Bone development Flashcards
what are the 2 types of centres of ossification
primary centres
secondary centres
where do primary centre come from
present at birth
A very orderly sequence
forms in the diaphysis
where do secondary centres come from
after birth
at ends of long bone
forms in epiphysis
bulbus sneds
ossification centres after birth
diaphysis
the shaft or central part of a long bone
epiphysis
end of bone
taller people
ossification happens for longer
epiphyseal line/plate
growth plate between diaphysis and epiphysis occurs in children
In adults = fuse together and no longer see the line
why can lifting weights stunt growth
disturb growth plates
should not fuse until adult
where is growth mainly from
the diaphysis side of the epiphyseal plate (e.g knee joint)
where to ossification centres meet
epiphyseal line
what can renters of ossification be used for
help to date individuals
when secondary ossification centres occur
when epiphyseal centres appear or fuse with diaphyses
help to date bones of individuals
when do primary and secondary centres fuse
during puberty
what changes to the rib cage happen as we age
typhoid process fuses with the body - middle age
manubrium fuses with the body - old age
costal cartilages ossify - old age (esp 1st rib)
what does manubrium fusing cause
restricts breathing - pump handle mechanism
what does costal cartilages ossifying cause
makes ribs of elderly people very vulnerable to fractures
as outer shell become brittle and they have less cartilage
what is the scapula like in children
relatively wide
what happens to scapula as we age
Maybe absorbed and thins out - especially in the fossa - creating roles
supraspinous ligament ossifies
what happens to supraspinous ligament in elderly
frequent ossifies
where does most of the growth occur in the humerus
most growth occurs at the superior end
where does most of the growth occur in the ulna
most growth occurs in the inferior end
where does most of the growth occur in the radius
most growth occurs in the inferior end
sternum parts
manubrium
body
xiphoid process
what is one of the first lines to develop in the hand
capitate bone
dominates other bones
primary centre 6 months
carpal bones
capitate
hamate
pisiform
trapezoid
trapezium
Triquetrum
scaphoid
lunate
what’s the last bone to ossify in the hand
pisiform
9–14 years
smallest bone
layers of bones in hand starting at wrist
carpal bones
metacarpals
phalanges
hand x ray at birth
big caps between bones
no main ossicailry centres
epiphysis are not visible
only main shaft has ossified
no carpal bones
hand x ray at 6 months
2 capi bones appear
what age do you see secondary ossification centres appear
1 year
mature at 2 years
x ray of hand at 3 years
secondary ossification centres matured
3rd carpal bone
when does 4th carpal bone appear
5 years
x ray of hand at 6 years
ulna bona has secondary ossification centres
7th carpal bona appeared
when does pisiform bone appear
8 carpal bones
9 years old
x ray at 10 years old
growth plate between epiphyseal and diaphysis
when does growth plate close
11 years
ossification centres fully closed
fusion or primary and secondary ossification plates
when do carpal bones start to fuse
15 years
main changes in bone structures at puberty
fusing od the ossification centres and closing the growth plate
what 3 bones make up the hip
ilium bone
ischium bone
pubic bone
when does the primary centre of ilium bone appear
3rd month
when does the primary centre of ischium bone appear
4th month
when does the primary centre of pubic bone appear
5th month
what age do the 3 hip bones fuse together
20-25 years
changes in lower limb bones
birth = lower limbs short - larger head
lower limbs grow rapidly when children start to walk l
why do babies have an expanded belly
smaller pelvis
makes the bladder, uterus and ovaries abdominal organs
when the child stands = pelvis tilts anteriorly
sacrum takes most of the body weight
what causes osteoarthritis
cartilage wears out
going up stairs when elderly causes
joint cartilage erosin
osteoarthritic pain
what cartilage is the most prone to degeneration
patella and femoral condyles - knee and hip
where are the medial and lateral condyles located
medial femoral condyle is located on the inside part of the knee whereas the lateral femoral condyle, which is bigger, is located on the outside part of the knee.
describe a neonatal skill (new born)
skull relatively large
face relatively small
lack of teeth
small madible
small sinuses
big sockets for eyes
inner and middle ears are of adult size
where and how does growth occur in the skull
along the periphery of bones
by absorbing the inner bone layer while depositing on the external surface
how are structure set to accommodate expansion
at an oblique angle
when does posterior fontanelle close and where is it
2 months
where 3 or 4 bones meet in the same spot
when for sphenoidal fontanelle close and where is it
3 months
where the frontal parietal and sphenoid bones all meet
when does mastoid fontanelle close and where is it
1 year
junction of squamous and lamb
when does the anterior fontanelle close
2 years
when do the occipital bones fuse together what are they called
3rd year
exoccipital
basioccipital
what muscle attaches to the mastoid process and why
sternocleidomastoid muscle attaches to the mastoid process
encourages the mastoid process to protrude by 2 years
where is the mastoid process
a bone on skull behind the ear
how is the mastoid protrusion stimulated
by the baby lifting their head in the 3rd month
what part of the skull fuses at 6 years
frontal hemispheres
what part of the skull reaches adult size at 7 years
orbital cavity
when does the sagittal suture close
between 22-31 years
when does the coronal suture close
between 24-40 years
when does the lambdoid future close
between 26-40 years
when do lower central incisors teeth develop
6 months
when does the upper central incisors usually start
8 months
when does the lower and upper central incisors teeth usually shed
6-8 years
what happens when the mandibular develops
increases in length height and thickness
how does the mandibular become thicker
addition on the outside
where does mandibular growth normally occur
alveolar border
what direction does the mandibular lengthen
posteriorly
how does the mental foreman grow
moving backwards
what is mandible like before 2 years
in two halves at brith
mandibular bone covers the teeth
how does mandible fuse
By a symphysis menti joint
what is the mandibular angle like
obtuse angle
adult angle - 110 degrees
what is higher the coronoid or the condyloid process
coronoid process is higher than the condyloid process
what does chewing do to the mandible
strengthens the mandible
what happens to the alveolar arches in development
alveolar arches elongate behind the mental foramen to make more space for teeth
helps reduce the mandibular angle to about 140 degrees
when does mandibular angle reduce to 110 degrees
when coroid process and condylar processes are similar heights
when happens when teeth are lost in elderly
loss of teeth = adsorption of the walls of the sockets
the superior portion of the alveolar arches recedes
multiple missing teeth = atrophy (wasting) of jaw bone
servers bone loss makes replacement of teeth difficult in later stages
what happens to elderly mandibular angle
mandibular angle drops and becomes more obtuse
140 degrees
chin biomes prominent
