Defin These Terms Flashcards
Organ
A group of tissues specialized for a particular function
Tissue
Groups of cells forming various building materials of the body
Homeostasis
A state of dynamic equilibrium in the body with respect to its internal environment and functions.
Set point
Ideal normal value of a variable around which homeostasis is maintained through a normal range of values that are acceptable to the body
Stress
A factor that causes one or more physiological variables to move away from its homeostatic set point
Control center
The part of the body, either central nervous system or endocrine gland, that receives information about a variable, determines the set point, and signals a response to correct imbalances
Receptor
A structure in the body that monitors the values of your body’s variables
Effector
A structure in the body that can change the value of variable in response to a signal from the control center
Negative-Feedback System
A control mechanism consisting of receptors, control center, and effectors through which homeostasis in the body is maintained by regulation of the body’s organ systems. It is called negative feedback because the control system opposes or reverses the original stress.
Selective permeability
The ability to let certain materials in or out while restricting others
Endocytosis
The process by which large molecules are taken into the cell
Exocytosis
Transportation of material from inside the cell to outside the cell using vesicles: also called secretion
Exocrine glands
Glands that secrete substances outward through a duct
Endocrine glands
Ductless glands that secrete hormones into the bloodstream
Merocrine glands
Exocrine glands that secrete without losing cellular material
Apocrine glands
Exocrine glands that have cytoplasm in their secretions
Holocrine glands
Exocrine glands that have secretions made up of disintegrated cells
Extracellular matrix
The chemical substances located between connective tissue cells
Fibroblasts
Spindle-shaped cells that form connective tissue proper
Stromal cells
“ Supporting” cells that provide structure or support for parenchymal cells
Parenchymal cells
“Performance” cells that provide the actual function of the tissue
Labile cells
Cells that undergo mitosis regularly and quickly
Stable cells
Cells that do not regularly undergo mitosis but are able to if the need arises
Permanent cells
Cells that cannot undergo mitosis