Bone and cartilage lab Flashcards
what is shown in this picture? how do we know what bone it is?
early stage formation of a flat bone (skull)
* can see the scalp (epidermis and dermis) with hair follicles on the right
what is shown here? what will eventually happen to it?
intramembranous ossification (condensed connective tissue membrane within which the centre of ossification appears)
* most of this will become ossified by spread of bone from the centre of ossification
* remaining condensed connective tissue will become the periosteum which surrounds the bone
what is shown in this picture?
the osteon which is the non-mineralised oragnic matrix of bone
what will the remainder of connective tissue surrounding the developing intramembranous bone become?
periosteum - condensed membranous tissue that is very close to bone
which cells are found surrounding developing bone?
osteoblasts
what is shown in this picture?
frontal section of the head - absence of the orbits as section is more posterior
what is shown in this picture?
tongue
what is shown in this picture? what is surrounding it?
Meckel’s cartilage
surrounded by the perichondrium
what is the funciton of Meckel’s cartilage? what are its remnants?
template for ossification in the mandible so is a precursor to the mandible, disappears with time (chrondroclastic reabsorption)
* malleus and incus of the middle ear and the sphenomandubular ligament are remnants
what is shown in this picture adjacent to the Meckel’s cartilage?
the developing mandible
* dark purple-pink is mineralised bone
* bright pink is non-mineralised = osteoid
what mechanism does the mandible form?
intramembranous ossification
what are the cells that are found within the bone tissue?
osteocytes (osteoblasts that have become trapped in bone)
what important anatomy can be seen in this picture between the developing mandible and Meckel’s cartilage?
inferior alveolar nerve
inferior alveolar artery
what can be seen in this picture and what stage are they at?
tooth germs
* bulb stage
what can be seen developing here, under the tongue?
submandibular gland
what part of the head is shown here?
horizontal section of the mandible
what can be seen here anteriorly near the future chin? what cells are seen inside it?
Meckel’s cartilage (dark purple)
chrondrocytes
what is begining to form here? what can you see around it?
ramus
* masseter muscle (to the left)
* medial pterygoid muscle (to the right)
what can be seen developing posterior to the ramus?
parotid salivary gland (behind ear)
what can be seen in this picture?
inner and outer cortical plates of the developing mandible, lateral to Meckel’s cartilage
inferior alveolar nerve (dark purple to the left) lying within the mandible
what can is shown in this picture? what is different about it?
cross section of the mandible with a developing molar
* can see the enamel and dentine in the molar
* enamel has not been mineralised yet, usully cannot see it as it is too mineralised
what part of the tooth is shown here?
forming root
what cells can be seen here in the inner socket next to the forming root? why are they needed? describe them
osteoclasts - large, multinucleated
resorbs bone around the forming root to allow it to grow into the bone
what are the saucer-shaped depressions in the bone called?
Howship’s lacunae
