Bones and Skeletal Tissues Flashcards
(29 cards)
What is the role of fibrocartilage? Where is it found? (3)
Transferring weight to our body for our lower limbs
- cartilage intervertebral disc
- Pubic symphysis
- Meniscus
Where is elastic cartilages found?
(2)
- Epiglottis
- Eustachian tube (external ear)
Where is hyaline cartilages found?
Most in our body
- costal cartilage
- articular cartilage of a joint
How does growth of a cartilage work? (2)
- Appositional growth
- occurs at surfaces - Interstitial growth
- Expand cartilage from within
Why does cartilage calcification occur?
- Sites where cartilage connects with bone
- It is about to be replaced by bone
- Cartilage has lack of nutrition/oxygen
How does cartilage calcification occur? (3)
- Chondrocytes get big and & secrete enzymes to wear away extracellular matrix
- calcium phosphate is deposited & matrix crytsalizes
- Chondrocytes die (leave space
What is the spongy bone texture called?
Trabeculae
What are the 2 layers of the periosteum?
What is it secured by?
- Fibrous
- Osteogenic
Perforating fibers
What covers the trabeculae of spongy bone, compact bones canals, marrow cavity?
Endosteum
Describe Lamellaes
-column-like matrix tubes
- fibers in 1 lamellae run in the same direction but not all tubes run in the same direction
What is the role of the perforating canals?
Come in at 90 degree angles and connects blood vessels & nerves
What is the microscopic anatomy of compact bone?
Lacunae
- small cavities that contain osteocytes
Canaliculi:
- hairlike canals that connect lacunae to each other
What is the microscopic anatomy of spongy bone?
Trabeculae
- contain irregularly arranged lamellae, osteocytes, canaliculi
(NO OSTEONS)
- Capillaries in endosteum supply nutrients
What is the structure of a long bone
Diaphysis
Epiphyses
Diaphysis (shaft)
- Yellow bone
- Bone marrow
Epiphyses (ends)
- red marrow
- has articular (hyaline) cartilage
Where do nerve fibers, and blood vessels enter bone?
via nutrient foramina
What is the role of the following organic chemical composition of bone:
Osteogenic/genesis
Osteoblast
Osteocyte
Osteoclast
Osteogenic/genesis
- active stem cels in periosteum
- bone tissue formation
Osteoblast
- synthesize osteoid (the matrix)
In matrix:
- Osteocytes
- Bone lining cells
Osteoclast
- break down the matrix
What type of bone is the most common in our body?
What does it have the most of?
Inorganic bone
- Biggest contributor to calcium
What does organic bone mainly consist of?
Mostly collagen
What are 3 stages of bone development? when does it occur?
What helps with bone tissue formation?
Osteogenesis (ostification)
- Bone formation (2nd month prenatal)
- Postnatal bone growth (until early adulthood)
- Bone remodeling and repair
(lifelong)
What occurs during step 1 bone formation?
- Endochondral ossification
- bone forms by replacing hyaline cartilage - Intramembranous ossification
- bone develops from fibrous membrane
- Forms flat bones
What occurs during step 2 of postnatal bone growth?
What are the 4 important functional zones in the epiphyseal plate?
Interstitial growth
- Increase length of long bone
- Proliferation
- Hypertrophic
- Calcification
- Ossification
Appositional growth
- increase thickness while actual amount of bone shaft does not change
(osteoclast break down endosteum)
What occurs during step 3 of bone remodeling?
How many years is spongy bone replaced? what about compact?
-Spongy bone replaced every 3-4 years
- Compact bone replaced every 10 years
How does osteoid calcifies?
Bone deposit
-Proteins of osteoid bind Ca2+
-osteoblasts release vesicles with phosphate
How does bone resorption occur
- Osteoclasts break compact bone
- Osteoblasts come in to make the matrix and remodel it
