3.4 Tissues of the Body

Question 1

What are tissues?

Answer 1

Assemblies of cells that perform specific functions in the body.

Question 2

What is histology?

Answer 2

The study of tissues, focusing on cell shape, size, arrangement, connections, and extracellular material.

Question 3

What is the extracellular matrix?

Answer 3

Material synthesized and secreted by tissue cells, essential for structure and communication.

Question 4

what are two components of the extracellular matrix (ECM)?

Answer 4

Proteoglycans and insoluble protein fibres like collagen, fibronectin, and laminin.

Question 5

What roles does the ECM play?

Answer 5

he ECM plays roles in growth, development, and cell death, with varying composition and consistency affecting tissue properties.

Question 6

What is the purpose of cell junctions?

Answer 6

Cell junctions hold cells together, enabling tissue formation.

Question 7

what are the three types of cell junctions?

Answer 7

Gap junctions, tight junctions, and anchoring junctions.

Question 8

What are tight junctions?

Answer 8

Junctions that create barriers by fusing adjacent cell membranes, regulating movement between external and internal environments.

Question 8

What are gap junctions?

Answer 8

The simplest form of junctions, allowing direct cell-to-cell communication through channels formed by connexins.

Question 9

What are the two types of anchoring junctions?

Answer 9

Cell-cell junctions (using cadherins) and cell-matrix junctions (using integrins).

Question 10

What are anchoring junctions?

Answer 10

Junctions that attach cells to each other or the ECM, providing mechanical strength.

Question 11

What analogy is used to describe anchoring junctions?

Answer 11

Anchoring junctions are like a picket fence, allowing materials to pass between cells (paracellular pathway).

Question 12

What are desmosomes?

Answer 12

The strongest cell-cell junctions, attaching to intermediate filaments of the cytoskeleton; can be spot or belt desmosomes.

Question 13

What are hemidesmosomes?

Answer 13

Junctions that anchor intermediate fibres of the cytoskeleton to fibrous matrix proteins like laminin.

Question 14

What is the function of epithelia?

Answer 14

Epithelial tissues protect the internal environment and regulate material exchange between internal and external environments.

Question 15

What are the types of epithelial tissues?

Answer 15

Exchange epithelia, transporting epithelia, ciliated epithelia, protective epithelia, and secretory epithelia.

Question 16

What is the difference between endocrine and exocrine glands?

Answer 16

Endocrine glands are ductless and release hormones into the bloodstream, while exocrine glands secrete products to external environments via ducts.

Question 17

Define secretion.

Answer 17

The process by which substances are produced and released by cells, particularly in secretory epithelia.

Question 18

What is the structure of epithelia?

Answer 18

Epithelia consist of one or more layers of cells connected by junctions, with a basal lamina separating them from underlying tissues.

Question 19

Where are leaky epithelia found?

Answer 19

In capillaries, where molecules can pass through gaps between cells, excluding large proteins.

Question 20

Where are transporting epithelia primarily found?

Answer 20

in the digestive tract and kidneys, where they regulate the exchange of ions and nutrients.

Question 21

What is the function of ciliated epithelia?

Answer 21

Ciliated epithelia move fluid and particles across their surface, found in the respiratory system and reproductive tract.