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
… describes a face up orientation
supine
… Describes the front or direction toward the front of the body. The toes are anterior to the foot.
Anterior (or ventral)
Anterior (or ventral)
Describes the front or direction toward the front of the body. The toes are anterior to the foot.
Posterior (or dorsal)
Describes the back or direction toward the back of the body. The popliteus is posterior to the patella.
… Describes the back or direction toward the back of the body. The popliteus is posterior to the patella.
Posterior (or dorsal)
Superior (or cranial)
describes a position above or higher than another part of the body proper. The orbits are superior to the oris.
… describes a position above or higher than another part of the body proper. The orbits are superior to the oris.
Superior (or cranial)
Inferior (or caudal)
describes a position below or lower than another part of the body proper; near or toward the tail (in humans, the coccyx, or lowest part of the spinal column). The pelvis is inferior to the abdomen.
… describes a position below or lower than another part of the body proper; near or toward the tail (in humans, the coccyx, or lowest part of the spinal column). The pelvis is inferior to the abdomen.
Inferior (or caudal)
… the side or direction toward the side of the body. The thumb (pollex) is lateral to the digits.
Lateral
Lateral
describes the side or direction toward the side of the body. The thumb (pollex) is lateral to the digits.
Medial
describes the middle or direction toward the middle of the body. The hallux is the medial toe.
… describes the middle or direction toward the middle of the body. The hallux is the medial toe.
Medial
… describes a position in a limb that is nearer to the point of attachment or the trunk of the body. The brachium is proximal to the antebrachium.
Proximal
Proximal
describes a position in a limb that is nearer to the point of attachment or the trunk of the body. The brachium is proximal to the antebrachium.
Distal
describes a position in a limb that is farther from the point of attachment or the trunk of the body. The crus is distal to the femur.
… describes a position in a limb that is farther from the point of attachment or the trunk of the body. The crus is distal to the femur.
Distal
… describes a position closer to the surface of the body. The skin is superficial to the bones.
Superficial
Superficial
describes a position closer to the surface of the body. The skin is superficial to the bones.
… describes a position farther from the surface of the body. The brain is deep to the skull.
Deep
Deep
describes a position farther from the surface of the body. The brain is deep to the skull.
A … is a two-dimensional surface of a three-dimensional structure that has been cut. Modern medical imaging devices enable clinicians to obtain “virtual sections” of living bodies.
section
A … is an imaginary two-dimensional surface that passes through the body.
plane
A plane is an imaginary two-dimensional surface that passes through the body. There are three planes commonly referred to in anatomy and medicine.
The sagittal plane is the plane that divides the body or an organ vertically into right and left sides. If this vertical plane runs directly down the middle of the body, it is called the midsagittal or median plane. If it divides the body into unequal right and left sides, it is called a parasagittal plane or less commonly a longitudinal section.
The frontal plane is the plane that divides the body or an organ into an anterior (front) portion and a posterior (rear) portion. The frontal plane is often referred to as a coronal plane. (“Corona” is Latin for “crown.”)
The transverse plane is the plane that divides the body or organ horizontally into upper and lower portions. Transverse planes produce images referred to as cross sections.
The … plane is the plane that divides the body or an organ vertically into right and left sides.
sagittal
The sagittal plane is the plane that divides the body or an organ vertically into right and left sides. If this vertical plane runs directly down the middle of the body, it is called … or …
the midsagittal or median plane.
The sagittal plane is the plane that divides the body or an organ vertically into right and left sides. If it divides the body into unequal right and left sides, it is called … or …
a parasagittal plane or less commonly a longitudinal section.
The … plane is the plane that divides the body or an organ into an anterior (front) portion and a posterior (rear) portion. The … plane is often referred to as a coronal plane. (“Corona” is Latin for “crown.”)
frontal
The … plane is the plane that divides the body or organ horizontally into upper and lower portions. … planes produce images referred to as cross sections.
transverse
The … and … are the largest body compartments. These cavities contain and protect delicate internal organs.
dorsal (posterior) cavity and the ventral (anterior) cavity
The … cavity allows for significant changes in the size and shape of the organs as they perform their functions. The lungs, heart, stomach, and intestines, for example, can expand and contract without distorting other tissues or disrupting the activity of nearby organs.
ventral
