Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Human Form and Function > Epithelium and Connective Tissue > Flashcards

Epithelium and Connective Tissue Flashcards

1
Q

Epithelial Tissue

A

Aggregated Polyhedral Cells, small amount of extracellular matrix (ECM).
Functions: Protective Lining ( can be specialized), Glandular Secretions and Transport

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

Connective Tissue

A

All sorts of different cell types. Some fixed, some forever voyaging. Generally quite a bit of ECM
Functions: Support and protect body structures, i.e. tends to attach epithelial tissues etc.

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

Muscle Tissue

A

Contractile tissue. NB: A muscle contains connective tissue, but muscle tissue is distinct (moderate amount of ECM)

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

Nervous Tissue

A

Conducts nerve impulses. Very little ECM

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

Epithelium has 3 primary functions:

A
  1. Covering, lining and protecting surfaces (Skin/epidermis)
  2. Absorption (intestinal lining)
  3. Secretion (e.g. Parenchymal cells of the gut)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Basement Membrane

A

ECM sheet attaching epithelium to connective tissue.
Cells anchored to basement membrane via HEMIDESMOSOMES.
50-100nm thick.
3 zones: lamina lucida, lamina densa, lamina fibroreticularis (epithelial tissue)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Epithelial Tissues are classified based on 2 factors:

A
  1. Layering (how many cells contact the basement membrane)

2. Shape of cells at the surface

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Epithelial Types

A
  1. Squamous (simple & stratified)
  2. Cuboidal (simple & stratified)
  3. Columnar (simple & stratified)
  4. Urothelium
  5. Pseudostratified columnar
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Cytoskeletal Components (3)

A
  1. Microfilaments
  2. Intermediate Filaments
  3. Microtubules
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Microfilaments

A

Composed of Actin.
6-8nm in diameter.
Structural function, microvilli, filopodia, gives shape to the cells
Forms tracks for myosin, giving contractility

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

Intermediate Filaments

A

Different in various tissues; vimentin (mesenchymal origin), cytokeratin
Around 10 nm in diameter
Anchors, structural
Non-contractile

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

Microtubules

A

Tubulin
Around 25 nm in diameter (bigger than other two)
Monorail system (kinesins); Cilia and Flagella (dynein)

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

How do cells attach?

A
  1. Tight junctions (Zonula Occludens)
  2. Cell to cell adhesive junctions (Zonula adherens)
  3. Focal Adhesion Junctions
  4. Desmosomes
  5. Hemidesmosomes
  6. Gap Junctions
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Tight Junctions (Zonula Occludens)

A

Homotypical interactions between transmembrane proteins.
Very narrow gaps between cells, controls movement of ‘stuff’ between cells
Maintains cell polarization
Bind to actin microfilaments
Roles in various cell signaling pathways

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

Cell to Cell Adhesive Juctions (Zonula Adherens)

A

Holds cells together (important)
Contact inhibition - cells knows what cells are around it and when they’re not they just keep growing and cancer forms.
Cadherins (outside) + Catinins (inside) complexes
Cadherins are Ca+ dependent
Vinculin and actinin attachments to actin filaments
Gap of 20nm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Focal Adhesion Junctions

A

Hold cells to extracellular matrix (bind cells to surfaces)
Similar to Cell-cell adhesions
Integrins replace cadherins as transmembrane component
Integrins interact with many ECM proteins eg collagen, fibronectin
Integrin receptors: role in cell signaling
Vinculin, actinin and talin attachments to actin filaments

17
Q

Desmosomes

A 
More Cell-Cell Adhesion
Attach to intermediate filaments
Heterotypical interaction
Gaps of 25 nm 
Help resist shearing forces
18
Q

Hemidesmosomes

A

More Cell-Matrix adhesion
Similar in appearance to desmosome (intracellular plaque visible)
Attach to intermediate filaments
Tightly attach to basal lamina by integrin-laminin and collagen XVII
Resist shear

19
Q

Gap Junctions

A 
Cell-Cell Aqueous Pores
6X connexins = 1X Connexon
Forms a 2nm pore, 2-3 nms between cells
Ions and small water soluable molecules may pass nucleic acids, sugars and proteins too large 
Propagation of electrical signals
20
Q

Progenitor Cells (pluripotent)

A

Turn into epithelial cells

21
Q

Epithelial Function: Protection

A

Provides a physical barrier due to junctions
Augmented by various secretions: mucus + cilia to trap and move things along, defensins in some cases
Provides a zone for antigen detection
Ex. ‘barrier epithelia’ skin, upper respiratory tract, oral mucosa, gut, urinary system

22
Q

Epithelial Function: Transport

A

Selective way
Active or Passive transport
Can secrete things (mucus/fluid) and can absorp things (GI tract)
Blood gases passively diffuse across an epithelial barrier
Most interactions with the outside world occur across an epithelial barrier

23
Q

Basic Characteristics of Connective Tissue

A

Cells are generally separated by ECM, generally not linked together. It is generally holding some other tissue in place, and not at a free (i.e. ‘outside’) surface.
Consists of cells, ECM fibers, and ECM ground substance
Cells derived from mesoderm, contains multipotent mesenchymal progenitor cellls

24
Q

Connective Tissue Function

A
  1. Mechanical/protective support of other tissues
  2. Stores interstitial fluid, water, electrolytes
  3. Involved in early repair of damaged organs, if repairs not complete, can lead to permanent scar formation/fibrosis
  4. Contains immune system cells and presents a physical barrier so provides defense and protection
25
Q

Fibroblasts

A

-Main go-to cell of connective tissue
-Highly motile, involved in ECM production and tissue repair
-Rarely have cell-cell connections (exception: periodontal ligament)
-Often have cytoskeletal (actin) connections from integrins to fibronectin the ECM (fibronexus)
-Many subtypes in many different tissues (pulp, PDL, oral mucosa)
-Fibroblasts age- slower healing with age
incredible diversity of secretory products

26
Q

Collagen

A 
Triple Helical Structure
Most abundant protein in the body
Dentin: mostly type I, some type III
Pulp: Mixture of collagen type I and III
Cartilage: type II
Basement membrane: Collagen IV
27
Q

Elastin

A

Fibroblast product

assembled into sheets or fibers

28
Q

Connective Tissue Ground Substance

A

Everything in between the cells (mainly proteoglycans and glycoproteins)
Gel-like
Gives compressive strength to tissues (cartilage)

Human Form and Function (1 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions