Peripheral Nervous System Flashcards
Sensation Sensory Receptors adaptation (21 cards)
Describe the role of sensory receptors in the body.
Sensory receptors are specialized cells that respond to changes in the environment (stimuli), leading to graded potentials that trigger nerve impulses.
How do mechanoreceptors function in the sensory system?
Mechanoreceptors respond to touch, pressure, vibration, and stretch, allowing the body to perceive these physical changes.
What types of stimuli do thermoreceptors detect?
Thermoreceptors are sensitive to changes in temperature, allowing the body to sense hot and cold.
Explain the difference between sensation and perception.
Sensation refers to the awareness of a stimulus, while perception is the interpretation of the meaning of that stimulus, both of which occur in the brain.
Define nociceptors and give examples of stimuli they respond to.
Nociceptors are sensory receptors that are sensitive to pain-causing stimuli, such as extreme heat or cold, excessive pressure, and inflammatory chemicals.
Describe the function of photoreceptors.
Photoreceptors respond to light energy, with the retina being a primary example where these receptors are located.
Explain the role of chemoreceptors in sensory perception.
Chemoreceptors respond to chemicals, playing a key role in the senses of smell and taste, as well as detecting changes in blood chemistry.
Differentiate between exteroceptors and interoceptors.
Exteroceptors respond to stimuli from outside the body, such as touch and temperature, while interoceptors respond to stimuli from internal viscera and blood vessels.
Describe the awareness of internal stimuli and its common effects.
Interoceptors respond to internal stimuli, which can cause discomfort but often go unnoticed by the individual.
How are sensory receptors classified?
Sensory receptors can be classified by the type of stimulus they respond to, their body location, and their structural complexity.
What is the function of proprioceptors in the body?
Proprioceptors respond to stretch in skeletal muscles, tendons, joints, and ligaments, informing the brain about body movements.
What types of receptors are found in the skin and what do they respond to?
Exteroceptors in the skin respond to touch, pressure, pain, and temperature.
Describe the categories of sensory receptors.
Sensory receptors are categorized into simple receptors of the general senses and receptors for special senses. Simple receptors monitor general sensory information throughout the body, while special senses include vision, hearing, equilibrium, smell, and taste, which are housed in complex sense organs.
Explain the general senses and their characteristics.
General senses include tactile sensations (touch, pressure, stretch, vibration), temperature, pain, and muscle sense. They do not have a one-to-one receptor function relationship, meaning receptors can respond to multiple stimuli.
Define nonencapsulated (free) nerve endings and their functions.
Nonencapsulated (free) nerve endings are abundant in epithelia and connective tissues, mostly consist of nonmyelinated, small-diameter group C fibers, and respond primarily to temperature, pain, or light touch.
How do thermoreceptors function in the body?
Thermoreceptors are specialized receptors that detect temperature changes. Cold receptors are located in the superficial dermis, while heat receptors are activated at temperatures between 32 to 48ºC in the deeper dermis.
Explain the role of nociceptors in sensory perception.
Nociceptors are pain receptors that are triggered by extreme temperature changes, pinching, or the release of chemicals from damaged tissue. They act as ion channels that open in response to heat, low pH, or certain chemicals.
Describe the activation of itch receptors in the dermis.
Itch receptors in the dermis can be triggered by chemicals such as histamine, which is released during allergic reactions or skin irritations.
What are the two types of nerve endings found in sensory receptors?
The two types of nerve endings found in sensory receptors are nonencapsulated (free) nerve endings and encapsulated nerve endings.
How do encapsulated nerve endings differ from nonencapsulated ones?
Encapsulated nerve endings are specialized structures that are typically more complex and are designed to respond to specific types of stimuli, while nonencapsulated (free) nerve endings are simpler and respond to a broader range of stimuli.
Explain the significance of the ‘no one-receptor-one-function’ relationship in sensory receptors
The ‘no one-receptor-one-function’ relationship indicates that many sensory receptors can respond to multiple types of stimuli, allowing for a more integrated and versatile sensory experience.
