Topic 3 - The Skeletal System (I-IV) Flashcards
1
Q
What is the function of the skeletal system? (5 things)
A
- Provides structure, support and protection
- essential for locomotion and movement
- site of blood cell formation (hematopoiesis)
- storehouse for some inorganic minerals, especially calcium
- indicator of sex, age, height, weight, racial background, and (to some extent) medical history
2
Q
How are bones classified?
A
by shape and location
3
Q
What are the shape classifications of bones?
A
- long bones
- short bones
- flat bones
- irregular bones
- pneumatic bones
- sesamoid bones
4
Q
Description of long bones
A
Longer than wide, cylindrical with a medullary cavity
5
Q
What are long bones the main components of? (And examples of the bones themselves)
A
- limbs
- humerus, radius, ulna, femur, tibia, fibula, metacarpals, metatarsals, phalanges
6
Q
Short bones description and examples
A
- roughly cubical
- carpals and tarsals
7
Q
Where are short bones found?
A
where mobility is needed, but space is limited
8
Q
Description of flat bones
A
Relatively thin bones
9
Q
Function of flat bones
Examples of the bones
A
- provide broad surfaces for muscle attachment and/or protection of underlying organs
- main site of blood cell formation in adults (hematopoiesis)
- i.e.: frontal, parietal, innominate, ribs, scapula
10
Q
Description of irregular bones
Examples of irregular bones
A
- irregular shape with numerous projections
- vertebrae some bones of skull (sphenoid, ethmoid), scapula
11
Q
What do pneumatic bones contain?
Pneumatic bone purpose?
Where are they found?
Examples of them:
A
- sizable air spaces
- reduce weight of the skull, thus reducing need for large neck muscles
- only found in some bones of he skull
- frontal, maxilla, sphenoid, ethmoid, temporal (mastoid process)
12
Q
Whet are sesamoid bones?
A
small round bones embedded within a tendon
13
Q
What is the purpose of sesamoid bones?
A
Alter the angle of muscle attachment to increase mechanical leverage
14
Q
Examples of sesamoid bones
A
Patella and sesamoids of hands and feet
15
Q
How are bones classified by location?
A
- axial vs. appendicular skeleton
- cranial skeleton vs. post-cranial skeleton
16
Q
Axial skeleton:
A
Bones of the skull, hyoid, vertebral column, and rib cage
17
Q
Appendicular skeleton:
A
Bones of the limbs and their attachment onto the axial skeleton
18
Q
Appendicular skeleton examples
A
Bones of the limbs and their attachment (Pectoral and pelvic girdles [excluding the sacrum])
19
Q
Cranial skeleton
A
Bones of the skull
20
Q
Post-cranial skeleton
A
Bones of vertebral column, hyoid, rib cage, limbs, pectoral girdle, pelvic girdle
21
Q
Bone Tissue: subcategories
A
- matrix
- bone cells
- abnormal growth of bone tissue
22
Q
Bone tissue composition has:
A
- matrix
- bone cells
23
Q
Bone matrix contains:
A
- fibers
- ground substance
24
Q
Bone matrix fibers:
What do they do?
A
- Type I collagen fibers;
- Provide strength to resist tensile forces (forces that are trying to tear them apart)
25
Ground substance of bone matrix:
- organic component
| - inorganic component
26
What is the organic component of the ground substance of bone matrix?
Proteoglycans (primarily composed of sulfate, keratin sulfate, nad hyaluronic acid) and glycoproteins (especially osteonectin and osteocalcin)
- osteonectin: connects on to collagen fibers
- osteocalcin: facilitates deposition of inorganic
27
What is the inorganic component of the ground substance of bone?
Hydroxyapatite, a calcium mineral composite, which provides strength to resist compressive forces
28
Bone cells consist of:
- osteoprogenitor cells
- osteoblasts
- osteocytes
- osteoclasts
29
Osteoprogenitor cells give rise to ___________
osteoblasts
30
Where are osteoprogenitor cells located?
located within the central and perforating canals of osteons, within the periosteum (cellular layer) and endosteum
31
Osteoblasts are originate from _____________.
Osteoprogenitor cells
32
Osteoblasts give rise to ______________
Osteocytes
33
What do osteoblasts do?
Lay down new bone tissue
34
Where are osteoblasts located
Within the central and perforating canals of osteons and within the periosteum (cellular layer) and endosteum
35
Osteocytes were formerly ______________.
Osteoblasts
36
Osteocytes are located ____________
Within the lacunae of the osteons of compact bone and bony struts of spongy bone
37
What do osteocytes do?
Maintain surrounding bone tissue and regulate mineral content.
38
Osteoblasts function is what?
Bone-destroying cells (destroy bone tissue). They refine the shape of the bone that osteoblasts laid down.
39
Describe osteoclasts
Large and multinucleated
40
Where do osteoclasts originate?
From the fusion of several monocytes.
41
What are the types of bone tissue?
- primary bone tissue (woven bone)
- secondary bone tissue (mature or lamellar bone)
- abnormal growth of bone tissue
42
Primary bone tissue is AKA
Woven bone
43
When does primary bone develop?
First, during fetal development
44
What is primary bone associated with?
The repair of fractures
45
What kind of fibers are found in primary bone, and how are they arranged?
- Collagen fibers
| - randomly arranged
46
In primary bone, is the mineral content high or low?
Low
47
Primary bone contains more ________ than __________/___________ bone tissue
Osteocytes
Mature/secondary
48
Secondary bone tissue is AKA
Mature or lamellar bone
49
What types of bone are classified under Secondary bone tissue (mature or lamellar bone)?
- compact (cortical) bone
- spongy (cancellous or trabecular) bone
- subchondral bone
50
What is compact bone AKA?
Cortical bone
51
What is compact (cortical) bone composed of?
Outer layer of densely packed bone tissue, composed of osteons (aka, Haversian systems), circumferential lamellae, and interstitial lamellae
52
What are osteons made up of?
- lamellae
- central (osteons or Haversian) canal
- lacunae
- canaliculi
- perforating (communicating or Volkmann's) canals
- circumferential lamellae
- interstitial lamellae
53
Lamellae are what?
What are the fibers made up of, and at what angle(s) are the fibers oriented to the adjacent layers?
Concentric layers of bone tissue.
Collagen
Right angles to the fibers in the adjacent layers
54
What is the central canal AKA?
Osteonic or Haversian
55
What does the central (osteonic or Haversian) canal contain?
What is it lined by?
- vascular structures and nerves
| - osteoprogenitor cells and osteoblasts
56
What are lacunae?
What is contained in them?
- Holes found between lamellae
| - osteocytes
57
What are canaliculi?
Passageways connecting lacunae to each other and to the central and perforating canals
58
Perforating (communicating of Volkmann's) canals do what?
Connect central canals to each other
59
What are perforating canals lined by?
Osteoprogenitor cells and osteoblasts
60
Circumferential lamellae are?
Multiple layers of mineralized matrix
61
What are the 2 kinds of circumferential lamellae?
External and inner circumferential lamellae
62
Where are the external circumferential lamellae located?
Immediately deep to the periosteum
63
Inner circumferential lamellae are located where?
At the perimeter of the medullary cavity
64
What are interstitial lamellae?
Layers of mineralized matrix, lying between and around osteons; the remains of partially destroyed osteons
65
Spongy (cancellous or trabecular) Ben is found where?
The interior of a bone
66
Describe spongy bone
Lattice/network of bony bars and struts (trabeculae), each consisting of just a few concentric layers of bone tissue
67
How many layers of concentric bone tissue are there in spongy bone?
A few
68
Where is the site that blood cells are manufactured?
Within the lattice/network of bony bars and shuts within spongy bone
69
What is subchondral bone?
Very thin layer of modified compact bone, lacking the extensive vascular channels
70
Where is subchondral bone found?
Underlying articular cartilage, making up the articular/facet surface
71
What is the morphology of a typical bone?
- diaphysis
- epiphysis
- epiphyseal plate (epiphyseal disk, growth plate)
- periosteum
- endosteum
- medullary cavity (marrow cavity)
- articular cartilage
72
What is the diaphysis of a bone?
body/shaft of the bone. Also the primary center of ossification
73
Epiphysis is often associated with what?
the area of articulation with another bone or site of excessive muscle tension
74
Where is the secondary center of ossification?
The epiphysis
75
Where is the primary site of ossification?
The diaphysis
76
What does the epiphyseal plate (epiphyseal disk, growth plate) do?
Connects diaphysis and epiphysis
77
What is the epiphyseal plate composed of?
Hyaline cartilage
78
The periosteum is what?
Fibrous structure covering the outer bone surface.
79
Where is periosteum not found?
Articular bone surfaces and where tendons and ligaments attach onto the bone
80
What are the 2 layers of periosteum?
- Fibrous layer
| - Cellular layer
81
How are tendons and ligaments anchored to the periosteum?
Via perforating/Sharpey's fibers
82
Which layer of periosteum is deep?
The cellular level
83
Which layer of periosteum is superficial?
Fibrous layer
84
The fibrous layer of periosteum consists of what?
sheet of dense irregular connective tissue containing type I collagen fibers, plus fibroblasts, blood vessels and nerve fibers (stressed for pathology)
85
The cellular layer of periosteum is _______ and contains bone ________ (primarily _________ ________ and ________.
Thin
Cells
Osteoprogenitor cells
Osteoblasts
86
What is endosteum?
A very thin connective tissue layer covering inner bone surfaces
87
Endosteum primarily consists of what?
A single layer of osteoprogenitor cells and osteoblasts
88
Where is the medullary cavity (marrow cavity) located?
The center of a long bone
89
What is the fxn of the medullary cavity in children? In adults?
- additional site of blood cell manufacture ('red bone marrow')
- adipose storage ('yellow bone marrow')
90
Where is articular cartilage found?
What is it composed of?
- covering articular surfaces
| - hyaline cartilage
