Ch. 6 Bones (E2) Flashcards
The compact, central, long part of the bone, the shaft, essentially.
What is the diaphysis?
The spongy end of the bone.
What is the epiphysis?
Where the diaphysis joins the epiphysis.
What is the metaphysis?
The space inside the diaphysis, which contains marrow.
What is the medullary cavity?
The inner lining of the medullary canal.
What is the endosteum?
The connective tissue covering the bone.
What is the periosteum?
The thin layer of hyaline cartilage covering the epiphyses.
What is the articular cartilage?
Another name for the Haversian system.
What is the osteon?
In which type of bone will you find osteons?
Compact bone
Rings of hard, calcified matrix found in the osteon.
What are lamellae?
This osteon structure carries lymphatics, blood vessels, and nerve fibers.
What is the central canal?
The { } canals branch from the central canal.
Volkmann’s
The extensions coming from osteocytes.
What are canaliculi?
Osteocytes are situated in small chambers referred to as these.
What are lacunae?
Found in spongy bone, these are the irregular latticework of thin bone plates in which the spaces are filled with marrow.
What are trabeculae?
Blood and nerve supplies are abundant in { } bone.
Spongy
Stem cells that generate osteoblasts and chondroblasts.
What are osteogenic/osteoprogenitor/osteochondral progenitor cells?
Osteoblasts produce…
Bone matrix i.e., mineral salts and collagen
Can osteoblasts divide?
No
Osteocytes are derived from…
Osteoblasts
These structures contain secretory lysosomes and are considered “bone breakers.”
What are osteoclasts?
Osteoclasts aid in bone reabsorption. What is bone reabsorption?
Removal of the bone matrix i.e., repair and remodelling
The organic part of the bone matrix, consisting of proteoglycans, glycoproteins, and collagen.
What are osteoids?
What are hydroxyapatites?
The inorganic component of the matrix that produces mineral salts that calcify/harden it
Give an example of a hydroxyapatite.
Tricalcium phosphate
All other inorganic components of the bone matrix, such as magnesium hydroxide, fluoride, and sulfate, are responsible for { } and { }.
1) Hardness
2) Strength
What are the 6 functions of the skeletal system?
1) Support
2) Protection
3) Movement
4) Mineral storage
5) Blood cell formation (red marrow)
6) Energy storage (yellow marrow)
The scientific term for blood cell formation.
What is hematopoiesis?
Intramembranous ossification occurs in { } bones.
Flat
What structure does intramembranous ossification not involve?
Cartilage
What are the 4 steps of intramembranous ossification?
1) Osteogenic cells > osteoblasts
2) Osteoblasts secrete osteoid/matrix
3) Osteoblasts > osteocytes
4) Outer layer - periosteum & compact bone, Inner layer - spongy bone
When does intramembranous ossification occur in vitro?
5 weeks
In endochondral ossification, most bones use { } for patterns.
Hyaline cartilage
What are the 4 steps of endochondral ossification?
1) Chondroblast formation
2) Primary ossification
3) Medullary cavity formation
4) Secondary ossification
In chondroblast formation, { } cells differentiate into { }, which become { }.
1) Stem
2) Chondroblasts
3) Chondrocytes
Connective tissue that develops around the cartilage.
What is perichondrium?
Primary ossification involves the { } of cartilage to make room for { } & { }.
1) Calcification
2) Blood vessels
3) Bone cells
The primary ossification center occurs { } from the { } surface.
1) Inward
2) Bone
Medullary cavity formation involves the { } of { } bone via { }.
1) Removal
2) Spongy
3) Osteoclasts
In secondary ossification, { } migrate from the { } towards the { }.
1) Osteoblasts
2) Diaphysis
3) Epiphyses
The hardening of cartilage during secondary ossification is referred to as…
Calcification
Which 2 major structures are formed during secondary ossification?
Osteoid and osteocytes
After secondary ossification, hyaline cartilage remains as these 2 forms.
What are articular cartilage & epiphyseal plates?
Interstitial growth is also referred to as…
Longitudinal growth
How does bone lengthening work?
Chondrocytes at the top of the epiphyseal plate divides, while the old cartilage underneath hardens and gets invaded by osteoblasts
What 3 types of hormones inhibit bone lengthening?
1) Growth hormones
2) Thyroid hormones
3) Sex hormones
Appositional growth is also referred to as…
Bone widening
What is the roles of osteoblasts and osteoclasts in appositional growth?
Osteoblasts - form new osteons along the outer surface of the diaphysis
Osteoclasts - reabsorb inner bone layers
Describe how PTH hormonally raises blood calcium.
When blood calcium is low, osteoclasts reabsorb bone and move calcium to the blood
Describe how calcitonin lowers blood calcium.
Reducing bone reabsorption, increasing calcium deposits in the matrix, and, thus, decreasing blood calcium
What are the 4 steps of bone repair?
1) Hematoma formation
2) Procallus formation
3) Osseous callus formation
4) Remodeling
What is the general mechanism behind osteoporosis?
Bone reabsorption > bone deposit
Why do smoking and menopause contribute to osteoporosis?
Smoking - reduced estrogen
Menopause - a lack of estrogen = nothing to stop PTH, which encourages bone resorption
How do drugs like Boniva treat osteoporosis?
Suppressing osteoclast activity
How does vitamin D help treat osteomalacia and rickets?
It provides calcium that hardens the matrix
