Structure & Function of the Skeletal System Flashcards
1
Q
Function
Skeletal system
A
- support soft tissues of body
- protect vital organs
- rigid levers for muscular movement
- storage of minerals
- blood cell production
2
Q
structure of skeletal system
A
connective tissues: bone & cartilage
3
Q
the skeletal system provides storage for what minerals?
A
Calcium & phosphorus
4
Q
Is the skeletal system vascular or avascular?
A
highly vascular
5
Q
what does high vascularization of the skeletal system allow for?
A
rapid exchange of minerals between bone & blood
6
Q
where are blood cells produced?
A
red bone marrow
7
Q
hematocytopoiesis
A
blood cell production
8
Q
function
red bone marrow
A
site of blood cell production
9
Q
function
yellow bone marrow
A
composed principally of fat (energy storage)
10
Q
tissue of mesodermal origin that consists of cells and protein fibers embedded in ground substance is called ____
A
connective tissue
11
Q
origin of connective tissue
A
mesoderm
12
Q
connective tissue consists of ____ and ____
A
cells and protein fibers
13
Q
categories of CT
A
loose & dense
14
Q
location of loose CT
A
throughout the body
15
Q
location
dense CT
A
Cartilage & bone
16
Q
loose CT
proportion of cells to ECM
A
cells>ECM
17
Q
dense CT
proportion of cells to ECM
A
ECM>cells
18
Q
two types of CT in skeletal system
A
bone & cartilage
19
Q
mineral component of bone
A
hydroxyapatite crystals (Ca & P)
20
Q
hydroxyapatite crystals are formed by ____ and ____
A
calcium & phosphorus
21
Q
General collagen fiber arrangement in bone
A
collagen fibers in bone matrix arranged in organized, specific structure (except in woven bone)
22
Q
collagen fiber arrangement in cartilage
A
random arrangement (except in fibrocartilage)
23
Q
is cartilage vacular or avascular?
A
avascular - receives nutrients through osmosis & diffusion
24
Q
how does cartilage receive nutrients?
A
osmosis & diffusion
25
which heals faster: bone or cartilage
bone (vascular)
26
types of cartilage
- hyaline
- fibrocartilage
- elastic
27
types of cartilage are recognized by ___?
arrangement of collagen in ECM
28
# hyaline cartilage
collagen fibers
- appear clear & smooth
- very fine fibers
- disorganized
29
precursor of most bones
hyaline cartilage
30
# hyaline cartilage
location
large amounts in skeletal system:
- percursor to most bones
- articular cartilage of synovial joints
- growth plates
31
# fibrocartilage
collagen fibers
- large amounts of collagen fibers
- densely packed
- organized
32
# fibrocartilage
location
found in joints:
- annulus fibrosus of IVD
- symphyses
- menisci
33
# elastic cartilage
collagen fibers
large amounts of protein (elastin)
34
# elastic cartilage
function
stretch without losing shape
35
# elastic cartilage
location
- external ear, nose
- some ligaments of skeletal system (connecting laminae)
36
# hyaline cartilage
function
protect articulating surfaces from wear & tear
37
# fibrocartilage
function
- structural (not found in bones)
- weight-bearing
38
# bone
collagen fibers
highly mineralized, regular in arrangement
39
phases of ECM
mineral & organic
40
what is the mineral phase of bone?
hydroxyapatite (Calcium phosphate & calcium carbonate)
41
how much of the bone is the mineral phase?
65-70% of bone
42
mineral phase structure
arranged in crystalline sructure (hydroxyapatite)
43
mineral phase function
hardness & brittleness
44
organic phase composition/structure
amorphous ground substance:
- proteoglycans & glycoproteins in which collagen fibers are embedded
- organized collagen fibers similar to fibrocartilage
45
what is the organic phase?
primary collagen component of bone
(amorphous ground substance)
46
# stress-strain curve
stress
force (weight-bearing, compressive)
47
# stress-strain curve
strain
tension (muscle pulling bone)
48
# stress-strain curve
elastic phase
bone will bounce back, no permanent deformation
49
# stress-strain curve
plastic phase
permant deformation
50
# stress-strain curve
yield point
point under strain where plastic range begins
51
# stress-strain curve
ultimate strain/stress
failure (fracture)
52
what components of ECM contribute to the stress-strain curve?
- mineral: need rigidity for support
- organic/collagen: need some give
53
bone classifications
- long
- short
- flat
- irregular
- sesamoid
54
long bone shape
tubular shaft with expanded ends
55
long bone locations
limbs (humerus, ulna, radius, femur, tibia, fibula, metacarpals, metatarsals, phalanges)
56
short bone shape
"cuboid"
57
short bone locations
- carpals (wrist)
- tarsals (ankle)
58
flat bone shape
- plate-like
- sandwich of 2 outer dense bone tables (cortical) with sponge-like bone (trabecular; diploe in cranium) between them
59
flat bone locations
cranial vault, sternum, ribs, scapula
60
irregular bone shape
irregular shape that doesn't fit other categories
61
irregular bone locations
- vertebrae
- bones of face & side of skull
62
sesamoid bone structure
develop within tendons of muscles
63
sesamoid bone function
move tendons away from center of joint, increase movement of muscle
64
sesamoid bone locations
patella (quadriceps tendon)
gastrocnemius tendon
flexor hallucis brevis tendon (big toe)
65
diaphysis
tubular shaft of long bones
66
epiphysis
- expanded proximal/distal end of a long bone
- multiple growth centers at one or both ends of some long bones
67
growth centers are located in the ____ of long bones
epiphysis
68
apophysis
site of muscle insertion
69
epiphysis vs apophyisis
epiphysis: growth centers, in joint articulation
apophysis: muscle & ligament attachment site
70
metaphysis
transitional zone between tubular shaft of diaphysis and epiphysis
71
epiphysis/apophysis in short/irregular bones
secondary ossification center
72
diaphysis in irregular/short bones
primary ossification center
73
what does primary/secondary ossification center mean?
forms first/second in development
74
layers of periosteum
osteogenic & fibrous
75
periosteum
outer lining of bone
76
osteogenic layer location
contact with bone surface
77
osteogenic layer structure
bone lining cells derived from osteoprogenitor cells that differentiate into osteoblasts
78
periosteum fibrous layer structure
- dense irregular CT
- fibers extend into bone matrix (Sharpey's fibers)
79
what are Sharpey's fibers?
fibers in fibrous layer of periosteum that extend into bone matrix
80
periosteum fibrous layer location
Outer layer, site of insertion for tendons
81
medullary cavity
cavity inside diaphysis of bone containing marrow
82
endosteum location
lines internal surface of cortical bone, separating it from bone marrow
83
endosteum function
helps supply osteoblasts for fracture repair & formation of Haversian systems in bone remodelling
84
periostitis
- inflammation of tissue beneath the periosteum
- thin layer of bone often forms (periosteal scab/reaction)
- caused by inflammation due to infection, stress or injury (eg. bone bruise)
- common in areas close to skin
85
osteomyelitis
- advanced infection of bone
- necrosis: area of bone starts to decay
- macrophages sent to sequestrum (infected bone)
- forms invulcrum (bone callus)
- cloaca (hole for pus/waste to escape)
86
what is advanced infection of bone called?
osteomyelitis
87
invulcrum
bone callus that surrounds area of infected/necrotic bone
88
sequestrum
area of infected bone
89
cloaca
space/hole through which inflammatory waste products (pus) escapes
90
blood is supplied to bone via ____
nutrient artery
91
nutrient artery enters medullary cavity via ____
nutrient foramen
92
what passes through compact bone into the medullary cavity through nutrient foramen?
nutrient artery
93
nutrient arteries in marrow cavity
spread throughout and lining endosteal surface
94
subperiosteal vessels are located ____
beneath periosteum
95
subperiosteal vessels are derived from ____
nutrient artery, epiphyseal & metaphyseal arteries
96
Haversian canals location
in bone matrix, parallel to long axis of bone
97
Volkmann's canals location
in bone matrix, transversely connected to Haversian canals
98
Volkmann's canals function
- transmit blood vessels & nerve fibers between adjacent Haversian canals
- connect innermost Haversian canals with nutrient arteries & endosteal blood vessels
99
# joints
innervation
same nerves that innervate muscles at joint
100
# periosteum
innervation
wide network of sensory nerves
101
# bone blood supply
innervation
myelinated & non-myelinated nerve fibers run with nutrient artery and branch into marrow cavity and Haversian canals
102
bones are highly innervated near ____
articular surfaces
103
the ____ is the tubular shaft of a long bone
diaphysis
104
spongey bone in the flat bones of the cranium is referred to as ____
diploe
105
types of bone
woven
lamellar:
- trabecullar (cancellous/spongey)
- compact (cortical)
- -circumferential lamellar, Haversian
106
# woven bone
structure
disorganized collagen fibers
structurally weak
107
immature bone
woven
108
first type of bone laid down in cartilage or mesenchymal template during embryonic development
woven bone (immature)
109
Mature bone
lamellar bone
110
types of lamellar bone
compact (cortical)
trabecular (cancellous/spongey)
111
types of compact bone
circumferential lamellar
Haversian
112
trabecular bone structure
- series of intersecting spicules or beams
- greater elasticity
113
spongey bone function
- support articular ends (distrubute force)
- elasticity prevents overlying cartilage from being excessively compacted during loading
114
primary osteons
circumferential lamellar bone (mature, compact)
115
lamellae
- bone layers in which collagen fibers have specific (parallel) orientation
- extend around circumference of the shaft of bone in layers deep to periosteum
116
lacunae
small spaces in bone matrix occupied by osteocytes
117
osteocytes
- "resting" bone cells between adjacent lamellae
- sense mechanical state of bone
118
blood vessel deep to periosteum surrounded by layer of advancing bone
osteon
119
canaliculi
- minute channels through which cellular processes pass
- communication of osteocytes with blood vessels & other osteocytes
- join osteocytes with each other & innermost osteocytes with blood supply in Haversian canal
120
circumferential lamellar bone function
- compressive strength - ability to bear weight
- tensile strength - ability to resist pull of muscles
121
circumferential lamellar bone collagen structure & functional properties
- fibers run parallel to long axis of bone in diaphysis; at articulations lie parallel to direction of muscle tension (tensile strength)
- mineral deposited in bone matrix around collagen (compressive strength)
122
haversian bone is known as ____ osteons
secondary
123
haversian bone location
- form in already existing bone to repair microfractures & other damage
- form within resorption space carved out by osteoclasts (Howship's lacunae)
124
Howship's lacunae
resorption space carved out by osteoclasts
125
blood vessels enter resorption space and bring ____
osteoblasts
126
Haversian canals
- contain arteriole & venule
- network of small channels in bone matrix for blood supply to bone
127
Volkmann's canals are not lined by ____
concentric lamellae
128
layers of mature bone matrix are ____
lamellae
129
transmission of blood vessels & nerve fibers between Haversian canals occurs via ____
Volkmann's canals
130
first type of bone laid down in callus of fracture
woven bone
131
where is red bone marrow primarily concentrated?
vertebrae
ribs
sternum
scapulae
clavicles
pelvis
cranium
proximal humeri & femora
132
Dense CT structure
Organized, specific structure
