L5-L6 Connective Tissue I Flashcards

1
Q

What the basic functions of connective tissue? (5)

A
  1. Structural framework of the body
  2. Conducts and translates muscle contractions into movement
  3. Forms stroma of glands and organs
  4. Medium for metabolic exchange
  5. Site of fat and mineral storage
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

General characteristics of connective tissue

A
  1. Low cell density, extensive extracellular matrix
  2. Tend to be highly vascular (except cartilage)
  3. Most retain stem/ mitotic cells (tissue growth and regeneration)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is connective tissue composed of? Which of the two is the MAJOR constituent?

A

Cells, and ECM* which is the major constituent

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the extracellular matrix (ECM) made of? (2)

A
  1. Ground substance

2. Fibers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are the ECM’s ground substance and fibers characteristics? (3)

A
  • Determines physical properties
  • Varies greatly with tissue type
  • Synthesized and secreted by cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is ground substance? (3)

A
  • Colorless, transparent, gel-like
  • Highly hydrated
  • Mixture of macromolecules
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are the three substances in the mixture of macromolecules in ground substance?

A
  1. Proteoglycans (PGs)
  2. Glycosaminoglycans (GAGs)
  3. Multiadhesive glycoproteins
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are the GAGs? (3)

A

Glycosaminoglycans:

  • Repeating disaccharide units
  • Negatively charged, attracts Na+
  • Hydrating element of ground substance
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are the PGs?

A

Proteoglycans:

- GAGs (glycosaminoglycans) covalently bonded to core protein

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are the functions of PGs? (2)

A
  • Cushion against compression (keeps puffy(

- Aids in material exchange

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Features of ground substance? (2)

A
  1. Extremely large aggregates of PGs

2. Enhance role of GAGs in the tissue- “biological sponge”occupies large volume; resists fluid movement

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is specific to the adhesive glycoproteins of ground substance? Also what is bound to that?

A

Bind cells to ECM, which has cell (cytoskeleton) attached to it

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

The ECM is made of collagen & elastic too, what are some characteristics? (3)

A
  1. Determines physical properties
  2. Varies greatly with tissue type
  3. Synthesized and secreted by cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is exclusive about collagen?

A

Most common protein in the body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are features of collagen fibers?

A
  1. Fibrous proteins present in large quan in CT
  2. Imparts tensile strength (flexible but not elastic)
  3. Often self-assemble into higher-order structures: fibrils, fibers, bundles
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the organization of collagen?

A

Muscle -> Tendon -> Collagen fiber -> Fibril (one dark + one light = periodicity)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What are the collagen fibrils vs fibers?

A

Collagen FIBRILS- each one strand (earthworm like) whereas FIBERS is when the fibrils bundles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is the *most common type of collage and what are some characteristics (3)?

A

Type I collagen:

  • HIGHEST tensile strength
  • Gross: white
  • LM: pink (acidophilic..which means stains with Eosin) fibers and bundles with H & E
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Where is Type I collagen found?

A

Bone, teeth, ligaments/ joint capsules, tendons, dermis of skin, fibrocartilage (all places where we find periodicity = collagen*)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What are Type II collagen?

A

Slender fibrils found in cartilage (bendy)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What are Type III collagen?

A

Reticular (hatch) fibers

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is the function of Type III Collagen?

A

Functions to filter fluid: appears delicate, branching, dark-staining with silver, ex) found in lymph nodes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

At EM we can see the basement membrane, which is made out of? What do they each secrete?

A

Basal lamina (secreted by ET) + Reticular lamina (secreted by CT)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Collage is secreted by___?

A

Epithelial tissue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What type of collagen are next to the anchoring fibrils? What are anchoring fibrils?

A

Type III; another type of collagen

26
Q

What are elastic fibers? (3)

A
  1. Imparts elasticity
  2. If present, usually accompanies COLLAGEN (tensile strength + elasticity)
  3. Core of elastin surrounded by sheath of microfibrils
27
Q

Which are thinner or thicker between elastic fibers and collagen?

A

Elastic fibers are thinner and darker than the thicker collagen

28
Q

How to tell elastic fibers from reticular tissue?** (explaination)

A

In EM, elastic fibers are all in a mush.. vs reticular tissue are branching (also dont see reticular tissue near collagen.. rather we would see them in areas where there is a need to strain fluids..eg lymph draining liq)

29
Q

What do elastic fibers don’t do (when compared to reticular fibers)?

A

They do not branch like reticular fibers

30
Q

What are connective tissue cells (2 types cells) and what is a main example?*

A
  1. SOME cells originate in and permanently reside in CTs (long-lived); fibroblasts are examples since they make fiber
  2. MOST cells develop elsewhere, migrate into CT to perform functions (host defense, WBCs); mast cells, macropahges, leukocytes are examples
31
Q

What are fibroblasts? What do they look like under LM?

A
  • Most abundant & widely distributed of fixed cells (growth, would healing, scar tissue formation)
  • LM: oval and elongated nucleus
32
Q

What do fibroblasts look like under TEM?

A

Individual collagen fibers form at discrete sites along the cell membrane

33
Q

Fibroblasts vs fibrocytes? What is important about their relations to one another?

A

FIBROBLASTS: actively making something
FIBROCYTE: not working at the moment (heterochromatic)

They are the same cell- but 2 different morphs

34
Q

When looking at fibroblast slide? What are things you need to identify?

A
  • What is it making? Collagen
  • ER? (sER or rER) rER b/c of all studs that are ribosomes
  • Therefore collagen is made of protein
  • Any secretory vesicles? Maybe one or two
35
Q

Describe adipocytes. (3)

A
  • White, spheroid cells
  • Synthesize and store fat
  • Artifact of processing
36
Q

What are the two type of adipocytes?

A
  1. Unilocular

2. Multilocular

37
Q

What are characteristics of unilocular adipocytes? (4)

A
  • Most common adipocyte
  • Large cell
  • Eccentric nucleus w/ thin rim of cytoplasm (“signet ring”)
  • Fat stored as single lipid inclusion (lipid droplet)
38
Q

What are characteristics of multilocular adipocyte?

A
  • Located in “brown adipose tissue”(which prod own heat.. non-shivering, thermogenesis)
  • Fat stored in multiple lipid inclusions
  • more mitochondria, heat production
39
Q

What are features of mass cells? (5)

A
  • Commonly in connective tissue
  • Large cell with round, centrally-placed nucleus
  • Cytoplasm has many dark (basophilic) granules
  • Released following exposure to sensitized antigens
  • Granules: histamine, heparin, leukocyte chemotactic factor
40
Q

Where are mast cells found? Why in these areas specifically?

A
  1. Skin
  2. Digestive system
  3. Respiratory system

Most commonly exposed to outside world (immune has to be strong)

41
Q

Steps of immediate hypersenstivity or anaphylactic reaction during normal inflammatory response in mast cell?

A

Histamine –> Leukocyte chemotactic factors –> WBCs

42
Q

Macrophages What are they? (3)

A
  • Long-living cells that originate in bone marrow and migrate out
  • Develop from precursors called monocytes
  • Have different names and somewhat different functions in different organs, but usually involved in host defense
43
Q

Why are some lysosomes in macrophages dark or light?

A

Old/ new eating (different stages of degradation)

44
Q

Where do macrophages reside in?

A

Connective tissue

45
Q

Features of macrophages? (3)

A
  1. “Big eater”- phagocytosis
  2. Large, very irregular outline (pseudopodia)
  3. Phagosomes, lysosomes (bubbly appearance)
46
Q

What are some organelles of macrophages?

A

Lysosomes, ER (digestive enzymes, sER, mitochondria- moving around intensively)

47
Q

Why do macrophages have psuedopodia?

A

Phagocytosis

48
Q

Why are the organelles suited for in a macrophage? (2)

A
  1. Organelles suited for degrading phagocytosed material

2. Organelles suited for synthesizing and secreting substances for immune response & enzymes that breakdown

49
Q

What facilitates migration?

A

Connective tissue extracellular matrix

50
Q

Macrophages reside in __?

A

Connective tissue

51
Q

What cells are transient?

A

Plasma cells & leukocytes

52
Q

What do plasma cells do? (3)

A
  1. Synthesize & secrete antibodies - organelles (made out of protein to fight antigens)
  2. Eccentric nucleus w/ extensive euchromatin
  3. Found mainly in GI and respiratory tracts
53
Q

What are leukocytes and what do they do?

A

WBCs that migrate into CT to perform host defense

54
Q

What is the special relationship between epithelial tissue and connective tissue?

A

You CANNOT have epithelial tissue without connective tissue nearby

55
Q

What is loose areolar connective tissue? Functions (3)?

A
  • Sparse, loosely arranged fibers (“open” appearance)
  • Abundance of ground substance (PG)
  • Primarily beneath epithelium (so can float thru, etc)
  • Primary site of immune & inflammatory reactions
56
Q

Describe DENSE connective tissue? (3)

A
  • Abundance of bundled fibers
  • Little ground substance (compact appearance)
  • Can be regular or irregular (directionality of tensile strength)
57
Q

Irregular dense CT vs Regular dense CT?

A

Irregular dense CT: disorganized

Regular Dense CT: “Boxcar nuclei”, wavy appearance

58
Q

What kind of adipocyte makes up white fat? (white adipose tissue)

A

UNILOCULAR

59
Q

What is a type of multilocular tissue?

A

Brown adipose tissue

60
Q

Where is brown adipose tissue found it? (babies, adults?)

A

Children

61
Q

Reticular tissue: types (I-III) physical feature?

A

Type I: thick, Type II: cartilage, Type III: Reticular tissue

62
Q

Where is reticular tissue found?

A
  • Found in organs that filter blood or lymph

- Also found in endocrine glands