BIO 206 Lab 5: The Integumentary System and Thermoregulation

Vocabulary flashcards covering the integumentary system, cutaneous receptors, feedback loop terminology, and mechanisms of heat gain and loss from Lab 5.

Integumentary System

The organ system primarily composed of the skin, along with accessory structures including hair follicles, nails, sweat glands, and sebaceous glands.

Touch Receptors

Specialized cells embedded within the layers of the skin that sense physical deformity of the skin or hairs and transmit information via sensory neurons into the central nervous system.

Nociceptors

Free nerve endings embedded within various layers of the skin that sense pain through the detection of chemicals released when cells are damaged.

Thermoreceptors

Free nerve endings embedded in the skin and internal organs that sense changes in temperature.

Vitamin D3

A steroid hormone synthesized in the epidermis from cholesterol upon exposure to ultraviolet (UV) radiation.

Calcitriol

The active form of vitamin D, converted by enzymes in the liver and kidney from vitamin D3, required for normal absorption of calcium and phosphorous from the digestive system.

Meissner Corpuscle

A touch receptor located in the skin that senses light touch and low-frequency vibrations.

Pacinian Corpuscle

A cutaneous sensory receptor that detects high-frequency vibration and deep pressure.

Hyperthermia

A physiological condition that occurs when body temperature rises above the normal set-point of $37^\circ\text{C}$ ($98.6^\circ\text{F}$).

Hypothermia

A physiological condition that occurs when body temperature falls below the normal set-point of $37^\circ\text{C}$ ($98.6^\circ\text{F}$).

Peripheral Thermoreceptors

Thermoreceptors located in the skin and internal organs (such as the stomach) that transmit sensory information to the hypothalamic thermoregulatory center via sensory neurons of the peripheral nervous system.

Central Thermoreceptors

Thermoreceptors located in the hypothalamus that monitor the temperature of blood flowing through that structure and communicate with the hypothalamic thermoregulatory center via interneurons.

Hypothalamic Thermoregulatory Center

A subnucleus of the hypothalamus that acts as an integrating center by processing temperature data and modulating the function of effectors to maintain temperature homeostasis.

Stimulus (Feedback Loop)

The step in a feedback loop representing the initial deviation of a physiological variable from an ideal set-point.

Sensor (Feedback Loop)

The step in a feedback loop, typically a specialized cell, that detects a deviation from an ideal set-point.

Afferent Pathway

The communication pathway in a feedback loop that transmits sensory data from the sensor to the integrating center.

Integrating Center

The step in a feedback loop that analyzes the meaning of sensory data and decides how to respond to the stimulus.

Efferent Pathway

The communication pathway in a feedback loop that carries command signals from the integrating center to the effector.

Effector

An organ or type of cell in the body that can influence the stimulus in response to regulatory signals.

Effector's Action

The step in a feedback loop that explains the specific physiological actions the effector performs to achieve the loop's objective.

Response (Feedback Loop)

The step in a feedback loop that represents the ultimate goal or outcome of the regulatory mechanism.

Positive Feedback Loop

A regulatory mechanism that amplifies or pushes a stimulus further away from an ideal set-point until an outside factor intervenes to stop it.

Negative Feedback Loop

A regulatory mechanism that acts to remove or negate a stimulus that is too high or too low relative to an ideal set-point.

Radiant Heat Gain

An increase in body temperature resulting from the absorption of infrared radiation from the environment, such as sitting near a campfire or being in direct sunlight.

Conductive Heat Gain

An increase in body temperature resulting from direct physical contact with a warmer object, such as a mug of coffee or a heating pad.

Convective Heat Gain

An increase in body temperature caused by warm air or water circulating around the body, such as from a hair dryer or in a hot tub.

Radiant Heat Loss

The emission and dissipation of heat from the body directly into a cooler surrounding environment.

Conductive Heat Loss

The direct transfer and loss of body heat caused by physical contact with a cooler object, such as an icepack or wet clothing.

Convective Heat Loss

The loss of body heat that occurs when cooler air or water circulates across the surface of the body, such as in a cool swimming pool or near an air conditioner vent.

Evaporative Heat Loss

A cooling mechanism where sweat glands secrete a hypotonic aqueous solution onto the skin, carrying heat away as the liquid evaporates.