Chapter 1 Terms

Question 1

Acclimatization

Answer 1

Environmentally induced improvement in functioning of a physiological system with no change in genetic endowment.

Question 2

Acquired reflex

Answer 2

Behaviors that appear to be stereotypical and automatic, but which in fact result from considerable conscious effort to be learned. Also called learned reflex.

Question 3

Adaptation

Answer 3

A biological characteristic that favors survival in a particular environment; (neural) decrease in action potential frequency in a neuron despite constant stimulus.

Question 4

Afferent pathway

Answer 4

Component of reflex arc that transmits information from receptor to integrating center.

Question 5

Autocrine agent

Answer 5

Chemical messenger secreted into extracellular fluid that acts upon cell that secreted it.

Question 6

Basement membrane

Answer 6

Thin layer of extracellular proteinaceous material upon which epithelial and endothelial cell sit.

Question 7

Cell

Answer 7

The simplest structural unit into which a complex multicellular organism can be divided and still retain the functions characteristic of life.

Question 8

Circadian rhythm

Answer 8

Occurring in an approximately 24 hour cycle.

Question 9

Collagen fiber

Answer 9

Strong, fibrous protein that functions as extracellular structural element in connective tissue.

Question 10

Connective tissue

Answer 10

One of the four major categories of tissues in the body.p major component of extracellular matrices, cartilage, and bone.

Question 11

Connective tissue cell

Answer 11

Cell specialized to form extracellular elements that connect, anchor, and support body structures.

Question 12

Developmental acclimatization

Answer 12

Potentially irreversible change in structure or function of one or more organ systems that occurs during early life and favors survival in specific environments.

Question 13

Effector

Answer 13

Cell or cell collection whose change in activity constitutes the response in a control system.

Question 14

Dynamic constancy

Answer 14

A given variable may vary in the short term but is stable and predictable when averaged over the long term (e.g. blood glucose levels vary throughout the day but over time are predictable).

Question 15

Elastin fiber

Answer 15

A protein with elastic or springlike properties; found in large arteries and in the airways.

Question 16

Endocrine gland

Answer 16

Group of epithelial cells that secrete into the extracellular space hormones that then diffuse into bloodstream. Also called a ductless gland.

Question 17

Entrainment

Answer 17

Adjusting biological rhythm to environmental cues.

Question 18

Epithelial cell

Answer 18

Cell at surface of body or hollow organ; specialized to secrete or absorb ions and organic molecules; with other epithelial cells forms an epithelium.

Question 19

Epithelial tissue

Answer 19

One of the four major tissue types in the body, comprised of aggregates of epithelial cells.

Question 20

Equilibrium

Answer 20

No net change occurs in a system; requires no energy.

Question 21

External environment

Answer 21

Environment surrounding external surface of an organism.

Question 22

Extracellular fluid

Answer 22

Fluid outside cell, interstitial fluid and plasma.

Question 23

Extracellular matrix

Answer 23

A complex consisting of a mixture of proteins interspersed with extracellular fluid.

Question 24

Feedforward

Answer 24

Aspect of some control systems that allows system to anticipate changes in a regulated variable.

Question 25

Free-running rhythm

Answer 25

Cyclical activity driven by biological clock in absence of environmental cues.

Question 26

Homeostasis

Answer 26

Relatively stable condition of internal environment that results from regulatory system actions.

Question 27

Hormone

Answer 27

Chemical messenger synthesized by specific endocrine cells in response to certain stimuli and secreted into the blood, which carries it to target cells.

Question 28

Functional unit

Answer 28

Small, similar subunits each performing the function of the organ (e.g. the kidneys’ functional units are called nephrons).

Question 29

Internal environment

Answer 29

Extracellular fluid (interstitial fluid and plasma)

Question 30

Interstitial fluid

Answer 30

Extracellular fluid surrounding tissue cells; excludes plasma.