Histology Flashcards
1
Q
Most abundant protein in body; Made up of three α-chains
A
Collagen
2
Q
What are the relevant types of collagen for therapists?
A
Types I and II
3
Q
What tissues do type I collagen make up? [made of two alpha1 (I) and one alpha2 (I)]
A
- Dermis of skin
- Fascia
- Bone
- Fibrous cartilage
- Ligaments
- Meniscus
- Tendons
- resist tension type stress
4
Q
What tissues are made of type II collagen? [all 3 chains made of alpha1 (II)]
A
- hyaline cartilage
- elastic cartilage
- resist compression type stress
5
Q
What types of collagen form fibrils which make up connective tissues and cartilage?
A
Types I, II, and III
6
Q
What types of collagen do not form fibrils [make up basal lamina, distributed uniformly throughout connective tissue]?
A
Types IV - IX
7
Q
What make Type I collagen?
A
- Fibroblasts - tendons, ligaments
2. Osteoblasts - bone
8
Q
What make Type II collagen?
A
Chondroblasts - cartilage
9
Q
What happens within the rER?
A
- Three α-chains combine to form a triple helix; Ends are loose
- The α-chains are enzymatically altered (Hydroxylation of proline and lysine residues; Requires vitamin C; Addition of sugar groups to the α-chains)
- The triple helix is now called procollagen
10
Q
What helps the procollagen (triple helix) stay soluble so the procollagen can get out of the cell?
A
loose ends
11
Q
What happens to procollagen once it exits the cell?
A
loose ends are cut off and connect with other collagen fibers and become a fibril
12
Q
The enzymes that performs the hydroxylation of proline and lysine residues
A
hydroxylases
13
Q
What is required for the function of hydrolxylases?
A
Vitamin C
14
Q
What removes the uncoiled part from the ends of procollagen?
A
Procollagen petidase
15
Q
another name for collagen
A
tropocollagen
16
Q
What is an example of a long bone?
A
- bones that have a shaft with a space inside the shaft
1. Metacarpals
2. femur
3. tibia
4. humerus
17
Q
What are the parts of a long bone?
A
- Diaphysis - shaft
- Epiphysis - end
- Articular surfaces covered with hyaline cartilage
18
Q
What is the main function of long bones?
A
lever systems for movement
19
Q
What are examples of short bones?
A
- Carpals
2. tarsals
20
Q
What are examples of flat bones?
A
- Ribs
- scapula
- parts of pelvic girdle
- bones of skull
21
Q
What are the functions of flat bones?
A
- Muscle attachment
2. protection
22
Q
Where do short bones generally exist?
A
regions of limited movement
23
Q
What are examples of irregular bones
A
- Vertebrae
- ossicles of the ear
- function is determined by location and a specialized purpose
24
Q
Enclosed within tendons or fascial tissue
A
Sesamoid bones
25
What are examples sesamoid bones?
1. Patella
| 2. pisiform
26
What is the function of sesamoid bones?
Improve moment arms for muscles and joints (can be weight bearing
27
Collagen fiber synthesis: _____ will combine to form _____, which combine to form fibrils
Microfibrils; subfibrils
28
What are the 3 classifications of muscles?
1. Skeletal muscle
2. Smooth muscle
3. Cardiac muscle
29
AKA voluntary muscle or striated muscle; multinucleate with nuclei in periphery; under voluntary control
Skeletal muscle
40-50% body mass of adults
25% of new born
30
What is the time to peak tension of skeletal m? what is its shape of fibers?
20-100ms; Cylindrical
31
AKA visceral muscle; usually come in two layers (one longitudinal, one transverse); no striations; involuntary control, but does require innervation for contraction; one nucleus per cell, centrally located
smooth muscles
| - in cylindrical organs
32
What is the time to peak tension of smooth m? what is its shape of fibers?
400-500ms; fusiform (spindle) shaped
33
Striated muscles in the heart; involuntary and has intrinsic rate of contraction; 1 or 2 nuclei (2 in perkinje fibers)
Cardiac muscle
34
What is the time to peak tension of cardiac m? what is its shape of fibers?
150 ms; branched
35
Where two cardiac muscle fibers attach to each other; allows depolarization of one m cell to depolarize adjacent cell
intercalated disks
36
What are the special features of cardiac muscles?
1. Intrinsic mechanism for contractions
2. More mitochondria than other muscle types (Over 90% of energy derived aerobically)
3. Intercalated disks
37
Can be ribbon-like; Ex. Sartorius, gracilis, rectus abdomens; Can shorten more than other types of muscles; Weaker than fusiform muscles
Longitudinal or parallel fiber type muscles
38
spindle shaped; Thick in the middle and tapered at each end; i.e., Biceps brachii; Moderately strong contractions
Fusiform
39
convergent; Broad fibers converge to a point; Pectorals major; Moderately strong contractions
fan-shaped
40
muscle fibers come off one side of tendon – look like half a feather; i.e., Palmar interossei, semitendinosus, peroneus longus muscle
Unipennate
41
muscle fibers come off both sides of tendon – look like whole feather; i.e., Rectus femoris
Bipennate
42
multiple septa (connective tissue) in muscle which extend into the muscle attachments; i.e., Deltoid
Multipennate
43
Four sided muscles; i.e., Quadratus lumborum, Quadratus femoris, Pronator quadratus
Quadrate muscles
44
Sphincteral muscles; Close an opening when they contract; i.e., Orbicularis oculi, Orbicularis oris
circular muscle
45
structure made up of more than one type of tissue
Organ
46
What layer of connective tissue in muscle forms fascia?
epimysium
47
what parts of the neuron receive and process info? which transfers info to somewhere else?
Cell body and dendrite; axon
48
What layer of connective tissue produces fascicles?
perineurium
49
Building up and breaking down of bone
bone remodeling
50
when does bone remodeling occur? why does it occur?
all throughout life;
1. Due to the stresses placed on it throughout life
2. Helps modulate the level of calcium in blood
51
When is bone deposition > bone resorption (positive bone balance)? When is bone resorption > bone deposition (negative bone balance)?
Growing years; during old age
52
Activates osteoclasts; Increases calcium absorption in the GI tract by increasing synthesis of Vitamin D; Decreases calcium loss in kidneys
PTH
| - increases calcium in the blood
53
What factors regulate bone deposition/ resporption?
1. PTH
2. Vit D
3. Calcitonin
54
Increases calcium absorption in the gut
Vit D
55
Increases bone deposition through acting on the osteoblasts
Calcitonin
| -intranasal spray for supplementation if needed
56
Decreased calcium levels in serum results in [increase/ decrease] bone resorption and [increase/ decrease] PTH secretion
Increase; increase
57
Increased calcium levels in serum results in [increase/ decrease] bone resorption and [increase/ decrease] PTH secretion
Decrease; decrease
58
What are the purpose of Haversian systems in compact bones?
1. Bone nutrients can get in; gets waste out
| 2. So bone can adapt to changing stresses put on it
59
How nutrients travel into and waste travels out of the cell; Osteocyte processes travel out of; Connect lacunae together; Connect lacunae to Haversian canal
Canaliculi
60
Outside of bony matrix bc it makes bone
Osteoblasts
61
Encased within the bony matrix; Process nutrients to modify the haversian system
osteocytes
62
layers of bone
Lamellae
63
Connect adjacent haversian canals
Volkmann's canal
64
carry blood vessels and nerves for the bone
Haversian canal
65
What makes up the haversian system?
1. Haversian canal
2. Volkmann's canal
3. Lacunae
4. Lamellae
5. Osteocytes
6. Osteoblasts
7. Canaliculi
66
AKA trabecular bone; Lacks haversian system; Does not have concentric lamellae; Lamellae instead are arranged in bars called trabeculae which form an irregular meshwork; Pattern determined by the direction of force or stress placed on the bone
Cancellous bone
67
What are spaces between trabecular filled with?
1. Red bone marrow
2. Osteocyte-containing lacunae which are connected by canaliculi (Capillaries pass through the marrow to nourish the osteocytes)
68
Where are long bones cancellous at?
ends of the bone
69
Where is cancellous bone located?
profund to compact bone
70
What is the center of the bone called? what does it contain?
Medullary canal; red bone marrow
71
What makes blood?
Red bone marrow
72
Most children's bones have red marrow in them. Adults have a number of bones that have red marrow lessen. What is red bone marrow replaced by?
yellow marrow (fat)
73
Primitive form of connective tissue
Mesenchyme
- develops from mesoderm
- develops model of bones around 5th week
74
When do primary ossification centers appear?
7th - 12th week
| - intramembranous ossification
75
When does endochondral bone formation (ossification)begin?
6th week
76
First place we begin to form bone; Arrival of vascular connective tissue into the model brings collagen-secreting osteoblasts into the center of the future diaphysis
primary ossification center
| - The body of the model, which is ossified from the primary ossification center, becomes the diaphysis of the bone
77
By birth, the primary ossification center has almost reached the ends of the cartilage bone model; Growth of a bone no longer occurs through growth within the diaphysis; Growth occurs at the ends of bones at this region
secondary ossification center
i. e., Epiphyseal plates, growth plates
- most form after birth
78
bone distal to the epiphyseal plate
epiphysis
79
Where are osteoblasts located? osteoclasts?
Deep layers of periosteum; medullary cavity
80
one out of every three amino acids in collagen is ____. 20 % are _____ and ______.
Glycine; Proline and hydroxyproline
81
The orientation of tropocollagen molecules is staggered. Microfibers combine to form _____, which combine to form ______.
Sub fibrils; fibrils
82
For increased strength, the collagen molecules are _____ linked. A lysine residue on one collagen molecule will join to an ______ on a different collagen molecule. One enzyme involved in this is ______, a copper-containing enzyme
covalently; amino acid; Lysyl oxidase
83
What disease is due to collagen deficiencies? symptoms include abnormalities of the eyes, severe scoliosis, hyper extensibility of skin and joints, hip dislocations, short stature, increased skin elasticity
Ehlers-Dalos syndrome
