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Physiology > Tissues & Extracellular Matrix > Flashcards

Flashcards in Tissues & Extracellular Matrix Deck (32)
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1
Q

Four types of tissue

A

Nervous, Muscle, Epithelial, Connective

2
Q

What makes Nervous tissue distinct?

A

Electrical impulses

3
Q

What makes muscle tissue distinct?

A

Contractile capabilities

4
Q

What are the three functions of epithelial tissue?

A
  1. Absorption (nutrients) 2. Secretion (mucus, glands) 3. covering, lining, protecting (tissue)
5
Q

What does epithelial tissue protect?

A

Integumentary system, GI tract, respiratory canal etc

6
Q

True/False: Epithelial tissue is vascular tissue

A

False

7
Q

Why is epithelial tissue avascular?

A

Cells are packed tightly together, leaving no space for blood vessels

8
Q

What is a basement membrane?

A

Basal lamina (epithelial cells) + Reticular lamina (connective tissue cells)

9
Q

How are the cells in lower layers different than other cells in epithelium?

A

They are usually mitotic - actively dividing and creating new cells to replace those towards the top. However, more mitosis usually leads to a potential for mistakes

10
Q

What are the two types of epithelial cells?

A

Membranous (lining & protection) and Glandular (secretion/absorption)

11
Q

What are the two parts of the basal lamina?

A

Lamina lucida (looks like empty space) and Lamina densa

12
Q

What are the functions of connective tissue?

A
  1. Binds structures together 2. Provides support, structure, and protection
13
Q

What are notable characteristics of connective tissue?

A
  1. Well vascularized
  2. Composed of cells & supporting ECM
  3. Cells are usually spaced far apart, not in direct contact with each other
14
Q

What is the ECM and what is it comprised of?

A

Predominantly associated with connective tissue

Comprised of:

  • Fibers
  • Ground Substance
15
Q

What are the three types of collagen?

A
  1. Fibrillar
  2. Sheet-forming
  3. Linking/anchoring
16
Q

Describe Fibrillar collagen

A
  • Long, thick strands
  • Types 1-3 collagen
  • Types 1&2 can be seen with a light microscope
17
Q

Describe sheet-forming collagen

A
  • Interlaced network of ultra-thin strands
  • Type IV
  • Major structural component of basal lamina
18
Q

Describe Linking/anchoring collagen

A
  • Short strands - connect fibrillar collagens to each other and to other components within the ECM
  • Type VII collagen - anchors reticular lamina to basal lamina
19
Q

Describe Reticular fibers

A
  • very thin fibers formed predominantly of type III collagen
  • main component of reticular lamina
  • forms flexible scaffolding within orgains like liver, spleen, lymph nodes, & red bone marrow
  • may be found scattered throughout ground substance
20
Q

Describe elastic fibers

A

thin fibers primarily made of the protein elastin, overlaid on scaffolding of glycoproteins

21
Q

Describe the ground substance

A
  • “maple syrup consistancy”
  • transparent mixture of macromolecules, widely varying in consistency
22
Q

What are the three components of ground substance?

A
  1. GAGs (glycosaminoglycans)
  2. Proteoglycans
  3. Glycoproteins
23
Q

What are glycosaminoglycans?

A

long linear polysaccharides

highly hydrophilic

highly viscous

polyanionic (negatively charged, attracting positively charged molecules)

24
Q

What is the largest and most ubiquitous glycosaminoglycan?

A

Hyaluronic Acid

(highly hydrophilic, lubricates joints/membranes)

25
Q

What are the 4 sulfated GAGs?

A
  1. Dermatin (epithelial production; skin)
  2. Chondroitin (cartilage)
  3. Keratan (hair/skin/nails)
  4. Heparin (blood)
26
Q

What are proteoglycans?

A

Large molecules consisting of numerous sulfated glycosaminoglycans bonded covalently to a large rod-like core protein (aggrecan & syndecan)

27
Q

What are glycoproteins?

A

Large, globular proteins covalently bonded to large monosaccharide chains (e.g. fibronectin; laminin)

28
Q

How does the ground substance hold/support fibers and cells?

A
  1. Linkages between cell-surface protein molecules & GAGs and/or glycoproteins anchor the cell in place
  2. GAGs & glycoproteins bind to the fibers, anchoring them & connecting them to cells/each other
  3. laminins bind underside of epithelial cells to fibers, creating basal lamina
29
Q

What are additional functions of the ground substance?

A
  • Passes nutrients from blood supply to cells
  • Passes waste from cells to blood supply via diffusion
  • Facilitates/regulates cell to cell communication in ECM
30
Q

What is interstitial/extracellular fluid?

A

Fluid in connective tissue that is not bound up by large molecules of ground substance

31
Q

What is interstitial fluid derived from?

A

Blood plasma via diffusion/filtration

*Much lower concentration of blood proteins because most proteins are too large to cross the vessel wall

32
Q
A