Skeletal System and Introduction to Bone Markings Flashcards
1
Q
Each bone is an organ composed of what tissues?
A
bone, cartilage, dense connective tissues,
epithelium, blood-forming tissue, adipose tissue, and nerve tissue
2
Q
the skeletal system is
A
the entire framework of bones and their cartilages
3
Q
Osteology
A
the study of bone structure and the treatment of bone disorders
4
Q
Functions of the skeletal system
A
Support Protection Assistance in movement mineral homeostasis blood cell production triglyceride storage
5
Q
Storage
A
structural framework for soft tissues to attach
6
Q
Protection
A
protects internal organs from injury
7
Q
Assistance in movement
A
muscles pull on bones to create movement
8
Q
Mineral homeostasis
A
minerals are stored in bone to be released later
9
Q
Blood cell production
A
some bones contain red bone marrow which produce red blood cells,
white blood cells, and platelets
10
Q
Triglyceride storage
A
some bones contain yellow bone marrow which is made of adipose and
stores triglycerides
11
Q
4 classifications of bone
A
long bones
short bones
flat bones
irregular bones
12
Q
long bones
A
greater length than width; consist of a shaft and a variable number of ends; usually
somewhat curved for strength
13
Q
examples of long bones
A
Femur, tibia and fibula, humerus, ulna and radius
14
Q
short bones
A
somewhat cube-shaped and nearly equal in length and width
15
Q
examples of short bones
A
Wrist and ankle bones
16
Q
flat bones
A
generally thin, afford considerable protection, and provide extensive surfaces for muscle attachment
17
Q
examples of flat bones
A
Cranial bones, sternum, ribs, scapula
18
Q
Irregular bones
A
have complex shapes and do not fit in the other categories
19
Q
examples of irregular bones
A
Vertebrae and some facial bones
20
Q
seasmoid bone
A
a bone that forms directly in the connective tissue of tendons; embedded in a tendon;
acts like a pulley and improves the transmission of muscle force by the tendon; largest in the body is the
patella, but there are also small sesamoid bones in the hands, wrists, feet, and ears
21
Q
typical long bone consists of
A
diaphysis
epiphysis
metaphysis
22
Q
diaphysis
A
the bone’s shaft or body
23
Q
epiphysis
A
the distal and proximal ends of the bone
24
Q
metaphysis
A
the region in a mature bone where the diaphysis joints the epiphysis
A growing bone contains an epiphyseal (growth) plate in each metaphysis to allow the diaphysis to grow in length
25
Articular cartilage
a thin layer of hyaline cartilage covering the part of the epiphysis where the
bone forms an articulation with another bone
26
periosteum
a tough sheath of dense irregular connective tissue and its associated blood vessels
that surrounds the bone surface wherever it is not covered by articular cartilage
27
medullary cavity
a hollow, cylindrical space within the diaphysis that contains fatty yellow
bone marrow in adults
28
endosteum
a thin membrane that lines the medullary cavity
29
4 major types of cells in bone tissue
Osteogenic
Osteoblasts
Osteocytes
Osteoclasts
30
Osteogenic
unspecialized stem cells that undergo cell division (the only ones) to create
osteoblasts
31
Osteoblasts
bone-building cells; synthesize and secrete collagen fibers and other organic
components needed to build the extracellular matrix of bone tissue
32
Osteocytes
mature bone cells; the main cells in bone tissue and maintain the exchange of
nutrients and wastes with the blood
33
Osteoclasts
huge cells that release enzymes and acids that digest the protein and mineral
components of bone; responsible for resorption (the breakdown of bone extracellular matrix)
34
Bone is made of
50% crystallized mineral salts (give bone hardness and strength)
25% collagen fibers ( gives bone flexibility and reinforcement)
25% water
35
Bone is not completely solid because
many small spaces between cells and extracellular matrix components
36
Bone can be classified as spongy or compact
Depending on the size and distribution of the spaces
37
What percent of skeleton is compact and spongy bone?
80% skeleton is compact bone
| 20% is spongy bone
38
Compact bone tissue
contains few spaces; strongest type of bone tissue
Arranged in repeating structural units called osteons
concentric lamellae
lacunae
canacliculi
perforating canals
39
Osteons
repeating structural units
Osteons have a central canal containing blood vessels, nerves, and lymphatic vessels;
longitudinal to the bone
40
Concenctric lamellae
rings of hard, calcified extracellular matrix around the canals
41
Lacunae
small spaces between the lamellae which contain osteocytes
42
Canaliculi
small channels radiating from the lacunae; filled with extracellular fluid
43
Perforating canals
allow blood vessels, lymphatic vessels, and nerves from the periosteum to
penetrate the compact bone transversely
44
Spongy bone tissue
makes up most of the bone tissue of short, flat, and irregularly shaped bones
contains no osteons
trabeculae
has red bone marrow
45
trabeculae
irregular lattice-works of thin columns of bone that make up spongy bone
between the trabeculae, the space is filled with red bone marrow
contains concentric lamellae, osteocytes that lie in lacunae, and canaliculi radiating from the lacunae
46
spongy bone is different from compact in 2 major ways
Spongy is light which reduces the weight so it moves more readily
The trabeculae of spongy bone tissue support and protect the red bone marrow and is the
only site of red bone marrow in adults
47
bone formation
called ossification
| occurs in 4 stages
48
4 stages of ossification
Initial formation of bones in an embryo and fetus
The growth of bones during infancy, childhood, and adolescence
The remodeling of bone (replacement of old bone tissue by new bone tissue throughout
life)
The repair of fractures throughout life
Initial bone formation
49
Embroyonic sksleton is composed of
mesenchyme
50
mesenchyme
meshwork of embryonic connective tissue)
shaped like bones
become ossified, providing a template for continuing ossification beginning during the 6th week of embryonic development
happens by intramembranous ossification
endochondral ossification
bone growth
51
intramembranous ossification
simpler method of bone formation; bone forms directly
| within mesenchyme in sheet-like layers
52
endochondral ossification
bone forms within hyaline cartilage that develops from
| mesenchyme
53
bone growth
bones grow in length and thickness during infancy, childhood, and
adolescence (until 18-25 years old)
54
bone length is related to
epiphyseal plate
chondrocytes that are constantly dividing and being converted to bone
When growth is complete, all of the chondrocytes are ossified and the bone stops growing
An epiphyseal line is present after the epiphyseal plate ossifies
55
bone thickness is produced by
the cells in the perichondrium
these differentiate into osteoblasts which secrete bone extracellular matrix
56
bone remodeling is
the ongoing replacement of old bone tissue by new bone tissue
takes place at different rates in different regions of the body
can be triggered by exercise, lifestyle, and changes in diet
57
bone resorption
the removal of minerals and collagen fibers from bone by osteoclasts
58
bone deposition
the addition of minerals and collagen fibers to bone by osteoblasts
59
fracture
any bone in a bone
60
partial fracture
an incomplete break across the bone, such as a crack
61
complete fracture
a complete break across the bone; the bone is broken into two or more pieces
62
closed ( simple)
the fractured bone does not break through the skin
63
open (compound)
the broken ends of the bone protrude through the skin
64
repair of a fracture
Phagocytes begin to remove any dead bone tissue
Chondroblasts form fibrocartilage at the fracture site that bridges the broken ends of the bone
The fibrocartilage is converted to spongy bone tissue by osteoblasts
Bone remodeling occurs; dead portions of bone are absorbed by osteoclasts and spongy bone is converted to compact bone
65
bone formation depends on several factors
Adequate vitamins (A, C, and D) and minerals (calcium, phosphorus, and magnesium)
Several hormones (androgens, estrogens, hGH)
Weight-bearing exercise
66
exercise and bone tissue
bone requires mechanical stress to remodel normally
When placed under stress, bone tissue becomes stronger through increased deposition of mineral
salts and production of collagen fibers
Demineralization
Primary mechanical stresses:
Pull of skeletal muscles
Pull of gravity
67
demineralization
loss of bone minerals
68
calcitonin
a hormone produced by the thyroid that can decrease the level of calcium in the
blood by inhibiting the action of osteoclasts; function isn’t totally clear because it can be present in excess or completely absent without causing clinical symptoms
69
parathyroid hormone ( PTH)
major regulator of the levels of calcium, magnesium, and
| phosphate ions in the blood; increases the number and activity of osteoclasts
70
calcitrol
the active form of vitamin D, produced in the kidneys; acts on the gastrointestinal
tract to increase the rate of calcium, magnesium, and phosphate ions absorbed from foods into the blood
71
Testosterone, estrogen, human growth hormone, and insulin-like growth factor
hormones that
| promote anabolism and bone growth
72
bony landmakers/nomenclature/ bone markings
serve as regions for ligament and tendon attachment or
| provide passage or space for nerves and vessels to pass
73
depressions
basins & channels that house muscles, tendons, nerves, & vessels
fossa
sulcus/groove
74
fossa
shallow depression (distal end of humerus, ilium)
75
sulcus or groove
narrow depression (head of humerus)
76
openings
holes & channels that allow passage of nerves, vessels, muscles, & tendons
```
sinus
fissure
foramen
meatus
canal
```
77
sinus
air-filled cavities (nose)
78
fissure
cleft or enlarged crack or slit in a bone (cranium sphenoid)
79
foramen
small to large, usually circular opening (vertebral foramen)
80
meatus
a tiny passageway (part of the skull that extends to the ear)
81
canal
tunnel or tube in a bone (Cranium)
82
Projections
form joints
```
condyle
head
facet
process
trochlea
```
83
condyle
a rounded projection at the end of a bone that articulates with other cones to
form a joint (femur)
84
head
a rounded projection atop the neck of a bone (Head of femur)
85
facet
a smooth, flat surface (rib meets vertebrae)
86
process
any prominent, bony growth that projects (olecranon process of ulna)
87
trochlea
a pulley-shaped structure (trochlea of the humerus)
88
attachment sites
attachment sites for tendons and ligaments
rounded
long & narrow sites
other prominences
89
long & narrow sites
crest,line, rdige
90
rounded
tubercle, tuberosity, trochanter
91
other prominences
epicondyles, processes, spines
