Chapter 15 - The Autonomic Nervous System and Visceral Reflexes - Study Guide - Testing Your Comprehension - Page 577: 4

The advantage for a wolf, or any other animal with fur or hair, of having its sympathetic nervous system stimulate the piloerector muscles is primarily related to thermoregulation and, to some extent, threat display. These muscles are responsible for causing the hair or fur to stand on end, a phenomenon commonly known as "piloerection." Here's how it benefits a wolf: **Advantage for a Wolf:** 1. **Thermoregulation:** Piloerection helps trap a layer of air between the raised hairs, creating an insulating barrier. This trapped layer of air acts as an additional layer of insulation, which is especially useful in cold environments. By raising the fur, the wolf can conserve body heat, preventing excessive heat loss during cold weather. This adaptation is essential for survival in harsh, cold climates, allowing the wolf to maintain its core body temperature more effectively. 2. **Threat Display:** Piloerection can also serve as a threat display. When a wolf feels threatened or wants to appear larger and more intimidating, it can raise its fur, making itself appear larger and potentially deterring potential threats. This is a common behavior observed in various animals as a defensive or aggressive posture. **In Humans:** In humans, the sympathetic nervous system can also stimulate the piloerector muscles, but the response is less pronounced due to our limited body hair and fur. When the sympathetic system stimulates these muscles in humans, it results in: 1. **Goosebumps:** Piloerection in humans is responsible for the formation of "goosebumps" on the skin. When the piloerector muscles contract, they cause the small hairs on our skin to stand up. This response is a vestigial reflex and is much less functional in humans compared to animals with denser fur. 2. **Limited Thermoregulation:** While piloerection in humans doesn't provide as much insulation as it does in animals with thicker fur, it can still have a minor effect on thermoregulation. However, the primary role of thermoregulation in humans is achieved through other mechanisms like sweating and shivering. 3. **Emotional Response:** In humans, piloerection can also occur as a response to emotional stimuli, such as fear, excitement, or arousal. It is often associated with the "chills" people experience when listening to music or experiencing strong emotions. In summary, the advantage for a wolf in having its sympathetic nervous system stimulate the piloerector muscles is primarily related to thermoregulation in cold environments and as a potential threat display. In humans, this response is less significant due to our limited body hair, but it can still occur in response to various stimuli, including emotional ones.

The advantage for a wolf, or any other animal with fur or hair, of having its sympathetic nervous system stimulate the piloerector muscles is primarily related to thermoregulation and, to some extent, threat display. These muscles are responsible for causing the hair or fur to stand on end, a phenomenon commonly known as "piloerection." Here's how it benefits a wolf: **Advantage for a Wolf:** 1. **Thermoregulation:** Piloerection helps trap a layer of air between the raised hairs, creating an insulating barrier. This trapped layer of air acts as an additional layer of insulation, which is especially useful in cold environments. By raising the fur, the wolf can conserve body heat, preventing excessive heat loss during cold weather. This adaptation is essential for survival in harsh, cold climates, allowing the wolf to maintain its core body temperature more effectively. 2. **Threat Display:** Piloerection can also serve as a threat display. When a wolf feels threatened or wants to appear larger and more intimidating, it can raise its fur, making itself appear larger and potentially deterring potential threats. This is a common behavior observed in various animals as a defensive or aggressive posture. **In Humans:** In humans, the sympathetic nervous system can also stimulate the piloerector muscles, but the response is less pronounced due to our limited body hair and fur. When the sympathetic system stimulates these muscles in humans, it results in: 1. **Goosebumps:** Piloerection in humans is responsible for the formation of "goosebumps" on the skin. When the piloerector muscles contract, they cause the small hairs on our skin to stand up. This response is a vestigial reflex and is much less functional in humans compared to animals with denser fur. 2. **Limited Thermoregulation:** While piloerection in humans doesn't provide as much insulation as it does in animals with thicker fur, it can still have a minor effect on thermoregulation. However, the primary role of thermoregulation in humans is achieved through other mechanisms like sweating and shivering. 3. **Emotional Response:** In humans, piloerection can also occur as a response to emotional stimuli, such as fear, excitement, or arousal. It is often associated with the "chills" people experience when listening to music or experiencing strong emotions. In summary, the advantage for a wolf in having its sympathetic nervous system stimulate the piloerector muscles is primarily related to thermoregulation in cold environments and as a potential threat display. In humans, this response is less significant due to our limited body hair, but it can still occur in response to various stimuli, including emotional ones.