A&P1 - LP#5 Flashcards
Tissue level of Organization & Epithelial Tissue
There are FOUR types of tissues
- Epithelial Tissue
- Connective Tissue
- Muscular Tissue
- Nervous Tissue
This type of tissue covers body surfaces, and lines hollow organs, body cavities and ducts; they also form glands
Allows the body to interact with both its internal and external environment
Epithelial Tissue
This type of tissue protects and supports the body and its organs. Various types bind organs together, stores energy reserves as fat, and helps provide the body with immunity to disease-causing organisms.
Connective Tissue
This type of tissue is composed of cells specialized for contraction and generation of force. Also generates heat that warms the body.
Muscular Tissue
This type of tissue detects changes in a variety of conditions inside and outside the body and responds by generating electrical signals called nerve action potentials that activate muscular contractions and glandular secretions.
Nervous Tissue
There are THREE types of Embryonic Tissue
- Endoderm
- Mesoderm
- Ectoderm
This type of embryonic tissue ultimately becomes the epithelial lining of the GI tract, respiratory tract and several other organs
Endoderm
This type of embryonic tissue gives rise to muscles, bones, and other connective tissues and the peritoneum
Mesoderm
This type of embryonic tissue comes the epidermis of the skin and the nervous system.
Ectoderm
There are FIVE types of cell junctions:
- Tight Junctions
- Adherens Junctions
- Desmosomes
- Hemidesmosoems
- Gap Junctions
This type of cell junction fuses together outer surfaces of adjacent plasma membranes to seal off passageways between adjacent cells.
Tight Junctions
This type of cell junction belts adjacent cells to one another with cadherins that enter into the intercellular space and connect.
Adherens Junctions
This type of cell junction attaches adjacent cells to one another with cadherins but the intermediate filaments are the supporting structure inside the cytosol that they attach to.
Desmosomes
This type of cell junction has integrin that anchors cells to the basement membranes
Hemidesmosomes
This type of cell junction has membrane proteins called connexins that form tiny fluid filled tunnels call connexsons. It allows the cells in a tissue to communicate with one another. In a developing embryo, some of the chemical and electrical signals that regulate growth and cell differentiation travel via these. It enables nerve or muscle impulses to spread rapidly among cells.
Gap Junctions
There are THREE major functions of Epithelial Tissue
- Selective barriers that limit or aid in transfer of substances into or out of cell.
- Secretory surfaces that release products produced by the cells onto their free surface (apical surface)
- Protective services that resist the abrasive influences of the environment
There are various surfaces to Epithelial tissue. They are…
- Apical (free) surface - faces the body surfaces
- Lateral surfaces - faces an adjacent cell
- Basal Surface - Opposite of apical, connects to the basement membrane.
Epithelium is classified according to TWO characteristics
- Arrangement of cells into layers
2. Shape of cells
There are THREE types of cells based on arrangement into layers:
- Simple Epithelium
- Stratified Epithelium
- Pseudostratified Epithelium
A single layer of cells that functions in diffusion, osmosis, filtration, secretion, or absorption.
Simple Epithelium
Two or more layers of cells used for protection from wear and tear.
Stratified Epithelium
Appears to have multiple layers of cells because the cell nuclei lie at different levels and not all cells reach the apical surface BUT it’s actually just a simple epithelium because all cells rest on the basement membrane. Those not reaching the apical surface may contain cilia - helps move particles along the epithelial tissue.
Pseudostratified Epithelium
Type cells classified by cell SHAPE:
- Squamous Cells
- Cuboidal Cells
- Columnar Cells
- Transitional Cells
This type of cell is thin and flat allowing for rapid passage of substances through them.
Squamous Cells
As tall as they are wide, this type of cell is shaped like a cube. They may have microvilli at the apical surface and function in secretion or absorption
Cuboidal Cells
This type of cell is much taller than they are wide, similar to columns. They protect underlying tissues and their apical surfaces may have cilia or microvilli. They often are specialized from secretion and absorption.
Columnar Cells.
This type of cell changes shape from squamous to cuboidal and back again. They are found in areas like the urinary bladder where it stretches to a larger size and them collapse to a smaller size.
Transitional Cells
Name EIGHT types of Epithelial Tissues:
- Simple Squamous
- Simple Cuboidal
- Simple Columnar (non-ciliated & ciliated)
- Pseudostratified Columnar (non-ciliated & ciliated)
- Stratified Squamous
- Stratified Columnar
- Stratified Cuboidal
- Transitional
- Single Layer with Flat Central Nucleus
- Found in heart, lungs, Blood Vessels, areas of less wear and tear
- Filtration & Diffusion.
Simple Squamous
Single layer cube shaped
Components of some glands ex: Thyroid & Pancreas
Secretion & Absorption
Simple Cuboidal
Columns – 1 Layer - Microvilli & Goblet Cells
GI Tract- Stomach & Anus and Some glands/ Gallbladder
Secretion & Absorption
Simple Columnar NON-CILIATED
Single Layer- Columns - Cilia & Goblet Cells
Bronchioles- leading to lungs; Fallopian Tubes
Moves debris out of airways; moves ovum/eggs
Simple Columnar CILIATED
Columns- 1 Layer - No Goblet Cells Various Nucleus position
Male Urethra
Absorption & Protection
Pseudostratified Columnar NON-CILIATED
Columns- 1 Layer - Cilia & Goblet Cells
Respiratory Tract
Traps foreign particles in mucous & eliminates it with movement of Cilia
Pseudostratified Columnar CILIATED
Several Layers - Apical are more squamous - Basal layers may be bigger
Keratinized- Skin; Non-Keratinized- Lines wet surface
Protection against absorption; 1st line of defense against microbes
Stratified Squamous
Multi-layer - Basal layer not columns - Odd shaped, uncommon tissue
Anal Mucous Membrane
Protection & Secretion
Stratified Columnar
Stratified Cuboidal- Stratified Squamous as needed for stretching
Bladder
Allows for stretch but maintains protective lining
Transitional
______________ may consist of a single cell or a group of cells that secrete substances into ducts (tubes), onto a surface, or into the blood. May be classified as endocrine or exocrine.
Glands
With this type of gland, secretions enter the interstitial fluid and diffuse directly into the bloodstream without flowing through a duct.
Ex: Pituitary Gland, Thyroid, Pancreas, Ovaries, Testes,
They Secrete Hormones
Endocrine Glands
With this type of glands, secretions pass into ducts that empty onto surface of a covering and lining epithelium, such as the skins surface or a lumen of a hollow organ.
Ex: sweat glands, oil glands, salivary glands, pancreas.
Secrete substances like sweat, oil, ear wax, saliva, digestive enzymes.
Exocrine Glands
Exocrine glands are classified based on their structure. What are the TWO basis for structural classification of exocrine glands?
Unicellular and Multicellular
Multicellular glands are categorized according to TWO criteria:
- Whether their ducts are branched or unbranched
2. The shape of their secretory portions.
Simple Gland
If the duct does not branch it is a simple gland
Compound Gland
If the duct branches it is a compound gland
Tubular Gland
Has tubular secretory parts
Acinar Gland
Has rounded secretory portions - Alveolar Gland
Tubuloacinar Gland
Has both tubular and more rounded secretory parts
The most common manner of secretion. This gland releases it product by exocytosis and no part of the gland is lost or damaged. ex: Salivary Gland and Pancreas
Merocrine Glands
This type of gland “buds” their secretions off through the plasma membrane, producing membrane-bound vesicles in the lumen of the gland. The end of the cell breaks off by “decapitation”, leaving a milky, viscous oderless fluid. This type of sweat only develops a strong ordor when it comes into contact with bacteria on the skins surface.
ex: Sweat Glands and Mammary Glands
Apocrine Glands
With this type of gland its secretions are produced by rupture of the plasma membrane, releasing the entire cellular contents into the lumen and killing the cell (cells are replaced by rapid division of stem cells). The sebaceous gland is an example of this type of gland because its secretion (sebum) is released with the remnants of dead cells.
Holocrine Glands
A ____________________ is a flat sheet of pliable tissue that covers or lines a part of the body.
Membrane
The majority of membranes consists of an epithelial layer and an underlying connective tissue layer that is called _________________________
Epithelial Membranes.
These Epithelial Membranes line “interior” body surfaces open to the outside:
- Digestive tract (traps nutrients to be absorbed)
- Respiratory tract (preventing foreign particles from entering the body)
- Reproductive tract.
Mucous Membrane
These Epithelial Membranes line some internal surfaces/body cavities, such as joints.
They are double layered and secrete serous fluid.
- Parietal layer next to body wall
- Serous fluid between layers
- Visceral layer next to organ.
Serous Membranes
This Epithelial Membrane consists of the skin. Its major function is protection.
Cutaneous Membranes
