Tissues Flashcards
List the 6 functions of Epithelial tissue
- Protection - covering + lining
- Filtration - biochemical substances
- Absorption - nutrients
- Sensation - sensory input
- Secretion
- Excretion
List 6 characteristics of of Epithelial Tissue
- Are polar
- Have cell junctions
- Are avascular
- Are innervated
- Have a basal lamina
- Have surface specialization
epithelial cells have a sense of direction relative to surrounding structures
Polarity
epithelial cell surface that faces the lumen
Apical Surface
Body cavity
Lumen
epithelial cell surface that faces the underlying connective tissue
Basal Surface
the attachments between the plasma membranes on the lateral surfaces of neighboring epithelial cells
Cell Junctions
cellular attachments that prevent substances from leaking across the tissue
Tight Junctions
cellular attachments that consist of a strong plaque that cements neighboring cells together
Desmosomes
intermediate filaments that extend from the plaque into the cytoplasm of each cell like anchors to stabilize a desmosome junction
Tonofilaments
junctions that link epithelial cells to the basement membrane
Hemidesmosomes
cellular attachments that link the cytoplasm of neighboring cells together via connexons in order to allow the exchange of ions, electrical signals, and nutrients
Gap Junctions
Transmembrane channel proteins that extend between the cytoplasm of neighboring cells
Connexons
the non-living meshwork of fibers that cements epithelial cells to the underlying connective tissue and allows for the exchange of molecules and substances between the epithelial cells and the connective tissue
Basement Membrane (Basal Lamina)
What is the difference between microvilli and cilia?
Microvilli - fingerlike projections that increase the surface area of the cell and enhance the cell’s ability to absorb or secrete
Cilia - hairlike projections that serve to aid in the transport of materials
What are 4 actions taken by vet staff to treat patients with parvovirus?
- Combat the dehydration
- IV fluid therapy with electrolyte supplements
- Antibiotics
- Anti-vomiting meds
What are the 3 ways epithelia can be classified?
- Number of layers of cells
- Shape of cells in the luminal tissue surface
- Presence of surface specializations
Explain the difference between simple and stratified epithelia
Simple = a single layer of cells
Stratified = multiple layers of cells
Explain the characteristics and structural differences in squamous, cuboidal and columnar epithelial cells
- Squamous - flat + hexagonal cells, central disc shaped nuclei, fragile
- Cuboidal - cubic cells, central round nuclei, fragile, ciliated or smooth
- Columnar - elongated cells, nuclei aligned toward the basement membrane, protective, ciliated or smooth
What is special about pseudostratified columnar epithelial tissue? Give 3 reasons
- Appear stratified > due to not all cells reaching the luminal surface
- Nuclei at different levels across the tissue
- Simple tissue
What is special about transitional epithelial tissue? Give 1 reason
Layer cell shapes are based on the level of tissue distension > relaxed (cuboidal) or stretched (squamous)
the accumulation of a protective, waterproof substance within some epithelial cells
Keratinization
cells that manufacture and store lubricating mucus that is secreted onto the luminal epithelial surfaces in the GI tract
Goblet Cells
specialized protein molecules that remain within the body
Secretions
substances that ultimately leave the body
Excretions
Explain the 6 classifications of glands
- Presence or absence of ducts - endocrine or exocrine
- Number of cells - unicellular or multicellular
- Shape of secreting ducts - simple or compound
- Structure of secretory portion - tubular, alveolar, or tubuloalveolar
- Type of secretion - mucoid or serous
- Manner of secretion storage and discharge - merocrine, apocrine, or holocrine
glands that produce and secrete hormones directly into the bloodstream and lymphatic system
Endocrine Glands
Glands that:
- Have no ducts or tubules
- Don’t have to act locally
- Products enter circulation
Endocrine Glands
glands that discharge secretions directly into nearby areas where they may cover cell surfaces or empty into lumen
Exocrine Glands
Glands that:
- Have ducts
- Act locally
- Products do not enter circulation
Exocrine Glands
a thick, sticky mixture of glycoproteins and proteoglycans that become mucus when mixed with water
Mucin
What is the only unicellular exocrine gland?
Goblet Cells
Multicellular Exocrine Glands are made of what 2 things?
- Secretory Unit
- Duct
produce secretions in secretory cells and is surrounded by connective tissues
Secretory Unit
carries out the secretion to the deposition site
Duct
classification if the main duct is unbranched
Simple
classification if the main duct is branched
Compound
glands with secretory units that form long channels of even width
Tubular Gland
glands with secretory units that form rounded sacs
Alveolar (Acinar) Glands
glands with secretory units that possess both tubular and alveolar qualities
Tubuloalveolar Glands
thick, viscous secretions that are composed of glycoproteins
Mucoid Secretions
watery secretions that contain a high concentration of enzymes
Serous Secretions
glands that contain both mucous and serous components
Mixed Exocrine Glands
glands that package their secretions into granular units and release them as they are made via exocytosis
Merocrine Glands
glands that store granules until the apex of the cell is full, pinch in two, release the apex into the duct system, repair the damage and then repeat the process
Apocrine Glands
glands that store granules until they are needed and release their secretory product via the degeneration of the cell
Holocrine Glands
Match the gland to the result of secretory process:
- Apocrine/Holocrine/ Merocrine
- Remains intact during process / cells are damaged and repaired during process / cells are destroyed during process
Apocrine - damaged + repaired
Merocrine - remain intact
Holocrine - destroyed
What are the 2 functions of connective tissue?
Bind and Support the organism and the body systems
What are 5 characteristics of connective tissue?
- Consist of cells embedded in a nonliving matrix
- Vascularized
- Ground Substance
- Extracellular Fibers
- Various types of cells
a medium through which nutrients and waste are exchanged with the bloodstream and can act as a barrier against invading microorganisms
Ground Substance (matrix)
strong, thick, white strands composed of collagen that are organized into bundles of long, parallel fibrils
Collagenous (White) Fibers
What are the most common types of fibers in connective tissue?
Collagenous Fibers
thin, delicate strands composed of collagen that branch into complicated networks
Reticular Fibers
delicate strands composed of elastin that branch into complex networks
Elastic (Yellow) Fibers
What are collagen and elastin and what is the difference between them?
- Both are proteins
- Collagen allows for firmer support. Elastin allows for flexible support.
What areas are the following extracellular fibers found in? Give an example of each
1. Collagenous Fibers
2. Reticular Fibers
3. Elastic Fibers
- Collagenous > areas of high stretching and contracting force > tendons/ligaments
- Reticular > highly cellular organs > lymph nodes
- Elastic > tissues that stretch constantly > blood vessel walls
connective tissue cells that remain in the tissue and are involved in the production and maintenance of the matrix
Fixed Cells
large, irregularly shaped cells that manufacture and secrete both the fibers and the ground substance characteristic of their particular matrix
Fibroblasts
Explain the life cycle of fibroblasts
- Initially > metabolically very active + reproducing
- Maturation > less active > names adopt suffix -cyte
- Cells convert back to -blast form if more matrix is needed later
fat cells
Adipocytes
Where are 4 places adipose tissue can be found?
- Under the skin
- Behind the eyeballs
- Around the kidneys
- In the omentum of the abdominal cavity
flat, star-shaped cells with long, outreaching arms that form net-like connections throughout the tissue they compose in order to facilitate immune responses and manufacture their associated fibers
Reticular Cells
connective tissue cells that pass in and out of the tissue as needed and are involved in the repair and protection of the tissue
Transient Cells
cells found in blood that move into connective tissue in large numbers during infections
Leukocytes