Human Physiology Lab
Human Physiology Lab
Special Senses
Cutaneous Senses and Vision
September 24/26, 2012
Our bodies are capable of sensing a wide spectrum of stimuli. We are consciously aware of some of the information our bodies perceive, but much of the information that is sensed is beyond our consciousness. Receptors responsible for perception of stimuli are found in many places: skin, eyes, ears, mouth, blood vessels, lungs, brain—frankly, every cell in the body has sensory receptors. These receptors are broadly classified as photoreceptors (sensitive to light), chemoreceptors (sensitive to chemicals), thermoreceptors (sensitive to warm or cold), mechanoreceptors (sensitive to stretch/pressure), and nociceptors (sensitive to damage).
Sensory receptors are found on neurons that bring information INTO the central nervous system; thus these neurons are called afferent neurons. Efferent neurons are neurons that carry information away from the central nervous system; these neurons are also called motor neurons or effector neurons since they are responsible for controlling responses of muscles, glands, and organs.
Cutaneous Senses
The cutaneous senses provide us with information about our immediate environment, allowing our integumentary system (skin) to detect differences in temperature, texture, weight, and shape of objects that we touch as well as the air. The receptors involved with these sensations are: cold receptors, warm receptors, touch receptors, pressure receptors, and nociceptors. Since it is difficult to distinguish between touch and pressure, we will consider the two together.
Cutaneous receptors are usually found in groups, and not alone. This is sometimes called a punctate arrangement of receptors. One small area of the skin can distinguish touch, while a neighboring area is sensitive to warmth. Nociceptors are unique in that they are spread in a more ubiquitous pattern.
Each receptor type is most sensitive to a particular energy
Special Senses
Cutaneous Senses and Vision
September 24/26, 2012
Our bodies are capable of sensing a wide spectrum of stimuli. We are consciously aware of some of the information our bodies perceive, but much of the information that is sensed is beyond our consciousness. Receptors responsible for perception of stimuli are found in many places: skin, eyes, ears, mouth, blood vessels, lungs, brain—frankly, every cell in the body has sensory receptors. These receptors are broadly classified as photoreceptors (sensitive to light), chemoreceptors (sensitive to chemicals), thermoreceptors (sensitive to warm or cold), mechanoreceptors (sensitive to stretch/pressure), and nociceptors (sensitive to damage).
Sensory receptors are found on neurons that bring information INTO the central nervous system; thus these neurons are called afferent neurons. Efferent neurons are neurons that carry information away from the central nervous system; these neurons are also called motor neurons or effector neurons since they are responsible for controlling responses of muscles, glands, and organs.
Cutaneous Senses
The cutaneous senses provide us with information about our immediate environment, allowing our integumentary system (skin) to detect differences in temperature, texture, weight, and shape of objects that we touch as well as the air. The receptors involved with these sensations are: cold receptors, warm receptors, touch receptors, pressure receptors, and nociceptors. Since it is difficult to distinguish between touch and pressure, we will consider the two together.
Cutaneous receptors are usually found in groups, and not alone. This is sometimes called a punctate arrangement of receptors. One small area of the skin can distinguish touch, while a neighboring area is sensitive to warmth. Nociceptors are unique in that they are spread in a more ubiquitous pattern.
Each receptor type is most sensitive to a particular energy