connective tissues

Question 1

what are connective tissues? give examples

Answer 1

tissues that connect, supports, binds or separates other tissues/ organs e.g. bone, ligament, fat

Question 2

give three roles of connective tissues

Answer 2

• binds and supports other tissues e.g. ligaments
• protects and insulates organs e.g. fat
• transports nutrients e.g. blood

Question 3

what is the principal cell of connective tissues and what does it produce?

Answer 3

fibroblasts produce collagen and other intercellular materials

Question 4

what can fibroblasts differentiate into?

Answer 4

cells responsible for producing CT e.g. chondroblasts which make cartilage and osteoblasts which produce bone

Question 5

where do all connective tissues derive from?

Answer 5

mesenchyme, which is a loose and fluid type of embryonic tissue derived from mesoderm layer

Question 6

what do all connective tissues contain?

Answer 6

cells, large amounts of amorphous ground substance and protein fibres

Question 7

what doesn’t ground substance include?

Answer 7

fibres such as collagen and elastic

Question 8

describe blasts?

Answer 8

immature cells that secrete matrix

Question 9

describe cytes?

Answer 9

mature cells that maintain matrix

Question 10

what is the matrix

Answer 10

protein fibres embedded in ground substance; compromised of proteoglycans; contains living cells and can be fluid, gel or solid

Question 11

what are the three roles of amorphous?

Answer 11

• supports cells
• binds cells
• acts as medium for exchange

Question 12

what are the two types of protein fibres

Answer 12

collagen and elastic

Question 13

describe arrangement and properties of collagen

Answer 13

• made from fibrous protein subunits linked to form a long straight fibre
• tough and resistant to tension but still flexible
• arranged in bundles

Question 14

describe properties and make up of elastic fibres

Answer 14

• consists of protein elastin which can be stretched 150% of relaxed length
• always returns to original shape e.g. skin
• contains lesser amounts of other proteins/ glycoproteins

Question 15

how are dense connective tissues arranged?

Answer 15

parallel to direction of forces exerted on particular body part where tissue is located

Question 16

what is dense regular tissue? Give two examples

Answer 16

Provides strong attachments between structures in one direction e.g. ligaments attach bone to bone= stabilise joints/ restrict excessive motion and tendons attach muscle to bone and transmit tensile loads

Question 17

do ligaments or tendons have more elastic fibres?

Answer 17

ligaments have more whereas tendons have few elastic fibres compared to ligaments

Question 18

what does dense regular tissue contain?

Answer 18

fibroblasts to produce collagen for the matrix as fibres are in parallel bundles to allow great tensile strength; some elastin fibres

Question 19

what is dense irregular tissue? give an example

Answer 19

provides strength in multiple directions e.g. deep fascia has sheet of connective tissues surrounding and protecting the muscle as dense irregular holds muscles together and separates into functional groups

Question 20

what does dense irregular tissue contain

Answer 20

fibroblasts and matrix consists of collagen fibres randomly arranged with a few elastin fibres

Question 21

what is the main difference between dense regular and irregular?

Answer 21

arrangement of fibres; all fibres oriented in one direction in dense whereas irregular fibres have multiple orientations

Question 22

what does cartilage contain?

Answer 22

tough and flexible CT that contains polysaccharides called chondroitin sulphates which bind with ground substance proteins to form proteoglycans

Question 23

what is embedded within the matrix of cartilage and what does it occupy?

Answer 23

chondrocytes occupy lacunae

Question 24

what are the three functions of cartilage?

Answer 24

• allows tissues to bear mechanical strength
• forms framework supporting soft tissues in respiratory tracts, ear, nose
• provides shock absorber

Question 25

what are the three types of cartilage?

Answer 25

hyaline, fibrocartilage and elastic cartilage

Question 26

what is hyaline cartilage? describe what it contains

Answer 26

most common form that consists of short and dispersed collagen as well as proteoglycans to cover articular surfaces at joint ; homogeneous

Question 27

where is hyaline cartilage found in adults?

Answer 27

forms articular surfaces of long bones, rib tips, rings of trachea and parts of skull

Question 28

what is shown if hyaline cartilage is under a microscope?

Answer 28

appears clear (translucent protoplasm) with cells located in spaces scattered in transparent background

Question 29

what are the three functions of hyaline cartilage ?

Answer 29

- reduces friction and absorbs shock - strong and flexible; found in nose and rib cage as covers bones where they meet moveable joints - at ends of bones to allow continued growth into adulthood

Question 30

what is fibrocartilage?

Answer 30

thick bundles of collagen fibres so it is tough and hence can resist pressure but also flexible

Question 31

what does fibrocartilage form between joints? give an example

Answer 31

discs and rings e.g. intervertebral discs

Question 32

what is elastic cartilage?

Answer 32

contains elastic fibre network and collagen as well as proteoglycans ; gives great flexibility so can withstand repeated bending

Question 33

where is elastic cartilage found?

Answer 33

- external ear flaps of many mammals to provide support