Chapter 12 - Section 12.2 - Study Guide - Assess Your Learning Outcomes - Page 471: 2

Sensory neurons, interneurons (association neurons), and motor neurons are three types of neurons found in the nervous system, each with distinct roles and functions. Here are the key differences between these neuron types: 1. **Sensory Neurons (Afferent Neurons):** - **Function:** Sensory neurons are responsible for detecting external stimuli (sensations) or internal changes (e.g., temperature, pressure, pain, or chemical signals) and transmitting this sensory information to the central nervous system (CNS). - **Location:** Sensory neurons are typically found in sensory organs such as the skin, eyes, ears, nose, and internal sensory receptors. - **Structure:** Sensory neurons have specialized receptor endings that detect specific types of stimuli. They have long dendrites that extend to the periphery, allowing them to capture sensory information. 2. **Interneurons (Association Neurons):** - **Function:** Interneurons serve as intermediaries between sensory neurons and motor neurons. They are responsible for processing and integrating sensory information within the CNS, allowing for complex decision-making, memory formation, and coordination of motor responses. - **Location:** Interneurons are primarily located within the CNS, including the brain and spinal cord. - **Structure:** Interneurons can have diverse structures and connections, as they form a complex network of synaptic connections with other neurons. 3. **Motor Neurons (Efferent Neurons):** - **Function:** Motor neurons transmit signals from the CNS to effector cells, such as muscles or glands, to initiate an appropriate response. They are responsible for carrying out motor functions, including muscle contractions and glandular secretions. - **Location:** Motor neurons are found both in the CNS (upper motor neurons) and in the peripheral nervous system (PNS) (lower motor neurons), which extend to target muscles or glands. - **Structure:** Motor neurons typically have long axons that project from the CNS or spinal cord to the target tissues. The synapses between motor neurons and their target cells are known as neuromuscular junctions (in the case of muscles) or neuroglandular junctions (in the case of glands). In summary, sensory neurons detect sensory stimuli and transmit this information to the CNS, interneurons process and integrate this sensory information within the CNS, and motor neurons convey commands from the CNS to effector cells to produce a response. Together, these three types of neurons play a crucial role in sensory perception, information processing, and motor control within the nervous system.

Sensory neurons, interneurons (association neurons), and motor neurons are three types of neurons found in the nervous system, each with distinct roles and functions. Here are the key differences between these neuron types: 1. **Sensory Neurons (Afferent Neurons):** - **Function:** Sensory neurons are responsible for detecting external stimuli (sensations) or internal changes (e.g., temperature, pressure, pain, or chemical signals) and transmitting this sensory information to the central nervous system (CNS). - **Location:** Sensory neurons are typically found in sensory organs such as the skin, eyes, ears, nose, and internal sensory receptors. - **Structure:** Sensory neurons have specialized receptor endings that detect specific types of stimuli. They have long dendrites that extend to the periphery, allowing them to capture sensory information. 2. **Interneurons (Association Neurons):** - **Function:** Interneurons serve as intermediaries between sensory neurons and motor neurons. They are responsible for processing and integrating sensory information within the CNS, allowing for complex decision-making, memory formation, and coordination of motor responses. - **Location:** Interneurons are primarily located within the CNS, including the brain and spinal cord. - **Structure:** Interneurons can have diverse structures and connections, as they form a complex network of synaptic connections with other neurons. 3. **Motor Neurons (Efferent Neurons):** - **Function:** Motor neurons transmit signals from the CNS to effector cells, such as muscles or glands, to initiate an appropriate response. They are responsible for carrying out motor functions, including muscle contractions and glandular secretions. - **Location:** Motor neurons are found both in the CNS (upper motor neurons) and in the peripheral nervous system (PNS) (lower motor neurons), which extend to target muscles or glands. - **Structure:** Motor neurons typically have long axons that project from the CNS or spinal cord to the target tissues. The synapses between motor neurons and their target cells are known as neuromuscular junctions (in the case of muscles) or neuroglandular junctions (in the case of glands). In summary, sensory neurons detect sensory stimuli and transmit this information to the CNS, interneurons process and integrate this sensory information within the CNS, and motor neurons convey commands from the CNS to effector cells to produce a response. Together, these three types of neurons play a crucial role in sensory perception, information processing, and motor control within the nervous system.