Skeletal Flashcards
1
Q
What does the skeletal system compose of?
A
Bone and cartilage
2
Q
What is the skeletal system divided into?
A
The axial and A
appendicular skeleton
3
Q
What is included in the axial skeleton?
A
The skull, vertebrae, sacrum ribs and sternum
4
Q
What is included in the appendicular skeleton?
A
Bones of upper and lower limbs including the scapula and clavicle
5
Q
What are the functions of bones?
A
Enables movement Protection of vital organs Structural support Storage of minerals Haematopoiesis (blood cell formation)
6
Q
What is the structure of bone?
A
It has a collagen fibre framework in mucopolysaccharide semisolid gel
7
Q
What is bone hardened by?
A
Precipitation of calcium phosphate crystals (hydroxyapatite)
8
Q
What is the difference between cartilage and bone?
A
Bone is calcified
9
Q
What three components make up bone?
A
Osteoblasts, osteocytes and osteoclasts
10
Q
What is the head of the bone called?
A
Epiphysis
11
Q
What section of bone sits just below the epiphysis?
A
Metaphysis
12
Q
What is the main function of metaphysis?
A
Region of growth in childhood
13
Q
where does the blood enter the bone
A
Nutrient foramen
14
Q
What is the middle section of bone called?
A
Diaphysis
15
Q
What cells can be found in the diaphysis?
A
Fibroblasts, mesenchymal cells
16
Q
What function do mesenchymal cells have?
A
Differentiating into osteoblasts, chondrocytes
17
Q
WHat tissue surronds the shaft of compact bone?
A
Periosteum
18
Q
What are the two major kinds of bone?
A
Trabecular and Coritcal
19
Q
What is trabecular bone?
A
Spongy and porous
Gives supporting strength to the ends of weight bearing bone
20
Q
What is coritcal bone?
A
Bone on the outside, forms the shaft of the long bone, provides stiffness and strength
21
Q
How are trabeculae bones formed?
A
Along the lines of stress
22
Q
What two types of canals carry blood to the bone?
A
Haversian and Volkman’s canals
23
Q
What do Haversian canals do?
A
Cary blood along the long axis of the bone
24
Q
What do Volkman’s canals do?
A
Carry blood perpendicularly
25
What is trabecular bone home to?
Haemopoiesis, formation of blood cellular components
26
What is the composition of bone?
Mostly protein fibres- collagen
Crystallised mineral salts, hydroxyapatite
Water
ossified calcium phosphate
27
What is an osteoblast?
bone forming cell, cover the surface of bone forming an osseous matrix in which it becomes enclosed as an osteocyte
28
What is an osteoclast?
osteophage; a large, multinucleated cell derived from haematopoietic cells response to mechanical stresses and physiological demands they resorb bone matrix by demineralization
29
What is an osteocyte?
– bone cell – trapped, “retired” osteoblasts. Mature bone cells - embedded in lacunae, relatively inactive. Maintain bone matrix through cell-to-cell communication (via projections in canaliculi) and influence bone remodelling. Mechanosensing
30
What is an osteoprogenitor?
Stem cell population, gives rise to osteoblasts (but also other cells)
31
Where do osteoblasts originate from?
Osteoprogenitor cells
32
What happens when osteoblasts become stimulated?
Will deposit collage as an organic matrix then hydroxyapatite
33
What happens to osteoblasts that become entombed in stimulation?
Mature into osteocytes
34
What does osteoclasts do?
Form a "sealing zone" on bone, regulated by hormones
35
What do osteocyte communicate by
Communicate via finger-like projections in canaliculi
36
What are canaliculi?
microscopic canals between the lacunae of ossified bone
37
What are lacunae?
a cavities or depressions, especially in bone
38
What is hypertrophy?
Too much bone formation
39
What is atrophy?
Too much bone resorption
40
Why is it important to maintain an equilibrium of bone formation and resorption?
To stop developing diseases such like hypertrophy and atrophy
41
What controls the activity of osteoclasts?
Calcitonin, decreases blood calcium levels
42
What controls the activity of osteoclasts?
Parathyroid hormone
43
What are the steps in trabecular bone remodelling?
Quiescence,
resorption by osteoclasts,
surface exposed osteoprogenitors adn differentiate into osteoblasts,
osteoblasts lay down new bone
44
What are the steps in cortical bone remodelling>
Osteoclasts form a cutting cone at the resorption front
At the closing cone, osteoblasts line the osteoid
45
What is Wolff's law?
Bone adapts to the load under which it is placed
46
When bones from in a fetus, where does the cartilage model come from?
Chondroblasts
47
When the cartilage model is developed in fetuses, what process does it go under?
Ossification to create endochondral (long bones) and intramembranous (flat bones)
48
Where does ossification begin?
In the diaphysis
49
After birth, where does bone then grow from?
The epiphysis and epiphyseal plate, end of the bone
50
What is required for bone growth to occur at the epiphyseal plate?
The plate of cartilage
51
What happens at the hypertrophic zone?
swelling of chondroblasts casuses spontaneous mineralisation
52
To stop any further bone growth what happens?
The epiphyseal plates fuse with the cartilage causing no more bone growth
53
How does the body deal with fractures?
Callus formation- osteoblasts form a woven bone to bridge gap however is weak
Lamellar bone is laid down as this is stronger as the collagen is organised
54
What are the three types of cartilage?
Elastic, hyaline, fribrocartilage
55
What cells make up hyaline cartilage?
Chondrocytes
56
What gives hyaline cartilage its impact resistance?
The extracellular being filled with water
57
What gives hyaline its structure?
Proteoglycans
58
What is the long bone head called?
Trabecular
59
What is the long bone cylinders called?
Compact
60
How are compact bones arranged?
Cylindrically in Haversian systems
61
What do osteoclasts do?
Large macrophage-like cells that digest bone
62
What do osteoblasts do?
Lay down framework in bone formation
63
What is a joint?
Where two or more ones meet
64
What is the function of joints?
Facilitate growth and transmit forces
65
What are the three types of joints by movement?
Synarthroses, amphiarthroses, diarthroses
66
How do synarthrose joints move?
They don't
67
How do amphiarthroses joints move?
Slightly movable joint in which the surfaces of bones are connected by ligaments or cartilage
68
How do diarthroses joints move?
A joint that can move freely in various planes
69
How do you classify joints by soft tissue structure?
Fibrous, cartilaginous, synovial
70
What are the three types of fibrous joints?
Sutures, syndesmosis and gomphosis
71
What are suture joints?
Joints between skull vault bones
72
What are syndesmosis joints?
Fibrous membrane between long bones eg radioulnar interosseous membrane
73
What are gomphosis joints?
Peg and socket, teeth in jaw
74
What are the two types of cartilaginous joints?
Primary (synchondrosis) and secondary (symphysis)
75
What is the layering of primary cartilaginous joint?
Bone- hyaline cartilage- bone
76
What is the layering of secondary cartilaginous joints?
Bone-hyaline cartilage- fibrocartilage- hyaline cartilage- bone
77
An example of primary cartilaginous joints
First costosternal joint
78
What type of cartilaginous joint do you find epiphyseal plates?
Primary
79
Example of secondary cartilaginous joints
Joints of the sternum, intervertebral discs and pubic symphysis
80
What are synovial joints?
Joints that allow friction-free movement
81
Example of synovial joint
Knee
82
What are the features of synovial joints?
Fibrous capsule with both intrinsic and extrinsic ligaments, hyaline cartilage, synovial membrane, intra-articular disc, bursae, synovial sheaths
83
What are intrinsic ligaments?
Ligaments that are part of the capsule
84
What are extrinsic ligaments?
Ligaments that are outside the capsule
85
What does it mean being double jointed?
The ligaments are very relaxed
86
What creates the frictionless surface of joints?
Hyaline cartilage
87
What secretes the synovial fluid that lubricates the joint?
Synovial membrane
88
What is synovial fluid made out of?
Hyaluronic acid and lubricin
89
What effect does exercise have on synovial fluid?
Decreases viscosity so lubrication improves
90
What are intra-articular discs?
Discs that are found in joints where there are rotatory movements
91
What are bursae?
Closed sacs lined with synovial membrane
92
An example of a bursae?
Sits anterior to the patella
93
What are synovial sheaths?
Specialised bursae that surround tendons where they are subject to pressure
94
How many planes do ball and socket joints move?
3
95
How many planes do hinge joints move in?
1
96
What factors influence stability?
Shape of the bones, strength and position of the ligaments, tone of surrounding muscles
97
What is osteoarthritis?
Inflammation of the joints
98
What causes osteoarthritis?
Degeneracy in the articular cartilage in weight bearing joints
99
What is rheumatoid arthritis?
Inflammation in the joints caused by an autoimmune disease
100
What causes rheumatoid arthritis?
Changes in synovium lead to destruction of articular cartilage
