connective tissue

Question 1

where does connective tissue originate

Answer 1

mesenchyme - tissue developing in the middle layer of the embryo ( mesoderm)

Question 2

describe mesenchymal stem cells

Answer 2

small, spindle- shaped cels with long branching processes that form a network

Question 3

what are the functions of connective tissue

Answer 3

• binds structures together
• provide support and protection
• fills spaces
• produces blood cells
• stores fat

Question 4

what are the types of fibrous connective tissue

Answer 4

• loose connective tissue - areolar
• dense connective tissue - regular and irregular

Question 5

what are the types of connective tissue with special properties

Answer 5

• adipose
• reticular
• mucous
• pigment

Question 6

what are the supporting types of connective tissue

Answer 6

cartilage and bone

Question 7

what is the classification of fibrous connective tissue based on

Answer 7

• ratio between fibres and amorphous ground substance
• arrangement of fibres

Question 8

what are the general characteristics of connective tissue

Answer 8

cells + extracellular matrix
- cells widely separated by extracellular matrix
- solid, semisolid or liquid
- matrix of connective tissue determine properties

Question 9

what is loose connective tissue characterised by

Answer 9

• low maintenance fibres - <25%
• great volume of ground substance and cells >75%
• always irregular

Question 10

what is dense connective tissue characterised by

Answer 10

• great maintenance of fibres >75%
• low volume of ground substance and cells
• can be regular and irregular

Question 11

what is the most abundant connective tissue in an organism

Answer 11

loose areolar connective tissue

Question 12

what are most cell types in loose connective tissue

Answer 12

transient wondering cells that migrate from local blood vessels to respond to a specific stimulus causing inflammatory and immune reactions

Question 13

what cells are in loose connective tissue

Answer 13

• Fibroblasts
• Macrophages
• Mast cells,
• Plasma cells,
• Fat cell (adipocytes)
• Pericytes
• Adventitial cells
• Pigment cells
  (melanocytes)
• Leukocytes migrating
  from blood vessels

Question 14

what is the most dominant cell in connective tissue

Answer 14

fibroblast

Question 15

what are the functions of fibroblasts

Answer 15

synthesis of fibres and components of ground substance

Question 16

what are myofibroblasts

Answer 16

involved in wound healing, assist in tooth eruption, pluripotent and develop in new cells

Question 17

what are macrophages

Answer 17

derived from monocytes and are part of mononuclear phagocyte system

Question 18

what are macrophages functions

Answer 18

• phagocytosis
• antigen processing and presentation to immune system
• secretion of growth factors and cytokines

Question 19

where are mast cells abundant in

Answer 19

loose connective tissue

Question 20

what are the functions of mast cells

Answer 20

secrete heparin and histamine
- involved in inflammatory reactions, allergies and hypersensitivity

Question 21

what are metachromasia

Answer 21

• granules of mast cells containing heparin and histamine change the blue stain to purple or red

Question 22

what is the mature form of fibroblasts called

Answer 22

fibrocytes

Question 23

what are the characteristics of plasma cells

Answer 23

• nucleus contains chromatin clumped in a clock face patter
• cytoplasm is basophilic and filled with rER
• golgi complex displaces nucleus to one side - perinuclear halo

Question 24

what are Russell’s bodies

Answer 24

when antibodies enter the circulation or stored in a form of inclusions

Question 25

what is the function of plasma cells

Answer 25

- final stage of development of B-lymphocytes - production of antibodies (humoral immunity)

Question 26

how are ring cells/ adipocytes formed

Answer 26

cytoplasm forms a thin peripheral layer around central droplets of fat

Question 27

what are the functions of adipocytes/ ring cells

Answer 27

- storage of neutral fats - production of heat

Question 28

what are adventitial cells

Answer 28

cells accompanying blood vessels and are in blood vessel regeneration

Question 29

what are pericytes

Answer 29

surround blood capillaries and are part of their wall they regulate capillary blood flow and growth

Question 30

where do pigment cells originate from

Answer 30

neural crest cells

Question 31

what are pigment cells/ melanocytes

Answer 31

- stellate with long branching processes and small round nucleus - cytoplasm contains melaanin granules

Question 32

what do melanin granules do

Answer 32

absorb ultra violet that give pigment to cells

Question 33

what happens when leukocytes migrate

Answer 33

migrate across capillary walls from the blood t connective tissue via diapedesis to increase inflammation

Question 34

what are reticular cells

Answer 34

similar in appearance to fibocytes

Question 35

what are the fibres in connective tissue

Answer 35

collagen - strength and forms bundles elastic - elasticity and thin

Question 36

what are ground substances

Answer 36

- varies from soft jelly to semisolid consistency - fills spaces between cells and fibres In connective tissue

Question 37

what are the functions of ground substances

Answer 37

- determines hardness and viscosity of tissue - regulates movement of substances between cells - prevents spread of microorganisms

Question 38

what are the 3 groups of ground substances

Answer 38

- glycosaminoglycans - proteoglycans - multi adhesive glycoproteins

Question 39

where is regular dense connective tissue found

Answer 39

- tendons and ligaments

Question 40

where is irregular dense connective tissue foud

Answer 40

reticular layer of dermis

Question 41

what do tendons consist of

Answer 41

fascicles of parallel collagen fibres

Question 42

what surrounds individual collagen fibres

Answer 42

fibrocytes which forms endotendineum

Question 43

what surrounds fascicles

Answer 43

protective layer of loose connective tissue with blood vessels and nerves called peritendineum

Question 44

what surrounds entire tendon

Answer 44

thicker layer of dense tissue - epitendineum

Question 45

what is adipose tissue

Answer 45

specialist type of connective tissue - composed of aggregation of adipocytes and reticular fibres

Question 46

what is the function of adipose tissue

Answer 46

- store fat - insults body from head loss - padding

Question 47

what is brown fat

Answer 47

mitochondrial protein called uncoupling protein which is involved in the main function of brown fat to generate heat

Question 48

what is the specific histological staining for reticular tissue

Answer 48

silver impregnation

Question 49

where is mucous tissue found

Answer 49

- principle component of Whartons jelly of umbilical cord - ground substance composed of hyaluronic acid, few fibres and fibroblasts

Question 50

what is the function of pigment tissue

Answer 50

protect organism against damaging effects of non-ionising UV irradiation

Question 51

what is melanin a determinant of

Answer 51

- skin colour - iris - stria vascularis of inner ear - birthmarks - some nuclei in brain

Question 52

what is white/ yellow adipose tissue

Answer 52

1 big droplet of fat found in adults

Question 53

what is brown adipose tissue

Answer 53

a lot of small droplets with lots of mitochondria

Question 54

what is reticular tissue made from

Answer 54

reticular cells and reticular fibres - also called lymphatic tissue

Question 55

what does reticular tissue produce

Answer 55

stroma of lymph nodes, spleen and red bone marrow - is part of immune system