Skeletal System Flashcards
1
Q
Periosteum
A
Membrane composed of dense irregular collagenous tissues
Forms a covering, rich with blood vessels & nerves
Surrounds outer surface of long bones
2
Q
What bone structure is the periosteum associated with?
A
LONG BONE structure
3
Q
Sharpeys ( aka perforating ) fibers
A
Made of collagen
Anchors periosteum firmly to underlying bone surface by penetrating deep into bone matrix
4
Q
Diaphysis
A
Shaft of long bone
Each end is its epiphyses
5
Q
Epiphysis
Covered with what?
A
Covered w/ a thin layer of hyaline cartilage (articular cartilage) found within joints (articulations) between bones
6
Q
Marrow cavity?
A
Within diaphysis, it’s a hollow cavity
Contains either red or yellow bone marrow, depending on bone & age of individual
7
Q
Compact bone
A
Hard, dense outer region that allows bone to resist linear compression & twisting forces among other stresses
(Linear compression is a vertical squash)
8
Q
Spongy bone Aka ...? Found? Structure? Functions?
A
Aka cancellous bone
Found inside compact bone
Honeycomb-like frame work of bone struts
Allows long bones to resist forces from many directions
Provides a cavity for bone marrow
9
Q
Endosteum
A
Thin membrane covering inner surfaces of bone
Contains different populations of bone cells involved in maintenance of bone homeostasis (building new cells -> skeleton every 10yrs)
10
Q
Epiphyseal lines
A
Found separating both proximal and distal epiphyses from diaphysis
Remnants of epiphyseal plates (growth plates), a line of hyaline cartilage found in delegating bones of children
-replaced by bone by age 18-21
11
Q
Short, flat, irregular, and sesamoid bones do not have what?
A
Do NOT have diaphyses, epiphyses, medullary cavities, epiphyseal lines, or epiphyseal plates
12
Q
Characteristics of Flat, Irregular, Short, & Sesamoid bones
A
- Covered by periosteum, blood vessels, & nerves like long bone
- Internal structure composed of 2 outer layers of think compact bone with a middle layer of spongy bone, & it’s associated bone marrow
- some flat & irregular bones of skull contain hollow air-filled spaces called sinuses, which reduce bone weight
13
Q
Sinuses
A
Hollow air-filled spaces that reduce bone weight
14
Q
Is bone living or nonliving?
A
Bone is a living tissue
15
Q
What are bones supplied with?
A
Well supplied w/ blood vessels & sensory nerve fibers
16
Q
What bones does blood supply to?
A
Supplies to short, flat, irregular, and sesamoid bones
17
Q
How are bones supplied with blood vessels and sensory nerve fibers?
A
Provided mostly by vessels in the periosteum that penetrate bone.
18
Q
How is blood supply divided?
A
Long bones get 1/3 blood supply from periosteum; mostly supplies compact bone
Remaining 2/3 is supplied by nutrient arteries
-enter bone through small hole in diaphysis called nutrient foramen
-supply internal structures of bone
19
Q
Osteoclasts
A
BREAK DOWN BONE
Responsible for bone resorption
20
Q
Bone resorption
What do each parts do?
Released where after doing its job?
A
Process where cell secretes hydrogen ions & enzymes that break down bone matrix
- hydrogen ions dissolve inorganic matrix; enzymes break down organic matrix
- substances released into blood where reused or excreted from the body as waster products
21
Q
Histology of compact bone
A
In cross section, resembles forest of tightly packed tress where each tree is a unit called an patron or a Haversian system
Rings of each tree are made up of thin layers of bone called lamellae
(Lamellae looks like a stacked cake)
22
Q
What does the skeletal system include?
A
Bones, joints, and associated supporting tissues.
Composed of bone marrow, dense irregular & irregular collagenous connective tissue
23
Q
Osteon structure components?
A
central canal, collagen fibers in lamellae, lacunae with osteocytes, lamellae, artery,vein, nerve, canaliculi
24
Q
lamellae in osteons?
aka?
A
each osteon contains between 4 & 20 lamellae arranged in layered ring structures also known as concentric lamellae
25
function of lamellae in osteon?
lamellar arrangement is very stress resistant
26
collagen fibers in osteon?
collagen fibers of neighboring lamellae run in opposite directions
VERY STRONG
27
Central canal in osteon?
Central (Haversian) canal- endosteum-lined hole found in center of each osteon where blood vessels & nerves reside to supply bone
28
Lacunae in osteons?
connected to one another by a network of canals in matrix called canaliculi
contains osteocytes
29
2 types of bone marrow
red & yellow
30
red bone marrow
loose connective tissue that supports islands of blood-forming hematopoietic cells
31
facts of red bone marrow?
| Age? Adult? Children?
amount DECREASES as a person ages
red marrow in adult is found only in pelvis, proximal femur, & humerus, vertebra, ribs, sternum, clavicles, scapulae, & some bones of the skull
Children need more red to assist in growth & development (adults dont need as much bc they are older & not growing)
32
Yellow bone marrow
composed of triglycerides, blood vessels, and adipocytes
33
Bone or osseous tissue
composed mostly of extracellular matrix w/ a small population of cells scattered throughout
34
What is the extracellular matrix of bone made of ?
Inorganic & organic matrix
35
Inorganic matrix consists of?
consisting of minerals make up about 65% of bones total weight
HARD
36
Organic matrix consists of?
makes up remaining 35%, consists of collagen fibers & usual ECM components
FLEXIBLE
37
main different between organic & inorganic matrix
inorganic- harden bone
| organic- flexible (bc collagen)
38
inorganic matrix
| made up of? which ones? function?
mainly calcium salts
bone stores around 85% total calcium ions in body as well as large amount of phosphorus:
ions form crystalline structure that makes bone one of hardest substances in body
bicarbonate, potassium, magnesium, and sodium are also found in inorganic matrix
39
Organic matrix
| aka? consists?
known as osteod; consists of protein fibers & bone-specific proteins
40
Collagen
| location? definition? function?
in organic bone matrix, predominant protein fibers
forms cross-links w/ one another
helps bone resist torsion (twisting) & tensile (pulling or stretching) forces
41
Bones continually change as ______ bone is ________ for raw materials to ________________
older bone is broken down for raw materials to build new bone
42
3 types of bone cells
osteoblasts
osteoclasts
osteocytes
43
osteoblasts
active bone cells found in periosteum & endosteum
| BUILD MATRIX WHEN WE NEED NEW BONE
44
Osteogenic cells
| aka? description?
Stem cells for bone
| Flattened cells that differentiate into osteoblasts when stimulated by specific chemical signals (type of stem cell)
45
Bone-building cells
perform bone deposition
| osteoblasts
46
bone deposition
osteoblasts secrete organic matrix materials & assist in formation of inorganic matrix
47
Osteocytes
| how are they made? definition?
mature bone cells
osteoblasts eventually surround themselves w/ bone matrix in lacuna, become osteocytes that are no longer actively synthesizing bone matrix
48
lacuna
small cavity
49
Spongy bone
| function? description?
usually not weight-bearing like compact bone so is much less densely packed
provide protective structure for bone marrow tissue
50
trabeculae
| location & description
struts or ribs of bone
covered w/ endosteum & usually not arranged into osteons, composed of concentric lamellae
IN SPONGY BONE
51
lacunae are found where?
in concentric lamellae, in trabeculae, in spongy bone
| contain osteocytes
52
how does spongy bone obtain blood supply?
no central or perforating canals supplying blood to trabeculae; obtain blood supply from vessels in bone marrow
53
ossification is what?
bone formation
54
how many types of ossification are there? what are they?
2
intramembraneous ossification
endochondral ossification
55
intramembraneous ossification
bone forms directly from mesenchyme-> osteogenic cells-> osteoblasts
-begins about 6th embryonic week during fetal development
56
where does ossification occur?
embryo & fetus development
infancy, childhood, adolescence
bone remodeling/repair
57
what bones form from intramembraneous ossification
| what happens if it's incomplete
FLAT, broad bones
-skull, mandible, clavicle
incomplete intramembraneous ossification causes Fontanels (soft spots) in newborn skull
58
Endochondral ossification
| what happens? what bones form? when are bones completely ossified?
bone forms within & replaces cartilage model
all bones below head except clavicle
most bones are completely ossified by age 7
59
Long bone growth
| means? due to? what happens to diaphysis? when does growth stop?
longitudinal growth in length
- due to cell division of chondrocytes in epiphyseal plate
- diaphysis of bone increases in length
- by age 18-21 growth stops
60
Growth in width
| means? what happens? how long can this go on?
appositional (width) growth
- osteoblasts btwn periosteum & bone surface make new bone
- forms new circumferential lamellae
- older deeper lamellae are removed or incorporated into osteons
- process can continue after longitudinal growth stops
61
Bone remodeling
| defintion? includes? adult vs child?
continuous replacement of old bone tissue formation & loss
- bone deposition & resorption
- adult: formation & loss occur simultaneously
- childhood: deposition occurs faster than resorption
62
Bone resorption
removal of minerals & collagen fibers by OSTEOCLASTS
63
bone depostion
Addition of minerals & collagen fibers by OSTEOBLASTS
| -About 5% of total bone mass is remodeled at any given time (skeleton every 10 yrs)
64
Factors affecting bone remodeling? (5)
```
Minerals
Vitamins
Hormones
Activity Level
Diet
```
65
Minerals that affect bone remodeling
magnesium, phosphorus, calcium in blood
| need 1,000 to 1,500 mg Ca per day
66
Vitamins that affect bone remodeling
Vitamin A- stimulates osteoblasts
Vitamin C- helps synthesize collagen
Vitamin D- calcium absorption
67
Hormones that affect bone remodeling
Growth hormones- stimulates cartilage & bone growth
Parathyroid hormones- stimulate osteoblasts
Calcitonin- stimulates osteoclasts
68
Activity level affecting bone remodeling
weight bearing exercise (makes osteoblasts work ->build up bone!)
69
Fracture
any break in a bone
70
Simple Fracture
skin & tissue around fracture remain tack
71
Compound Fracture
Skin & tissues around fracture are damaged
72
Stress Fracture
Series of microscopic fissures in bone
| w/o evidence of injury to other tissues
73
Types of fractures (5)
```
comminuted
greenstick
impacted
spiral
simple
```
74
comminuted fracture
splintered or crushed bone
75
greenstick fracture
partial fracture
76
impacted fracture
one end of fractured bone forcefully driven into interior of the other (jump off building)
77
spiral fracture
bone twists in opposite directions (football)
78
simple fracture
bone breaks totally w/o breaking the skin
79
Demineralization
loss of Ca & minerals from extracellular matrix bc of aging
- after age 30 females and after age 60 in males osteoblasts slow down
- about 30% of Ca in bones lost by age 70
80
what happens to bone when aging?
loss of bone mass & brittleness
81
Loss of bone mass
| means?
more bone is lost than made
increase in osteoclast activity
demineralization
82
Brittleness
decreased rate in protein synthesis & production of collagen fibers
83
Skeletal diseases (9)
```
Paget's disease
Osteoporosis
Osteophytes (Bone Spurs)
Hallux Valgus (Bunions)
Rickets
Scurvy
Scoliosis
Lordosis
Kyphosis
```
84
Paget's Disease
abnormal bone remodeling process
most common in adults
heredity
Symptoms: pain bone deformity, arthritis
85
Osteoporosis
Deterioration of cartilage & bone
Caused by aging & genetics
Bones become brittle & break easily (FRAGILE)
Symptoms: joint swelling, muscle weakness, limited movement (why older ppl break hip)
86
Osteophytes (bone spurs)
bony projections develop along edges of bone - near joints
caused by osteoartritis/osteoporosis
Symptoms: pain or loss of motion in joints, inflammation
87
Hallux valgus (Bunions)
Enlargement of bone at joint of base of big toe
caused by narrow toe shoes
Symptoms: swelling, displacement of big toe
88
Rickets
Softening/weakening of bones due to lack of vitamin D
Symptoms: Bowed legs, curved spine, fragile bones
(like in Africa, under developed countries)
89
Scurvy
Abnormalities in bone development, epiphyseal disease, lifting of periosteum
lack vitamin C
Symptoms: Loose teeth, bleeding gums, degeneration of cartilage
(like pirate teeth)
90
Scoliosis
Curvature of spine from side to side
'S' shape
Symptoms: lean to 1 side, uneven shoulder or waist height
91
Lordosis
Curvature of spine from front to back
"sway back"
Symptoms: sway back, pain in lumbar region
92
Kyphosis
Curvature of upper spine
'Dowers Hump'
Symptoms: leaning forward, hump back
93
Functions of the skeletal system? (6)
```
Protection
Mineral storage & acid-base homeostasis
Blood cell formation
Fat storage
Movement
Support
```
94
Protection
skeleton protects underlying vital organs such as the brain
95
Mineral storage and acid-base homeostasis
bone stores minerals such as Ca and phosphorus which are necessary for electrolyte & acid-base balance
store house for Ca P and MG salts (P & Mg for pH balance)
96
Blood cell formation
red bone marrow is the site of blood cell formation (hematopoiesis)
97
Fat storage
```
yellow bone marrow stores triglycerides
fat cells (adipocytes) used for fuel by cell (ATP)
```
98
Movement
muscles produce body movement via their attachment to bones
| MUSCLE CONTRACT->BONES MOVE (MUSCLES MAKE BONES MOVE)
99
Support
the skeleton supports the weight of the body
| provides structural framework (HARD BONES)
100
Long bone
| definition & examples
bone is longer than it is wide, named for overall shape
| ex. Femur, Tibia, Humerus
101
short bone
| definition & examples
bone is about as long as it is wide, roughly cubed shape
| ex. wrist or carpal & ankles or tarsals
102
Flat bone
| definition & examples
bone is broad, flat, and thin
| ex. ribs,pelvic, sternum (breastbone) MOST BONES IN SKULL
103
irregular bone
| definition & examples
bone's shape does not fit into other classes, irregular shape
ex. vertebra and certain skull bones
104
sesamoid bone
| definition & examples
round, flat bone found within tendon
- specialized bones located within tendons, usually small, flat & oval-shaped
ex. kneecap, within tendons
105
how are the bones classified ?
by shape, into 5 classes
106
difference between long & short bone
long- named for overall shape
| short- roughly cubed shape
107
Intramembraneous ossification means what?
within (intra) 2 layers (membraneous)
108
process of intramembraneous ossification
1) osteoblasts develop in the primary ossification center
2) osteoblasts secrete organic matrix which calcifies
3) early spongy bone is formed
4) early compact bone is formed
109
endochondral ossification means what?
inside (endo) replacing cartilage (chondral)
110
process of endochondral ossification
1) chondroblasts in the perichondrium differentiate into osteoblasts
2a) Osteoblasts build bone collar on bone;s external surface as bone begins to ossify from the outside
2b) Simultaneously, internal cartilage begins to cacify & chondrocytes die
3 )In primary oss, center, osteoblasts replace calcified cartilage w/ early spongy bone; secondary oss. centers & medullary cavity develop
4) As medullay cavity enlarges, remaining cartilage is replaced by bone; epiphyses finish ossifying
111
process of fracture repair
1) Hematoma fills gap btwn bone fragments (Hematoma formation (blood clot) -6-8 hrs after fracture)
2) Fibroblasts & chondroblasts infiltrate hematoma, & soft callus forms (fibrocartilaginous callus form cartilage& fibers to form soft callus, about 3 wks to form)
3) Osteoblasts build bone (bony callus, forms hard callus lasts 3-4 months to make callus)
4) Bone callus is remodeled & primary bone is replaced w/ secondary bone (remodeling, restores new bone structure) (takes about 1 yr, area stronger than any other bc its new!)
112
functions of osteoblasts & osteocytyes
1) osteogenic cells differentiate into osteoblasts
2) osteoblasts deposit bone until they are trapped & become osteocytes
3) osteocytes maintain the bone extracellular matrix
113
mono-nucleic vs multi
osteocytes and osteoblasts- 1 nuclei
| osteoclasts, large ruffled w/ multi nuclei
