Human Tissues/Homeostasis and Feedback Mechanisms Flashcards
Tissue Types
Connective
Epithelial
Muscle
Neural
Connective Structure
characterized by extracellular material that separate cells from one another
Connective Function
enclosing and separating connecting tissues to one another
supportive, moving, storing cushioning insulating, transporting, protecting
Connective Example
cells of the immune system and blood
Epithelial Structure
classified according to the number of cell layers and shapes
Epithelial Function
protecting underlying structures
acting as barriers
permitting the passage of substances secreting substances
Epithelial Example
skin, linings of internal organs
Muscle Structure
cells of muscles resemble long threads called fibers
Muscle Function
providing movement
Muscle Example
heart, organs of digestive system
Neural Structure
cells are composed of dendrites, cell bodies, and axons
Neural Function
coordinating and controlling many body activities
Neural Example
brain, spinal cord
Homeostasis
existence and maintenance of a relatively constant environment within the body. Each cell of the body is surrounded by a small amount of fluid, and the normal functions of each cell depend on the maintenance of its fluid environment within a narrow range of conditions, including temperature, volume, and chemical content
variables
conditions- temperature, volume, and chemical content
For example, body temperature is a variable that can increase in a hot environment or decrease in a cold environment.
Feedback Mechanisms
Positive
Negative
Negative Feedback Mechanisms
Most systems of the body are regulated by negative
Help maintain homeostasis
Negative means that any deviation from the set point is made smaller or is resisted.
The maintenance of normal blood pressure is a negative-feedback mechanism. Normal blood pressure is important because it is responsible for moving blood from the heart to tissues
Positive-feedback mechanisms
are not homeostatic and are rare in healthy individuals
Positive means that when a deviation from a normal value occurs, the response of the system is to make the deviation even greater.
usually creates a cycle leading away from homeostasis and, in some cases, results in death. Inadequate delivery of blood to cardiac muscle is an example of positive feedback
