Connective Tissue Morphology

Question 1

connective tissue definition

Answer 1

Tissue that is found between other tissues elsewhere in the body

Question 2

three components in all connective tissue

Answer 2

ground substance, fibers and cells

Question 3

what does the ground substance and fibers combine to form?

Answer 3

extracellular matrix

Question 4

what is the ground substance?

Answer 4

a complex of proteoglycans, GAGs and multiadhesive glycoproteins such as laminin and fibronectin

Question 5

function of connective tissue

Answer 5

supporting matrix, transmission of forces, facilitation of movement, fat storage, insulation, cushioning, infection repair, growth factor gradients

Question 6

GAGs examples

Answer 6

uronic acidm, hyaluronic acid, glucosamine, galactosamine

Question 7

function of GAGs

Answer 7

form viscous pericellular network which binds to water and ensures that ECM is hydrated

small, highly sulphated GAGs bind to proteins, prevent them from diffusing out

high negative charge sequester cations

Question 8

multiadhesive glycoprotein functions

Answer 8

multiple binding sites for integrins

large molecules allow adhesion of cells to substrate

laminin, binding sites for integrins

fibronectin, binding sites for collagen, GAGs and integrins

Question 9

different fibres in connective tissue

Answer 9

collagen, reticular fibres and elastic fibres

Question 10

what are reticular fibres?

Answer 10

collagen type 3- form an extensive network of thin fibers that can support cells

heavily glycosylated

Question 11

what do the reticular fibres support?

Answer 11

adipocytes, smooth muscle, nerve fibres and small blood vessels

Question 12

elastic fibres structure

Answer 12

thinner than type 1 collagen

composite of fibrillin to form microfibrils

lysine rich areas interspersed with hydrophic lysine and proline regions

Question 13

elastic fiber function

Answer 13

important for stretch and recoil

Question 14

what produces the different fibres?

Answer 14

all produced by fibroblasts

Question 15

cells in connective tissue?

Answer 15

fibroblasts, mast cells, adipocytes, macrophages,

Question 16

fibroblast function

Answer 16

produce and maintain the majority of ECM components

synthesise and secrete collagen and elastin, GAGs, proteoglycans,

Question 17

mast cell functions

Answer 17

localised release of bioactive substances involved in local inflammatory response

Question 18

where are mast cells located?

Answer 18

near blood cells, mesenteries and tissues that line the digestive and respiratory tracts

Question 19

what molecules are released from mast cells + function?

Answer 19

heparin- GAG- anticoagulant

histamine- promote vascular permeability and contraction of smooth muscle

serine proteases- mediators of inflammation

eosinophil- attract leukocytes

cytokines

phospholipid precursors that become prostaglandins

Question 20

adipocyte function

Answer 20

store lipids as neutral fats in cytoplasm

produce heat

Question 21

two different types of adipose tissue

Answer 21

white and brown adipose

Question 22

white adipose structure

Answer 22

mature adipocytes with one large triglyceride droplet

nucleus on periphery

Question 23

white adipose function

Answer 23

stores fats from chylomicrons and VLDLs

free fatty acids and glycerol synthesis

insulation, padding

Question 24

brown adipose structure

Answer 24

more cytoplasm

many smaller fat droplets

more centrally located nucleus

Question 25

brown adipose function

Answer 25

heat generation- non shivering thermogenesis

Question 26

where is brown adipose mainly located?

Answer 26

young children mainly lost in adults but found around kidneys adrenal glands, aorta and mediastinum

Question 27

macrophage structure

Answer 27

irregular surface of pleats, protrusions and indentations well developed golgi, many lysosomes

Question 28

macrophage function

Answer 28

phagocytes, abundant at sites of inflammation break down ECM and debris

Question 29

three different connective tissue diseases

Answer 29

Ehlers Danlos, Marfans and osteogenesis imperfecta

Question 30

explain ehlers-danlos

Answer 30

set of diseases caused by a mutation in collagen, leading to its poor strength causes loose skin, problems with wound healing, hypermobile joints and fragile blood vessels

Question 31

explain Marfan's

Answer 31

mutation in FBN1 gene, encoding fibrillin 1, essential in the formation of elastic fibres results in tall individuals with long and thin limbs flexible joints and scoliosis increased risk of aortic aneurysms

Question 32

explain osteogenesis imperfecta

Answer 32

brittle bone disease lack of collagen 1, mutations in COL1A1 or COL1A2 results in amino acid substitution of glycine to bulkier amino acid which results in steric hindrance changes the interactions between collagen and hydroxyapatite crystals which makes bones brittles

Question 33

four different types of tissue/

Answer 33

epithelial, connective, muscle and nervous

Question 34

6 types of connective tissue

Answer 34

loose connective tissue dense connective tissue bone cartilage blood lymph