connective tissues

Question 1

what is connective tissue?

Answer 1

the most abundant tissue in the human body

Question 2

what are example of connective tissues?

Answer 2

• bone (structural integrity)
• cartilage (protects joints)
• tendons/ligaments (connects muscle to bone)
• adipose tissue (store energy)
• mesentery (connects intestine to abdomen
• layers under skin/around organs (support)

Question 3

what is the structure of tendons (connective tissue)?

Answer 3

• dense fibrous tissue
• fires run parallel, which increases strength to help transfer the force of muscle contractions to bone

Question 4

what are the components of connective tissue?

Answer 4

• ground substance
• fibres
• cells

Question 5

what makes up the extracellular matrix and what is its function?

Answer 5

ground substance and fibres

it provides structural and biochemical support for cells

Question 6

what is ground substance?

Answer 6

• provides biochemical support
• clear, semi-solid gel
• composed of glycoproteins and complex carbohydrates (hyaluronic acid and glucosamine)
• water binding ability
• provides tissue volume
• supports intracellular exchange of substances

Question 7

what are the two main types of fibres in connective tissue?

Answer 7

collagen and elastin

Question 8

what is the role of fibres in connective tissue?

Answer 8

• provides structural support and tensile strength

Question 9

describe collagen fibres

Answer 9

• strongest fibres
• most abundant fibres
• provide tensile strength
• secreted by ECM by connective tissue cells
• around 28 different types
• type 1- found in fibrous tissues eg dermis of skin
• type 2- hyaline cartilage contains this
• type 3- found in highly cellular organs eg liver- has a delicate branched reticular network

Question 10

describe elastin fibres

Answer 10

• long and branched
• wavy to provide stretch and recoil ability
• secreted into ECM by connective tissue cells
• found in the skin, lungs, blood vessels, bladder etc.

Question 11

what do - blast cells do?

Answer 11

synthesise the extracellular matrix

Question 12

what do -cyte cells do?

Answer 12

maintain the extracellular matrix

Question 13

what do -clast cells do?

Answer 13

breakdown the extracellular matrix

Question 14

what is the most common connective tissue cell?

Answer 14

fibroblasts- secrete fibres and components of ground substance

Question 15

what do odontoblast cells do?

Answer 15

synthesise dentine in the teeth

Question 16

what do adipocyte cells do?

Answer 16

maintain the ECM in adipose tissue

Question 17

what do osteoclast cells do?

Answer 17

recycle (breakdown) ECM in bone

Question 18

what makes connective tissue highly vascularised?

Answer 18

• blood vessels and lymphatics
• immune cells which survey tissues for invading pathogens/cell damage
• exceptions are cartilage, tendons and ligaments

Question 19

what is loose connective tissue proper mostly made up of?

Answer 19

ground substance (fewer fibres)

Question 20

what is dense connective tissue proper mostly made up of?

Answer 20

fibres

Question 21

what are examples of loose connective tissue proper?

Answer 21

• areolar
• adipose
• reticular

Question 22

describe areolar loose connective tissue

Answer 22

can be found beneath the skin, submucosa and surrounding capillaries
- universal packing material

Question 23

describe adipose loose connective tissue

Answer 23

can be found in isolation or in small clusters deep beneath the skin , breasts, abdomen and pads of fingers/toes
- energy storage, shock absorption and insulate

Question 24

what are examples of highly cellular organs?

Answer 24

liver, lymph nodes, spleen

Question 25

what are examples of dense connective tissues?

Answer 25

- dense regular - dense irregular - elastic

Question 26

describe regular dense connective tissue

Answer 26

closely packed collagen fibres running in the same direction, providing tensile strength - found in tendons and ligaments

Question 27

describe irregular dense connective tissue

Answer 27

closely packed interwoven fibres fibres running in different directions - found in dermis of skin and forming a protective capsule around organs

Question 28

describe dense elastic connective tissue

Answer 28

it is the only dense regular tissue dominated by elastic fibres- allows stretch and recoil - found in arteries, skin, lungs and underlying epithelium

Question 29

what is scurvy?

Answer 29

- a disease caused by a lack in vitamin C - defective collagen formation - leads to loose teeth, skin haemorrhages and even death - treated with vitamin C - symptoms include fatigue, gum disease, anaemia, poor wound healing etc.

Question 30

what is vitamin C required for?

Answer 30

collagen synthesis - it has a triple helix structure arising from collagens unusual abundance of amino acids, glycine, proline and hydroxyproline - without the structural support from collagen, blood vessels, tendons and skin become fragile

Question 31

what is SLE?

Answer 31

systemic lupus erythematosis - autoimmune disease - target tissues which antigens attack include skin, bones, tendons and kidney - oral symptoms include dry and painful oral cavity - oral manifestations are the buccal and palatal lesions

Question 32

what is sjogren's?

Answer 32

an autoimmune disease - affects the glands which produce tears and saliva - symptoms include dry eyes and mouth - oral manifestations are increased dental caries and candidiasis - can occur independently or accompany other disorders eg SLE