Connective Tissue Flashcards Preview

Cell Biology Exam 2 > Connective Tissue > Flashcards

Flashcards in Connective Tissue Deck (52):
1

Function of Connective Tissue

-Structure
-Defense and protection
-Nutrition
-Fat deposit for cushioning, insulation, and energy reserves

2

Where does connective tissue derive from

mesoderm and neural crest from ectoderm

3

Chondroblasts

responsible for synthesis and elaboration of the ECM's associated cartilage

4

Osteoblast

synthesis and elaboration of bone

5

Where do undifferentiated mesenchymal cells come from

mesoderm and in some ares of the body can also come from neural crest cells from ectoderm

6

Function of active fibroblasts

synthesize and elaborate components of ECM

7

Organelles of active fibroblasts

-euchromatic nucleus
-large column of rER and thus also a basophilic cytoplasm
-Well-developed golgi apparatus seen proximate to the nucleus
-Mitochondria to supply fuel for protein synthesis

8

Inactive fibroblasts are also called

quiescent or fibrocyte

9

Organelles of inactive fibroblasts

-decreased rER
-less elaborate golgi
-slender nucleus and condensed chromatin
-more eosinophilic cytoplasm

10

Cortisol

has putative antifibrotic activities including inhibition of fibroblast growth and deposition of collagen
-Prolonged administration can lead to decrease in bone

11

Why do active fibroblasts have increased activity

due to need to synthesize extracellular material for wound healing. Greater capacity to divide during wound healing

12

What happens if you are defienct in vitamin C

hydroxylation step is compromised, get decreased collagen synthesis - scurvy

13

Procollagen peptidases

Will enzymatically cleave the propeptides to make the molecules less soluble so they can assemble.

14

Extensions of helix

propeptides on each end, which maintain the solubility of this structure and can be processed internally by fibroblast

15

Myofibroblasts

-Possess characteristics of fibroblasts and smooth muscle cells
-Has actin and myosin (so they have contracile activity)
-become more numerous in wound healing

16

Dupuytren's contracture

-Palmar aponeurosis, a triangular shaped collagenous structure in palm of hand
-Repair of microvascular ischemia in tissue leads to active myofibroblast and fibroblasts
-Increased elaboration of type III collagen, which forms cross links with myofibroblasts, leading to contractions of 4th and 5th digits

17

White adipocytes

-look like empty spaces, tissue processing removes the lipid droplet, leaving a signet ring appearance
-Nucleus pushed out to periphery

18

Apidocytes

synthesize leptin, thus have endocrine function

19

Leptin

works to suppress appetite by signaling decrease in caloric intake
-mutation leads to morbid obesity

20

Lipdystrophies

-can be acquired or due to genetic defect
-loss of body fat may be general or confined to specific body regions

21

Brown adipocytes

-multilocular
-nucleus is centrally located
-peripherally located cytoplasm, which is acidophilic due to large column of mitochondria
-cancer of brown adipose tissue is rare but possible

22

Functions of brown adipose tissue

produce heat, especially in newborns to regulate body temperature

23

Why do infants need brown fat

-they can't shiver
-ATP synthesis capability is uncoupled so we use mitochondrial steps to produce heat rather than to synthesize ATP

24

Do adults have brown fat?

Yes, some. Can be seen by putting them in a cold environment then imaging

25

Mast cell

has metachromatic granules.

26

What happens when antibody antigen complex binds to RC receptor on cell surface of mast cell

-cell massively releases its contents
-leads to increased mucous, vasodilation, and bronchospasms due to leukotrienes.

27

Macrophage

-derived from monocyte
-centrally located nucleus with an indentation, well developed rER and golgi complex primarily to form lysosomes

28

What types of phagocytic cells are derived from a monocyte

microglia, Kupffer cells in liver, alveolar macrophages in lug, and osteoclasts in blood

29

Giant Cells

-macrophages fuse together in states of chronic inflammation

30

Migratory cells

migrate into CT from blood

31

Plasma cell

-Basophilia
-Large negative Golgi
-Clock face nucleus
-antibodies are secreted via the constitutive pathway

32

2 waves of leukocytes in response to cardiac injury

-1st wave - neutrophils
-2nd wave - monocytes (~2 days after damage)

33

Function of neutrophils

clean up and remove damaged tissue

34

Classifications of Connective Tissue

embryonic, proper, and specialized

35

2 subclasses of embryonic

mesenchymal and mucus

36

CT proper has 2 subclasses

loose or dense

37

dense connective tissue

arranged in irregular or regular pattern

38

specialized connective tissue types

1. adipose
2. reticular
3. cartilage
4. bone
5. blood

39

Mesenchymal connective tissue

-least differentiated
-large amount of ECM materials, including group substance and type 3 reticular fibers

40

Mucous connective tissue

-found in wharton's jelly in umbilical cord
-Expansion of ECM and fibroblasts where type I and III collagen are being formed

41

Loose connective tissue

-abundant, viscous, amorphous with hyaluronic acid, GAGs, proteoglycans, and glycoproteins
-lies immediately deep to epithelium and surrounds blood vessels

42

Cells present in loos connective tissue

fibroblasts, macrophages, adipose cells, mast cells, and undifferentiated cells

43

Dense regular collagenous connective tissue

-type I collagen fibers (acidophilic) densely arrayed in parallel
-elongated, basophilic nuclei of fibroblasts
-ex) tendons and ligaments

44

Ligaments

-fibers less regularly arranged, higher % of ground substance, and a greater mixture of elastic fibers
-constitute of dense cartilaginous tissue
-greater degree of stretch due to elastic fibers

45

Mucoid degeneration of anterior cruciate liagment

-pt presents with knee pain or restricted movement
-in the MRI, ACL has celery stalk appearance
-treatment usually not needed

46

Dense regular connective tissue of elastic fibers

-sparse, viscous, amorphous with hyaluronic acid, GAGs, proteoglycans, and glycoproteins
-Elastin forms thin sheets of fenestrated membranes. -Elastic fibers branch and run parallel to one another
-has fibroblasts
-located in: ligamenta flava, supensory ligament of penis, vocal ligament, and arteries

47

Elastin

forms lamellae and laminae in blood vessels

48

Dense irregular connective tissue

1.Sparse, viscous, amorphous with hyaluronic acid, GAGs, proteoglycans, and glycoproteins
2.Tightly packed, type I collagen fibers oriented in many axes. Elastic fibers are interspersed (and darker in color).
3.Scattered fibroblasts
4.Location: Organ capsules, dermis of skin. and sleeve around nerves

49

Ehlers-Danlos

-Defect in type I collagen
-Presents with hyperelasticity of skin, hypermobility of joints

50

Elastic tissue in dermis is susceptible to what

UV damage

51

Reticular tissue in liver

1.Little ground substance
2.Reticular fibers (type III collagen)
3.Reticulocytes and other cell types
4.Location: Red bone marrow, liver, and lymphatic tissues/organs

52

Adipose connective tissue

1.Spare ground substance
2.Reticular fibers are found between adipocytes
3.Adipocytes
4.Subcutaneous areas, abdominal cavity
5.Thin layers of cytoplasm, empty-looking cells