14 Connective Tissue

Question 1

Whats in the connective tissue?
Main cells?
Main products?

Answer 1

Connective tissue cells, extracellular proteins/glycoproteins and gels.

Cells include: fibroblast, chondrocytes, osteocytes and stem cells.

Main products: fibres, ground substance and wax/gel like materials

Question 2

The main connective tissue: connective tissue proper.

What are the two?

Answer 2

Loose connective tissue: areola tissue

Dense connective tissue: fibrous/collagenous tissue.

Question 3

Loose connective tissue/ areolar tissue
What cells and fibres has it got in it?
whats its functions?

Answer 3

resident cells such as fibroblasts and macrophages. Also other wbc and mast cells. contains 2 fibres: collagen and elastin. Has a gel like extracellular matrix: proteoglycans and hyaluronic acid.
Function: packaging around organs and stabiliases them. widely distributed.

Question 4

Loose :
Fibroblasts
myofibroblasts

Answer 4

secretes the fibres and the gel-like materials.
important in wound healing process and formation of scar tissue. Have lots of RER.
myo: modified fibroblasts that contain actin and myosin which are responsible for wound contraction when tissue loss occurs.

Question 5

Loose:

Macrophages

Answer 5

derived from blood monocytes and move into the loose ct especially during local inflammation.
degrade foreign organisms, antigen presenting cell.

Question 6

Loose:

Mast cell

Answer 6

have lots of granules full of histamines, heparin, cytokines. found in loose ct near blood cells. coated in IgE.

Question 7

Loose:
Adipocytes white
structure? function?

Answer 7

Generated from immature fibroblasts or mesochymal stem cell. mostly white in loose ct. they are called unilocular because they have one large fat droplet inside them.
Organelles squeezed to one side cus huge fat droplet.
Acts as fat absorber and energy store

Question 8

Loose:

Adipocytes brown

Answer 8

multilocular. dont have many as adults, but do as a child. has multiple lipid droplets and many mitochondria. nucleus in middle of cell.

Question 9

Loose:
Collagen: the 4 types

Answer 9

type 1 most widely distributed. fibrils aggregate into fibres and fibres bundle
type 2 fibrils do not form fibres
type 3 reticulin
type 4 present in basal lamina of basement membrane

Question 10

Ground substance

Answer 10

viscous clear substance, feels slippery. composed of proteoglycans and GAGS (polysaccharides). GAGs attract water to hydrated gel that permits rapid diffusion

Question 11

Dense connective tissue: two types? Examples?

Answer 11

Irregular:
contains fibroblasts, collagen 1 fibres in all directions. resists stresses in all direction. Examples: deep layer of the dermis and the submucosa of the intestines.
Regular:
contains fibroblasts, collagen 1 fibres in arallel. Resists stress in only one direction. Examples: tendons, ligaments, aponeuroses.

Question 12

Myotendinous junction

Answer 12

Where skeletal muscle fibres connect with tendon collagen bundles. Very strong.

Question 13

Tendon anatomy. whats its made up of?

Answer 13

very strong. made of mainly water and collagen and a little elastin. collagen= 70% type 1 and 30% type 3 (reticulin)

Question 14

Ligaments

Answer 14

regular dense tissue. connect bone to bone. Not straight undulate. wrapped in loose connective tissue (fascicles)

Question 15

Fascia

Answer 15

connective tissue of three types: superficial, deep, visceral/parietal. made up of fibrous ct, wavy pattern parallel to the direction of pull

Question 16

Clinical CT diseases: scurvy

Answer 16

Vitamin C deficiency. vit c is required for the intracellular production of procollagen. it hydroxylates proline and lysine. so being deficient causes poor wound healing and impaired bone formation, gum disease, bleeding.

Question 17

Clinical CT diseases: marfans

Answer 17

autosomal dominant disorder/ fibrillin 1 gene is affected so abnormal elastic fibre. wing span more than height, very tall, long limbs, risk of aortic rupture, exhibit arachnodactyly. Ao

Question 18

Whens elastin made?

Answer 18

only in fetal development not in adults. can lose it through sunlight and smoking.

Question 19

Clinical CT diseases: osteogenesis imperfecta

Answer 19

brittle bone disease. mutated collagen fibres that do not knit together. high risk of broken bones and fractures, blue sclera of eyes, flexible joints, poor tooth development, very short normally.