Cells and tissues: connective Flashcards
Key functions of Connective tissue
bind, support, strengthen other tissues; transport; energy storage. can be highly vascular except for cartilage and tendons. supplied by nerves
composition of Connective
extracellular matrix and cells
extracellular matrix
made of ground substance and 3 protein fibres in different proportions that determines the structure/function of ECM
Ground substance
proteins (like gelatin), water, polysaccharides (sugars: glycosaminoglycans/mucopolysaccharides)
proteoglycans
gags and core proteins
Glycosaminoglycans
Sulphated which bind to core protiens to form proteoclycans:
-dermantan sulphate
-herparin sulphate
-keratan sulphate
-chondroitin sulphate
Non sulphated:
hyaluronic acid:
hyaluronic acid
non sulphated gag: does not bind directly to protein backbone but is joined to various proteoglycans. highly polar, traps water making GS more jelly like for cushioning.
GAG applications
Hyaluronic acid: lubricates joints and maintains eye shape
hyaluronidase: made by WBCs, sperm, and some bacteria, makes GS more liquid.
Chondroitin sulphate
support and provide adhesive features for cartilage, bone, skin, blood vessels
keratan sulphate
found in bone cartilage, cornea of the eye
dermatan sulphate
found in skin, tendons, blood vessels, heart valves
Exopthalmos
swollen thyroid gland from autoimmune over-activation leads to deposition of GAGs and influc of water to swell they eye
Protein fibres in ECM
secreted by cells in connective tissue:
collagen
reticular fibres
elastic fibres
Collagen
parallel bundles of thick, strong fibres, but flexible to resist pulling forces. found in bone, cartilage, tendons, ligaments
Reticular fibres
made of collagen with glycoprotein around them. Strength and support. fine bundles found in reticular lamina (BM) and ECM, adipose tissue, nerve fibres, smooth muscle
Elastic fibres
thinner than collagen. fibrous network made of elastin coated in fibrilin for strength and stability. found in skin, blood vessels, and lung
Marfan Syndrome
Too much fibrilin in elastic fibres. changes binding of growth factors resulting in tall thin individuals. chromosome 15
Cell types in connective tissues
fibroblasts
adipocyte
macrophage/histiocyts
plasma cell
mast cells
leucocytes
fibroblasts
migratory and widely distributed in CT. secretes componants of matrix (fibres and ground substance) and for BM
adipocytes
under skin and aroudn organs, store tryglycerides (fat)
Macrophage (CT)
phagocytic fixed and wandering
lung - dust cells
liver - kupffer cells
skin - langerhans
some wander in CT to sites of infection or inflamation
Plasma cells (CT)
from b-lymphocyte. produce antibodies in CT of gut, lung, salivary, lymph nodes, spleen, bone marrow
mast cells (CT)
produce histamine to dilate blood vessels
leucocytes
white blood cells that migrate out from blood
Connective tissue classifications
embryonic
mature
embryonic CT
mesenchyme
mucous
mucous CT (Embryonic)
supportes umbilical cors, protects blood vessels
Mesenchyme CT (embryonic)
gives rise to all other CT. made of CT cells in semifluid GS, with reticular fibres
mature connective tissue
loose
dense
blood
lymph
cartilage
bone
loose MCT
areolar (packing and support)
adipose (insulation, energy, temperature control)
reticular (forms stroma, binds smooth muscle, red blood cell filter for spleen and microbes for lymph nodes
dense MCT
regular (regularly arranged collagen: tendons, ligaments, aponeuroses, slow healing)
irregular (tensile or pulling in many direction, occurs in sheets, collagen irregularly arranged)
elastic (elastic fibres and fibroblasts, allows stretching. strong and can recoil to original shape
Cartilage Supporting MCT
cartilage:
-hyaline for flexibility and movement, a bit weak
- elastic for strength and eleasticity, maintain shape
-fibrocartilage for support and joing structures together. strongest
Supporting MCT: Bone
Compact
spongy
Compact bone/cortical bone
outer layer, shaft of long bones, made of rod units called osteons. stores calcium and phosphourous. protection and support
spongy bone/cancellous bone
porous inner bone under compact bone. no osteons. stores yellow marrow and red marrow
Bone cells
osteogenic: stem cells that lay down collagen
osteoblasts: form bone, more collagen and mineralisation proces
osteocytes: mature bone trapped in mineralised ECM (nutrient and waste exchange)
osteoclast: large, breaks down bone and formed from blood monocytes
osteon structure
lamellae
lacunae
canaliculi
central canal
lamellae
for hardness concentric rings of mineral salts
lacunae
small spaces for osteocytes (mature bone cells)
canaliculi
little canals with Extracellular fluid that provide a route for oxygen and nutrients
central haversian canal
canal for blood lymph and nerves in bone
chondroblasts
lay down collagen when bone breaks and repair needs to hapen.
Fluid connective tissue
blood and lymph
Blood as CT
ECM = plasma, formed elements = red, white, and platelets, lymphocytes (immune response)
