Chapter 13 - Section 13.2 - Study Guide - Assess Your Learning Outcomes - Page 504: 3

Entire nerves are classified as sensory, motor, or mixed based on the predominant type of nerve fibers they contain and the primary functions they serve. Here's the basis for classifying entire nerves into these categories: 1. **Sensory Nerves**: - **Composition**: Sensory nerves predominantly consist of afferent nerve fibers, which carry sensory information from sensory receptors in the body to the central nervous system (CNS), such as the spinal cord or brain. - **Function**: These nerves are primarily responsible for transmitting sensory input related to touch, pain, temperature, proprioception (body position awareness), and other sensory modalities from the periphery (e.g., skin, muscles, and joints) to the CNS. - **Examples**: The optic nerve (CN II), the auditory nerve (CN VIII), and the olfactory nerve (CN I) are examples of sensory nerves associated with vision, hearing, and smell, respectively. 2. **Motor Nerves**: - **Composition**: Motor nerves consist primarily of efferent nerve fibers, which transmit motor commands and signals from the CNS to effector organs and tissues, such as muscles and glands. - **Function**: These nerves are responsible for controlling muscle contractions, both voluntary (somatic motor nerves) and involuntary (visceral motor nerves), and for regulating glandular secretions and other effector responses. - **Examples**: The facial nerve (CN VII), which controls facial expressions, and the oculomotor nerve (CN III), which controls eye movements, are examples of motor nerves. 3. **Mixed Nerves**: - **Composition**: Mixed nerves contain both sensory (afferent) and motor (efferent) nerve fibers, making them versatile in their functions. - **Function**: Mixed nerves serve both sensory and motor functions. They carry sensory information from the periphery to the CNS and transmit motor commands from the CNS to muscles and other effectors. - **Examples**: The most common examples of mixed nerves are found in the peripheral nervous system (PNS). For instance, spinal nerves are typically mixed nerves. They contain sensory fibers that convey sensory information from the body to the spinal cord and motor fibers that control skeletal muscles. In summary, the classification of entire nerves as sensory, motor, or mixed is based on the predominant type of nerve fibers they contain and the primary functions they perform. Sensory nerves are mainly involved in sensory input, motor nerves are primarily responsible for motor control, and mixed nerves have both sensory and motor functions. Understanding these classifications helps in the study of nerve functions and their roles in sensory perception and motor responses.

Entire nerves are classified as sensory, motor, or mixed based on the predominant type of nerve fibers they contain and the primary functions they serve. Here's the basis for classifying entire nerves into these categories: 1. **Sensory Nerves**: - **Composition**: Sensory nerves predominantly consist of afferent nerve fibers, which carry sensory information from sensory receptors in the body to the central nervous system (CNS), such as the spinal cord or brain. - **Function**: These nerves are primarily responsible for transmitting sensory input related to touch, pain, temperature, proprioception (body position awareness), and other sensory modalities from the periphery (e.g., skin, muscles, and joints) to the CNS. - **Examples**: The optic nerve (CN II), the auditory nerve (CN VIII), and the olfactory nerve (CN I) are examples of sensory nerves associated with vision, hearing, and smell, respectively. 2. **Motor Nerves**: - **Composition**: Motor nerves consist primarily of efferent nerve fibers, which transmit motor commands and signals from the CNS to effector organs and tissues, such as muscles and glands. - **Function**: These nerves are responsible for controlling muscle contractions, both voluntary (somatic motor nerves) and involuntary (visceral motor nerves), and for regulating glandular secretions and other effector responses. - **Examples**: The facial nerve (CN VII), which controls facial expressions, and the oculomotor nerve (CN III), which controls eye movements, are examples of motor nerves. 3. **Mixed Nerves**: - **Composition**: Mixed nerves contain both sensory (afferent) and motor (efferent) nerve fibers, making them versatile in their functions. - **Function**: Mixed nerves serve both sensory and motor functions. They carry sensory information from the periphery to the CNS and transmit motor commands from the CNS to muscles and other effectors. - **Examples**: The most common examples of mixed nerves are found in the peripheral nervous system (PNS). For instance, spinal nerves are typically mixed nerves. They contain sensory fibers that convey sensory information from the body to the spinal cord and motor fibers that control skeletal muscles. In summary, the classification of entire nerves as sensory, motor, or mixed is based on the predominant type of nerve fibers they contain and the primary functions they perform. Sensory nerves are mainly involved in sensory input, motor nerves are primarily responsible for motor control, and mixed nerves have both sensory and motor functions. Understanding these classifications helps in the study of nerve functions and their roles in sensory perception and motor responses.