Lab Quiz 1 Material (02/06/2025) Flashcards
An organized aggregation of cells that functions in a collective manner.
What is a tissue?
List the 4 basic types of tissues that make up all organs.
1) Epithelium
2) Connective
3) Muscle
4) Nerve
This tissue type covers body surfaces, lines body cavities, and forms glands.
What is epithelium?
This tissue type underlies or supports the other 3 basic tissues, both structurally and functionally.
What is connective?
This tissue type is made up of contractile cells and is responsible for movement?
What is muscle?
This tissue type receives, transmits, and integrates information from outside and inside the body to control the activities of the body.
What is nerve?
In classifiying the basic tissues, two different definitional parameters are used. The basis for the definition of epithelial and connective tissue is primarily {…} (morphological OR functional?), while for muscle and nerve tissue, it is primarily {…} (morphological OR functional?).
1) Morphological
2) Functional
In what two manners is epithelium characterized?
1) Close cell apposition
2) Presence of a free surface
Epithelial cells are usually joined by specialized cell-to-cell junctions, which create a selective barrier between these two environments (i.e., epithelium separates these spaces).
What are the external environment & underlying connective tissue?
Describe the intercellular space between epithelial cells in 2 key points.
1) Minimal
2) Devoid of any structure, except where junctional attachments are present
Free surfaces of epithelium are characteristic of 3 main anatomical surfaces. Please list these surfaces.
1) Exterior of the body
2) Outer surface of many internal organs
3) Lining of body cavities and tubes that ultimately communicate with the exterior of the body
The epithelium also forms {…} and their ducts that help secrete their products onto a free surface or into the lumen of a tube.
Glands
Classifications of epithelium are usually based on 2 parameters. What are these parameters?
1) Shape of cells
2) Number of cell layers
List the 3 epithelial cell shapes.
1) Squamous (flat)
2) Cuboidal
3) Columnar
List the 2 epithelial layer types.
1) Simple (single layer)
2) Stratified (multiple layers)
What is the purpose of special structural surface modifications on epithelium?
To perform special functions
What are the 3 special structural surface modifications that simple epithelia may possess?
1) Microvilli
2) Stereocilia
3) Cilia
What are the 2 special structural surface modifications that stratified epithelia may possess?
1) Keratinized exterior of body
2) Non-keratinized lumen of internal organs
All epithelia rest on this structural attachment site for overlying epithelial cells and underlying connective tissue.
What is the basal lamina?
Why is epithelium an avascular tissue?
The blood vessels from connective tissue are restricted from passing through the basal lamina
What are the 2 methods in which epithelial cells receive nutrients?
1) Absorption from the free surface
2) Diffusion from underlying tissues
The intervening spaces occupied by material produced by connective tissue cells make up this cellular network.
What is the extracellular matrix?
What 2 factors does the classification of connective tissue take into account?
1) Nature of the connective tissue cells
2) Composition/organization of extracellular matrix
Where does embryonic connective tissue derive from?
The mesoderm
This type of connective tissue is found to be closely associated with most epithelia.
What is loose connective tissue?
What 2 main components does the extracellular matrix for loose connective tissue consist of?
1) Loosely arranged collagen fibers
2) Numerous cells, including fibroblasts
What is the purpose of fibroblasts in the extracellular matrix?
NOTE: Think about why collagen is essential to the matrix
To form and maintain the extracellular matrix
This type of connective tissue contains numerous, densely-packed collagen fibers and is ideal for where strength is required.
What is dense connective tissue?
List the 3 examples of specialized connective tissue mentioned in the text.
1) Bone
2) Cartilage
3) Blood
This specialized connective tissue has a matrix mineralized by calcium and phosphate molecules associated with collagen fibers.
What is bone?
This specialized connective tissue possesses a matrix that contains a large amount of water bound to hyaluronan aggregates.
What is cartilage?
This specialized connective tissue consists of cells and an extracellular matrix in the form of a protein-rich fluid called plasma that circulates throughout the body, transporting oxygen and removing carbon dioxide and metabolites from the tissues.
What is blood?
How does adipose differ from other types of specialized connective tissue?
Its predominant distinguishing features are related to the cells (adipocytes) and NOT to the extracellular matrix
For what purpose do adipocytes serve?
Energy storage
Epithelium also forms the secretory, or {…}, portion of glands and their ducts.
Parenchyma
Specialized epithelial cells can also function as receptors for…
The special senses (smell, taste, hearing, and vision)
What are the 3 principal characteristics of epithelial cells?
1) Forming cell junctions
2) Functional and morphological polarity
3) Basal surface attached to underlying basement membrane
What are the 3 distinct morphological surface domains of epithelial cells?
1) Free surface (apical domain)
2) Lateral domain
3) Basal domain
Epithelial cells that lack a free surface (apical domain) aggregate to form this tissue type.
What is epithelioid tissue?
List 6 organs in which you will find epithelioid tissues.
NOTE: To be more specific, there are 4 organs and 2 glands mentioned in the text
1) Testes
2) Ovaries
3) Pancreas
4) Adrenal gland
5) Pituitary gland
6) Thymus
List 2 conditions under which epithelioid patterns may form.
1) Connective tissue macrophages responding to injury/infection
2) Tumors derived from epithelium
Epithelium creates a {…} barrier between the external environment and underlying connective tissue.
Selective
Which layer of cells determines the classification of stratified epithelium’s shape?
The surface layer
Aside from the number of cell layers and shape of surface cells, what is another factor for classifying epithelium’s structure?
Specialization of the apical cell surface domain (i.e., the presence of special structural surface modifications)
What are 2 special categories/classifications of epithelium?
1) Pseudostratified epithelium
2) Transitional epithelium (urothelium)
What is so special about pseudostratified epithelium?
It appears stratified since some cells don’t reach the free surface, but all cells rest on the basement membrane, unlike truly stratified epithelium (i.e., it is SIMPLE EPITHELIUM)
What is so special about transitional epithelium?
NOTE: Be sure to mention the number of layers
It is a stratified epithelium with specific morphological characteristics that allow it to distend
The epithelial lining of blood and lymphatic vessels is called this.
What is endothelium?
The epithelial lining of the ventricles and atria of the heart is called this.
What is endocardium?
The epithelium that lines the walls and covers the contents of the closed cavities of the body (i.e., the abdominal, pericardial, and pleural cavities).
What is mesothelium?
Epithelial cells are polygonal in shape, generally oriented along the axis of the vessel, with the exception of these vessels, which are found in lymphatic tissues.
What are postcapillary venules?
How is the endothelium of postcapillary venules shaped? Columnar, cuboidal, or squamous?
It is cuboidal
What is another name for these postcapillary venules?
High endothelial venules (HEV)
The columnar epithelium of the stomach and gastric glands serves this function.
What is secretion?
The columnar epithelium of the intestines and proximal convoluted tubules in the kidneys serves this function.
What is absorption?
The epithelium involved in transporting materials via motile cilia or transport to and from connective tissue serves this function.
What is transportation?
The stratified squamous epithelium of the skin (epidermis) and the urothelium (transitional epithelium) of the urinary bladder serves this function.
What is mechanical protection?
The epithelium that receives and transduces external stimuli serves this function.
What is receptor function?
In some pseudostratified epithelia, basal cells are the {…} cells that give rise to the mature functional cells of the epithelium, thus balancing cell turnover.
Stem
The asymmetric organization of different cellular components to enable specialized functions.
What is cell polarity?
What 2 factors determine the functional polarity of all 3 cell domains?
1) Biochemical characteristics of each surface
2) Geometric arrangements of cells
