Chapter 5 skeletal system Flashcards
Skeletal system
bones joints cartilages ligaments
skeletal subdivisions
Axial skeleton appendicular skeleton
bone in an adult
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function of bones
support the body protect soft organs allow movement due to attached muscle store minerals and fats blood cell formation
bone tissue
compact bone outside osteon spongy bone-inside
classification of bone shape
Long bones short bones flat bones irregular bones
long bones
typically longer than wide expanded end femur, humerus
short bones
generally cube shaped carpals and tarsals
flat bones
thin flattened and usually curved skull, ribs and sternum
irregular bones
irregular shape do not fit other classification categories vertebrae, hip bones
long bone structure
Diaphysis epiphysis periosteum perforating fibers articular cartilage epiphyseal plate epiphyseal linemedujllary cavity
diaphysis
shaft wall thick layer of compact bone covering spngy bone
epiphysis
expanded joints forms joints spngy bone covered by compact bone
periosteum
outside covering of the diaphysis blood vessels just underneath fibrous connective tissue membrane
perforating fibers
secure periosteum to the underlying bone
articular cartilage
covers external surface of epiphysis located on articulated surface made of hyaline cartilage decreases friction at joint surfaces
epipyseal plate
flat plate of hyaline cartilage seen in young growing bone
epiphyseal line
remnant of epiphyseal plate seen in adult bones
medullary cavity
cavity inside diaphysis lined by endosteum contains yellow marrow in adults contains red marrow in infants highly vascular
microscopic anatomy of bone
osteon central canal lamellae lacunae nutrient foramen perforating canal canaliculi
osteon
funtional unit of compact bone containing central canal and matrix rings
central canal
opening in the center of an osteon carries blood vessels and nerves
lamellae
rings around the central canal
lacunae
cavities containing osteocytes between lamellae
nutrient foramen
on surface of bone where blood vessels enter and leave
perforating canal
canal perpendicular to the central canal carries blood vessels and nerves
canaliculi
tiny canals radiate from central canal to lacunae form transparent system connecting all bone cells to nutrient supply
Bone formation
ossification intramembranous ossification endochondral ossification bone growth appositional growth
ossification
bone formation calicification of bone
intramembranous ossification
begins as fibrous sheet produces flat bones
endochondral ossification
bone develops from hyaline cartilage model six weeks fetal development to early 20s most bones develop this way
bone growth
epiphyseal plates allow for longitudinal growth of long bones during childhood new cartilage is continuously formed older cartilage becomes ossified epiphyseal plate ossifys then growth stops
appositional growth
process by which bones grow in diameter
bone remodeling
process of reabsorption and depostion that occurs throughout life 3-5percent annually
remodeling factors
blood calcium level pull of gravity and muscles on the skeleton
cells involved in remodeling
osteoclasts secure substances that break down calcified extracellular matrix Acids dissolve inorganic components Lysosomal enzymes digest organic components Osteoblasts secrete new bone
types of bone cells
osteocyte mature bone cells osteoblast bone forming cells osteoclasts bone destroying cells
Axial skeleton
forms longitudinal axis of the body support head neck and trunk 3 parts
parts of axial skeleton
Skull and hyoid vertebral column ribs and sternum
Skull
two sets of bones cranial and facial bones are joined by sutures only mandible is attached f=reely moving
bones of hard palate
maxilla palatine
bones of nasal septum
ethmoid vomer
paranasal sinuses
hollow portions of bones surrounding the nasal cavity frontal maxillary ethmoid sphenoid
functions of paranasal sinuses
lighten the skull give resonance and amplification to voice
hyoid bone
only bone that does not articulate with any other bone serves as a movable base for tongue aids is swallowing and speech
fetal skull
large compared to infants body frontanels fibrous membranes connecting the cranial bones allow bone to grow convert to bone within 24 months
vertebral column
24 bones separated by discs 7 cervical 12 thoracic 5 lumbar 5 sacrum fused 4 coccyx fused
spine curvature
primary are spinacurvatures of the thoracic and sacralsecondary are spinal curvatures of cervical and lumbar
primary spinal curve
present from birth convex posteriorly
secondary spinal curve
develope after birth convex anteriorly
spinal curvature disorders
scoliosis abnormal lateral curve kyphosis exaggerated thoracic curve lordosis abnormal anterior convexity of lumbar
Vertebrae
body anterior weight bearing portion foramen canal which spinal cord passes spinous process
cervical vertebrae
Atlas C1 Axis C2 transverse foramen 2 holes spinous points down
thoracic vertebrae
long pointed spinous process large body horseshoe shaped articulate with ribs giraffe
lumbar vertebrae
large rounder bodies supports body weight no facet for rib lumbering moose
sacrum
formed by fusion of 5 vertebrae
coccyx
formed by fusion of 4 vertebrae tailbone
total number of vertebrae
child 33 adult 26
bony thorax
forms a cage to protect major organs sternum ribs thoracic vertebrae
ribs
true ribs 1-7 false ribs 8-12 floating ribs 11-12
appendicular skeleton
126 bones limbs pectoral girdle pelvic girdle
pectoral girdle shoulder
clavicle collarbone scapula shoulder blade
clavicle
elongated s shaped bones forms joint with sternum only joint that attaches upper limb to axial skeleton
scapula
flat triangular bone articulates with clavicle and humerus
bones of upper limbs
humerus brachium extends from scapula to elbow antebrachium 2 bones ulna medial bone radius lateral bone
Manus hand
8 carpals wrist bones 5 metacarpals palm 14 phalanges fingers
Pelvic girdle
2 coxal bones ossa coxae composed of 3 fused bones illium ischium pubis protects several organs, reproductive, urinary and part of large intestine
Lower limbs
Femur heaviest and strongest in body crural region 2 bones tibia shinbone larger and medial fibula lateral to tibia thins and sticklike, non weight bearing
Foot bones
7 tarsals largest talus calcaneus heelbone 5 metatarsals top 14 phalanges toes
joint
articulation holds bones together allows for mobility
joint classifications
functionally structurally
Funtional joints
synarthoses immovable joints amphiarthoses slightly movable joints diarthoses freely movable joints
structural joints
fibrous joints cartilaginous joints synovial joints
fibrous jointts
generally immovable articulating bones held together by fibrous tissue no joint cavity
cartilaginous joint
immovable or slightly movable bones connected by cartilage no cavity
synovial joint
freely movable joint articulating bones separated by cavity most complex most joints in body
synovial joint features
hyaline cartilage covers ends of bones fibrous capsule encloses joint surface dense connective tissue joint cavity is fill with synovial fluid lubricates articulating surfaces
ligaments
structures associated with synovial joint
bursae
flattened fibrous sac filled with synovial fluid not part of joint reduces friction between muscles and bone, tendon and bone
tendon sheath
elongated bursa that wraps around a tendon
menisci of knee
fibro cartilage pads shock absorbers limit lateral movement
ligaments
cruciate ligaments limit anterior-posterior movement of knee ligamentum capitus of hip
types of synovial joints
plane joint hinge joint pivot joint condyloid joint saddle joint ball and socket joint
Plane joint
articulating surfaces nearly flat between carpal and tarsal bones
hinge joint
convex surface fits into a concave surface elbow, knee interphalangeal
pivot joint
cylyndrical surface rotates with a ring of bone atlas and axis vertebrae proximal radius and ulna
condyloid joint
ovoid condyloe fitting into and elliptical cavity between metacarpal and phalanges
saddle joint
articulating surfaces have both concave and convex areas carpal bones and 1st metacarpal
ball and socket joint
bone with globular or egg shaped head articulating with the cup cavity of another bone hip and shoulder
1
Osteon
2
Lamellae
3
Collagen Fiber
4
periosteum
5
spongy bone
6
perforating canal
7
central canal
8
lacuna
9
osteocyte
10
canaliculi
