L6. Connective Tissues

Question 1

What are the functions of connective tissues

Answer 1

1. provide structural support
2. lipid storage
3. medium for exchange
4. protective function
5. defence

Question 2

Where do connective tissues originate from?

Answer 2

mesenchyme / mesenchymal layer

Question 3

What does the C.T consists of

Answer 3

• ECM

- cells

Question 4

Which tissue type has the most ECM?

Answer 4

CT

Question 5

Describe C.T

Answer 5

• made up of ECM and cells
• derived from the mesenchyme
• vascularized

Question 6

What makes up the ECM

Answer 6

• Ground substances

- Fibers

Question 7

What are the 3 different types of fibers?

Answer 7

collagen
reticular fibers
elastic fibers

Question 8

What are the 3 different ground substances?

Answer 8

GAG
proteoglycan
glycoprotein

Question 9

What is the characteristics of GAG

Answer 9

-vely charged
attracts Na+
attracts H2O ; allows high compression
long chains of carbohydrate
stains blue on HE stain

Question 10

What is the characteristic of proteoglycan?

Answer 10

hydration allows for diffusion 
contains GAG chains (long+unbranched) 
attracts water 
90% of weight is due to GAG 
compressive
stains blue in HE
keeps CT hydrated and gel like

Question 11

What is the function of glycoprotein?

Answer 11

• acts as an adhesive
• link components of the ECM together
• link ECM to cells
• up to 60% of mass is due to short branched sugar chains

Question 12

What is the characteristic of collagen?

Answer 12

• collagen type 1 fibers have more tensile strength
• thick , appear in bundles
• consists of tropocollagen ( 3 interwoven collagen peptide helices) to make fibrils
• appears STRIATED

Question 13

What is the characteristic of reticular fibers?

Answer 13

Forms a reticular net
found in highly cellular organs
type 3 collagen fibers that are highly glycosylated

Question 14

What is an example of proteoglycan?

Answer 14

aggracan

Question 15

What is an example of glycoprotein

Answer 15

fibronectin

Question 16

What is the characteristic of elastin?

Answer 16

distensible elastin polymers
glycoprotein wrapped around elastin polymers
found in tissues where stretch /coil is needed

Question 17

What structure will have elastin?

Answer 17

vessels ( like artery)

Question 18

What structure will have reticular fibers?

Answer 18

lymphoid nodes

Question 19

What progenitor cells can be found in the ECM in CT?

Answer 19

hematopoietic stem cells

mesenchyme stem cells

Question 20

What cells are derived from the mesenchyme stem cells

Answer 20

fibroblast
adipocytes
pericytes

Question 21

What cells are derived from the hematopoietic stem cells

Answer 21

plasma cells
mast cells
macrophages

Question 22

What are the characteristics of fibroblast?

Answer 22

• large nucleus
• extensive ER and golgi
• derived from undifferentiated mesenchymal cells
• most abundant cell in CT

Question 23

What are the characteristics of pericytes?

Answer 23

• attach to vessels stabilize them
• contractile
• pleuripotent stem cell properties

Question 24

What are the characteristics of adipocytes?

Answer 24

• cytoplasm filled with lipid droplets
• separated by dense irregular CT called septae
• nuclei is eccentric
• lipids are washed out during dehydration

Question 25

What are the characteristics of mast cells?

Answer 25

-part of inflammation response secretes histamine (vasodilator, broncho constrictor) and heparin(anti-coagulant) sensitive to pollen, foreign particules

Question 26

What are the characteristics of macrophages?

Answer 26

numerous vacuoles, vesicles, endosomes,lysosomes kidney shaped nucleus motile phagocytic derived from monocytes

Question 27

What are the characteristics of plasma cells?

Answer 27

clock face nucleus prominent golgi apparatus ( pale staining) prominent RER ( STAINS BLUE) differentiated lymphocytes

Question 28

What is the 5 types of connective tissue

Answer 28

1. loose connective tissue 2. regular dense connective tissue 3. irregular dense connective tissue 4. reticular C.T 5. adipose C.T

Question 29

Describe the loose connective tissue

Answer 29

high cells high Ground substance low fibers high diffusion index, flexible, mallaeble

Question 30

Describe the regular dense connective tissue

Answer 30

resistant to stress in one direction low cell , low ground substance lots of collagen type 1 fibers high amount of fibers

Question 31

Describe the irregular dense connective tissue

Answer 31

high amount of fibers resistant to stress in all directions may contain elastin fibers and collagen type 1 fibers fibers are irregularly arranged in all directions

Question 32

Describe the reticular C.T

Answer 32

highly cellular many reticular fibers ( type 3 collagen)

Question 33

Describe the adipose C.T

Answer 33

high number of adipocytes in groups ( lobules) | lobules are separated by sleeves of irregular connective tissue

Question 34

Where do we find loose connective tissue

Answer 34

lamina propria

Question 35

Where do we find regular dense connective tissue

Answer 35

found in tendons, muscles, ligaments

Question 36

Where do we find irregular dense connective tissue

Answer 36

found in dermis of skin and covering os some organs

Question 37

Where do we find reticular C.T

Answer 37

found in lymphoid structures

Question 38

Where do we find adipose C.T

Answer 38

dynamic, found in many CT sites ( hypodermis)

Question 39

What is the parenchyma

Answer 39

epithelial secretory unit

Question 40

what is the stroma (for epithelial morphogenesis and support)

Answer 40

surrounding connective tissues in gland

Question 41

What is a gland?

Answer 41

surface epithelial cells that penetrate underlying connective tissues and secrete substances they syntehsize

Question 42

Unicellular glands are

Answer 42

single secretory cells that embed in a surface epithelium

Question 43

Multicellular glands are

Answer 43

clusters of secretory cells surrounded by CT | secrete into a duct

Question 44

What are the 2 types of multicellular gland systems

Answer 44

1. simple : only 1 duct ( no branch) | 2. compound: more than 1 duct ( branch)

Question 45

What are the 2 shapes of a secretory unit

Answer 45

1. tubular | 2. alveolar

Question 46

What are the 2 types of secretory glands ( what they secrete)

Answer 46

1. serous gland | 2. mucous gland

Question 47

What is a serous gland

Answer 47

secrete a enzyme-rich fluid, cytoplasm of parenchymal binds to eosin (eg. pancreas)

Question 48

What is a mucuos gland

Answer 48

secrete glycoprotein and proteoglycans that form a lubricant; bind to heotoxylin ( blue- due to -ve charge) (eg. salivary gland)

Question 49

Give an example of a serous gland

Answer 49

pancreatic duct

Question 50

Give an example of a mucous gland

Answer 50

salivary gland

Question 51

What are fixed cells in the C.T?

Answer 51

``` mast cells adipocytes fibrocytes pericytes (sometimes macrophages) ```

Question 52

What are transient cells in the CT?

Answer 52

numerous WBC, plasma cells