Connective Tissues Flashcards
What is the most abundant tissue in the body?
Connective tissues
What is the function of connective tissues?
Provide structural and functional support to other tissues and organs they comprise
Give examples of connective tissues? (6)
- Bone - structural integrity
- Cartilage - protect joints, structural integrity
- Tendons and ligaments - connect muscle to bone, protect joints
- Adipose tissues - energy source
- Mesentery - connects intestine to abdomen
- Layers under skin & around organs - support
What 3 features define connective tissue?
Ground substance
Fibres
Cells
(1+2= extracellular matrix)
What differs in the arrangement of cells in epithelial and connective tissues.
In connective tissues cells are separated by the extracellular matrix
I’m epithelial tissues cells are tightly bound
What does the extracellular matrix do in connective tissues ?
Provides structural and biochemical support to the cell.
Most mass comes from ECM
Describe the ground substance.
- clear semi solid gel
- provides biochemical support
- composed of glycoproteins and complex carbs (hyaluronic acid/ glucosamine)
- water binding ability
- provides tissue volume
- supports intracellular exchange of substances
= substances produced by one cell can diffuse through GS to reach nearby cells
Describe fibres.
Function: provide structural support and tensile strength
2 types = collagen & elastin
Both secreted into ECM by connective tissues
What is collagen?
Strongest & most abundant provide tensile strength
What is elastin?
Long and branched
Provides stretch and recoil ability
Describe the collagen alpha helix in connective tissues.
1 collagen molecule forms alpha helix with 3 more to form triple helix structure.
Numerous of these join together to form individual collagen fibrils and numerous fibrils come together to form collagen fibre
VERY STRONG
How many types of collagen is there?
Describe the main 3.
28
1.found in fibrous tissues (dermis of the skin, tendons, ligaments, bone)
2.hyaline cartilage
3.delicate branched ‘reticular’ network found in highly cellular organs (liver)
What does elastin do and where is it found?
Confers elasticity to tissues
Found in large amounts in:
Skin
Lungs
Blood vessels
Bladder
What is the function of a fibroblast?
-synthesise ECM
-most common type of connective tissue cells
-give rise to more specialised cells
-secrete fibres/components of GS
What is the function of odontoblasts?
Synthesise ECM
synthesise Dentin in teeth
What is the function of adipocytes?
Maintain ECM in adipose tissue
What is the function of Osteoclasts?
Recycle (breakdown) the ECM in bone
What is the function of osteoblasts and osteocytes?
Secrete and maintain mineralised ECM in the bone
Why are connective tissues described as highly vascularised?
What are the exceptions?
- have lots of blood vessels and lymphatics going through tissue
- have immune cells, survey tissues for invading pathogens/cells damage
Exceptions - cartilage, tendons and ligaments
Why is it difficult for cartilage, tendons and ligaments to repair?
Cartilage = no blood vessels
Tendons/ Ligaments= very few blood vessels
What is dense connective tissue made up of?
Give 3 examples.
Mostly fibres
Regular
Irregular
Elastic
What is loose connective tissue made up of?
3 examples
Mostly ground substance
Areolar
Adipose
Reticular
What is connective tissues proper?
Category of diverse structure and functions
Loose or dense depending on arrangement of fibres
What is areolar tissue and where is it found?
Universal packing material - supports and binds other tissues
Found beneath skin, submucosa and surrounding capillaries
What can areolar tissue contain?
Collagen and elastin fibres
Immune cells
Functions of adipose tissue and where is it found?
Function: energy store, shock absorption, insulation
Found deep beneath skin, breast, in abdomen, finger and foot pads
Contains collagen fibres
What is reticular connective tissue?
Delicate branched network (type 3 collagen) providing internal structure to highly cellular organs eg. Liver, lymph nodes, spleen.
What is dense regular connective tissue?
Closely packed collagen fibres running in same direction
What does dense regular connective tissue provide and where is it found?
Tensile strength and stability to joints
Found in tendons and ligaments
What is dense irregular connective tissue and what does it provide?
Closely packed interwoven fibres running in different directions
Provides strength in different planes
Where is dense irregular connective tissue found and what does it form?
Found in dermis of skin, forms protective capsule around organs
What is elastic connective tissue?
Dense regular tissue dominated by elastic fibres
What does elastic connective tissue allow and where is it found?
Allows tissues to recoil after stretching
Found in arteries, skin, lungs, and underlying transitional epithelium
Packed full of elastic fibres
What causes scurvy and what does it lead too?
Lack of vitamin C
Leading to defective collagen formation
Loss of teeth, skin haemorrhages, death
Who is likely to get scurvy and what is the treatment for it? Yea
Alcoholics, children, elderly (malnutrition)
Treatment: citrus fruits, tomatoes, vit c supplements
What is the structure of collagen and how does it arise?
Triple helix structure
Arises from unusual abundance of 3 amino acids:
Glycine
Proline
Hydroxyproline
What would happen without collagens structural support?
Blood vessels, tendons and skin would become fragile.
What happens if there is a lack of vit C in collagen chains?
Collagen chains aren’t sufficiently hydroxylated and they can’t fork alpha helix chains.
Name 2 connective tissues disorders with oral manifestations?
Systemic lupus erythematosis
Sjogren’s
What is systemic lupus erythematosis?
Autoimmune disease - antibodies target host tissues
Oral symptoms of systemic lupus erythematosis?
Dryness and soreness
Oral manifestations include buccal and palatial lesions
What tissues does systemic lupus erythematosis attack?
Skin
Bones
Tendons
Kidneys
Unnecessarily destroys them
What is Sjogrens?
Autoimmune disease
Autoantibodies affect glands that produce tears and saliva
Symptoms of sjogrens?
Dry eyes and mouth
Oral manifestations = increased dental caries and candidiasis (fungal disease)
