Ny State Living Environment Unit 3: Homeostasis & Human Body

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Aging

Back 1

The process of getting older. Generally refers to developmental changes that occur as we approach the later years of our life expectancy.

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AIDS

Back 2

A disease of the immune system that destroys cells of the immune system that normally fight infections and cancers, leaving the body vulnerable to disease. Caused by the HIV virus.

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Allergic reaction

Back 3

An immune response to an otherwise harmless substance. Symptoms include local or systemic inflammation and, itching, sneezing, and/or other problems depending on the type of substance and the areas of the body affected. Can be life-threatening. For example, when eating a certain food is the cause, the effect will be different than when breathing pollen is the cause.

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Antibiotic

Back 4

A drug used to treat mainly bacterial infections. NOT effective against viruses but frequently over-prescribed for that purpose. Many bacteria have developed resistance to these medications due partly to misuse.

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Antibody

Back 5

A chemical produced by specialized white blood cells that mark or otherwise help to destroy pathogens. Produced by immune system cells in response to a pathogen during initial exposure (infection), these chemicals then remain in the body after infection to fight future infections more effectively.

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Antigen

Back 6

Generally a molecule (protein or carbohydrate embedded in cell wall or membrane of a pathogen) that causes the body to launch an immune response. It is the molecule that antibodies bind with (see antibody).

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Balance

Back 7

Having a variety of conditions maintained in a relatively narrow range to maintain a healthy cell, organism, or ecosystem. When one condition is out of the normal range, it can affect other conditions.

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Balanced internal environment

Back 8

Having a set of internal bodily conditions maintained in a relatively narrow range necessary to maintain health. Homeostasis.

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Behavior

Back 9

The instinctive or learned actions that an organism takes in response to internal and external stimuli.

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Breakdown

Back 10

When a relatively large material is made into smaller parts or when a complex molecule is reduced to simpler molecules. Digestion and respiration, for example.

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Cancer

Back 11

A disease characterized by uncontrolled cell growth that can spread throughout the body and lead to organ malfunction or failure and eventually death if not treated early and effectively.

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Cancerous cell

Back 12

A cell that has begun dividing in an uncontrolled way. Often destroyed by the immune system, but diseases that affect the immune system can leave the body unable to effectively deal with these types of cells.

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Cellular communication

Back 13

When cells send and receive "messages" to and from each other. These messages are in the form of chemicals such as hormones and neurotransmitters.

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Chemical signals

Back 14

Hormones and neurotransmitters that send "messages" from one cell to another. One message, for example, might tell cells to "divide." Another might tell them to "stop dividing."

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Circulation

Back 15

Refers to the movement of materials within cells or an organism. Can occur by simple diffusion or by complex organ systems.

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Control mechanisms

Back 16

A method for maintaining a narrow range of conditions in an organism (see feedback mechanism).

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Coordination

Back 17

The control and regulation of the multitude of life activities carried out by living things. Higher orders of animals have a nervous system that largely performs this task.

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Corrective actions

Back 18

The body's response to internal changes that bring the system back to the normal range. Example: When you are lying down and suddenly stand up, your blood pressure drops. The body responds by increasing heart rate to bring blood pressure back to a normal range.

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Death

Back 19

The irreversible ending of life activities for a cell, tissue, organ, or organism.

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Deviations

Back 20

Movement of a condition or state away from a set point or range. Example: Normal body temperature is around 37.0 degrees Celsius. A change to 36.0 degrees or 38.0 degrees would be a movement away from the set range.

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Diagnosing

Back 21

Examining a problem or illness and determining the most likely cause.

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Digestion

Back 22

The breaking down of complex food materials into simpler forms that can be absorbed, transported, and used for cellular activities.

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Disease

Back 23

Failure or inability to maintain the body's internal conditions or homeostasis. Can be caused by genetic disorders, viruses, bacteria, exposure to toxins, etc.

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Eliminate waste

Back 24

To rid the body of unwanted materials produced by cellular metabolism or digestion.

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Engulf

Back 25

A process by which cells "swallow" or take in materials by surrounding and enclosing them within a portion of the cell membrane. (see image card).

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Excretion

Back 26

The process of getting metabolic waste out of the organism. Urination, sweating, breathing out (CO2) are examples.

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Feedback mechanism

Back 27

A self-regulating system in which a condition is 1) maintained within a narrow range (negative) or 2) elevated beyond normal conditions (positive). A negative example would be the glucose/insulin system for maintaining blood sugar levels. A positive example is uterine contractions during labor: the contractions cause a hormone to be released that increases contractions, which again increases the release of the hormone, which increases contractions, and so on.

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Heart rate

Back 28

The number of times the heart beats in one minute. It changes in response to activity, stress, illness, etc.

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Homeostasis

Back 29

The active maintenance a set of internal conditions within in a relatively narrow range.

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Homeostatic feedback mechanism

Back 30

A self regulating system in which a condition is maintained within a narrow range. An example would be the glucose/insulin system for maintaining blood sugar levels. When blood sugar is high, insulin is released by the pancreas, which lowers blood sugar levels, which in turn causes the pancreas to stop releasing insulin (see image card).

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Hormone

Back 31

A chemical messenger produced in one part of the body and released into the blood where it travels to specific "target cells" and causes the target cells to take some kind of action. Insulin is a hormone. When it binds with target cells, it causes the target cells to take in glucose from the blood.

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Host

Back 32

The organism that is infected by a pathogen. Most commonly used in conjunction with "parasite."

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Imbalance

Back 33

A state in which one or more conditions in a cell, organ, organism, or ecosystem is outside the "normal," healthy range.

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Immune system

Back 34

The system that protects the organism against disease caused by pathogens or (sometimes) cancers.

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Immunity

Back 35

In general: the state of being protected from disease-causing organisms (pathogens) and some cancers. More narrowly, in humans it refers to the presence of antibodies against the individual antigens produced by SPECIFIC pathogens.

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Infections

Back 36

The presence of one (usually) disease-causing organisms in or on another organism. Does not always cause disease or symptoms of disease.

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Infectious agent

Back 37

A potentially disease-causing organism or particle. Includes viruses, bacteria, protists, small invertebrates such as worms, head lice, etc.

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Insulin

Back 38

A hormone that is released in response to elevated blood sugar levels that causes target cells (mostly in the liver and skeletal muscles) to take in glucose, thereby lowering blood sugar level.

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Internal environment

Back 39

The materials and conditions INSIDE of a cell or organism. Compare with "external conditions."

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Learned behavior

Back 40

Response to changes in the environment or internal conditions that are acquired during one's lifetime, as opposed to instinctive or automatic responses.

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Mammal

Back 41

A class of animals that includes humans. The majority have hair or fur, give live birth to their young, and produce milk for nursing new-borns.

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Microbes

Back 42

Any microscopic organism. Mainly bacteria, protists, some fungi, and even some tiny multi-cellular organisms.

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Minerals

Back 43

Inorganic elements found in the soil or water that are essential for living things. In general they are taken in by plants or other producers directly from the soil or water. Consumers then eat the producers (or other consumers that ate plants) and take these elements in from their food. Examples include iron, calcium, potassium, etc.

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Monitor

Back 44

To observe, literally or figuratively, to make sure that conditions remain within a particular range. In most cases, this is an unconscious, automatic process involving feedback mechanisms rather than conscious or even unconscious notice.

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Movement

Back 45

A change of location or position. Describes materials within a cell, structure, organism, (circulation, for example) or entire cells and organism as they go from place to place (locomotion, migration, etc.).

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Nerve cell

Back 46

A specialized cell designed to transmit messages, both electrical and chemical, from one part of the body to another or to make decisions about a course of action in response to a message from another part of the body.

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Normal state

Back 47

The healthy range of a particular factor (temperature, blood sugar level, blood pressure, etc.) in an individual or cell when that cell or individual is not stressed or diseased or otherwise impaired.

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Nutrient

Back 48

A substance (other than O2 and CO2) that is manufactured, absorbed, or otherwise taken in from the environment that is essential for life. Includes carbohydrates, lipids, proteins, vitamins, minerals, and water.

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Nutrition

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1. The manner in which a particular organism gets it food. Can be autotrophic or heterotrophic. 2. The study of the types and portions of foods that are necessary for good health.

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Organ malfunction

Back 50

When an organ, such as the heart, brain, kidneys, etc., stops working properly. Can be a cause or symptom of a disease. Can range from a minor inconvenience to a major health problem to fatal, depending on the organ and what exactly goes wrong with it.

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Pancreas

Back 51

An organ located just behind the stomach that produces both hormones (insulin, e.g.), which are secreted into the blood stream, and digestive enzymes, which are secreted into the small intestine.

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Parasite

Back 52

An organism that lives in or on a host, usually for a prolonged period of time, and gets its nutrition from the host. Generally the term is reserved for protists, fungi, some plants, and invertebrates, but sometimes used loosely for bacteria as well.

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Pathogen

Back 53

A disease-causing particle (virus, e.g.) or organism (bacteria, fungi, etc.).

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Receptor

Back 54

Molecules on the surface of a cell that bind with specific chemicals from another cell. An important part of how cells communicate with each other. The chemicals that bind to receptors may be hormones, or chemicals produced by nerve cells (neurotransmitters), etc.

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Regulatory

Back 55

adjective. Refers to the body's mechanisms for maintaining homeostasis.

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Respiratory rate

Back 56

The number of times an organism breathes or otherwise actively takes in oxygen and lets out carbon dioxide.

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Steady state

Back 57

Synonymous with dynamic equilibrium or homeostasis - maintaining internal conditions within a relatively narrow range.

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Transplanted

Back 58

adjective. Usually refers to an organ or tissue from one organism or individual that is placed into another organism or individual.

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Transport

Back 59

Circulation. The movement of materials, particularly the movement of materials across a membrane in cells.

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Vaccination

Back 60

An injection of a dead or weakened pathogen that triggers an immune response. The body then produced antibodies against the dead or weakened pathogen, giving the person immunity to the disease cause by the pathogen.

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Viral disease

Back 61

The common cold, flu, AIDS, etc. (Caused by viruses.)

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Virus

Back 62

A disease causing particle. They are not considered living things but they do contain either DNA or RNA, and are capable of replicating (reproducing) ONLY inside a host cell.

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White blood cells

Back 63

Blood cells that help fight infection in a number of ways. Some produce antibodies, some engulf pathogens, some mark pathogens for destruction by other cells.