Ch. 1 Learning Objectives Flashcards
List the four major type of tissues
Epithelial - covers and lines
Connective - provides support
Muscle - enables movement
Nervous System - controls work
What is Histology?
Study of tissues
Describe the function of the epithelial tissues
- acts as an interface layer that separates and defines the beginning and ending a different types of tissues
- protects, covers, and lines
- Filters biochemical substances
- Provides sensory input
- absorbs nutrients
- ## Manufactures secretion/excretion of biochemical substances through goblet cells/glandular epithelium
List and describe the characteristics used to classify different epithelial tissues
- Polar; has a sense of direction to surrounding structures
- Apical Surface; faces the lumen or body cavity
- Basal surface; side of the cell that faces the underlying CT
- Lateral Surface; connected to neighboring cells by junctional complexes
- Avascular; lack blood vessels or capillaries
- Innervated; provide sensory input
differentiate among the three major types of cellular junctions found between epithelial cells
Tight Junctions
- formed by the fusion of the outermost layers of the PM of adjoining cells
- strip that wraps around the whole circumference of the cell, like a belt
- no leaks
- found in urinary bladder, digestive tract
Desmosomes
- strong, welded plaque that connects the PM of adj. cells.
-mech. coupling formed by filaments that interlock w. one another
- tonofilaments; bases for the membrane junction
-has hemidesmosomes
- found in the skin, heart, and uterus
Gap Junctions
- connected cells linked by tubular channel proteins called connexons
- transmembrane proteins; allows the exchange and passage of ions, nutrients
- found in the intestinal epi cells, heart, and smooth muscle tissue
Define and describe the structure of the basement membrane
- foundation of the epi cell. Its’ strength and elasticity help prevent the cell from being torn off
- nonliving meshwork of fibers that cements the epi cell to the underlying CT
How does the basement membrane act as a partial barrier between the epithelial cell and the underlying connective tissue?
Where are the Cilia and Microvilli found in the body?
Microvilli aka Brush border
occur on cells that are involved in absorption/secretion
intestinal + urinary tracts
Cilia are found in the respiratory and urogenital tracts
Why do some epi cells have cilia and microvilli? what role do they play?
3 characteristics that define an epithelial cell are
- Number of Layers
- Shapes of the Cells
3.Presence of Surface Specializations
Types of Epithelia by Layer
- Number of Layers
- One Layer; Simple Epithelia
- Many layers; Stratified Epithelia
Types of Epithelial by Shapes
- Shapes of the cell
- Squamous
- Cuboidal
- Columnar
Types of Epithelial by Surface Specializations
- Presence of surface specializations
- Cilia
-Keratinized / nonkeratinized
Epi tissue is characterized as simple, stratified, or pseudostratified. What does this mean?
Location in the body for:
Simple Squamous
Simple Cuboidal
Simple Columnar
Stratified Squamous
Pseudostratified Columnar
Transitional
Simple Squamous
- lining surfaces; passage of gas or liquid; blood vessels
- inner lining of the lung; air sacs
-filtration membraned of kidneys
Simple Cuboidal
-surface of ovaries
- secretory portions of glands; thyroids
- linings of the ducts from the; liver, urine, milk, pancreas, kidneys, and salivary glands
Simple Columnar
- many excretory ducts
- digestive tracts, stomach; small intestine
- uterine tubes, uterus, and small bronchi of the lungs
Stratified Squamous
- linings of mouth, esophagus, vagina, and rectum
Stratified Cuboidal
- Large Excretory Ducts; sweat glands, mammary glands, and salivary glands
Stratified Columnar
- rare; select parts of the respiratory, digestive, and reproductive systems
Pseudostratified Columnar
- respiratory tract, male reproductive tract; trachea
Transitional
-Portions of urinary tract; urinary bladder, ureters, urethra, and calyxes of the kidney
