Chapter 9

Question 1

the physiological state of the body in which internal physical and chemical conditions are kept within a range that is suitable for life processes

Answer 1

homeostasis

Question 2

the extracellular fluid, which consists of the fluid that surrounds the cells and tissues in the body and the plasma portion of the blood

Answer 2

internal environment

Question 3

the fluid that surrounds the body cells

Answer 3

interstitial fluid

Question 4

a system that monitors internal and external conditions and changes bodily functions to maintain homeostasis

Answer 4

homeostatic mechanism

Question 5

the response of a system that acts to maintain equilibrium by compensating for any changes made to the system

Answer 5

negative feedback

Question 6

the element of a feedback system that detects changes in the environment

Answer 6

sensor

Question 7

the optimal value for a given variable of a system

Answer 7

set point

Question 8

the element (or elements) of a feedback system that acts to return the system to its optimal state

Answer 8

effector

Question 9

the element of a feedback system that compares existing conditions with ideal conditions

Answer 9

integrator

Question 10

the response of a system that acts to increase the effect of any changes made to the system

Answer 10

positive feedback

Question 11

the regulation of internal temperature by negative feedback mechanisms

Answer 11

thermoregulation

Question 12

an animal that maintains a stable body temperature regardless of the temperature of the external environment

Answer 12

homeotherm

Question 13

an animal whose body temperature varies with, and often matches, the temperature of the external environment

Answer 13

poikilotherm

Question 14

an animal that maintains its body temperature by internal mechanisms

Answer 14

endotherm

Question 15

an animal that maintains its body temperature by absorbing thermal energy from the environment

Answer 15

ectotherm

Question 16

the process by which an animal gradually adjusts to temperature changes in its environment

Answer 16

thermal acclimatization

Question 17

a short-term state of reduced metabolic rate and body temperature that reduces the demand for energy during the night or day

Answer 17

torpor

Question 18

a state of greatly reduced metabolic rate and activity that enables an animal to survive the winter by reducing the demand for energy when food is unavailable

Answer 18

hibernation

Question 19

a state of torpor that enables an animal to survive the summer by reducing the demand for energy

Answer 19

estivation

Question 20

the pressure that results from a difference in solute concentration between the two sides of a selectively permeable membrane

Answer 20

osmotic pressure

Question 21

the property of the solution on one side of a selectively permeable membrane that has the lower concentration of water

Answer 21

hyperosmotic

Question 22

the property of the solution on one side of a selectively permeable membrane that has the higher concentration of water

Answer 22

hyposmotic

Question 23

the property of two solutions that have equal water concentrations

Answer 23

isoosmotic

Question 24

the process of actively regulating the osmotic pressure of bodily fluids and cells

Answer 24

osmoregulation

Question 25

a structure in a single-celled organism that maintains osmotic equilibrium by pumping excess fluid out of the cell

Answer 25

contractile vacuole

Question 26

an excretory organ in some invertebrates that is used to reabsorb and eliminate wastes

Answer 26

metanephridium

Question 27

the main organ of excretion in insects, which is used to carry wastes to the intestines

Answer 27

Malpighian tubule

Question 28

the tiny functional unit of the kidney that filters wastes from the blood

Answer 28

nephron

Question 29

a small folded structure in the human kidney that encircles the glomerulus

Answer 29

Bowman's capsule

Question 30

a network of capillaries within the Bowman’s capsule that performs the first step in the filtration of blood

Answer 30

glomerulus

Question 31

a vessel that supplies blood to the nephrons in the human kidney

Answer 31

afferent arteriole

Question 32

a vessel that carries away filtered blood from the nephrons in the human kidney

Answer 32

efferent arteriole

Question 33

a net of capillaries in the nephrons that reabsorb essential ions and minerals from filtered blood

Answer 33

peritubular capillaries

Question 34

the duct portion of a nephron that connects the Bowman’s capsule to the loop of Henle

Answer 34

proximal convoluted tubule

Question 35

the U-shaped part of the duct that connects the proximal convoluted tubule to the distal convoluted tubule

Answer 35

loop of Henle

Question 36

the duct portion of a nephron that connects the loop of Henle to the ducts that lead to the renal pelvis

Answer 36

distal convoluted tubule

Question 37

the process in which blood and fluid pass through a selectively permeable membrane

Answer 37

filtration

Question 38

the transfer of water, ions, and nutrients back to the interstitial fluid via passive and active transport

Answer 38

reabsorption

Question 39

a membrane protein that passively transports water molecules

Answer 39

aquaporin

Question 40

the removal of waste materials from the blood and intercellular fluid

Answer 40

secretion