Chapter 3 Flashcards
Tissues
A group of cells that have similar structure and function together as a unit = form organs
Histology
The study of tissues
Epithelial Tissue
Covers exposed surfaces, lines internal passageways and chambers, and forms glands
Connective Tissue
Fills internal spaces, provides structural support for other tissues, transports materials within the body, and stores energy
Muscle Tissue
Specialized for contraction, including skeletal muscle, cardiac muscle, and smooth muscle
Nervous Tissue
Carries information from one part of the body to another in the form of electrical impulses
Epithelia
Layers of cells covering internal or external surfaces
Glands
Structures that produce fluid secretions
Physical Protection
One of the essential functions of epithelial tissue, protecting from abrasion and destruction by chemical/biological agents
Control Permeability
Any substance that enters or leaves the body must cross an epithelium
Provide Sensation
Epithelial tissue is sensitive to stimulation because it has a large sensory nervous supply
Produce Specialized Secretions
Epithelial tissue produces secretions, also known as glands
Polarity
Presence of structural and functional differences between the exposed surface (apical) and attached surface (basal)
Cellularity
Interconnections that bind epithelial cells closely together
Attachment
Epithelial cells adhere to the basal surface and underlying tissues to establish cell border and resist stretching
Avascularity
Epithelial tissue lacks blood supply; nutrients are obtained by diffusion or absorption
Regeneration
Epithelial tissue is continuously replaced through stem cell division, with a higher rate of cell division than other tissues
Apical Surface
The part of the epithelial cell exposed to an internal or external environment
Basolateral Surface
The base (basal surface) where the cell attaches to underlying cells and the sides (lateral surfaces) where the cell contacts its neighbors
Intercellular Connections
Support and communication between epithelial cells
Cell Adhesion Molecules (CAMs)
Transmembrane proteins that bind epithelial plasma membranes to each other and to extracellular materials
Gap Junctions
Allow rapid communication and passageway for small molecules and ions to pass from cell to cell
Tight Junctions
Encircle the apical regions of epithelial cells, acting as a barrier to maintain structure and permeability
Desmosomes
Provide anchorage sites for intermediate filaments and maintain tissue architecture