Histology

Question 1

List the hierarchical design from most basic to most organized and give and example of each one

Answer 1

Chemical- Oxygen
Cell- adipocyte 
Tissue- epithelial tissue
Organ- heart
Organ system- cardiovascular system
Organism- the human body

Question 2

Name Five Principal Tissues of Human Body and then describe them simply

Answer 2

Epithelial Tissue- cells in contact; always on surface or lining.

Connective and Supportive tissue- cells scattered; they have extra cellular material between cells

Hematolymphoid Complex- a fluid tissue; blood and lymph

Muscle Tissue- cells contract

Nervous Tissue- wire like communication network

Question 3

Epithelial Cells vs Connective Tissue

Compare and Contrast

Answer 3

Epithelial cells are many, touching and connected, avascular.
Connective Tissue has fewer cells, extracellular space where fibers, blood vessels, etc are

Question 4

General Functions of Epithelial Tissue

think -tions

Answer 4

protection
absorption
exchange
secretion ie enzymes, oil, sweat

Question 5

Classification of Epithelial Tissue; how are they classified?

Then list the three shapes and two varieties.

Answer 5

They are classified by the cell shape and how many layers there are.
Shapes: Squamous, Cuboidal, Columnar
Varieties: Simple and Stratified

Question 6

Basal Lamina
define
function

Answer 6

Noncellular gel consisting of various proteoglycans and type IV collagen suspended in water solution.

Provides epithelial layer with support base while collagen provides tensile strength and proteoglycans provide resilience.

Also, basal lamina is anchor and a filter mechanism to regulate molecular movement between epithelium and connective tissue.

Question 7

Simple Squamous Epithelium
structure
distribution
fx

Answer 7

structure: Single layer of flat scale like cells. Centrally located nucleus.
distribution: Lines entire cardiovascular system (endothelium) heart and blood vessels. Lining of cavities and outer surface of organs (mesothelium)
fx: reduces friction

Question 8

Simple Cuboidal Epithelium
structure
distribution
fx

Answer 8

structure: simple cube-like polygon shaped cells with central nucleus.

distribution: lines glands ie thyroid and ducts
fx: secretion

Question 9

Simple Columnar Epithelium
structure
distribution
fx

Answer 9

structure: single layer of tall, column-like cells with central nucleus, cilia or no cilia
distribution: lining of GI tract (wo cilia) ie fundus of stomach to rectum
fx: absorbtion, secretion, protection

Question 10

Pseudo-stratified Columnar Epithelium
structure
distribution
fx

Answer 10

structure: all layers reach bottom but not the top. Central nucleus with cilia or wo cilia.
distribution: lining of respiratory tubes ie trachea and bronchi (cilia)
fx: secretion, sticky filter.

Question 11

Stratified Squamous Epithelium
structure
distribution
fx

Answer 11

structure: top layer flat, scale like cells, multilayered
distribution: epidermis
fx: protection

Question 12

Stratified Cuboidal Epithelium

Stratified Columnar Epithelium

Answer 12

not common and not discussed ie mucosa in the pharynx

Question 13

Transitional Epithelium or urothelium
structure
distribution
fx

Answer 13

structure: In transition in shape; cuboidal/squamous
distribution: urinary tract tissue/ urothelium
fx: stretch and impede exchange

Question 14

Name the 3 types of Connective and Supporting Tissue:

Answer 14

General (soft) connective tissue
 connective tissue
 reticular tissue
 adipose tissue
Cartilage
Bone

Question 15

Fixed Cells: Name the three cells and what they do

Answer 15

Mesenchymal Cell- stem cell, smaller than fibrocyte, can become fibrocyte or adipocyte
Fibroblast- main cell of c.t., produce fiber components, active at sites of repair
Adipocyte- arise from stellate cells, large lipid droplet, appear in groups, fat storage

Question 16

Wandering Cells: name the four and what they do

Answer 16

Macrophage- principal phagocyte, resting and active (histiocyte), become active and migrate to repair tissue
Mast Cell or Mastocyte- develop from hemopoietic stem cells. Detect foreign substances and initiate inflammatory response.
Lymphocyte: the smallest wandering cell, abundent in submucosal c.t. of respirtory and digestive tract, second most numerous of leukocyte after nuetrophils that migrate in pathological conditions.
Plasma cell or plasmocyte: producers of antibodies that participate in humoral immune responses. Common in intestine passages.

Question 17

Extracellular Matrix in Connective Tissue

what three things:

Answer 17

Ground Substance-gel-like water substance that is nutritive
Fibers- collagen, long, non-branching, white, protein, slightly wavy, resist stretch
Elastic Fibers- thing, branching, protein, elastin, yellow, they can streeeeetch

Question 18

How is classification of Connective Tissue done?

Answer 18

By the most prominent features, not as straightforward as epithelial tissues

Question 19

Connective Tissue Proper

Name the 6

Answer 19

Loose c.t. (areolar)– general glue–everywhere
Dense irregular c.t. – wrapping tissue- dermis
Dense regular c.t. – binding tissue– tendons
Elastic c.t.– recoil– blood vessels
Reticular tissue – filter – lymph nodes, spleen
Adipose tissue – energy storage – everywhere

Question 20

Define Ground Substance

Answer 20

The ground substance makes up the extracellular matrix in C.T.

a thin, gel-like, substance w high water content. It’s nutritive for cells ie fibrocytes to excrete fibers

Question 21

What are the principal fibers of connective tissue and name fx role of each one.

Answer 21

collagen: long, nonbranching protein structure. Tensile strength to resist stretch.
elastic: branching, thin, protein. To stretch and almost perfectly recoil.