Unit 3 Part 1 Flashcards
(133 cards)
1
Q
made up of several different tissues working together: bone, cartilage, dense connective tissue, epithelium, various blood forming tissues, adipose tissue, and nervous
tissue.
A
Bone
2
Q
Skeletal System Functions
A
▪ Makes up body framework - gives body shape
▪ Supports the body
▪ Protects vital internal organs
▪ Assistance in movement
▪ Mineral homeostasis (storage and release)
▪ Blood Cell production
▪ Triglyceride storage
3
Q
Classification of Bones is according to:
A
shape
location
structure
development
4
Q
Classification of Bones According to Shape
A
long
short
flat
irregular
sesamoids
sutural
5
Q
– longer than wide
– Have a shaft with heads at both ends
– Contain mostly compact bone
A
Long Bones
6
Q
Examples of long bone
A
Femur, humerus, tibia,
fibula, radius, ulna, phalanges (all
bones of the limbs except the knee
cap or patella)
7
Q
- Shaft
- Composed of compact bone
A
Diaphysis
8
Q
- Ends of the bone
- Composed mostly of spongy bone
A
Epiphysis
9
Q
- Outside covering of the diaphysis
- Fibrous connective tissue membrane
A
Periosteum
10
Q
- Secure periosteum to
underlying bone
A
Sharpey’s fibers
11
Q
- Supply bone cells with
nutrients
A
Arteries
12
Q
– Covers the external surface of the epiphyses
– Made of hyaline cartilage
– Decreases friction at joint surfaces
A
Articular cartilage
13
Q
– Cavity of the shaft
– Contains yellow marrow (mostly fat) in adults
– Contains red marrow (for blood cell formation) in infants
A
Medullary cavity
14
Q
formation of blood cells
A
hematopoiesis
15
Q
formation of blood cells takes place mainly in
A
red marrow
16
Q
In infants, red marrow is found in the
A
bone cavities
17
Q
Red marrow functions
A
formation of red blood cells, white blood cells
and blood platelets
18
Q
– cube-shape
– Contain mostly spongy bone with thin coat of
compact bone
A
Short Bones
19
Q
example of short bones
A
carpals (wrist), tarsal (ankle) bones
20
Q
– Irregular in shape, weird shapes
– Do not fit into other bone classification
categories
A
Irregular Bones
21
Q
examples of irregular bones
A
Vertebrae, hip bones, 2 skull bones (sphenoid
and the ethmoid bones)
22
Q
Develop in certain tendons where there is considerable
friction, tension and physical stress
A
Sesamoid bones
23
Q
-Located in sutures between certain cranial bones
A
Sutural bones
24
Q
Structure of Short, Irregular, and Flat Bones
A
-Thin plates of periosteum-covered compact bone on
the outside and endosteum-covered spongy bone
within.
- Have no diaphysis or epiphysis
-Contain bone marrow without marrow cavity
25
internal spongy bone layer
diploë
26
whole arrangement of flat bone resembles a
stiffened sandwich
27
form the long axis of the body
Axial
28
number of bones in axial
80
29
Involved in locomotion and manipulation of the environment
appendicular
30
number of bones in upper extremities
64
31
number of bones in lower extremities
62
32
connective tissue as seen by widely spaced cells separated by matrix
osseus tissue/bone
33
4 types of cells in bone tissue
Osteogenic/Osteoprogenitor Cells
Osteoblasts
Osteocytes
Osteoclasts
34
* undergo cell division
* undifferentiated/unspecialized bone cells derived from mesenchyme
* become osteoblasts
* found in the inner lining of the endosteum and periosteum
Osteogenic/Osteoprogenitor Cells
35
* Bone-building cells
* Cannot divide
* Form matrix and collagen fibers
* Synthesize and secrete collagen fibers and proteoglycans, glycoproteins
* Collagen forms osteoids
* Influence deposit of Ca++, PO4 (initiate calcification)
* Estrogen, PTH stimulate activity
* Found in both the periosteum and endosteum
Osteoblasts
36
strands of spiral fibers that form matrix
osteoids
37
* Mature bone cells that sit in lacunae and the
principal cells of bone tissue
* Osteoblasts that have become trapped by the secretion of matrix
* No longer secrete matrix
* Responsible for maintaining the bone tissue; long lived cells
* Stimulated by calcitonin; inhibited by PTH
* Osteocyte is “trapped” within the pink matrix
Osteocytes
38
* derived from the fusion of monocytes – engulf bony material
* Cells that digest bone matrix
* Secrete enzymes (digestive enzymes) that digest matrix
* Active osteoblasts stimulate its activity
* Concentrated in the endosteum
pumps out hydrogen ions to create an acid environment that eats away at the matrix.
Osteoclasts
39
* 25% Water
* 25% Protein or organic matrix
* 90% Collagen Fibers
* 10% Chondroitin Sulfate, small proteogylcans, glycoproteins (osteonectins)
* 50% Crystalized Mineral Salts
* Hydroxyapatite (Calcium Phosphate)
* Other substances: Bicarbonate, magnesium,
potassium, sodium, Lead, Gold, Strontium,
Plutonium, etc.
Extracellular Matrix
40
provide bone’s hardness and the ability to resist compression
Inorganic mineral salts
41
provide bone’s flexibility
Organic collagen fibers
42
Bone Tissue - Matrix
– compact bone has very few such spaces
– spongy bone has many such spaces
43
-solid mass; dense & hard
-forms the outer layer of bone structure
-functional unit --- Haversian system
Compact bone
44
contain spaces filled with bone marrow
= incomplete Haversian system
Cancellous or Spongy
45
good at providing protection and support
Compact bone
46
lightweight and provides tissue support
Spongy bone
47
Compact bone is arranged in units called
osteons or Haversian systems
48
contain blood vessels, lymphatic vessels, nerves
Osteons (Haversian canal)
49
what surrounds haversian canal
concentric rings of osteocytes
calcified matrix
50
concentric ring of matrix lacuna-openings
between lamellae for osteocytes;
represent older osteons
Lamella
51
mature bone cell; found in lacunae
Osteocytes
52
in center of lamella; houses vessels; vertically oriented
Haversian canal
53
radiating channels between lacuna
and Haversian canal for nutrients and wastes
Canaliculi
54
crosswise canals from Haversian canal to exterior containing blood vessels and nerves
Volkmann canal
55
does not contain osteons.
consists of trabeculae surrounding many red marrow filled spaces
forms most of the structure of short, flat, and irregular bones, and the epiphyses of long bones
Spongy bone
56
Latticework of thin plates of bone
Found in ends of long bones and inside flat bones such as the hipbones, sternum, sides of skull, and ribs.
trabeculae
57
enter the diaphysis through Volkmann’s canals
accompanied by nerves
Periosteal arteries
58
enters the center of the diaphysis through a nutrient foramen.
nutrient artery
59
All embryonic connective tissue begins as
mesenchyme
60
bone tissue formation;
begins when mesenchymal cells provide the template for subsequent ossification.
Osteogenesis (ossification)
61
Stages of bone development
– Bone formation
– Postnatal bone growth
– Bone remodeling and repair
62
bone development that begins in the 2nd month of
development
bone formation
63
bone development until early adulthood
postnatal bone growth
64
lifelong bone development
Bone remodeling and repair
65
Bones form in 4 situations
* embryological and fetal development
* grow before adulthood
* remodel
* fractures heal
66
Two Types of Ossification
Intramembranous ossification
Endochondral ossification
67
-Membrane bone develops from fibrous membrane
- Forms flat bones
-Dermal ossification
-A connective tissue membrane is replaced by bone
Intramembranous ossification
68
normally occurs in the deeper layers of connective tissue of the dermis of the skin.
dermal/intramembranous ossification
69
intramembranous ossification process
Ossification centers appear in the fibrous connective tissue membrane.
Calcification
Formation of trabeculae
Development of periosteum
70
-replacement of cartilage by bone and forms most of the bones of the body
- development of the cartilage model.
-Begins in the second month of development
-Uses hyaline cartilage “bones” as models for bone construction
-Requires breakdown of hyaline cartilage prior to
ossification
Endochondral Ossification
71
Endochondral Ossification process
development of cartilage model
growth of cartilage model
development of primary ossification center
development of medullary(marrow) cavity
development of secondary ossification center
formation of articular cartilage and epiphysial plate
72
Bones grow in thickness
appositional growth
73
bones lengthen by the addition of bone material on the diaphyseal side of the epiphyseal plate
interstitial growth.
74
layer of hyaline cartilage in the metaphysis of a growing bone
Epiphyseal plate
75
important functional zones of Epiphyseal plate
– resting cartilage
– proliferating cartilage
– hypertrophic cartilage
– calcified cartilage
76
* nearest the epiphysis and consists of small, scattered chondrocytes.
* The cells do not function in bone growth; they anchor the epiphyseal plate to the epiphysis of the bone.
Zone of Resting Cartilage
77
* Slightly larger chondrocytes are arranged in stacks
* These chondrocytes undergo interstitial growth
* The chondrocytes in this zone divide to replace those that die
Zone of Proliferating Cartilage
78
* Consists of large maturing chondrocytes
arranged in columns
Zone of Hypertrophic Cartilage
79
* Only a few cells thick and consists mostly of
chondrocytes that are dead
* Osteoclasts dissolve the calcified cartilage, and
osteoblasts and capillaries from the diaphysis invade
the area.
* The osteoblasts replace the calcified cartilage
*becomes the new diaphysis that is firmly cemented
Zone of Calcified Cartilage
80
cartilage is replaced by bone on the
diaphyseal side of the plate.
81
the epiphyseal plates closes at what age
18 in females, 21 in males
82
With the appearance of the ___,
bone growth in length stops completely.
epiphyseal line
83
gradual process and the degree to which it occurs is useful in determining bone age, predicting adult height, and establishing age at death from skeletal remains, especially in infants, children, and adolescents.
Closure of the epiphyseal plate
84
healing process of fracture involves 3 different phases in 4 steps
-reactive phase is an early inflammatory phase.
-reparative phase: fibrocartilaginous callus formation
-reparative phase: bony callus formation.
-bone remodeling phase
85
Factors Affecting Bone Growth
* Minerals
* Vitamins
* Hormones
* Exercise
* Aging
86
- Makes bone matrix hard, bone
growth
Calcium
87
low blood calcium levels
Hypocalcemia
87
low blood calcium levels
Hypocalcemia
88
high blood calcium levels.
Hypercalcemia
89
Makes bone matrix hard, bone growth
Phosphorus
90
- Controls activity, distribution, and
coordination of osteoblasts/osteoclasts
Vitamin A
91
- For protein synthesis
Vitamin B12
92
Helps maintain bone matrix, deficiency leads to decreased collagen production
Vitamin C
93
disorder due to a lack of Vitamin C
Scurvy
94
Helps build bone by increasing calcium absorption from foods in the GIT; “Rickets an osteomalacia" disease
Vitamin D(Calcitriol)
95
For protein synthesis
Vitamin K
96
Promotes general growth; stimulates epiphyseal plate
activity
97
Stimulate osteoblasts, promote cell division at the
epiphyseal plate and in the periosteum, and enhance synthesis of the proteins needed to build new bone.
insulin-like growth factor
98
Promotes normal bone growth and
maturity by increasing synthesis of proteins.
Insulin
99
Promotes normal bone growth and maturity (stimulates osteoblasts); modulates activity of growth hormone
Thyroid Hormones
100
Increases osteogenesis at puberty and is
responsible for gender differences of skeletons;
End growth by inducing epiphyseal plate closure
Estrogen and Testosterone
101
increases osteoclast activity leading to bone resorption
and increase blood calcium
Parathyroid hormone (PTH)
102
hormone from the thyroid gland that increases the deposition of calcium by osteoblast and thus lowering blood calcium level
Calcitonin
103
loss of minerals
demineralization
104
decrease in protein
decrease in :
growth hormone
collagen production
bones become brittle and susceptible to fracture
105
ongoing replacement of old
bone tissue by new bone tissue
Bone Remodeling
106
Occurs where bone is injured or added
strength is needed
Bone Deposition
107
* Accomplished by osteoclasts
* Secretion of:
– Lysosomal enzymes that digest organic matrix
– Acids that convert calcium salts into soluble forms
* Dissolved matrix is transcytosed
Bone Resorption
108
– grooves formed by
osteoclasts as they break down bone matrix
Resorption bays
109
Calcium
most abundant essential mineral in the human body
110
range of calcium in adult
8.6 to 10.3 mg/dL.
111
amount of calcium
99% in the bone and teeth.
1% is in the extracellular fluid and blood
112
reservoir for calcium and phosphate
skeleton
113
Calcium is necessary for
– Transmission of nerve impulses
– Muscle contraction
– Neurotransmitter and hormone release
– Blood coagulation
– Enzyme function
– Secretion by glands and nerve cells
– Cell division
– Membrane integrity and permeability
114
high changes in blood levels of calcium
Cardiac arrest
115
low changes in blood levels of calcium
Respiratory arrest
116
2 hormones that
antagonistically maintain blood [Ca2+] at
homeostatic levels
Parathyroid hormone
and calcitonin
117
Calcium regulation three tissues:
Bone ,intestine and kidney
118
three hormones
Parathyroid hormone, calcitonin, and activated vitamin D
119
* Secreted if blood calcium falls.
* It acts on bone, kidney and intestine.
Parathyroid Hormone
120
PTH decreases urinary Ca2+ excretion
and increases urinary phosphate excretion.
kidney
121
PTH increases calcitriol (active
form of Vitamin D) synthesis which increases
Ca2+ absorption in the small intestine
intestine
122
INCREASES BLOOD CALCIUM LEVELS
parathyroid hormones
123
Secreted from parafollicular cells of thyroid
If blood calcium gets too high, --- “tone down” blood calcium levels.
-inhibits osteoclast activity
-Stimulates osteoblast activity .
Calcitonin
124
DECREASES BLOOD CALCIUM LEVELS
calcitonin
125
A lipid soluble vitamin.
PTH stimulates --- synthesis
can be acquired from 2 sources
Vitamin D
126
stimulate absorption of Ca2+ from the intestine.
acts on osteoblasts
stimulates osteocytic osteolysis
1,25-(OH)2-D
127
“thy” up “high”
Parathyroid hormone (PTH)
128
- tone Ca++ down
-Ca++ come “on in”
Calcitonin
129
- tri to rise Ca ++
Calcitriol
130
At birth, most long bones are well ossified
except __
epiphyses
131
Bone mass decreases with age beginning in
4th decade
132
bone resorption predominates at
old age
