Connective Tissue🧩 Flashcards
Fill in the gaps:
Connective Tissue has ____________ depending on ____________ of the tissue.
Connective Tissue has a diverse structural arrangement depending on location and function of the tissue
What is the most abundant tissue within the human body and why?
Connective Tissue
- Because connective tissues constitute a proportion of all of our organs
What is a general rule of thumb for the function of connective tissue?
function of connective tissues is to provide structural and/or functional support to the other tissues and organs that they comprise.
What are all the functions of connective tissues?
-Provide structural and functional support
-Supportive an connective framework- holds everything in place whilst providing flexibility and movement
-Other functions;
Energy Storage
Organs Protection
Structural Integrity
Give examples of connective tissues
- Bone (structural integrity)
- Cartilage (protect joints, structural integrity)
- Tendons and ligaments (connect muscle to bone, protect joints)
- Adipose tissue (energy storage)
- Mesentery (connects intestine to abdomen)
- Layers under skin and around organs (support )
Since these connective tissues perform different functions, each will have a different structural arrangement that reflects and supports their function
For a tissue to be classified as connective tissue, it must have what 3 main components?
-Ground Substance
-Fibres
-Cells
What makes up the extracellular matrix
-Ground Substance
-Fibres
Are the three main components of connective tissue (Ground Substance, Fibres, Cells) similar?
Each of these three components can differ tremendously depending on the function of the tissue
What is the structure of connective tissues like?
Composed of cells surrounded and separated from each other by the extracellular matrix
How does the Structure of connective tissues contrast with epithelial tissue structure?
In epithelial tissues, their cells are tightly anchored to each other to form a barrier, but the cells in connective tissue are not typically in direct contact with each other.
Expand on this Diagram
- Cells separated by extracellular matrix (ECM)
- ECM provides structural and biochemical support for cells
- Most of the mass of connective tissues comes from the extracellular matrix
What is the structure of the extracellular matrix
Is composed of two components:
- Fibres
- Ground Substance
What is ground substance like?
a semi- solid gel (like jelly)
-Its full of water
-lacks structural Integrity
Since ground substance lacks structural integrity, what is integrity of the extracellular matrix provided by?
Fibres
How is structural integrity of the extracellular matrix provided by fibres?
-These fibres can come in a variety of different arrangements
-Can criss-cross through the tissue to provide a supporting framework for both the ground substance and the cells
What does ground substance provide?
-Biochemical Support to tissue
-Tissue Volume
-Compression Resistance- If body is squished or damage, tissue absorbs some of the impact
What is ground substance composed of?
*Composed of glycoproteins and complex carbohydrates e.g.
-Hyaluronic acid
-Glucosamine,
What can ground substance bind to?
-Water
-Has a profound water binding ability, as it is a water like gel
What does ground substance support?
intercellular exchange of substances- exchange of substances between cells
What is the function of fibres?
Provide Structural Support and tensile strength
What are the two types of fibres?
-Collagen
-Elastin
Describe collagen fibres?
strongest and most abundant, provide tensile strength
Describe elastin fibres?
long and branched, provide stretch and recoil ability to tissue.
How are collagen fibres secreted?
- Secreted into ECM by connective tissue cells
What is collagen composed of?
-Subunits (fibrils), which are made up of myofibrils
-Fibrils are rope-like structures that are long and thin
-How many different types of collagen have been identified?
-What are the most common types?
-At least 28 different types
-Most tissue are types I-IV (1-4)
Where is type I collagen found? describe its arrangement?
found in fibrous tissues (dermis of skin, tendons, ligaments, bone)
-Irregular arrangement which provides strength in multiple directions
Where is type II collagen found?
Hyaline Cartilage
What colour does Type I collagen stain with H&E
Pink
What is type III collagen and where is it found?
-Delicately branched reticular fibres
-Supporting networks found in highly cellular organs e.g. Lymph Nodes and Liver
What does Type IV collagen do and where is it found?
-Forms Network
-Found in basement membranes
Where is elastin synthesised and secreted?
Synthesised and secreted into ECM by connective tissue cells
What is the function of elastin fibres?
Confers elasticity to tissues
Where is elastin found in large amounts?
-Skin
-Blood Vessels
-Lungs
-Bladder
(Wherever the tissue need to stretch and recoil)
How does elastin stain with H&E?
eosirphilic (pink)
What is the function of the cells in connective tissues?
to synthesise, secrete and recycle ECM
What are the 3 categories of cell found in connective tissue and their function?
**blasts – synthesise ECM
**cytes – maintain ECM
***clasts – breakdown ECM
The full name of cells in connective tissues come from what
Where they come from (1st part)
Function (2nd part)
What are fibroblasts and what are their function?
-Most common connective tissue cell type
-Secrete fibres and components of ground substance
What do odontoblasts do?
Synthesise dentine in teeth
What do chondrocytes do?
-Secrete and maintain ECM in cartilage
What do adipocytes do?
maintain ECM in adipose tissue
What do osteoclasts do?
recycle (breakdown) ECM in bone
What do osteoblasts and osteocytes do?
Osteoblasts Secrete and maintain mineralised ECM in bone
Unlike epithelium, what are connective tissues?
are highly vascularised, contain lots if blood and lymph vessels that run through the tissue
- Contain blood vessels and lymphatic’s
- Contain immune cells that survey tissues for invading pathogens/cell damage
What are the exceptions to vascularisation of connective tissue?
Exception – cartilage, tendons and ligaments have no or fewer blood vessels
So if these tissues get damaged they either take a long time to repair (as in the case of tendons and ligaments) or they’re not going to repair or regenerate (as in the case of cartilage)
What are 3 classifications of connective tissue?
-Connective tissue proper
-skeletal connective tissues
-fluid connective tissues
What connective tissues are classified as connective tissue proper?
- Broad category of diverse structure and functions
- Have Loose or dense depending on arrangement of fibres
What connective tissues are classified as skeletal?
- Cartilage
- Bone
What connective tissues are classified as fluid (off classification)?
- Blood
- Lymph
CONNECTIVE TISSUE PROPER connective tissues can be divided into what two categories?
-Describe what each category is like
-LOOSE- Mostly ground substance, fewer fibres
-DENSE- Mostly fibres, less ground substance
Loose connective tissue proper can further divided into what three classifications
-Areolar tissue
-Adipose tissue
-Reticular tissue
Describe Areolar Tissue (type of loose connective tissue proper)
-What is it and its function?
-Where is it found?
Universal packing material – supports and binds other tissues
Found beneath skin, submucosa, surrounding capillaries
Describe Adipose Tissue(type of loose connective tissue proper)-
What is it and its function?
-Where is it found?
-Functions include, energy storage, shock absorption, insulation
-Found deep beneath skin, breasts, in the abdomen, finger and foot pads
What is adipose tissue composed of?
Adipocytes- found in isolation or in small clusters
Describe Reticular Tissue (type of loose connective tissue proper)
-What is it and its function?
-Where is it found?
-Delicate, branched network (type III collagen)
-providing internal structure to highly cellular organs (liver, lymph nodes, spleen)
What 3 classifications can dense connective tissue proper be divided into?
-Dense regular
-Dense irregular
-Elastic
What 3 classifications can dense connective tissue proper be divided into?
-Dense regular
-Dense irregular
-Elastic
What is Dense irregular tissue and where is it found?
(Type of Dense connective tissue proper)
-Closely, packed interwoven fibres running in different directions
-Found in dermis of skin, forms protective capsule around organs
What is Dense regular tissue and where is it found?
(Type of Dense connective tissue proper)
Closely, packed collagen fibres running in same direction
Provides tensile strength – found in tendons and ligaments.
What is elastic tissue and where is it found?
(Type of Dense connective tissue proper)
-Dense regular tissue dominated by elastic fibres
-Allows tissues to recoil after stretching
-Found in arteries, skin, lungs and underlying transitional epithelium
Name 3 Connective tissue disorders with oral manifestations
-Scurvy
-Systemic Lupus Erythematosis (SLE)
-Sjogren’s
What is scurvy caused by?
What does it lead to?
-lack of vitamin C, leading to defective collagen formation
- Loose teeth, skin haemorrhages, potential death
What is scurvy caused by?
What does it lead to?
-lack of vitamin C, leading to defective collagen formation
- Loose teeth, skin haemorrhages, potential death
Why is vitamin C important?
Vit C is a co-factor required for collagen synthesis
What is the structure of vitamin C and how does it arise
-triple-helical structure
-arises from an unusual abundance of three amino acids:
Glycine
Proline
Hydroxyproline
What happens without the structural support of collagen?
blood vessels, tendons, and skin become fragile.
Systemic lupus Erythmatosis (SLE)
What is it?
What are the target tissues?
Symptoms?
Oral Manifestations?
-Autoimmune disease – autoantibodies target host tissues
-Target tissues include, skin, bones, tendons, kidneys
-Oral symptoms include dryness and soreness
-Oral manifestations include buccal and palatal lesions
Sjogren’s
What is it?
Symptoms?
Oral Manifestations?
How can it occur?
-Autoimmune disease – autoantibodies affects glands that produce tears and saliva
-Symptoms include dry eyes and mouth
-Oral manifestations include increased dental caries and candidiasis
-Can occur independently or accompany other disorders, such as, SLE or rheumatoid arthritis
