The pit below each eye is where the organs are most sensitive to the waves of warm-blooded prey, and the photo above shows how a mouse might appear to a snake.
Even in total darkness, snakes can find prey quickly.
All animals rely on many different types of sensory systems to maintain their equilibrium.
In order to survive, animals need to be able to maintain their health and find the necessary resources.
These kinds of pressures have resulted in the evolution of many different types of sensory cells, which are capable of detecting changes in internal or external conditions, and of communicating that information to the central nervous system.
Some sensory cells are modified and others are specialized.
The sensory receptor's plasma membrane has a lot of stimuli that react to them.
The temperature and a certain chemical might affect the sensitivity of these membrane proteins.
When this happens, the ion channels open.
Nerve impulses are carried by a sensory nerve fiber within the PNS to the central nervous system.
There is no difference between the nerve impulses generated by different types.
All of the impulses are discussed in Section 37.2, regardless of whether they arise in the eyes, ears, nose, mouth, skin, or internal organs.
A response that is appropriate for the particular type of stimulation is brought about by the interpretation of the nerve impulses in the appropriate areas of the brain.
Artificial stimulation of the nerves that normally carry impulses in the ear or the eye are seen by the brain as sound or light.
Interoceptors get stimuli from inside the body, such as changes in blood pressure and blood volume.
Interoceptors located within internal organs are sometimes referred to as visceroceptors.
An animal can detect information in its environment with a few types of exteroceptors.
They respond to heat or light.
is an example, as are the sensors of snakes.
The eyes detect light.
Maintaining equilibrium and detecting changes that are perceived as sound or touch are both done by méntoreceptors.
The hypothalamus and skin are where thermoreceptors are located.
It is not known how much nonhuman animals have perception of their world.
Some snakes can detect invisible energy.
Some whales can hear sounds hundreds of miles away.
Dogs have a sense of smell that is more sensitive than humans, and they can be trained to detect drugs, human remains, blood, and even bedbugs.
Several studies have shown that dogs can detect some types of human cancer.
Biologists are fascinated by the sensory systems because they allow us to experience our world.
There are a variety of mechanisms that animals use to perceive their environment.