skeletal system Flashcards
functions of skeletal system
support
protection
movement
red blood cell and hormone production
mineral, growth factor, and fat storage
long bone
femur
flat bone
skull
short bone
metacarpals
irregular bone
vertebrae
sesamoid bone
patella
red bone marrow
red blood cell production
yellow bone marrow
stores fat
compact bone
dense outer layer
smooth and solid
contains osteons
found in the diaphyses of long bones
majority of skeleton
gives strength and support
stores calcium
spongy bone
honeycomb of flat pieces of bone deep to compact bone (trabeculae)
found at the ends of long bones, ribs, skull, pelvis, and vertebrae
helps make bones lighter
volkman’s cannal
connects blood vessels and nerves of the periosteum, medullary cavity, and central canal
runs perpendicular
lamellae
bony layers of osteon
collagen fibers allow resistance to twisting
canaliculi
tiny canals in osteon that connect lacunae to each other and central canal
osteocyte
mature bone cell that monitors and maintains the mineralized bone matrix
osteonic canal
aka haversian canal
houses blood vessels, lymphatic vessels, and nerves
runs parallel
osteoblasts
matrix synthesizing cell responsible for bone growth
osteoclasts
bone resorbing cell
intramembranous ossification
bone develops from fibrous membranes (flat bones)
osteoid is secreted by osteoblasts within the fibrous membrane and calcifies
spongy bone and periosteum form
compact bone replaces spongy bone
red marrow in spongy bone appears
endochondral ossification
bone formed by replacing hyaline cartilage (long bone)
interstitial growth
allows increase in the length of long bones
appositional growth
allows increase in bone thickness
osteoblasts beneath periosteum secrete bone matrix on external bone
osteoclasts remove bone on endosteal surface
importance of calcium
nerve transmission
muscle contraction
blood coagulation
cell division
secretion of glands and nerve cells
bone remodeling
in response to stress or hormones
growth hormone
most important in stimulating epiphyseal plate activity in infancy and childhood
sex hormones
promotes adolescent growth spurts
end growth by inducing epiphyseal growth closure (epiphyseal line)
PTH
resorption of Ca2+
releases more calcium
calcitonin
removes blood Ca2+ levels temporarily if in high doses
rickets
bowed legs caused by vit. D deficiency or Ca2+
osteomalacia
bones poorly mineralized
inadequate Ca2+ salts
soft and weak bones
osteoporosis
bone resorption outpaces deposit
kyphosis
excessive curvature of spine
lordosis
excessive curvature of the lower portion of the spine
scoliosis
sideway curvature of the spine
herniated disk
a rupture b/w the rubbery cushions b/w the vertebrae
axial
long axis of the body
skull, veretebral column, rib cage
appendicular
bones of the upper and lower limbs
girdles attaching limbs to axial skeleton
open fracture
aka compound fracture
skin is penetrated
closed fracture
aka simple fracture
skin is not penetrated
nondisplaced fracture
ends retain normal position
displaced fracture
ends outside of normal position
complete fracture
broken all the way through
incomplete fracture
not broken all the way through
comminuated fracture
bone fragments into 3 or more pieces
compression fracture
bone is crushed
spiral fracture
ragged break due to excessive twisting force
epiphyseal fracture
epiphysis separates from diaphysis
depressed fracture
broken bone portion is pressed inward
greenstick fracture
incomplete fracture most common in children
closed reduction
realignment of bone w/o surgery
open reduction
realignment of bone involving surgery
immobilization
braces or casts can help in immobilization of the joints for treating a fracture
sharpey’s fibers
secure to bone matrix
osteogenic layer
contains osteogenic cells (primitive stem cells)
periosteum
outer fibrous layer of dense irregular CT
osteogenic cells
mitotically active stem cells in periosteum and endosteum
aka osteoprogenitor cells
osteoblasts
secrete osteoid
compact bone
lamellar bone
red marrow
found within trabeculae and dipole
in medullary cavities in newborns
long bone have little red marrow (heads of femur and humerus only)
epiphyseal plate closure
18 years (females)
21 years (males)
mechanical stress
controls where bone remodeling takes place
hormones
controls whether and when bone remodeling takes place
hematoma formation
- hematoma forms
- soft callus forms
- bony callus forms
- bone remodeling occurs
drugs that treat osteoporosis
biphosphonates
selective estrogen receptor modulators
statins
denosumab
paget’s disease
high ratio of spongy to compact bone
poorly mineralized
usually in spine, pelvis, and skull
treated calcitonin and biphosphonates
osteomyelitis
leukocytes enter
release lytic enzymes
pus spreads to impair local blood flow (sequestra)
involucrum (new bone formation)
leptin
hormone released by adipose tissue
role in bone density regulation
inhibits osteoblasts
serotonin
neurotransmitter regulating mood and sleep
most made in the gut
secreted into blood after eating
interferes with osteoblast activity
serotonin reuptake inhibitors cause lower bone density
osteoid seam
unmineralized band of bone matrix
calcification front
abrupt transition zone between osteoid seam and older mineralized bone
number of bones of the skull
22
occipital bone
articulates with C1 (atlas)
sella turcica
houses pituitary gland
temporal bone
contains squamous, tympanic, petrous, and mastoid
frontal bone
connected to the rest of the cranium posteriorly via the coronal suture
maxillary sinus
largest paranasal sinus
manubrium
articulates with clavicles and ribs 1-2
body of sternum
articulates with costal cartilages of ribs 2-7
xiphoid process
point of muscle attachment
not ossified until age 40
ribs
attach posteriorly to bodies (head) and transverse processes (tubercle) of thoracic vertebrae
cervical vertebrae
have transverse foramina
lumbar vertebrae
weight bearing
number of bones of the upper limb
30 bones
radius
head articulates with capitulum of humerus and radial notch of ulna
ulna
forms major point of elbow joint w/ humerus
3 fused bones of coxal bone
illum (articulates w/ sacrum)
ischium (posterioinferior)
pubis (forms pubic symphysis)
tarsal bones
cuboid
navicular
medial
intermediate
lateral cuneiform
fetal skull bones
mandible and frontal bones are unfused
fontanelles
anterior
posterior
mastoid
sphenoidal
carpals
scaphoid
lunate
triquetrum
pisiform
trapezium
trapezoid
capitate
hamate
temporal bone
carotid canal passes through here
mandibular foramina
hole dentists inject lidocaine to prevent pain while working on lower teeth
inferior nasal concha
facial bone
atlas
has no body
pectoral girdle
clavicle and scapula
humerus
contains radial groove
olecranon process
children are often told to keep this process off the table while eating
ulna
head found at distal end
talus
keystone of medial longitudinal arch
fibula
contains lateral malleolus
lesser wings of sphenoid bone
contains optic canals
cribriform foramina
olfactory nerves pass through here
cervical and lumbar vertebrae
not present in birth
develop later
olecranon process
allows flexion and extension of arm
trochlear notch
forms hinge joint w/ humerus
pivot joint
formed b/w radius and ulna
allows pronation and supination
ischial tuberocity
can be felt on a hard chair
pubic tubercles
can be palpated on the anterior surface of the body, close to the midline
synarthrosis
not moveable
usually fibrous
found in the skull, teeth, and 1st pair of ribs and sternum
amphiarthrosis
partially moveable
usually cartilaginous
found at the pubic symphysis and the joint b/w tibia and fibula (fibrous)
diarthrosis
highly moveable
make up majority of joints
all are synovial
origin
attachment to immoveable bone
insertion
attachment to moveable bone
ligament
connects bone to bone
tendon
connects muscle to bone
cartilage
resists compressive forces
syndemoses
bone connected by ligaments (fibrous tissue)
synchondrosis
bar/plate of hyaline cartilage that unites bones
all are synarthrosis
cartilage of 1st rib w/ manubrium
stabilizing factors at synovial joints
shape of articular surfaces (minor role)
ligament number and location (limited role)
muscle tendons that cross joint (major role)
nonaxial
slipping movements only
uniaxial
movement in one plane
biaxial
movement in 2 planes
multiaxial
movement in or around all 3 planes
structure of synovial joint
bone separated by fluid-filed joint cavity
contains hyaline cartilage at bone ends
contains an articular joint capsule
contains synovial fluid
contains ligaments
contains nerves and blood vessels
contains fatty pads
contains menisci (fibrocartilage separates articular cartilages)
contains bursae
contains tendon sheaths
articular joint capsule
external fibrous layer (dense irregular CT)
inner synovial membrane (loose CT; makes synovial fluid)
stabilizes joint
tendon sheaths
elongated bursa wrapped completely around tendon subjected to friction
synovial fluid
filtrate of plasma and hyaluronic acid
contains phagocytic cells to remove microbes and debris
lubricates and nourishes articular cartilage
reinforcing ligaments
capsular (thickened part of fibrous layer)
extracapsular (outside the capsule)
intracapsular (deep to capsule; covered by synovial membrane
joint cavity
filled w/ synovial fluid
allows for frictionless movement
shoulder girdle
relatively less strong than pelvic girdle
lightweight
pelvic girdle
relatively more strong than shoulder girdle
weight-bearing
quadriceps tendon
aka patellar tendon
contain medial and lateral retinaculum and patellar ligament
femoropatellar ligament
plane joint
tibiofemoral joints
biaxial joint
knee joint
vulnerable to lateral (horizontal) blows
absorbs vertical blows
cartilage tears
repaired w/ arthroscopic surgery
greater risk of osteoarthritis
RICE
rest
ice
compression
elevation
helps prevent hyperextension of knee
fibular and tibial collateral ligaments
oblique popliteal ligament
arcuate popliteal ligament
prevents anterior-posterior displacement
ACL and PCL (intracapsular ligaments)
plane joint
nonaxial
gliding movement
intercarpal and intertarsal joints/ joints b/w vertebral articular surfaces
hinge joint
uniaxial
flexion and extension
elbow and interphalangeal joints
pivot joint
uniaxial
rotation (pronation and supination)
proximal radioulnar and atlantaraxial joint
condylar joint
biaxial
flexion and extension/ adduction and abduction
knuckle and wrist joints
saddle joint
biaxial
adduction and abduction/ flection and extension
joints of the thumbs
ball and socket joint
multiaxial
all 3 movements
shoulder and hip joints
bursitis
inflammation of the bursa
sprain
reinforcing ligaments stretched of torn
dislocation
bones forced out of alignment
ankylosis
stiffness of a joint due to bone fusion
osteoarthritis
excessive release of enzymes that break down articular capsule
rheumatoid arthritis
chronic, inflammatory, autoimmune disease
lyme disease
caused by bacteria transmitted by tick bites
tendonitis
inflammation of tendon sheaths
subluxation
partial dislocation of a joint
ACL
prevents tibia from sliding forward in the knee joint
cruciate ligaments
ligaments that protect the alignment of the femoral and tibial condyles and limit the movement of the femur anteriorly and posteriorly
Extracapsular ligaments stabilizing the knee include
fibular and tibial collateral ligaments, which prevent lateral or medial rotation
TMJ
joint most easily dislocated
knee
most susceptible to sport injuries
only partially enclosed in a joint capsule
collateral ligaments
found in elbow and knee joints
endosteum
location of osteoclasts
role of vit. c in bone growth
collagen synthesis
hyoid bone
supports tongue
whiplash
can cause damage to medulla oblongata of the brain via the dens of the axis
extension
increases the angle of articulating bones
flexion
decreases the angle of articulating bones
steps of interstitial growth
proliferation zone= cartilage cells undergo mitosis
hypertrophic zone= older cartilage cells enlarge
calcification zone= matrix calcifies, cartilage begins to die, matrix begins deteriorating, blood vessels invade cavity
ossification zone= new bone forms
