Histology - Connective Tissue

Question 1

What are 3 functions of connective tissue

Answer 1

Space filler and mechanical support; main fat and calcium store; attachment and protection

Question 2

Name the 2 types of connective tissue

Answer 2

Soft connective tissue; hard connective tissue

Question 3

What are the 4 types of resident cells of connective tissue

Answer 3

Fibroblasts; adipose cells; osteocytes; chondrocytes

Question 4

What are fibroblasts

Answer 4

Elongated cells with tapered ends that are widely distributed

Question 5

What is the function of fibroblasts

Answer 5

They produce and maintain the extracellular matrix

Question 6

What is the function of adipose cells

Answer 6

With the release of fatty acids into the bloodstream, they provide energy for other cells

Question 7

What does the extracellular matrix of connective tissue consist of

Answer 7

Fibres; ground substance; tissue fluid

Question 8

What is the most abundant protein in the human body

Answer 8

Collagen; makes up roughly 25% of total body protein

Question 9

Describe the structure of collagen type 1

Answer 9

Inelastic and has a tensile strength (on a weight for weight basis) similar to mild steel

Question 10

What are elastic fibres composed of

Answer 10

The proteins elastin and the microfibril fibrillin

Question 11

What are reticular fibres made of

Answer 11

These thin fibres are made of type III collagen

Question 12

What are the 2 types of soft connective tissue

Answer 12

Loose (most common) and dense

Question 13

Where can loose connective tissue be found

Answer 13

Mesentery; adipose tissue; stroma of many organs

Question 14

Name the 2 forms of dense connective tissue and give examples of each

Answer 14

Regular = fibres aligned (e.g. tendon); irregular = fibre bundles run in many directions (e.g. dermis of skin)

Question 15

What are the 2 types of hard connective tissue

Answer 15

Bone and cartilage

Question 16

Describe what cartilage is

Answer 16

Semi-rigid connective tissue consisting chiefly of scattered cells surrounded by an amorphous appearing ECM

Question 17

What does the ECM contain in hyaline

Answer 17

75% water; 25% organic material

Question 18

What is the connective tissue called that surrounds cartilage

Answer 18

Pericondrium

Question 19

How many layers does the pericondrium have; and name them

Answer 19

2; outer fibrous layer and inner chondrogenic layer

Question 20

What is the outer fibrous layer of the pericondrium’s main function

Answer 20

Provides support

Question 21

What does the inner chondrogenic layer of the pericondrium provide

Answer 21

New chondroblasts to the adjacent cartilage

Question 22

What does hyaline cartilage look like in real life

Answer 22

Blue-white and translucent

Question 23

Name the 3 types of cartilage

Answer 23

Hyaline; elastic cartilage; fibrocartilage

Question 24

Describe how elastic cartilage is different to hyaline cartilage

Answer 24

ECM contains a preponderance of elastic fibres, making it very flexible

Question 25

What is fibrocartilage a mixture of

Answer 25

Dense regular connective tissue and islands of cartilage cells and and cartilage matrix

Question 26

Is bone permeable

Answer 26

No

Question 27

Name the 5 main functions of bone

Answer 27

Support; levers for movement; protection; calcium store; haemopoiesis (formation of blood cells, esp. in bone marrow)

Question 28

What is bone composed of (include %)

Answer 28

Bioapatite (65%); collagen (23%); 10 & (water); non-collagen proteins (2%)

Question 29

What type of bone forms the outer shell of the shaft

Answer 29

Dense cortical

Question 30

What type of bone occupies the ends of bone (epiphyses)

Answer 30

Cancellous/trabecular

Question 31

What arteries provide the interior of bone

Answer 31

Osteonal arteries

Question 32

Name the 4 bone cells

Answer 32

Osteoblasts; osteocytes; osteoclasts; osteoprogenitor cells

Question 33

What is the function of osteoblasts; and how big are they

Answer 33

They are bone forming cells; roughly 15-30 micrometres across

Question 34

What are osteocytes; and how big are they

Answer 34

Bone cells trapped within the bone matrix; roughly 25 micrometres across

Question 35

What is the function of osteoclasts; and how big are they

Answer 35

Large multinucleated cells responsible for bone reabsorption; 40 micrometres across or more

Question 36

What is the function of osteoprogenitor cells

Answer 36

Serve as a pool reserve of osteoblasts

Question 37

What is the periosteum

Answer 37

Dense connective tissue sheath surrounding the bone except at articular surfaces

Question 38

How many layers does the periosteum have when bone is being made

Answer 38

2; an outer fibrous layer and an inner osteogenic layer of osteoprogenitor cells and osteoblasts

Question 39

How many layers does the periosteum have when no new bone is being made

Answer 39

Just 1; the inner layer is inconspicuous