which bones from the skull are from the cranium?
occipital, frontal, ethmoid, spheniod, parietal (2), temportal (2)
What is the cranial cavity?
a fluid filled chamber that cushions and supports the brain
Which bones form the calvaria?
occiptal, parietal, and frontal bones
What stabalize the position of the brain and are attatched to the inner surface of the cranium?
blood vessels, nerves, and membranes
What does outer surface of the skull provide?
areas of attatchment for muscles of eyes, jaws, and head
What does the jont between occipital and 1st vertebrae of neck stabilize?
the positions of the brain and spinal cord
Superficial Bones
paired maxillae, lacrimal, nasal, zygomatic, mandible. Provide areas for the attatchment of muscles that control facial features and assist in the manipulating of food
Deep Bones
paired palatine inferior nasal conchae, median vomer. separate the oral and nasal cavities. increase surface area of cavities. help form the nasal septum.
Sinuses
air filled chambers that make bone lighter and mucous membrane lining produces mucus that cleans air.
Joints or Articulations
form where two bones interconnect, not mandible and cranium contact.
Where are sutures located? What are the 4?
between immovable joings of the skull bones in adults, bones are tied together. The 4 are Lamdoif, coronal, sagital, and squamous.
Lambdoid Suture
arches across the posterior surface of the skill, separates the ocipital bone from the two parietal bones
Coronal Suture
attatches the frontal bone to the parietal bones of either sides
Sagital Suture
extends from lambdois suture to the coronal suture, between the parietal bones
Squamous Suture
one on each side of the skull forms the boundary between the temporal bone and the parietal bone of that side
Orbital Complexes
protect and support openings of the digestive/respirtory system and sense organs for vision and smell
Orbits are what? Name all 7?
bony recesses that contain the eyes. each orbit contains frontal, maxilla, ethmoid, zygomatic, palatine, sphenoid, and lacrimal
Nasal Complexes
bones that enclose the nasal cavities and the paranasal sinuses
Superior wall includes?
frontal, sphenoid, ethmoid
Lateral walls includ?
maxillae,lacrimals, ethmoid, nasal conchae, and nasal bones
List the Paranasal Sinuses?
sphenoid, ethmoid, frontal bone, maxillia, palatine bone
What are the Paranasal Sinuses?
lighten skull bones, provide mucus
Fontanelles
Largest fibrous areas between the cranial bones.
Anterior Fontanelle
(exists 2 years after birth) largest, located at the intersection of the frontal, sagital, and coronal surfaces in the anterior portion of the skull, called "soft spot
Occipital Fontanelle
(disapear 1-2 months after birth) junction between the lambdoid and sagital sutures
Sphenoidal Fontanelle
junctions between the squamous and coronal sutures
Mastoid Fontanelles
(dissapear 1-2 months after birth) junctions between the squamous and lambdoid suture
Vertebral Column
26 bones, provides column of support, bears weight of head, neck, and trunk, protects spinal cord, helps mantain upright body position, 28 inches, several curves
Cervical Curve
neck
Thoratic Curve
upper back
Lumbar Curve
lower back
Sacral Curve
gluteal region
Vertebral Body
transfers weight along the axis of teh vertebral column, interconnected by ligaments, separated by fibrous cartliage
Vertebral Arch
forms the posterior margin of each vertebraal foreman, vertbrae form the canal, walles called pedicles along margins, roof called laminae
Articular Processes
arise at junction between pedicules and the laminae
Cervical
c1-c7 create the neck, extend from occipital bone to the thorax, smallest, support head weight
Vertebra Prominens (c7)
has a long, slender spinous process, ended in a broad tubercycle
Thoratic
12 vertebrae, heart shaped body
Coccyx
consists of 3-5 coccygeal vertebrae, begin fusing at age 25 to late adulthood,
Thoracic Cage
includes thoaracic vertebrae, ribs, and sternum. Ribs and sternum form rib cage, protects heart, lungs thymus, and other structures in cavity, serves as an attatchment site for muscles
Ribs (Costae)
very mobile, curved, flattened bones
Rib pairs (12)
1-7 (true ribs, connected to sternum, increase in length) 8-12 (false, dont directly attach) 11 and 12 are floating ribs
Xiphoid process (sternum)
smallest part of sternum, attatched to inferior surface of body
Sternum
flat cone forming anterior midline of the thoracic wall
Manubrium (sternum)
triangular, superious portion, articulates with clavicles and carilage of 1st ribs, contains jugular notch
Body (sternum)
tongue shaped, attatches to the inferior portion of manubrium. attatched ribs 2-7
Sacrum
fused components, marked by transverse lines, protect reproductive, digestive, uninary system organs, curved