Chapter 1.6 Components of Homeostatic Control Systems

Acquired Reflexes

Behaviors that appear to be stereotypical and automatic but that in fact result from considerable conscious effort to be learned

Afferent Pathway (Sensory Neurons)

Component of reflex arc that transmits information from receptor to integrating center

Effector

Cell or cell collection whose change in activity constitutes the response in a control system

Efferent Pathway (Motor Neurons)

Component of reflex arc that transmits information from integrating center to effector

Hormone

Chemical messenger synthesized by specific endocrine cells in response to certain stimuli and secreted into the blood, which carries it to target cell

Integrating Center (Hypothalamus)

Brain region that compares the actual value of a variable such as body temperature to a set point

Learned Reflexes

Behaviors that appear to be stereotypical and automatic but that in fact result from considerable conscious effort to be learned

Local Homeostatic Responses

Responses acting in immediate vicinity of a stimulus, without nerves or hormones, and having net effect of counteracting stimulus

Receptor

Protein either on cell surface, in the cytosol, or in the nucleus that binds a chemical messenger such as a hormone or neurotransmitter and mediates its action; (in sensory system) specialized peripheral ending of afferent neuron, or separate cell intimately associated with it, that detects changes in some aspect of environment

Reflex

Biological control system linking stimulus with response and mediated by a reflex arc

Reflex Arc

Neural or hormonal components that mediate a reflex; usually includes receptor, afferent pathway (sensory), integrating center (CNS), efferent pathway (motor), and effector

Stimulus

Detectable change in internal or external environment