L5: Connective Tissues Flashcards
What are the four main tissue types?
- Epithelial;
- Connective;
- Muscle;
- Nervous.
What is the function of connective tissues?
To provide structural and functional support
Give three examples of connective tissues.
- Bone (structural integrity);
- Cartilage (protect joints, structural integrity);
- Tendons and ligaments (connect muscle to bone, protect joints);
- Adipose (energy storage);
- Mesentery (connects intestine to abdomen);
- Layer under skin and around organs (support).
Give an example of a connective tissue that provides structural integrity.
Bone
What features define connective tissues?
- The extracellular matrix (ECM): ground substance and fibres;
- Cells.
What is the general structure of connective tissues?
Cells separated by ECM
What is the function of the ECM of connective tissues?
To provide structural and biochemical support for cells
What are the two major components of ECM?
- Ground substance;
- Fibres.
Which component of the ECM provides biochemical support?
Ground substance
Describe the general appearance and composition of ground substance.
Clear, semi-solid gel composed of glycoproteins and complex carbohydrates (such as hyaluronic acid)
Other than biochemical support, what are the other roles of ground substance?
- Provide water-binding ability;
- Provide tissue volume;
- Support intercellular exchange.
Which component of the ECM provides structural support and tensile strength?
Fibres
What are the two main types of fibres within connective tissues?
- Collagen - tensile strength;
- Elastin - stretch and recoil ability.
What type of fibre is most abundant in connective tissues?
Collagen
What component of connective tissues secretes collagen in to the ECM?
Collagen is secreted from connective tissue cells
What type of collagen is found in fibrous tissues? Such as the dermis of the skin, tendons, ligaments and bone
Type I
What type if collagen is present in hyaline cartilage?
Type II
Whereis type III collagen typically present?
Highly cellular organs such as the liver
What component of connective tissues secretes elastin in to the ECM?
Fibroblasts
Provide two examples of where elastin is found in large amounts.
- Skin;
- Lungs;
- Vessels;
- Bladder.
What are the three major types of cells found in connective tissues?
- xblasts;
- xcytes;
- xclasts.
What do xblasts do?
Synthesise ECM (bing bang/blast)
What do xcytes do?
Maintain ECM (site/cyte maintenance)
What do xclasts do?
Breakdown ECM
What are the functions of odontoblasts, adipocytes and osteoclasts?
- Synthesise dentin in teeth;
- Maintain ECM in adipose tissue;
- Recycle (breakdown) ECM in bone.
What is the most common connective tissue cell type and what are their function?
Fibroblasts - Secrete fibres and components of ground substance
Which type of connective tissue cell secretes and maintains cartilage within the ECM?
Chondroblasts
What do osteoblasts and osteocytes do?
Secrete and maintains mineralised ECM in bone
What is the significant difference between epithelial and connective tissues?
Connective tissues are highly vascularised (contain blood vessels and lymphatics- immune cells)
What type of connective tissue is not vascularised?
Cartilage
What are the two types of ‘connective tissue proper’ and what determines their type?
- Loose and dense;
- Loose, mostly ground substance;
- Dense, mostly fibres/proteins.
What type of connective tissue is areolar tissue?
Loose connective tissue, ‘universal packing material’
What are the major functions of adipose tissue (loose CT)?
- Energy storage;
- Shock absorption;
- Insulation.
What is the general structure of reticular tissue (loose CT)?
Branched network of type III collagen, provides internal structure to highly cellular organs e.g. liver, lymph nodes
What is the difference between regular and irregular dense connective tissues?
- Regular: closely packed collagen fibres running in the same direction;
- Irregular: closely packed, interwoven fibres running in different directions.
Provide an example of a regular and irregular dense connective tissue.
- Regular: Tendons/ ligaments;
- Irregular: Dermis of skin and protective capsules or organs.
What type of connective tissue has ideal elastic properties?
- Elastic;
- Dense, regular CT;
- Dominated by elastic fibres;
- Lungs, arteries, skin.
What component of connective tissue does scurvy, caused by vitamin C deficiency, target?
Collagen, defective formation
What type of disease is systemic lupus erythematosis (SLE) and what tissues does it target?
- Autoimmune;
- Skin, bones, tendons, kidneys.
What type of disease is Sjogren’s and what tissues does it target?
- Autoimmune;
- Glands (tears and saliva).
