Reflex Arc Diagram and Definitions

Central Nervous System (CNS)

• Comprises the brain and spinal cord, central to processing information and coordinating actions.

Reflex

• Represents an automatic response to stimuli, crucial for quick reactions to environmental changes.

Receptor Cells

• Specialized cells located in sense organs responsible for detecting stimuli, playing a vital role in sensory perception.

Sensory Neuron

• Transmits impulses from receptor cells to the CNS, essential for relaying sensory information.

Relay Neurone

• Situated within the CNS, this neuron conveys impulses from sensory neurons to motor neurons, facilitating communication within the nervous system.

Motor Neuron

• Carries impulses from the CNS to effectors, enabling movement and responses to sensory inputs.

Effector

• Executes the response to stimuli, such as muscle contraction, essential for an organism’s interactions with its environment.

Response

• The observable behavior triggered by a stimulus, such as reflexively moving a finger away from a painful stimulus.

Sense Organs

• Include the eyes, skin, ears, nose, and tongue, responsible for gathering sensory information from the environment.

Stimulus

• Refers to any change in the environment that prompts a response, exemplified by a pin prick.

Brain

• Functions as the control center of the nervous system, responsible for receiving and processing messages.

Fight or Flight Response

• Involves the nervous, muscular, and skeletal systems, mobilizing the body for immediate physical reaction to threats.

Automatic Reflex Response

• A rapid reaction that involves only the spinal cord, bypassing the brain, allowing for quick responses to dangers.

Stimulus-Response Process

• Begins with sensory receptors detecting a stimulus, sending signals via sensory neurons to the brain, which then instructs motor neurons to trigger muscle and gland activity.

Reflex Arc Response Example

• Eyelids shutting when an object approaches the face demonstrates an immediate reflex action facilitated by the reflex arc.

Homeostasis

• Refers to the stable internal conditions necessary for survival, maintained through various physiological processes.

Nervous System

• A complex network that detects environmental stimuli via receptors and neurons, facilitating appropriate responses.

Components of the Nervous System

• Includes the brain, spinal cord, and neurons, all integral to sensory processing and reflex activities.