Support tissue

Question 1

What are the types of connective tissue?

Answer 1

1. Ordinary
2. Supporting
3. Vascular

Question 2

How is ordinary tissue classified

Answer 2

1. Loose CT - fibres create a loose open framework (adipose, areolar, reticular)
2. Dense CT - Fibres densely packed (Elastic, dense regular, dense irregular)

Question 3

How is supporting CT classified

Answer 3

1. Cartilage - Forms solid rubbery matrix (hyaline, elastic, fibrocartilage)
2. Bone - forms solid crystalline matrix (compact, spongy)

Question 4

How is vascular CT classified?

Answer 4

1. Blood - Contained in cardiovascular system

2. Lymph - Contained in lymphatic system

Question 5

What are the 3 germinal layers in the embryo

Answer 5

1. Endoderm (inner)
2. Mesoderm - where connective tissue is derived from, from mesenchyme tissue
3. Ectoderm (outer)

Question 6

What is the major type of cell population in connective tissue?

Answer 6

FIBROBLAST and FIBROCYTES = most important cell

Question 7

How do you identify fibroblasts, where locates and what responsible?

Answer 7

1. well distributed in CT
2. responsible for active production of extracellular matrix, fibres adn ground substance:
3. Large centrally located nucelus
4. granular appearance
5. pointing cytoplasm

Question 8

When the fobroblast has done it job how do you identify

Answer 8

Now called fibrocyte

1. Looks like: nucleus condensed, small darkly staining, no granular structure

Question 9

How do you identify a mature fibroblast from a fibrocyte

Answer 9

1. Fibroblast = actively produce extracellular matrix = ground substance and fibres. Prominent nucleoli which is elongated, basophilic cytoplasm, lighter stain
2. Fibrocyte: resting phase = condensed, elongated in direction of collagen fibres, fine processes, difficult to see with LM, involved in the maintenance of the ECM, can differentiate into other types of CT cell, darkly staining

Question 10

Ordinary connective tissue: Loose areolar

Answer 10

1. Fibroblasts everywhere
2. Plasma cells, mast cells, macrophages
3. Collagen, elastic, reticular fibres
4. Blood vessels
5. e.g. under skin: epidermal layer = dermis connective tissue layer, lining of GI, resp and urinary tract

Question 11

Histologically what does collagen tissue look like

Answer 11

lightly stained, surrounds fibroblasts and cytes, swooshy appearance

Question 12

Ordinary connective tissue: loose adipose

Answer 12

1. Function: reserve for food, act as fuel, insulate against heat loss, supports and protects organs
2. cell type = adipocyte
3. fat stores in large vacuole so nucleus is pushed to boundary
4. appear clear empty cells as fat dissolved when processing = nothing to stain.
5. Chicken wire
6. each adipocyte is supported by a delicate network of collagen and reticular fibres
7. few fibrocytes, mast cells, sparse amorphous ground substance

Question 13

How to differentiate between brown and white fat

Answer 13

1. white = one big vacuole
2. Brown = many “droplets” within a circle
3. Brown = nucleus can sometimes be inc centre, white nucleus os always pushed to periphery

Question 14

Ordinary connective tissue: loose reticular

Answer 14

1. Around BV
2. hard to discriminate as finer fibres
3. function = filter fluid, cells can’t pass through
4. stained by silver impregnation

Question 15

Ordinary connective tissue, dense irregular

Answer 15

1. lots and lots of collagen fibres = dense
2. Collagen fibre no clear arrangement = hip hazard! swirly
3. reticulum layer in dermis of skin
4. fibroblasts, BV, immune cells, collagen fibres

Question 16

Ordinary connective tissue: dense regular

Answer 16

1. fibres regularly arranged in longitudinal bundles (collagen or elastic) in parallel
2. Specific sites e.g. tendons, ligaments
3. in between muscle fibres = CT component endomesium
4. bundles = thick
5. fibrocytes sit in direction of muscle fibres

Question 17

Ordinary connective tissue: Dense Elastic

Answer 17

Elastic connective tissue

1. squiggly lines
2. bladder, lungs, aorta: expand and recoil
3. Protein in elastic fibre = elastin

Question 18

What is liquid/ fluid connective tissue

Answer 18

1. blood: plasma and lymph

2. Cells circulate in a liquid extracellular matric

Question 19

Explain the role of connective tissue in the basement membrane

Answer 19

1. allows cell adhesion - anchoring junction: hemidesmosomes
2. diffusion barrier: epi lining is deprived of blood circulation so O2 and nutrients diffuse from underlying CT to absement membrane to underlying cells
3. Regulation of cell growth: interface between epi lining adn CT = limits epi growth

Question 20

Supporting tissue: Hyaline Cartilage

Answer 20

1. chondrocyte = contained in a lacuna = dormant and responsible for maintenance
2. chondroblast = produces ECM = large nuclei = darker well rounded cell

Question 21

Supporting tissue: Fibro Cartilage

Answer 21

1. fibrous and cartilagenous connective tissue

2. Function = flexibility and hardness e.g. annulus fibrosus of intervertebral disk of back bone : inner bit

Question 22

Supporting tissue: Elastic cartialge

Answer 22

1. recoil
2. elastic fibres along with chondrocyte and blasts
3. e.g. ears hard but can move