Connective Tissue Flashcards
1
Q
What is the most prominent type of tissue in the body?
A
Connective Tissue
Connective tissue is found in every organ of the body except in the nervous system.
2
Q
Where is connective tissue found in the body?
A
In every organ of the body except in the nervous system
Connective tissue provides support and connection for other tissues.
3
Q
What are the main functions of connective tissue?
A
- Provide structural support
- Connect tissues and organs
- Play a role in various physiological processes
These functions are crucial for maintaining the integrity of organs.
4
Q
How is connective tissue characterized?
A
By an abundance of extracellular material and a relative paucity of cells
This characteristic allows for the various functions of connective tissue.
5
Q
What are the two major groups of connective tissue?
A
- Connective Tissue Proper
- Special Types of Connective Tissue
Each group has distinct properties and functions.
6
Q
What is connective tissue composed of?
A
Extracellular substance or matrix, and cells
The composition allows connective tissue to perform its various roles in the body.
7
Q
What is the embryonic origin of all connective tissues?
A
All connective tissues originate from embryonic mesenchyme (Mesoderm)
In some cases, contributions of the connective tissues come from neural crest cells derived from ectoderm, particularly in craniofacial regions.
8
Q
What is another name for mucous tissue?
A
Wharton’s jelly
Mucous tissue is common in embryos.
9
Q
What characterizes mucous tissue?
A
A gelatinous consistency with an abundance of amorphous and jelly-like ground substance mainly composed of hyaluronic acid.
10
Q
Where is mucous tissue primarily found?
A
In the umbilical cord.
11
Q
What are the primary functions of mucous tissue?
A
- Acts as a protective cushion for the umbilical blood vessels by absorbing mechanical shocks
- Prevents compressions of the umbilical cord by ensuring continuous blood flow to the fetus.
12
Q
What components make up the composition of mucous tissue?
A
- Extracellular Matrix
- Proteoglycans
- Glycosaminoglycans
- Collagen Fibers
- Mesenchymal Stem Cells.
13
Q
What role do glycosaminoglycans play in mucous tissue?
A
Responsible for water retention and resilience.
14
Q
What is the role of collagen fibers in mucous tissue?
A
Provide mechanical support.
15
Q
What are the main functions of connective tissue?
A
- Envelopes muscle
- Acts as an avenue for passage of blood vessels and nerves
- Forms interior of organs and other parts of the body
- Venue for exchange of gases and substances between blood and other basic tissues
- Provide the cells for immune system
Each function plays a crucial role in maintaining the structural integrity and physiological processes of the body.
16
Q
What does connective tissue provide for the body?
A
A framework and support for organs
This includes structures like bone and cartilage.
17
Q
What is the composition of connective tissue?
A
Cells and Extracellular Matrix
The extracellular matrix includes ground substance and protein fibers.
18
Q
What are the two main components of the extracellular matrix?
A
- Ground substance
- Protein fibers
The ground substance is a medium for diffusion, while protein fibers provide structural support.
19
Q
What is interstitial fluid?
A
Filtrate of plasma through the capillary
It is highly permeable to water, electrolytes, and solutes of small masses.
20
Q
What is the major constituent of connective tissue?
A
Extracellular Matrix
This is except for blood and lymph.
21
Q
What are collagen fibers known for?
A
Providing tensile strength greater than steel and resistance to stretching
They are slightly flexible but inelastic.
22
Q
What is the composition of collagen fibers?
A
Mainly composed of collagen arranged in a triple helix structure
Collagen fibers make up approximately 25% of the body’s dry weight.
23
Q
What is the diameter range of collagen fibers?
A
2 to 10 micrometers
They collect into bundles and are distinguishable in histologic preparations.
24
Q
What is the significance of the Masson trichrome stain?
A
Differentiates connective tissue components using three colors
It stains cytoplasm red, collagen fibers blue or green, and nuclei blue to black.
25
What does Hematoxylin stain in histologic preparations?
Acidic structures such as nuclei and ribosomes
## Footnote
It usually colors these structures blue to purple.
26
What does Eosin stain in histologic preparations?
Basic structures such as cytoplasm and collagen
## Footnote
It usually colors these structures pink.
27
Fill in the blank: Collagen fibers are the most _______ fiber in connective tissue.
abundant
## Footnote
They differ in amount across various connective tissues.
28
What are the three categories of protein fibers based on their structures?
1. Fibrillar collagen
2. Sheet-forming collagen
3. Linking or anchoring collagen
## Footnote
These categories are based on the interactions of their a-chains subunits.
29
What is the most abundant and structurally significant class of collagen in the body?
Fibrillar collagen
## Footnote
It provides tensile strength, structural integrity, and support to tissues.
30
What type of collagen is responsible for providing extremely strong fibrils and is found in tendons, organ capsules, and dermis?
Type I collagen
## Footnote
It forms large, eosinophilic bundles called collagen fibers.
31
Where can Type II collagen be found?
In cartilage
## Footnote
Type II collagen is specifically associated with cartilage tissue.
32
What type of collagen is found in reticular fibers such as those in skin, blood vessels, and lymphatic organs?
Type III collagen
## Footnote
Type III collagen is important for the structure of reticular fibers.
33
What is the main characteristic of sheet-forming collagen?
Forms a mesh-like structure
## Footnote
It creates a flexible network by cross-linking its triple helices into sheetlike structures.
34
Which types of collagen are classified as sheet-forming collagen?
Type IV and Type X
## Footnote
These types interact with laminin and proteoglycans to form a basement membrane.
35
What is the role of Type IV collagen?
Major component of the basal laminae
## Footnote
It is associated with Type I and found in structures like the placenta and hair.
36
What is the function of linking or anchoring collagen?
Links fibrillar collagens to one another and to other components of the ECM
## Footnote
This category includes short collagens that provide structural connections.
37
What is the role of Type VII collagen?
Binds Type IV and anchors the basal lamina to the underlying reticular lamina
## Footnote
It provides mechanical strength in the skin and mucus membranes.
38
What is the function of Type IX collagen?
Stabilizes the collagen matrix in cartilage
## Footnote
It binds Type II collagen fibrils to ECM components.
39
What is the contribution of Type XII collagen?
Contributes to tensile strength and stability under mechanical stress
## Footnote
It plays a role in maintaining the integrity of collagen structures.
40
What is the responsibility of Type XIV collagen?
Ensures proper alignment and spacing of collagen fibrils
## Footnote
This is crucial for the structural organization of collagen in tissues.
41
What is the primary composition of elastic fibers?
Elastin and microfibrils
## Footnote
Elastic fibers are mainly composed of elastin, which provides their unique properties, and microfibrils that help maintain structure.
42
What are the properties of elastin?
Highly insoluble protein, resistant to boiling and hydrolysis by acid, alkali, and enzymes
## Footnote
Elastin is a crucial protein in elastic fibers that allows them to stretch and recoil.
43
What is the diameter of elastic fibers?
1.0 um
## Footnote
This size allows elastic fibers to branch and anastomose effectively.
44
What visual characteristics do elastic fibers have when stained?
Stains dark blue or black with special stains like Verhoeff or Orcein
## Footnote
These stains are used to highlight elastic fibers in histological studies.
45
How much can elastic fibers stretch compared to their original length?
About 1.5 times their original length
## Footnote
This property is crucial for the function of tissues that undergo frequent stretching.
46
Name three structures abundant in elastic fibers.
* Ligamenta flava
* Auricle and external elastic meatus of the ear
* External nose
## Footnote
These structures require elasticity for their function.
47
What are elastic lamellae?
Fenestrated sheets in the wall of large blood vessels, especially arteries
## Footnote
They play a key role in the ability of blood vessels to stretch and recoil.
48
What type of connective tissue are reticular fibers primarily composed of?
Collagen type III
## Footnote
This type of collagen is essential for providing structure and support in various organs.
49
What is the diameter range of reticular fibers?
0.5 to 0.2 um
## Footnote
Their fine diameter allows them to form delicate supportive networks.
50
Where can reticular fibers be commonly found?
* Liver
* Lymph nodes
* Spleen
* Hematopoietic organs
## Footnote
These locations benefit from the supportive networks provided by reticular fibers.
51
What staining characteristics do reticular fibers exhibit?
Argyrophilic and can be seen with silver stain
## Footnote
They are also positive for periodic acid Schiff staining.
52
What is the ground substance in connective tissue?
Gel-like material
## Footnote
It plays a crucial role in the extracellular matrix (ECM).
53
What are proteoglycans, and where are they mostly found?
Main structural component of ECM, found in the basement membrane of epithelial cells
## Footnote
They contribute to the gelatinous character of the ground substance.
54
What are glycosaminoglycans?
Long unbranched polysaccharides that are part of the ECM
## Footnote
They are essential for the function and structure of the ground substance.
55
Name two multi-adhesive glycoproteins in the ECM.
* Laminin
* Fibronectin
## Footnote
These glycoproteins play key roles in cell adhesion and the structural integrity of tissues.
56
What are resident cells?
Long-lived cells that permanently reside in connective tissue
## Footnote
Responsible for maintaining tissue structure and functions.
57
What are mesenchymal cells?
Multipotential stem cells of most connective tissue
## Footnote
Bound to embryo and in the umbilical cord.
58
What is the role of reticular cells?
Supportive cells in connective tissue
## Footnote
They play a role in the formation of the reticular fiber network.
59
What is a macrophage?
A type of immune cell responsible for phagocytosis
## Footnote
They help in the defense against pathogens.
60
What are fibroblasts?
Most abundant cells in connective tissue proper that produce and maintain ECM
## Footnote
They secrete and synthesize organic components of the ground substance, precursor of collagen, and elastic fibers.
61
What are fibrocytes?
Smaller, idle or resting cells that maintain the existing ECM component
## Footnote
They can be reactivated to fibroblasts.
62
What is the diameter range of adipocytes?
50 to 150 um
## Footnote
They are responsible for fat storage and insulation.
63
What is the primary function of adipocytes?
Storage of fat and lipid, production of heat, and cushioning
## Footnote
They also insulate the skin and other organs.
64
What are mast cells?
Granulated immune cells that promote allergic reactions
## Footnote
They are oval or irregular shaped and filled with basophilic granules.
65
What do mast cells contain?
Heparin, histamine, and proteases
## Footnote
These are mediators of inflammation.
66
True or False: Mast cells are derived from hematopoietic stem cells.
True
## Footnote
They are counterparts of basophils found in the blood.
67
Fill in the blank: Fibroblasts are responsible for producing _______.
Extracellular matrix (ECM)
## Footnote
They are characteristic cells in connective tissue.
68
What appearance do adipocytes have due to their large fat vacuole?
Signet ring appearance
## Footnote
The fat vacuole compresses the nucleus to the periphery.
69
What is the function of mast cells in the immune response?
Detect invasion by microorganisms and promote allergic reactions
## Footnote
They are involved in immediate hypersensitivity reactions.
70
What are visiting/transient cells?
Mobile cells that migrate in the connective tissue from the blood stream in response to specific stimuli such as injury, infection, and inflammation
## Footnote
These cells play a crucial role in the inflammatory response.
71
What are macrophages derived from?
Monocytes (bone marrow precursor)
## Footnote
Macrophages are specialized immune cells belonging to the mononuclear phagocyte system.
72
What is the primary function of macrophages?
Immune defense, tissue homeostasis, and inflammation
## Footnote
They are essential for responding to pathogens and repairing tissue.
73
What is the typical size range of macrophages?
10 to 30 um in diameter
## Footnote
Their size allows them to engulf pathogens effectively.
74
What shape is the nucleus of a macrophage?
Eccentrically located, oval or kidney-shaped nucleus
## Footnote
This shape assists in their function and mobility.
75
What are histiocytes?
Macrophages in connective tissue
## Footnote
They are key players in immune response within the tissue.
76
What are plasma cells responsible for?
Producing antibodies
## Footnote
They play a vital role in the immune response.
77
Describe the appearance of plasma cells.
Large, ovoid cells with basophilic cytoplasm
## Footnote
The basophilic nature indicates high protein synthesis activity.
78
What cellular structures are abundant in plasma cells?
Rich in RER and large Golgi apparatus near the nucleus
## Footnote
These structures are essential for antibody production.
79
What is the typical shape of a plasma cell's nucleus?
Generally spherical but eccentrically placed
## Footnote
This placement is characteristic of active cells.
80
How do leukocytes enter connective tissue?
By migrating between endothelial cells lining venules (diapedesis)
## Footnote
This process is crucial for the immune response.
81
What happens to leukocytes during inflammation?
Their numbers increase greatly
## Footnote
This is part of the body's defense mechanism.
82
What is the function of leukocytes in connective tissue?
Defensive response to injury or foreign substances
## Footnote
They are part of the vascular and cellular defense mechanisms.
83
How long do leukocytes typically function in connective tissue?
Only for a few hours or days
## Footnote
They undergo apoptosis after their role is fulfilled.
84
What is Loose Connective Tissue also called?
Areolar tissue
## Footnote
Forms a layer beneath the epithelial lining of many organs and fills spaces between fibers of muscle and nerve.
85
Where can Loose Connective Tissue be found?
* Hypodermis
* Tunica adventitia of blood vessels
* Lamina propria and submucosa of digestive tract
* Respiratory and genital tracts
## Footnote
Supports structures that are normally under pressure and low friction.
86
What is the primary function of Adipose Tissue?
Reserve energy rich materials
## Footnote
During inadequate caloric intake, stored energy is released in the form of fatty acids.
87
What distinguishes White Adipose Tissue?
* Most common in adults
* Signet ring cells
* Unilocular
* Specialized for long term energy storage
## Footnote
Contains triglycerides stored in a single large droplet.
88
What is a characteristic of Brown Adipose Tissue?
* Energy reserve with no insulating function
* Most commonly found in infants
* Multilocular
* Helps mediate heat production via thermogenesis
## Footnote
Contains small lipid inclusions.
89
What type of collagen fibers are abundant in Reticular Tissue?
Type III collagen
## Footnote
Provides a framework with specialized microenvironments for cells in hemopoietic tissue and some lymphoid organs.
90
Where can Reticular Tissue be found?
* Bone marrow
* Liver
* Pancreas
* Adrenal glands
* All lymphoid organs except the thymus
## Footnote
Contains abundant fibers of Type III collagen.
91
What characterizes Dense Connective Tissue?
* Fewer cells, mostly fibroblasts
* Bundled Type I collagen fibers predominating over ground substance
## Footnote
Offers resistance and protection.
92
What defines Dense Regular Connective Tissue?
* Type I collagen bundles arranged according to a definite pattern
* Collagen fibers aligned with fibroblasts
* Offers great resistance to traction forces
## Footnote
Examples include tendons, aponeurosis, ligaments, and corneal stroma.
93
What is the structure of Dense Irregular Connective Tissue?
* Collagen fibers appear randomly interwoven
* No definite orientation
* Forms a 3-dimensional network
## Footnote
Provides resistance to stress from all directions.
94
Where can Dense Irregular Connective Tissue be found?
* Deep dermis layer of skin
* Capsules surrounding most organs
* Periosteum of bones
* Dura mater
## Footnote
Offers protection and support to various structures.
95
What is the primary function of cartilage?
Durable form of supporting connective tissue
## Footnote
Cartilage provides structural support and flexibility to various parts of the body.
96
What type of cells are found in cartilage?
Chondrocytes
## Footnote
Chondrocytes are the specialized cells responsible for the maintenance and synthesis of the cartilaginous matrix.
97
What is characterized by an increase in glycosaminoglycans and proteoglycans?
Extracellular matrix (ECM) concentration
## Footnote
The ECM concentration allows cartilage to withstand mechanical stress without permanent distortion.
98
What is the most common type of cartilage?
Hyaline cartilage
## Footnote
Hyaline cartilage is known for its smooth and low-friction surfaces in joints.
99
What type of collagen is predominantly found in hyaline cartilage?
Type II collagen
## Footnote
Type II collagen is essential for the structural integrity of hyaline cartilage.
100
What role does hyaline cartilage play in adults?
Provides smooth, low-friction surfaces in joints
## Footnote
This function is crucial for facilitating movement and reducing wear in joint surfaces.
101
What does hyaline cartilage form in embryos?
Temporary skeleton
## Footnote
The temporary skeleton formed by hyaline cartilage is gradually replaced by bone during development.
102
Give an example of where hyaline cartilage can be found.
* Articular cartilage
* Costal cartilage
* Nasal cartilage
* Trachea and bronchi
* Embryonic skeleton
## Footnote
These examples illustrate the diverse locations where hyaline cartilage is essential for structure and function.
103
What is a lacuna in the context of cartilage?
Cavity in the matrix holding chondrocyte
## Footnote
Lacunae are small spaces within the cartilage matrix that house the chondrocytes.
104
How do chondrocytes in hyaline cartilage appear?
Spherical and isolated or small in isogenous groups
## Footnote
This arrangement helps maintain the integrity and function of the cartilage.
105
What type of cartilage is highly bendable?
Elastic cartilage
## Footnote
Elastic cartilage is known for its flexibility and resilience.
106
What fibers are found in the matrix of elastic cartilage?
Elastic fibers and Type II collagen fibers
## Footnote
This composition allows elastic cartilage to return to its original shape after bending.
107
What is the primary function of fibrocartilage?
Provides cushioning, tensile strength, and resistance to tearing and compression
## Footnote
Fibrocartilage is crucial in areas that experience significant mechanical stress.
108
Give an example of fibrocartilage.
* Intervertebral disk
* Pubic symphysis
* Menisci of the knee
* Temporomandibular joint
## Footnote
These examples highlight the role of fibrocartilage in joints and connective tissues that require durability and support.
109
What are the primary functions of bones?
Support, movement, mineral storage
## Footnote
Bones provide a framework for the body, facilitate movement, and store important minerals like calcium and phosphorus.
110
What are the main components of bone?
Bone Matrix, Osteocytes, Osteoblasts, Osteoclasts
## Footnote
Osteocytes are found in cavities, osteoblasts are growing cells, and osteoclasts are giant multinucleated cells involved in bone resorption.
111
What percentage of total bone mass does compact bone represent?
80%
## Footnote
Compact bone, also known as cortical bone, is denser and forms the outer layer of bones.
112
What is the functional unit of compact bone?
Osteon
## Footnote
Osteons are cylindrical structures that contain a central canal and are absent in spongy bone.
113
What are lamellae in the context of compact bone?
Concentric tubes
## Footnote
Lamellae are layers of bone matrix that form the structure of osteons.
114
How does nutrient diffusion occur in compact bone?
From vessels in the central canal
## Footnote
Nutrients diffuse through the canal to reach osteocytes.
115
What structural feature of compact bone increases resistance to twisting forces?
Alternating direction of collagen fibers
## Footnote
The arrangement of collagen fibers within lamellae helps to provide strength.
116
What is the Haversian System?
Complex of concentric lamellae surrounding a central canal
## Footnote
The Haversian system contains blood vessels, nerves, loose connective tissue, and endosteum.
117
What percentage of total bone mass does spongy bone represent?
20%
## Footnote
Spongy bone, also known as cancellous bone, is less dense and found at the ends of long bones and in the interior of others.
118
What is spongy bone called when it is found in flat bones?
Diploe
## Footnote
Diploe refers to the internal structure of flat bones, consisting of two layers of compact bone surrounding spongy bone.
119
What are trabeculae in spongy bone?
Interconnected thin spicules
## Footnote
Trabeculae form a lattice-like structure that provides support and houses bone marrow.
120
Fill in the blank: The cells responsible for bone formation are called _______.
Osteoblasts
## Footnote
Osteoblasts play a crucial role in building new bone tissue.
121
True or False: Osteons are found in spongy bone.
False
## Footnote
Osteons are a feature unique to compact bone.
122
What is blood?
Fluid within blood vessels
## Footnote
Blood is considered an atypical connective tissue.
123
Why is blood classified as connective tissue?
It develops from mesenchyme and consists of blood cells, surrounded by a nonliving fluid matrix called blood plasma.
## Footnote
Blood does not connect things or provide support like typical connective tissue.
124
What is the nonliving fluid matrix of blood called?
Blood plasma
## Footnote
Plasma surrounds the blood cells.
125
What are the main components of blood?
* Red blood cells (erythrocytes)
* White blood cells (leukocytes)
* Platelets (thrombocytes)
## Footnote
These components are suspended in blood plasma.
126
What is the primary function of blood?
Transports gases, nutrients, wastes, and other substances.
127
Where is blood located?
Within the blood vessels.
128
What is the function of erythrocytes?
Transport oxygen.
129
What is the role of thrombocytes?
Hemostasis and/or blood clotting.
130
What are the types of leukocytes?
* Neutrophils
* Lymphocytes
* Monocytes
* Eosinophils
* Basophils
## Footnote
Each type has a specific function in the immune response.
131
What is the function of neutrophils?
Fight bacterial infections.
132
What is the role of lymphocytes?
Cellular immunity and antibodies.
133
What do monocytes differentiate into?
Macrophages.
134
What is the function of eosinophils?
Combat parasitic infections and allergic reactions.
135
What do basophils release during allergic reactions?
Histamine.
