Chapter 3: Tissues Flashcards
What is Histology
The study of Tissues
What are four major types of Tissues
- Epithelial
- Connective
- Muscle
- Nervous
What are the characteristics of Epithelial Tissue
Tightly Packed cells
Avascular ( Lack of Blood Cells)
What are the two main forms of Epithelial Tissue
- Surface epithelium
- Glandular epithelium
Surface Epithelium has what type cell shape
Squamous
Cuboidal
Columnar
What type of layers can Surface Epithelium have
Simple
Stratified
Cell Junctions are what hold cells together to form tissues. What are the 4 types of Cell Junctions
Tight Junctions
Adhering Junctions
Gap Junctions
Desmosomes
Hemidesmosomes
What are Tight junctions
Strands of Transmembrane proteins fuse adjacent cells together. Nothing can get through.
Good for a “water tight” seal
Ex: Stomach. Bladder
What are Adhering junctions
Adhesion belt like Velcro made of plaque surrounds the cell
“Good for keeping Epithelial surface from slipping/ sliding out of position”
What are Gap junction
They allow cells to communicate to each other, share nutrients & transfer chemical/ electric signals
What are Desmosomes
Incorporates plaque, cadherins, and the cytoskeleton
Keeps cells from being pulled apart
What are Hemidesmosome
Similar to desmosome they are half
They anchor cells to the basement membrane
Squamous Epithelium looks like
Flat fried eggs shaped
Cuboidal Epithelium looks like
Cube shaped
Columnar Epithelium looks like
Very tall cells that look like columns
If we have a single layer of cells that is named
Simple
If we have several layers of cells that are top of each other that is named
Stratified
What is Transitional Epithelium
Going from RELAXED to STRETCHED
What is Pseudostratified
It is giving off the appearance that it is several layers but it is actually a single layer
What is Cilia
Cilia gives directionality to what is passing by
What is Microvilli
Increases the surface area of the cell
What is Surface Epithelium
Long sheets of cells that lines and covers surfaces
Those surfaces can be external (Epidermis) or internal
What gives the cells the toughness they need to survive wear and tare
Keratin
What is Glandular Epithelium
Type of Epithelium is specialized to produce and secrete (release) substances
What type of Glandular Epithelium ( Endocrine Gland)
Do not have ducts
Secretes hormones
What type of Glandular Epithelium ( Exocrine Gland)
Have ducts
Secretes everything else but NOT hormones
When an exocrine gland has a single duct it is called
Simple
When an exocrine gland has multiple ducts it is called
Compound
I the secreting portion of the gland looks like a tube it is called
Tubular
What is the shape of a exocrine gland called when its very rounded like a grape
Acinar
When a secreting portion of a gland looks coiled it is called
Coiled
Functional classification of Exocrine Glands
Tells us how the gland released the product
Merocrine= Also called Eccrine glands, releases the secretion via exocytosis
Apocrine= Release secretion by pinching off the apical portion of the cell
Holocrine= Store their secretion until they rupture and release their contents
Functions of Epithelial Tissue
Protection
Secretion
Excretion
Absorption
Sensory
General function of Connective Tissue
Support and connect the other tissues
Characteristics:
Cells + Extracellular matrix
Highly Vascularized (lots of blood vessels)
What is Dense (Fibrous) Connective Tissue
- Cells: **Fibroblast ** fibroblast is a type of cell that contributes to the formation of connective tissue
Dense REGULAR Connective Tissue
- Protein fibers are arranged in parallel bundles
- Located in the Tendons and Ligaments
Dense IRREGULAR Connective Tissue
- Protein fibers running in different directions
- Located in Fibrous pericardium, dura mater, sclera, perichondrium and periosteum
What is Adipose tissue
- Cells ** Adipocytes**
Functions:
- Energy reserve
- Insulate against heat lost
- Support and protects organs
What is Cartilage Tissue
Cartilage Tissue is AVASCULAR
- Cells Chondrocytes
Sub-types
Hyaline= Tough but also flexible; most abundant cartilage in our body. Located: front of nose, trachea.
Elastic= The most elastic out of the 3 types of cartilage. Locations outer ear, epiglottis.
Fibrous= Toughest one out the 3 types of cartilage. Locations pubic symphysis.
