Homeostasis

Question 1

physiological and behavioral systems are responsible for … the maintenance of a stable, balanced, internal environment

Answer 1

homestasis

Question 2

changes in the internal environment can affect … the psychological process that induces or sustains a certain behavior

Answer 2

motivation

Question 3

is the regulation of the body temp

Answer 3

thermoregulation

Question 4

generate their own heat through internal processes, like metabolism and muscular activity

• this gives organisms an advantage they aren’t tied to certain environments

Answer 4

endotherms

Question 5

who get most of their heat from the environment

• both try to maintain their temps within an ideal range for optimal functioning of cells: too hot and proteins lose their correct shape and malfunction, too cool and chemical reactions in the body occur too slowly

Answer 5

ectotherms

Question 6

in keeping with thermoregulation… if a desired value, the set point, is deviated from, compensatory action begins. Once the desired value is reached, it feeds back and turns the system off

… systems are the primary homeostatic mechanism

The set zone refers to the range of tolerance in a system

Answer 6

negative feedback

Question 7

• receptors in the skin, body core, and hypothalamus detect temp and transmit that information to the spinal cord, brainstem and hypothalamus
• if body temp is outside the set zone, these neural regions can initiate physiological and behavioral responses to return temp to the set zone

Answer 7

basic mammalian thermoregulatory system

Question 8

physiological systems show … monitored by more than one mechanism

Answer 8

redundancy

Question 9

there are 2 separate thermoregulatory systems in the rat hypothalamus:

• the … of the hypothalamus controls the physiological responses to cold, such as shivering and constriction of blood vessels
• the … controls behavioral regulation of temp, such as turning on heat lamps or cooling fans

Answer 9

pre-optic area (POA)

lateral hypothalamus

Question 10

behavioral regulation of temp:
1. change … of the body surface (like huddling or extending limbs)

2. change external … (by using clothing or nests)
3. change … (moving into sun or shade)

Answer 10

1. exposure
2. insulation
3. surroundings

Question 11

thermoregulation through behavior is especially important to … but exhibited by endotherms as well

Answer 11

ectotherms

Question 12

skin surface
body core
hypothalamus/POA

Answer 12

receptors

Question 13

spinal cord
brainstem
hypothalamus/POA

Answer 13

neural regions

Question 14

behavioral responses
- shivering
- heat-seeking/avoiding behaviors

physiological responses
- constriction or dilation of blood vessels
- sweating
- respiration
- thyroid hormone secretion

Answer 14

effectors

Question 15

land animals must prevent dehydration – excessive water loss

Answer 15

fluid regulation

Question 16

the fluid part of the body contained within cells (inside)

Answer 16

intracellular compartment

Question 17

the fluid in the space outside of cells, divided between interstitial fluid (fluid between cells) and blood plasma (outside)

Answer 17

extracellular compartment

Question 18

water is always moving between these compartments to ensure our cells:

Answer 18

have the water they need for processes

Question 19

molecules of a substance (solute) dissolved in another substance (solvent) will move until a uniform concentration is achieved

Answer 19

diffusion

Question 20

passive movement of solvent through a semipermeable membrane between solutions of different solute concentration until both sides become equal

Answer 20

osmosis

Question 21

the force that pushes or pulls water across the membrane

Answer 21

osmotic pressure

Question 22

if the extracellular fluid is … concentrated than 0.9% water will move out of the cells to the extracellular space

Answer 22

MORE

Question 23

if the extracellular fluid is … than 0.9% NaCl, water will move into cells

Answer 23

LESS

Question 24

both conditions can cause cells to :

Answer 24

not work properly or can be damaging