Chapter 1.3 Flashcards
… is the maintenance of relatively stable internal conditions despite continuous changes in environment
* A dynamic state of equilibrium, always readjusting as needed
* Maintained by contributions of all organ systems
Homeostasis
Homeostatic control of variables involves three components: …, …, and …
receptor, control center, and effector
In a … system, a stimulus—a deviation from a set point—is resisted through a physiological process that returns the body to homeostasis
negative feedback system
Normal childbirth is driven by a … loop. A … loop results in a change in the body’s status, rather than a return to homeostasis.
positive feedback loop
X-Ray of a Hand
… allows the internal structures of
the body, such as bones, to be seen in X-rays.
High energy electromagnetic radiation
Your body can store some of the … in its tissues, and draw on those reserves if you fail to consume them in your diet for a few days or weeks.
micronutrients
Atmospheric pressure is pressure exerted by the mixture of gases (primarily… and …) in the Earth’s atmosphere. Although
nitrogen and oxygen
A … is the physiological value around which the normal range fluctuates.
set point
A … is the restricted set of values that is optimally healthful and stable.
normal range
… feedback is a mechanism that reverses a deviation from the set point. Therefore, … feedback maintains body parameters within their normal range. The maintenance of homeostasis by … feedback goes on throughout the body at all times.
Negative feedback
A negative feedback system has three basic components
…
…
…
A sensor
The control center
An effector
Negative Feedback
A … is a component of a feedback system that monitors a physiological value. This value is reported to the control center.
A sensor, also referred to a receptor,
Negative Feedback
The … is the component in a feedback system that compares the value to the normal range. If the value deviates too much from the set point, then the … activates an effector.
control center
Negative Feedback
An … is the component in a feedback system that causes a change to reverse the situation and return the value to the normal range.
effector
Humans have a similar temperature regulation feedback system that works by promoting either heat loss or heat gain (Figure 1.10b). When the brain’s temperature regulation center receives data from the sensors indicating that the body’s temperature exceeds its normal range, it stimulates a cluster of brain cells referred to as the “heat-loss center.” This stimulation has three major effects:
Blood vessels in the skin begin to dilate allowing more blood from the body core to flow to the surface of the skin allowing the heat to radiate into the environment.
As blood flow to the skin increases, sweat glands are activated to increase their output. As the sweat evaporates from the skin surface into the surrounding air, it takes heat with it.
The depth of respiration increases, and a person may breathe through an open mouth instead of through the nasal passageways. This further increases heat loss from the lungs.
When the brain’s temperature regulation center receives data from the sensors indicating that the body’s temperature exceeds its normal range, it stimulates a cluster of brain cells referred to as the “heat-loss center.” This stimulation has three major effects:
Blood vessels in the skin begin to dilate allowing more blood from the body core to flow to the surface of the skin allowing the heat to radiate into the environment.
As blood flow to the skin increases, sweat glands are activated to increase their output. As the sweat evaporates from the skin surface into the surrounding air, it takes heat with it.
The depth of respiration increases, and a person may breathe through an open mouth instead of through the nasal passageways. This further increases heat loss from the lungs.
A body that is lying down is described as either … or …
prone or supine.
… describes a face-down orientation
Prone