Bone - Mace (Exam 2) Flashcards
(107 cards)
1
Q
What are the types of supporting cartilages?
A
- Hyaline
- Fibrocartilage
- Elastic
2
Q
What are the types of bones (osseous CT)?
A
- Compact bone tissue
- Spongy bone tissue
3
Q
What cartilage is made of dense regular CT and anchors bone to bone?
A
Ligaments (think about the āIā as looking like a bone to help remember bone-to-bone)
4
Q
What cartilage is made of dense regular CT and anchors muscle to bone?
A
Tendons
5
Q
Cartilage is composed of semi-rigid connective tissue that is ___ (more/less) flexible than bone
A
more
6
Q
Cartilage contains a semisolid matrix. What is it composed of?
A
Ground substance, collagen, and elastic fibers, but NO calcium salt
7
Q
What component of cartilage produces matrix and surrounds themselves until they become trapped in little cavities (lacunae)?
A
Chondroblasts
8
Q
Once chondroblasts are enclosed in lacunae, what do they become?
A
Chondrocytes
B (blasts) comes before C (cytes)
9
Q
What component of cartilage is a sheath of dense irregular connective tissue that surrounds elastic and most hyaline cartilage?
A
Perichondrium
10
Q
Perichondrium contains a reserve population of ____ that contribute to cartilage growth throughout life
A
chondroblasts
11
Q
In its mature state, cartilage is ___ (no blood supply)
A
Avascular
12
Q
Since cartilage is avascular how does it receive nutrients?
A
- Diffusion - brings nutrients and removes wastes
- This is why cartilage heals slowly after damage
13
Q
What would heal more slowly - a meniscal tear or fractured bone?
A
Meniscal tear (due to being made of cartilage and decreased blood supply)
14
Q
Where are some areas that fibrocartilage is located in the body?
A
- Pelvis
- Pubic symphysis
- Intervertebral discs
15
Q
Where are some areas that hyaline cartilage is located in the body?
A
Areas of high movement:
- Ends of bones
- Connecting ribs to sternum (costal cartilage)
16
Q
What area of the body has both fibrocartilage and hyaline in the same joint?
A
Knee
(Ends of bones = hyaline and in between there are menisci = fibrocartilage)
17
Q
The center for growth in a bone occurs at?
A
The epiphyseal plate (growth plate)
18
Q
What is the most common type of cartilage?
A
Hyaline
19
Q
What type of cartilage has a glassy appearing matrix and contains invisible fine collagen fibers?
A
Hyaline cartilage
20
Q
Hyaline cartilage is usually covered by?
A
Perichondrium
(āChondrium coversā)
21
Q
Hyaline cartilage is located in areas of high movement. What are some other specific areas of the body you would find it?
A
- Tip of nose
- Trachea & bronchioles, most larynx
- Costal cartilage
- Articular cartilage
- Epiphyseal plate
- Fetal skeleton (hyaline CT can transform into bone)
22
Q
What type of cartilage contains a conspicuous weblike mesh of elastic fibers?
A
Elastic
23
Q
Elastic cartilage is covered by?
A
Perichondrium (same as hyaline)
24
Q
What type of cartilage provides flexible, elastic support in the outer ear and epiglottis?
A
Elastic
25
What type of cartilage is _not associated_ with bones?
Elastic
26
What type of cartilage contains _large, course_ parallel bundles of collagen fibers?
Fibrocartilage
27
What cartilage is _not_ covered by perichondrium?
Fibrocartilage
28
What type of cartilage _resists compression_ and _absorbs shock_ in the pubic symphysis, menisci, TMJ, and intervertebral discs?
Fibrocartilage
29
What is fibrocartilage sensitive to in particular in pregnant females?
Sensitive to hormones - in the last few weeks of pregnancy the pubic symphysis and intervertebral discs soften - allowing for more flexibility and delivery of the baby
30
What is the danger with the flexibility of fibrocartilage?
In pregnant patients - they need to be counseled regarding stretching and be careful to not overstretch as their fibrocartilage softens
31
What are the main functions of bone?
1. Support and protection
2. Movement
32
How do bones provide support and protection?
* Provide structural support
* Serve as framework for the body
* Protect many delicate tissues
* rib cage - heart & lungs
* cranial bone - brain
* vertebrae - spinal cord
* pelvis - urinary/reproductive organs/GI tract
33
How do bones provide movement for the body?
* Serve as attachment sites for skeletal muscles, soft tissue, and some organs
* Function as a system of levers, muscle contraction - exerting a pull on the skeleton
34
The process of the production of blood cells and platelets occurs in red bone marrow and is called?
Hemopoiesis
35
The red bone marrow contains what types of cells?
Stem cells that form red blood cells, white blood cells, and platelets
36
The bone contains most of the body's reserve of what two minerals?
Calcium and phosphate
37
The regulation of Ca++ in the blood stream is important for what functions?
* Nerve function
* Brain function
* Muscular contraction
38
Where are lipids stored at in some adult bones?
_Yellow bone marrow_ in shafts of bones
(When young you need to have a lot of extra blood for growth, repair, and development - as adults - not as much growth so red marrow transforms to yellow)
39
Articular cartilage at the ends of bone are?
Avascular!
40
The epiphyseal plate is in the region of mature bone between the diaphysis (shaft) and the epiphysis (two ends), which is called?
The metaphysis
41
In children the epiphyseal plate is a _thin layer_ of what type of cartilage?
Hyaline
(epiphyseal plate - often break in children)
42
In adults what does the eiphyseal plate turn into?
Epiphyseal line (remnant of epiphyseal plate, increased calcium deposit)
43
The _tough sheath_ covering the outer surface of bone is called?
Periosteum
44
The periosteum is the outer fibrous layer of bone made up of what type of cartilage?
Dense irregular CT
45
What is the function of the periosteum?
* _Protects_ bone from surrounding structures
* _Anchors_ blood vessels and nerves to bone surface
* _Attachment_ site for ligaments and tendons
46
The inner cellular layer of the periosteum includes what types of cells?
* Osteoprogenitor cells
* Osteoblasts
* Osteoclasts
47
What covers all _internal surfaces_ of bone within the _medullary cavity_?
Endosteum
48
The endosteum contains what types of cells?
* Osteoprogenitor cells
* Osteoblasts
* Osteoclasts
(Same as inner cellular layer of periosteum)
49
The periosteum is formed by what layers?
1. Fibrous (dense irregular CT)
2. Inner cellular layer (osteoprogenitor, blasts, cytes)
3. Connective fibers (connect to compact bone itself)
50
Red bone marrow is also known as myeloid tissue or hemopoietic tissue. What does red marrow contain?
* Reticular connective tissue (has matrix)
* Immature blood cells
* Fat
51
Where is red bone marrow located at in children?
* Spongy bone
* Medullary cavity of long bones
52
Where is red bone marrow located at in adults?
* Portions of the axial skeleton
* flat bones of skull, vertebrae, ribs, sternum, coxae
* Proximal epiphyses of humerus and femur
53
Yellow bone marrow is the product of red bone marrow \_\_\_\_
Degeneration
54
Yellow bone marrow is a fatty substance that may convert back to red bone marrow during what types of events?
* Severe anemia
* Starvation
55
What is the 2nd most abundant connective tissue in the body?
Bone tissue (12-15% of adult human body wt)
56
What tissue provides greater support: bone or cartilage?
Bone
57
What are the 4 types of cells in bone?
1. Osteoprogenitor cells
2. Osteoblasts
3. Osteocytes
4. Osteoclasts
58
What type of bone cells are stem cells that produce cells that differentiate into osteoblasts?
Osteoprogenitor cells
59
What type of bone cell is located in _periosteum and endosteum_ (next to medullary cavity)?
Osteoprogenitor cells
(**P**rogenitor = **P**eriosteum & endosteum)
60
What type of bone cell is positioned on bone _surfaces_ and synthesizes and secretes _osteoid_?
Osteo**_blasts_**
(**b**lasts **o**ff **o**steoid)
61
What is osteoid?
* Initial semisolid form of bone matrix (protein type gel)
* Later calcifies
62
What type of bone cell _becomes entrapped_ within the matrix they produce?
Osteo**_blasts_**
**_(_B**lasts - **B**ecome entrapped)
63
What type of bone cells are mature cells that were derived from osteoblasts?
Osteocytes
64
What type of bone cells have the ability to form lost matrix, _maintain_ the bone matrix and detect _mechanical stess_ on bone?
Osteocytes
65
What type of bone cells may trigger deposition of _new bone matrix_?
Osteocytes
66
What type of bone cells are large, multinucleated, and phagocytic?
Osteoclasts
67
What type of bone cells are derived from _fused_ bone marrow cells and are located on the bone _surface_?
Osteoclasts
68
What type of bone cells are involved in breaking down bone?
Osteo**_clasts_**
(**C**lasts **C**hew)
69
What are the organic components of bone tissue and what are the functions?
* **Osteoid** (collagen protein, proteoglycans, glycoproteins) produced by osteoblasts
* Give bone _tensile strength_ by resisting stretching
* Contribute to bone _flexibility_
(**o**steoid = **o**rganic)
70
What are the inorganic components of bone tissue matrix?
* Made of crystals of calcium phosphate called **hydroxyapetite**
* Contains calcium carbonate, sodium, magnesium ions
* Crystals deposited around collagen fibers
71
What component of the bone matrix hardens the matrix and accounts for relative rigidity of bones?
Inorganic components (hydroxyapatite)
72
There needs to be a balance of organic and inorganic substates in the bone tissue matrix and correct proportion allows for?
Optimal functioning
73
If there is _loss of protein_ in the bone tissue matrix what can occur?
Brittle bones
(ex: starvation)
74
If there is insufficient calcium in the bone tissue matrix what can occur?
Soft bones - more osteoid = bowing
(Seen in Rickets)
75
Compact bone tissue is composed of?
Osteons (Haverdian systems)
76
The basic functional and structural units of mature compact bone are?
Osteons (small cylindrical structures)
77
Osteons are oriented ___ to bone diaphysis
parallel
78
What structure of compact bone is _cylindrical_, lies at the _center_ of the osteon (runs parallel), and houses _blood vessels and nerves_?
Central canal
79
Perforating canals are also called ___ \_\_\_ and run from one osteon to another
Volkmann canals
80
What structure of compact bone houses _blood vessels and nerves_, runs _perpendicular_ to the central canals, and helps _connect_ multiple central canals within different osteons?
Perforating canals (Volkmann canals)
(**per**forating = **per**pendicular
81
Rings of matrix surrounding the central canal in compact bone are called?
Concentric lamellae
82
Rings of matrix that run immediately internal to bone periosteum are called?
_External_ circumferential lamellae
83
Rings of matrix that run internal to the endosteum are called?
_Internal_ circumferential lamellae
84
Rings of matrix _between_ osteons in compact bone are called?
**_Inter_**stitial lamellae
85
What are canaliculi?
Tiny interconnecting channels within bone connective tissue
86
What structure of compact bone _extends from each lacuna_, travels through lamellae, and connects to other lacunae and central canal?
Canaliculi
87
What structure of compact bone houses osteocyte projections permitting _intercellular contact_?
Canaliculi
88
What structure of compact bone allows the travel of nutrients, minerals, gases, and wastes _between blood vessels and osteocytes_?
Canaliculi (they do a lot - these are the ones that look like little eyelashes)
89
What type of bone tissue has **_no_** osteon?
Spongy bone
90
What type of bone tissue contains a lattice of rods and plates that are called **trabeculae**?
Spongy bone
91
What is the function of trabeculae?
* Form a meshwork of crisscrossing bars that provide great resistance to stresses
* Contain parallel lamellae, canaliculi connect lacunae, **no** central canals or perforating canals
* Space between trabeculae = filled with bone marrow
92
Bone remodeling is a continual process of bone ___ and \_\_\_
Deposition and resorption
93
What is true regarding bone remodeling?
a. stops after adolescents
b. occurs at periosteal and endosteal surfaces of a bone
c. dependent on the coordinated activities of osteoblasts, clasts, and cytes
d. occurs at the same rate in all bones
e. B & C are correct
e. B & C are correct
94
Bone remodeling continues throughout childhood and occurs at ___ rates
Different rates
* distal part of femur replaced every 4-6 months
* diaphysis of femur not completely replaced over a lifetime
* 20% of adult skeleton replaced yearly
95
The relative acitvity of osteoblasts, clasts, and cytes in bone remodeling is influenced by ___ \_\_\_ and the ___ the bones receive.
The relative acitvity of osteoblasts, clasts, and cytes in bone remodeling is influenced by _mechanical_ _stress_ and the _hormones_ the bones receive.
96
What is mechanical stress a result from?
From muscle contraction and gravitational forces (e.g. wt bearing exercise)
97
What bone cell detects mechanical stress and what events follow?
* Osteo**_cytes_** detect mechanical stress
* Communicate to osteoblasts --\> inc synthesis of osteoid (in areas of mechanical stress) --\> deposition of mineral salts
98
What hormone stimulates the liver to produce another hormone called **somatomedin**?
Growth hormone
99
What hormones stimulate growth of cartilage in the epiphyseal plate?
* Growth hormone
* Somatomedin
100
What hormone stimulates the metobolic rate of osteoblasts?
Thyroid hormone
101
What stimulates calcium deposition in bone and _inhibits_ osteoclast activity?
Calcitonin
102
What hormone causes _bone loss_ (bone resoption) by stimulating the osteoclast activity?
Parathyroid hormone
103
What hormone _stimulates osteoblast_ activity and _growth_ of the epiphyseal plate?
Sex hormones (estrogen and testosterone)
104
What increases bone loss and _impairs growth_ at the epiphyseal plates in children?
Glucocorticoids
105
What inhibits osteoprogenitor cells from differentiating into osteoblasts when there are chronically high levels?
Serotonin
106
Describe the mechanism of bone formation
1. Secretion of **osteoid**
2. _Calcification_ - when hydroxyapatite crystals are deposited
1. Ca++ and phosphate ions precipitate out, form crystals
3. Requires **Vit D (calcitriol** - active form) for enhancing Ca++ absorption from GI tract
4. **Vit C** required for _**c**ollagen formation_
5. **Ca++ and phosphate** required for _**c**alcification_
107
Describe the mechanism of bone resorption
1. Bone matrix _destroyed_ by substances made from _osteoclasts_
2. **Proteolytic enzyme** released from lysosomes in osteoclasts
3. Ca++ and phosphate _dissolved_ by **hydrochloric acid**
4. May occur when _blood Ca++ low_
