Tissues Flashcards
groups of specialized cells and the extracellular substances surrounding
them
Tissues
the microscopic study of tissue structure
Histology
- Found both inside and outside the body
- Forms the layers that cover the surfaces and line the hollow organs of our body
Epthelium
Functions of Epithelia
- Protecting underlying structures
- Acting as a barrier
- Permitting the passage of substances 4. Secreting substances
- Absorbing substances
Shape and number of layers of epithelial cells can change if they are subjected to long-term irritation or other abnormal conditions
Clinical Impact
- Structures that hold them to each other or to the basement membrane.
- Mechanically bind the cells together
- Help form a barrier to the movement of molecules
- Provide a mechanism for intercellular communication
Cell Connections
Cell connection structures that mechanically bind epithelial cells together
Desmosomes
Bind cells to the basement membrane
Hemidesmosomes
barrier to movement of molecules or ions between epithelial cells
Tight Junctions
allow for intercellular communication
Gap Junctions
Composed of epithelium supported by a network of connective tissue
Glands
- produce chemicals called hormones
- ductless glands
- extensive network of blood vessels
Endocrine
categorized on the basis of their structure and mode of secretion
Exocrine
refers to the tube in contact with the epithelial tissue free surface
Duct
responsible for producing the secreted material
Secretory Portion
Unicellular example
Goblet Cell
Unicellular mode of secretion
Mecrorine
Multicellular Simple structural subtype
Simple tubular
Simple branched tubular
Simple acinar
Simple branched acinar
Multicellular Simple example
Glands in stomach, Gastric glands in stomach, Sebaceous glands, and thyroid glans
Multicellular Simple mode of secretion
Merocrine
Merocrine
Holocrine
Merocrine
Compound Structural subtype
Compound tubular
Compound acinar
Compound tubuloacinar
Compound example
Mucous glands of duodenum, Mammary glands, and Pancreas
Compound mode of secretion
Merocrine
Apocrine for fatty portion
Merocrine for protein-rich portion
Merocrine
Glands forming a straight tube with no branching of the secretory
portion
Simple tubular
several tubular secretory portions branching from the single duct
Simple branched tubular
glands with a single saclike secretory portion
Simple acinar
glands with several acinar secretory portions branching from the single duct
Simple branched acinar
glands with multiple ducts, each with a narrow tubular secretory portion
Compound tubular
glands with multiple ducts, each with several saclike secretory portions
Compound acinar
glands with multiple ducts, each with several tubular and acinar secretory portions
Compund tuboloacinar
- release of secretory products through
- exocytosis most common
Merocrine secretion
release of secretory products when a portion of the free surface of the
epithelial cell pinches off
Apocrine
release of secretory products through shedding of entire cells
Holocrine
consists of cells separated from each other by abundant extracellular matrix
Connective Tissue
Functions of Connective Tissue
- Enclosing and separating other tissues - Connecting tissues to one another
- Supporting and moving parts of the body
- Storing compounds
- Cushioning and insulating
- Transporting
- Protecting
create the matrix
“Blasts”
maintain
“Cytes”
break it down for remodeling
“Clasts”
3 major components of Extracellular Matrix
- Protein fibers
- Ground substance
- Fluid
3 types of protein fibers of the matrix
Collagen
Reticular
Elastic
consist of a protein core attached to many long polysaccharides
Proteoglycans
The amount of fluid in the matrix is correlated with the ________ and ____________ of ground substance molecules
type and quantity
Classification of Connective Tissues
Embryonic
Adult
This connective tissue has fewer fibers, more ground substance
Loose Connective Tissue