Afferent signals from external stimuli are carried by the _.
a) visceral motor division
b) somatic sensory division
c) somatic motor division
d) visceral sensory division
The Correct Answer and Explanation is :
The correct answer is:
b) somatic sensory division
The nervous system relies on various divisions to process and respond to different types of information from within the body and the external environment. The term “afferent” describes the pathways by which sensory information is transmitted from receptors to the central nervous system (CNS). Afferent signals are essentially sensory signals, and they include both somatic (body-related) and visceral (organ-related) sensory inputs.
Somatic Sensory Division
The somatic sensory division specifically refers to the pathways responsible for transmitting sensory information from external stimuli, such as touch, pain, temperature, and body position, to the CNS. These stimuli are usually detected by sensory receptors located in the skin, muscles, joints, and tendons. When receptors in these locations pick up signals from the environment, such as heat or pressure, they convert them into electrical impulses. These impulses are then carried through the somatic sensory neurons to the spinal cord and brain, where they are processed to create a response or awareness of the stimulus.
Other Options Explained
- Visceral Motor Division: This division, part of the autonomic nervous system, sends efferent signals from the CNS to control involuntary functions in smooth muscle, cardiac muscle, and glands. It does not carry sensory (afferent) signals.
- Somatic Motor Division: The somatic motor division also involves efferent signals but controls voluntary movements in skeletal muscles, sending signals from the CNS to the muscles to produce movement.
- Visceral Sensory Division: This division does handle afferent signals but specifically from internal organs (viscera), such as pain or fullness from the stomach, rather than from external stimuli.
Understanding these divisions helps clarify how the body maintains homeostasis and responds to internal and external environments, differentiating between conscious sensations (like touch) and subconscious monitoring (like blood pressure).