Connective tissue Flashcards
overall connective tissue function:
structural/ metabolic support for other tissues (eg. epithelium)
connective tissue feature and consists of:
well vascularised (mostly)
cells, extracellular matrix (fibres + ground substance)
connective tissue all develop from:
embryonic mesenchymal cells
blast:
immature cell
cyte:
mature cell
cells either fixed and wondering:
resident and transient
list the 4 types of cells:
fibroblasts, adipocytes, chondroblasts and osteoblasts
list the 5 defence-function cells:
mast cell, macrophages, lymphocytes, plasma cells and eosinophils
fibroblast/cyte difference-
info/ function/ cell consists of:
blast:
most common cell, large, abundant cytoplasm processes, oval nucleus, lots of rER/ GA
quiescent (inactive) cyte: smaller, spindle shaped with elongated nucleus
synthesis of collagen, elastic, reticular fibres and extracellular material
WOUND REPAIR!
cell function/ features/ location: adipocytes
- fat storage, energy, insulation, also involvement in hormones/ growth factors
- eg. in loose connective tissue
- cytoplasm and flat nucleus forms rim around large lipid droplet
macrophage features/ function/ develop from:
- irregular shaped with small branched projections,
- destroys bacteria/ cellular debris (phagocytosis)
- developed from monocytes (WBC)
- fixed and wondering
mast cells: develop/ features, function
- develop in bone marrow, differentiate in connective tissue
- inflammatory and allergic response (granules contain histamine-allergy/ heparin-blood thinner)
- also kill bacteria
types of fibres in extracellular matrix:
collagen, reticular, elastic
types of ground substance and features:
fluid, semisolid, solid
water + complex carbs + glycoproteins
extracellular matrix function:
mechanical/ structural support for tissue, biochemical barrier -> regulate metabolic functions in surrounding cells
collagen fibres features/ composition:
- most abundant, closely packed and organised,
- flexible, high tensile strength
- collagen protein
Type I collagen function/ location:
resistance to force, tension and stretch
eg. skin, bones, tendons and organs’ capsules
Type II collagen function/ location:
resistant to pressure
eg. hyaline and elastic cartilage
Type III collagen function/ location:
reticular fibres/ support
eg. organs, smooth muscle
Type IV collagen function/ location:
support/ filtration
eg. associated with basal lamina of epithelial cells
elastic fibre: compostion/ function/ location
thin, protein elastin,
help tissue stretch/ distend
eg. skin, lung, bladder
reticular fibre: features/ function/ location
very thin, type III collagen, and high glycoprotein levels
- provides support framework for cellular components (stroma) of various tissues/ organs eg. reticular tissue
types of embryonic connective tissue:
mesenchyme, mucous connective tissue
types of mature connective tissue:
proper, specialised
types of connective tissue proper:
loose and dense connective tissue:
types of specialised connective tissue:
cartilage, bone, blood and lymphoid
types of loose connective tissue and main feature:
areolar, reticular, adipose
fibres loosely intertwined between cells
types of dense connective tissue and main feature:
more thicker, closely packed fibres/ less cells
regular, irregular, elastic
types of cartilage:
hyaline, fibrocartilage, elastic
cartilage features/ function and composition
avascular, firm consistency (mechanical stress, shock absorbing, bone growth and development)
in lacunae (small cavities in cartilage matrix) contain chondrocytes- synthesise extracellular matrix, also have extensive e. m
areola connective tissue: features/ function/ located
most common type of tissue, contains all 3 fibres
- well vascularised, delicate (not resistant to stress)
- eg. subcutaneous: surrounds lymph/blood vessels, nerves, body organs, lamina propria, dermis of skin (superficial layer)
reticular connective tissue: features/ function
intertwined reticular fibres
- forms stroma (framework)
- binds smooth muscle cell
- reticular fibres filter blood/ lymph
adipose connective tissue: features/ function/ located
- adipocytes
- subcutaneous (under skin)
- eg. heart, kidney, yellow marrow (long bones)
- insulation, energy, protection, support
regular connective tissue: composition/ features/ function/ location
lots: collagen fibres
few: cells
little: ground substance
- strong attachment between structures
densely packed aligned collagen fibres in bundles, between fibrocyte rows
eg. tendons, ligaments, aponeuroses (flat sheet of con. tissue-> muscle)
irregular connective tissue: composition/ features/ function/ located
like regular c.t (most collagen fibres, few cells, lil ground sub.)
random packed fibres in 3D
- strength, resist stretch/tear in all directions
eg. fasciae, deep dermis layer, digestive tract (submucosa)
sprained ligament: grades, feature
Grade I: stretching, small tears
Grade II: larger, incomplete tear
Grade III: complete tear
elastic connective tissue: features/ function/ located
elastic fibres, fibroblast between spaces, yellowish
- stretching
- eg. lungs, elastic arteries, some ligaments
hyaline cartilage: features/ function/ located
- glossy, bluish-white
- chondrocytes + collagen (Type II mainly) in hydrating (60-80% water) gel of glycoproteins/ proteoglycans
- cushioning, low friction surface (joints), flexible, support respiratory system
eg. end of long bones, anterior end of nose, ribs, larynx, trachea, foetal skeleton (growth/repair in adults is limited)
can calcify in endochondral bone formation
fibrocartilage: features/ function/ located
dense reg ct. + cartilage
- chondrocytes/ fibroblasts found in bundles of collagen fibres (Type I + II) and proteoglycans (protein + sugar)
- collagen fibres PARALLEL to line of stress
- limited repair in adults
eg. pubic symphysis, menisci of knee
- support/ fusion, resist deformation under stress
elastic cartilage: features/ function/ located
hyaline cartilage + network of elastic fibres
- flexibility/ support
eg. external ear/ auditory canal, epiglottis
