connective tissue

Question 1

what do all connective tissues have in common

Answer 1

cells, extracellular fibres and a fluid called ground substance

Question 2

give 6 functions of connective tissues

Answer 2

provide structural framework for the body, transport substances from one region to another, provide protection for delicate organs, support + surround + interconnect other tissue types, store energy, defend the body from invasion by microorganisms

Question 3

what is connective tissue proper

Answer 3

loose connective tissue and dense connective tissue (subdivided into dense regular and dense irregular). these are distinguished by the ratio of ground substance to fibrous tissue

Question 4

give a brief description of the composition of connective tissue proper

Answer 4

contains fibres, viscous ground substance, fixed cells and wandering cells

Question 5

what are fixed cells

Answer 5

stationary cells that are involved in local maintenance, repair, defense and energy storage

Question 6

name the 4 types of fixed cells

Answer 6

fibroblasts, fixed macrophages, adipocytes, stem cells

Question 7

what are fibroblasts

Answer 7

slender/star shaped cells that synthesise and secrete connective tissue fibres + hylauronic acid of ground substance

Question 8

what are fixed macrophages

Answer 8

are scattered among fibres and phagocytose damaged cells and pathogens

Question 9

what are adipocytes

Answer 9

these are fat cells consisting of a single enormous fat droplet and the number of them depends on the type of Connective Tissue (CT)

Question 10

what are stem cells

Answer 10

cells which respond to injury or infection by dividing to produce daughter cells that differentiate into fibroblasts, macrophages or other CT cells

Question 11

what are wandering cells

Answer 11

include free macrophages which are highly mobile, and mast cells

Question 12

what are mast cells

Answer 12

found near blood vessels and are packed with histamine and heparin.

Question 13

what does histamine do

Answer 13

increases blood flow to the area

Question 14

what does heparin do

Answer 14

prevents blood clotting

Question 15

what are the three basic types of fibre

Answer 15

collagen, reticular, elastic

Question 16

what are the features of collagen

Answer 16

long straight unbranched, each fibre is a bundle of fibrils composed of protein collagen. the fibres are strong and stiff

Question 17

describe the structure of reticular fibres

Answer 17

these contain collagen fibrils interwoven into a tough flexible network

Question 18

describe the structure of elastic fibres

Answer 18

they contain protein elastin, they are branched and wavy, return to original length after being stretched

Question 19

write a note on areolar connective tissue

Answer 19

surrounds blood vessels, nerve bundles, muscles and organs. fills spaces between organs and connects skin to muscle

Question 20

write a note on adipose tissue

Answer 20

lipid rich (from adipocytes) connective tissue. comprises 20-25% of total body weight in healthy people. main function is to store energy as lipids/fat

Question 21

write a short note on reticular tissue

Answer 21

reticular fibres form a thin reticular network. these are found in diff tissues and support frameworks in the liver, lymphoid organs, capillary endothelia and muscle fibres

Question 22

write a note on dense regular connective tissue

Answer 22

collagen fibres are densely packed + parallel. found in ligaments and tendons

Question 23

write a note on dense irregular connective tissue

Answer 23

fibres are not parallel, and consists of mostly collagen fibres. has less ground substance than loose connective tissue

Question 24

what is the firm gel called that makes up the ground substance in cartilage

Answer 24

chondroitin

Question 25

what are chondrocytes

Answer 25

they are the only cells found in health cartilage and they are located in pockets called lacunae. they lack nerve fibres. they are avascular (obtain nutrients via diffusion through matrix)

Question 26

what are three types of cartilage

Answer 26

hyaline, elastic, fibrocartilage

Question 27

what does avascular mean

Answer 27

that nutrients are obtained through diffusion through matrix

Question 28

write a note on hyaline cartilage

Answer 28

most abundant, contains a lot of collagen fibres. tough and slightly flexible. located connecting ribs to sternum, embryonic skeleton, covers the end of long bone, nose, trachea, pharynx

Question 29

write a note on elastic cartilage

Answer 29

contains a lot of elastic fibres, maintains the shape of a structure while allowing great flexibility. located in external ear, epiglottis, vocal chords

Question 30

write a short note on firbocartilage

Answer 30

has little matrix with a lot of collagen fibres. provides tensile strength with the ability to absorb compressive shock. located in intervertebral disks, bones of pelvis, disks of knee joint