Connective Tissue Flashcards
What is the most abundant of the 4 tissue types?
Connective tissue
What is meant by connective tissue having ‘diverse’ structure and functions?
- Energy storage
- Organ protection
- Structural integrity
What are examples of connective tissue?
- Bone
- Cartilage
- Tendons and ligaments
- Adipose tissue
- Mesentery
- Layers under skin and around organs
What is the function of bone?
Structural integrity
What is the function of cartilage?
- Protects joints
- Structural integrity
What is the function of tendons and ligaments?
- Connects muscles to bone
- Protects joints
What is the function of adipose tissue?
Fat storage
What is the function of mesentery?
Connects intestine to abdomen
What is the function of connective tissue layers under the skin and around organs?
Support
What are the 3 main components of connective tissues?
- ECM:
- Ground substance
- Fibres
- Cells
What is the function of ECM?
Provides structural and biochemical support for cells
What is ECM composed of
Ground substance and fibres
What is the function of ground substance?
- Provides biochemical support
- Profound water-binding ability
- Provides tissue volume
- Supports intercellular exchange of substances
What is the composition of ground substance?
- Clear, semi-solid gel
- Composed of glycoproteins and complex carbohydrates
- hyaluronic acid
- glucosamine
What do fibres in ECM do?
Provide structural support and tensile strength
What are the 2 main types of fibres in ECM?
- Collagen (strongest and most abundant, provide tensile strength)
- Elastin (long and branched, provide stretch and recoil ability)
How many types of collagen are there and what are the first 3 types?
28 different types
- Type I: found in fibrous tissues (dermis of skin, tendons, ligaments, bone)
- Type II: Hyaline cartilage
- Type III: delicate branches ‘reticular’ network found in highly cellular organs (livers and LN’)
What is type 2 collagen tissue?
Hyaline cartilage
What is elastin secreted into the ECM by?
Fibroblasts
What does elastin do?
Confers elasticity to tissues
Where is elastin found in large amounts in the body?
- Skin
- Lungs
- Blood vessels
- Bladder
What does xxxblasts mean?
To build up/create/produce/synthesise
What does xxxcytes mean?
To maintain
What does xxxclasts mean?
To breakdown
What are the most common tissue cell type?
Fibroblasts
What do fibroblasts do?
Secrete fibres and components of ground substance
What do chondrocytes do?
Secrete and maintain ECM in cartilage
What do osteoblasts and osteocytes do?
Secrete and maintain ECM in bone
Which tissues are highly vascularised?
Connective tissues
- They contain blood vessels and lymphatic’s
- They contain immune cells which survey tissues for invading pathogens/cell damage
The exception to this is cartilage
What is connective tissue proper?
- Broad category of diverse structure and functions
- Loose or dense depending on arrangement of fibres
- Generally connects tissues to each other, fills spaces between organs and provides metabolic support
What is loose connective tissue?
- Has much more ground substance and a relative lack of fibrous tissue
What is dense connective tissue?
- Has much more fibrous tissue and lack of ground substance
What is dense regular connective tissue?
Found in structures such as tendons and ligaments, is characterised by collagen fibres arranged in an orderly fashion, giving it tensile strength in one direction
What is dense irregular connective tissue?
Provides strength in multiple directions by its dense bundles of fibres arranged in all directions
What is areolar tissue?
- Loose connective tissue
- Universal packing material - supports and binds other tissues
- Found beneath the skin, submucosa, surrounding capillaries
What is adipose tissue?
- Loose connective tissue
- Functions include - energy storage, shock absorption, insulation
- Found deep beneath skin, breasts, in the abdomen, finger and foot pads
What is reticular tissue?
- Loose connective tissue
- Delicate branched network (type III collagen) providing internal structure to highly cellular organs (liver, lymph nodes, spleen)
What is dense regular tissue?
- Dense connective tissue
- Closely, packed collagen fibres running in same direction
- Provides tensile strength - found in tendons and ligaments
What is dense irregular tissue?
- Closely, packed interwoven fibres running in different directions
- Found in dermis of skin, forms protective capsule around organs
What is elastic tissue?
- Allows tissues to recoil after stretching
- Found in arteries, skin, lungs and underlying transitional epithelium
What is Scurvy caused by and what does it lead to?
- Caused by lack of vitamin C
- Leads to defective collagen formation which leads to loose teeth, skin haemorrhages and even death
What is Dystrophic epidermolysis bullosa caused by and what does it lead to?
- Cause by defect in collagen VII, which anchors the epidermis to the dermis
- Injuries lead to severe blistering of skin
- patient often malnourished due to internal trauma of epithelial surfaces
What is systemic lupus Erythematosis caused by and what does it lead to?
- Autoimmune disease - antibodies target host tissues
- Target tissues include skin, bones, tendons, kidneys
- Oral symptoms include dryness and soreness
- Oral manifestations include buccal and palatal lesions
What is Sjogren’s cause by and what does it lead to?
- Autoimmune disease - affects glands that produce tears and saliva
- Symptoms include dry eyes and mouth
- Can occur independently or accompany other disorders, such as, SLE or rheumatoid arthritis
- Oral manifestations include increased dental caries and candidiasis
