Chapter 4 Tissue Level of Organization

Question 1

What is tissue?

Answer 1

A tissue is a group of cells that usually have a common embryonic origin in an embryo and function together to carry out specialized activities

Question 2

4 Tissue Types

Answer 2

Epithelial

Connective

Muscular

Nervous

Question 3

Cell Junctions

Answer 3

Points of contact between cells to hold them together

Question 4

Epithelial Tissue vs. Connective Tissue

Answer 4

Epithelial tissue has many cells tightly packed together and little to no extracellular matrix

while

Connective tissue has very few scattered cells surrounded by large amounts of extracellular matrix

Question 5

General Features of Epithelial Tissue

Answer 5

Cells are arranged in sheets and are densely packed

Many cell junctions are present

Epithelial cells attach to a basement membrane

Epithelial tissue is avascular (lack of blood vessels) but does have a nerve supply

Mitosis (type of cell division) occurs frequently

Question 6

Classification of Epithelial Tissue

Answer 6

Arrangement of Layers

Simple, pseudo-stratified, Stratified

Cell Shape

Squamous, Cubcidal, Columnar

Question 7

The name of the specific type of stratified epithelial tissue depends on the shape of the apical cells

Answer 7

Table 4.1 in your textbook shows examples of each of the epithelial tissues – notice the similarities and differences! (just a side note)

Question 8

Glandular Epithelium

Answer 8

A gland is a single cell or a mass of epithelial cells adapted for secretion

The secretions of endocrine glands enter the interstitial fluid and diffuse into the bloodstream

The secretions of exocrine glands enter ducts that empty onto the surface of a covering/lining epithelium such as the skin surface or the lumen of the stomach

Question 9

Types of Cell Junctions

Answer 9

Tight
Adherens
Desmosomes
Hemidesmosomes
Gap