connective tissues Flashcards
what are connective tissues? give examples
tissues that connect, supports, binds or separates other tissues/ organs e.g. bone, ligament, fat
give three roles of connective tissues
- binds and supports other tissues e.g. ligaments
- protects and insulates organs e.g. fat
- transports nutrients e.g. blood
what is the principal cell of connective tissues and what does it produce?
fibroblasts produce collagen and other intercellular materials
what can fibroblasts differentiate into?
cells responsible for producing CT e.g. chondroblasts which make cartilage and osteoblasts which produce bone
where do all connective tissues derive from?
mesenchyme, which is a loose and fluid type of embryonic tissue derived from mesoderm layer
what do all connective tissues contain?
cells, large amounts of amorphous ground substance and protein fibres
what doesn’t ground substance include?
fibres such as collagen and elastic
describe blasts?
immature cells that secrete matrix
describe cytes?
mature cells that maintain matrix
what is the matrix
protein fibres embedded in ground substance; compromised of proteoglycans; contains living cells and can be fluid, gel or solid
what are the three roles of amorphous?
- supports cells
- binds cells
- acts as medium for exchange
what are the two types of protein fibres
collagen and elastic
describe arrangement and properties of collagen
- made from fibrous protein subunits linked to form a long straight fibre
- tough and resistant to tension but still flexible
- arranged in bundles
describe properties and make up of elastic fibres
- consists of protein elastin which can be stretched 150% of relaxed length
- always returns to original shape e.g. skin
- contains lesser amounts of other proteins/ glycoproteins
how are dense connective tissues arranged?
parallel to direction of forces exerted on particular body part where tissue is located
what is dense regular tissue? Give two examples
Provides strong attachments between structures in one direction e.g. ligaments attach bone to bone= stabilise joints/ restrict excessive motion and tendons attach muscle to bone and transmit tensile loads
do ligaments or tendons have more elastic fibres?
ligaments have more whereas tendons have few elastic fibres compared to ligaments
what does dense regular tissue contain?
fibroblasts to produce collagen for the matrix as fibres are in parallel bundles to allow great tensile strength; some elastin fibres
what is dense irregular tissue? give an example
provides strength in multiple directions e.g. deep fascia has sheet of connective tissues surrounding and protecting the muscle as dense irregular holds muscles together and separates into functional groups
what does dense irregular tissue contain
fibroblasts and matrix consists of collagen fibres randomly arranged with a few elastin fibres
what is the main difference between dense regular and irregular?
arrangement of fibres; all fibres oriented in one direction in dense whereas irregular fibres have multiple orientations
what does cartilage contain?
tough and flexible CT that contains polysaccharides called chondroitin sulphates which bind with ground substance proteins to form proteoglycans
what is embedded within the matrix of cartilage and what does it occupy?
chondrocytes occupy lacunae
what are the three functions of cartilage?
- allows tissues to bear mechanical strength
- forms framework supporting soft tissues in respiratory tracts, ear, nose
- provides shock absorber
what are the three types of cartilage?
hyaline, fibrocartilage and elastic cartilage
what is hyaline cartilage? describe what it contains
most common form that consists of short and dispersed collagen as well as proteoglycans to cover articular surfaces at joint ; homogeneous
where is hyaline cartilage found in adults?
forms articular surfaces of long bones, rib tips, rings of trachea and parts of skull
what is shown if hyaline cartilage is under a microscope?
appears clear (translucent protoplasm) with cells located in spaces scattered in transparent background
what are the three functions of hyaline cartilage ?
- reduces friction and absorbs shock
- strong and flexible; found in nose and rib cage as covers bones where they meet moveable joints
- at ends of bones to allow continued growth into adulthood
what is fibrocartilage?
thick bundles of collagen fibres so it is tough and hence can resist pressure but also flexible
what does fibrocartilage form between joints? give an example
discs and rings e.g. intervertebral discs
what is elastic cartilage?
contains elastic fibre network and collagen as well as proteoglycans ; gives great flexibility so can withstand repeated bending
where is elastic cartilage found?
- external ear flaps of many mammals to provide support
