Chapter 6: Bone Tissue Flashcards
What are the diaphysis, epiphysis and metaphysis of a long bone?
Which part has the growth plate?
What is the growth plate replaced with when growing stops?
epiphysis: end of bone, metaphysis: before end of bone, diaphysis: shaft of bone
metaphysis has the growth plate
growth plate become epiphyseal line when growing is done
What is articular cartilage?
What is the connective tissue that covers the epiphysis, diaphysis and metaphysis called? Does it have cells for growth in the outer layer?
What is the connective tissue that covers part of the epiphysis called?
cartilage that covered the epiphysis in joints (to lubricate and absorb shock)
periosteum; no, cells for growth are in the inner layer
articular cartilage
How does the periosteum attach to the bone?
Does the periosteum have blood vessels, nerves or both?
What is the cavity that stores yellow bone marrow and blood vessels called?
with perforating fibres (Sharpey’s fibres)
both
medullary (it’s in the diaphysis)
Where is the endosteum membrane located?
Where is the red bone marrow located in a long bone?
Is the extracellular matrix in bone mostly water, mineral salts or collagen?
around the medullary cavity (has bone forming cells and connective tissue)
in the epiphysis and metaphysis (ends of bones) in the spongy tissue
mostly mineral salts (55%; 30% collagen and 15% water)
Is hydroxyapatite the most common mineral salt in bone?
Is more of the bone compact or spongy?
yep
compact (80%)
Which type of bone tissue cells are stem cells?
a. osteocytes
b. osteoblasts
c. osteoprogenitor
d. osteoclasts
Are they made from mucous cells? Are they mostly found in periosteum, endosteum and blood vessels?
stem cells: osteoprogenitor
no, from mesenchyme
yep
Which type of bone tissue cell makes collagen and initiates calcification?
a. osteocytes
b. osteoblasts
c. osteoprogenitor
d. osteoclasts
bone builder: osteoblasts
Which type of bone tissue cell is mature and maintains bone?
a. osteocytes
b. osteoblasts
c. osteoprogenitor
d. osteoclasts
mature: osteocytes
Which type of bone tissue cell is huge and made from monocytes (WBC)?
a. osteocytes
b. osteoblasts
c. osteoprogenitor
d. osteoclasts
Are they mostly in the periosteum or endosteum?
Do they break down or create bone?
osteoclasts, in endosteum, break down bone with enzymes/acids (“resorption”)
Is compact bone made of trabeculae or osteons?
Are osteons made of columns or rings?
Does compact bone or spongy bone have red and yellow marrow?
Is the bulk of diaphysis of bones compact or spongy?
osteons
rings
spongy
compact
Are Volkmann canals where blood vessels go through or fibres?
What is the matrix in bone called: lacunae, lamellae or canaliculi?
What is the space in bone called: lacunae, lamellae or canaliculi?
What are the connections in bone called: lacunae, lamellae or canaliculi?
blood vessels
lamellae
lacunae (has the osteocytes)
canaliculi
Which of the following don’t have red marrow: hips, ribs, sternum, vertebrae, top of humerus and femur, fingertips?
What is the main hole in diaphysis for the main artery called?
When does ossification (bone formation) begin in an embryo: 2 weeks or 6 weeks?
fingertips
nutrient foramen
6 weeks
Which type of ossification is simpler? Which uses hyaline cartilage? Which is used to make the clavicle, mandible, face bones and skull?
Which type of ossification is more common?
a. endochondral
b. intramembraneous
simpler: intramembraneous
uses hyaline cartilage: endochondral
makes clavicle/mandible/face/skull: intramembraneous
more common: endochondral
Put the four steps of intramembraneous ossification in order:
a. trabecular formation
b. calcification
c. periosteum development
d. development of ossification centre
d, b, a, c
ossification centre (osteoblasts secrete matrix), calcification (mineral deposits, lacunae and canaliculi form), trabecular formation (spongy bone forms with blood vessels), periosteum development (compact bone develops on surface)
Put the 6 steps of endochondral ossification in order:
a. chondroblasts become chondrocytes, surrounding matrix begins to calcify and lacunae form
b. secondary ossification centres form in the epiphysis (without medullary cavities)
c. mesenchyme becomes chondroblasts which secrete cartilage, perichondrium covering forms
d. primary ossification centre develops with nutrient artery and capillaries; osteoblasts form and make trabecular; perichondrium becomes the periosteum
e. articular cartilage and epiphysis plates form
f. the medullary cavity is made by osteoclasts in the diaphysis
c, a, d, f, b, e
Which type of growth makes a bone thicker? Longer?
a. interstitial
b. appositional
appositional: thicker, interstitial: longer
Match the type of fracture with its description:
a. open/compound
b. communicated
c. greenstick
d. impacted
e. Pott
f. Colles
i. two ends smashed together
ii. one side breaks and the other bends
iii. end of leg broken in fibula
iv. skin broken by bone
v. end of radius broken and end displaced
vi. bone splintering at impact site
a & iv (open: skin broken)
b & vi (communicated: splintering at impact)
c & ii (greenstick: one breaks, one bends)
d & i (impacted: two ends smashed together)
e & iii (Pott: end of leg broken in fibula)
f & v (Colles: end of radius broken and displaced)
In bone growth in length there are two main events:
- cartilage interstitial growth
- cartilage replaced with bone by endochondral ossification
Match the two events with their locations:
a. epiphyseal plate on epiphyseal side
b. diaphyseal side of epiphyseal plate
- a (cartilage interstitial growth in epiphyseal plate on epihyseal side)
- b (cartilage replaced by bone on diaphyseal side of epiphyseal plate)
Match the four zones of the epiphyseal growth plate to their descriptions:
a. zone 1: resting cartilage
b. zone 2: proliferating cartilage
c. zone 3: hypertrophic cartilage
d. zone 4: calcified cartilage
i. chondrocytes in stacks, cartilage dividing and matrix secreting
ii. cartilage becomes bone by endochondral ossification and becomes part of diaphysis
iii. large maturing chondrocytes in columns
iv. anchors epiphyseal plate to epiphysis
a & iv, b & i, c & iii, d & ii
What age does bone growth stop in males and females?
Which cell does bone resorption? Depostion?
a. osteoclast
b. osteoblast
Which type of bone is remodelled more:
compact or spongy
18 in females, 21 in males
resorption: osteoclast, depositon: osteoblast
spongy (20% remodelled per year vs 4% of compact)
Put the appositional (thickness) growth steps in order:
a. ridges fuse into a tunnel for the blood vessel; periosteum becomes endosteum (tunnel lining)
b. peristeal cells differentiate into osteoblasts which secrete collagen and other matrix materials; osteoblast cells differentiate into osteocytes; bone ridges form around a periosteal blood vessel
c. circumferential lamellae are made and more periosteal blood vessels are enclosed
d. concentric lamellae are made by endosteum osteoblasts; osteon made
b, a, d, c
What is the purpose of an osteoclast’s ruffled border?
What is Paget’s disease?
What is a stress fracture?
tight seal so enzymes/acids can work effectively
Paget’s disease: brittle, enlarged, hard bones
stress facture: not visibly broken, many tiny fissures (common in tibia)
Which minerals are required in large supply for bone formation? Which are in lower supply?
calcium, magnesium, fluoride, manganese, phosphorus
lot: calcium and phosphorus
less: manganese, fluoride, magnesium
Match the vitamin to their role in bone formation.
a. vitamin A
b. vitamin C
c. vitamin D
d. vitamin K
e. vitamin B12
i. used in collagen production
ii. stimulates osteoblasts
iii. detoxifies homocysteine
iv. used for protein synthesis
v. helps with calcium absorption
a & ii, b & i, c & v, d & iv, e & iii
Match the hormone to their role in bone formation.
a. IGF (insulin like growth factors)
b. T3 and T4
c. insulin
d. sex hormones
e. calcitriol
f. parathyroid hormone
g. calcitonin
i. from thyroid, stimulate osteoblasts
ii. increase synthesis of bone proteins
iii. promotes calcium absorption
iv. stimulate growth spurt and shut down growth in adulthood, part of bone remodelling
v. increases calcium deposition in bones
vi. made by liver and bone tissue, response to hGH, stimulate osteoblasts, promote cell division in growth plate and periosteum, enhance protein synthesis
vii. increases calcium levels in the blood
Which hormone is the most important?
a & vi, b & i, c & ii, d & iv, e & iii, f & vii, g & v
IGFs are the most important
How does estrogen affect osteoblasts?
Which heals faster: bone or cartilage?
In the treatment of a fracture, what is reduction?
estrogen promotes osteoblast apoptosis
bone heals faster (more blood available)
reduction: setting a fracture so it is aligned (closed: manually done; open: skin open, surgical)
What is the difference between an anchondroplastic dwarf and a pituitary dwarf?
- which is treatable
- which has a proportionate body shape
- what causes each
anchondroplastic
- cartilage not converted to bone
- disproportionate (normal trunk, short limbs, large head)
- untreatable
pituitary dwarf
- undersecretion of hGH
- proportionate
- can be treatable in youth with hGH
Put the bone fracture repair steps in order:
a. Soft callus phase (cartilage fills gap)
b. Reactive phase (blood clot forms)
c. Hard callus phase (cartilage converted into spongy bone)
d. Bone remodelling (calcium and phosphate deposits turn create compact bone)
b, a, c, d
What is a normal calcium level in the blood?
9-11 mg/100mL
What type of receptor does parathyroid hormone respond to?
Which cell, organ and hormone does parathyroid hormone affect?
Which hormone is the counter hormone to parathyroid hormone? Which cell secretes this hormone? What is its effect?
cAMP receptors
stimulates osteoclasts, kidneys (so more calcium is conserved from the urine) and calcitriol (so more calcium is absorbed from food)
calcitonin from parafollicular cells in thyroid; it inhibits osteoclasts
In aging, bones become weaker. Demineralization is a loss of what and brittleness is a loss of what?
Bone scan with radioactive gamma emission is the standard test for bone density. What do hot spots and cold spots indicate?
Bone mineral density test is similar to which type of test?
demineralization: loss of calcium and minerals
brittleness: loss of protein
hot spot: high blood flow, cold spot: low blood flow
x-ray
Match the bone condition to its description:
a. osteoporosis
b. rickets
c. osteomalacia
d. osteoarthritis
e. osteomylelitis
f. osteopenia
g. osteosarcoma
i. degeneration of articular cartilage
ii. bone mass declines (typically due to estrogen declining)
iii. specific type of low bone mass due to low bone synthesis
iv. bone infection, usually Staph
v. in childhood, rubbery bones due to deficiency of vitamin D
vi. bone cancer
vii. in adulthood, rubbery bones due to deficiency of vitamin D
a & ii, b & v, c & vii, d & i, e & iv, f & iii, g & vi
