Humans are warm-blooded animals who maintain a constant body temperature despite the environmental temperature changes. They generate heat through metabolic processes. The body temperature of humans is 37°C. In humans, the hypothalamus is responsible for the temperature regulation of the body. The regulation of the body temperature is known as thermoregulation. It recognizes the change in body temperature and changes are made through effectors such as muscles, sweat glands, hair, etc. Constant body temperature is maintained by controlling the heat production and heat loss from the body.
Key Areas Covered
1. How Does the Body Regulate Temperature
– Thermoregulation, Hypothalamus
2. What are the Mechanisms that Regulate the Body Temperature
– Heat-Releasing Mechanisms, Heat-Producing Mechanisms
Key Terms: Body Temperature, Heat-Producing Mechanisms, Heat-Releasing Mechanisms, Hypothalamus, Thermoregulation
How Does the Body Regulate Temperature
Thermoregulation is an important aspect of homeostasis in humans. Humans, as well as other mammals, are capable of adapting to a wide range of climate conditions such as cold, hot, and humid conditions Most of the bodily heat is produced by deep organs such as liver, brain, and heart and, the contraction of skeletal muscles. The physiological control of the body core temperature primarily occurs through the hypothalamus. Hypothalamus is assumed as the body’s ‘thermostat’. Two types of thermoreceptors are involved in the sensation of temperature. They are the receptors sensitive to the cold and the receptors sensitive to warm temperatures. Nerves transmit the impulses from those two types of receptors to the hypothalamus. Negative feedback mechanisms that are controlled by the hypothalamus are involved in maintaining a constant core temperature. Thermoregulation by the hypothalamus is shown in figure 1.
Figure 1: Thermoregulation
What are the Mechanisms that Regulate the Body Temperature
When the body temperature is high, hypothalamus initiates heat-releasing mechanisms to increase the heat loss from the body. They are;
- The dilation of superficial arteries to release internal heat to the air through the skin.
- Sweat glands secrete sweat on the skin, allowing the heat loss through the skin by evaporation.
- Metabolism inside the body is decreased by controlling the release of thyroid hormones.
When the body temperature is low, hypothalamus initiates heat-producing mechanisms to increase the production of heat inside the body. They are;
- The constriction of superficial arteries to reduce the internal heat loss from the body.
- Shivering of the smooth muscles to generate heat.
- Metabolism is increased by releasing thyroid hormones.
Conclusion
Warm-blooded animals such as humans regulate their internal body temperature at a constant value. In humans, it is maintained at 37 °C. Hypothalamus is the organ involved in the thermoregulation in vertebrates. When the body temperature is increased, hypothalamus stimulates the heat-releasing mechanisms to increase the heat loss from the body. When the body temperature is decreased, hypothalamus stimulates the heat-producing mechanisms to increase the heat production in the body. However, a constant body temperature is maintained in a wide range of environmental conditions.
Reference:
1. “GCSE Bitesize: Temperature control.” BBC, Available here.
Image Courtesy:
1. “2523 The Hypothalamus Controls Thermoregulation” By OpenStax College – Anatomy & Physiology, Connexions Web site, Jun 19, 2013 (CC BY 3.0) via Commons Wikimedia
Leave a Reply