Homeostasis (Topic 5)

Question 1

What is intracellular fluid? (2)

Answer 1

Inside the cell (cytosol)

Question 2

What is extracellular fluid? (2)

Answer 2

Outside of the cell (plasma and interstitial fluid)

Question 3

What is the difference between plasma and interstitial fluid? (2)

Answer 3

• Plasma is in the blood vessels
• interstitial fluid is outside of the blood vessels

Question 4

What are some common physiological barriers that must be maintained in within a range? (3)

Answer 4

• temperature
• blood sugar
• pH
• salinity
• blood pressure

Question 5

What is dynamic constancy? (4)

Answer 5

Physiological variables can change dramatically over a 24-hr. period, but in average, remain stable in the long run

Question 6

T/F. An organism may be homeostatic for one variable but not for another. (5)

Answer 6

true

Question 6

T/F. An organism may be homeostatic for one variable but not for another. (5)

Answer 6

true

Question 7

What is an example of homeostasis penalizing one variable to control another? (5)

Answer 7

sacrificing water balance to regulate temperature

Question 8

What is heat stroke? (5)

Answer 8

When you run out of water to balance your temperature

Question 9

What is pathophysiology? (5)

Answer 9

when one or more variables are not in homeostasis

Question 10

How does the body respond to changes? (6)

Answer 10

• behavioral changes
• physiological regulation
• tolerance

Question 11

What is tolerance? (6)

Answer 11

Tolerating a variable that is slightly out of range

Question 12

What is a behavioral change? (6)

Answer 12

A voluntary action
ex: moving into the shade

Question 13

What is a physiological regulation? (6)

Answer 13

an involuntary action
ex: shivering and sweating

Question 14

How does shivering help? (6)

Answer 14

muscles contract and use energy, then creates heat

Question 15

how does body balance sensory input? (7)

Answer 15

Body balances sensory input with functional output

Question 16

What is the set point? (7)

Answer 16

target value for the variable (average)

Question 17

What is an error signal? (7)

Answer 17

difference between the true value and the set point

Question 18

Why is homeostasis not perfect? (7)

Answer 18

The body varies (oscillates) within a range of normal values around a average value.

Question 19

Practice slide 8 (flow chart of homeostatic control systems)

Answer 19

yay slide 8

Question 20

What is steady state? (9)

Answer 20

when a variable is not changing (staying in range) but energy is added to keep it steady
Ex: Shivering

Question 21

What is equilibrium? (9)

Answer 21

no change, no energy required
Ex: Perfect temperature room

Question 22

What are feedback systems? (10)

Answer 22

Processes that are influenced by the amount of product

Question 23

What is negative feedback? (10)

Answer 23

change in a variable that results in a response in the opposite direction
ex: increase in blood sugar; response is to lower blood sugar

Question 24

What is positive feedback? (11)

Answer 24

a change in a variable that results in a response in the same direction

Question 25

Which is most common, positive or negative feedback? (11)

Answer 25

negative feedback

Question 26

What is positive feedback best for? (11)

Answer 26

Making things happen fast ex: repairing damages - platelets attract more and more platelets to heal a cut

Question 27

Does positive feedback directly maintain homeostasis? (11)

Answer 27

does not directly maintain homeostasis, but it is important to make some things happen quickly

Question 28

What does feedforward regulation depend on? (12)

Answer 28

Depends on sensory receptors that detect environmental change before an internal imbalance.

Question 29

What is an example of feedforward regulation? (12)

Answer 29

sweating as soon as you step outside when its hot, even though your body hasn't had time to get hot

Question 30

What is an example is resetting of set points? (12)

Answer 30

A fever

Question 31

What is a set point reset? (12)

Answer 31

A set point changing

Question 32

What is feedforward regulation? (12)

Answer 32

Response of control system before the change in controlled physiological variable.

Question 33

What is a reflex?

Answer 33

specific, involuntary, unpremeditated, unlearned responses

Question 33

What is a reflex? (13)

Answer 33

specific, involuntary, unpremeditated, unlearned responses

Question 34

What is an example of a reflex? (13)

Answer 34

patellar reflex and pulling away from a hot stove

Question 35

What is a learned reflex? (13)

Answer 35

a response that is not "built in"; takes training

Question 36

What is an example of a learned reflex? (13)

Answer 36

- dodging a softball to the face - hitting the brakes when driving and something jumps in front of you

Question 37

What is a stimulus?(13)

Answer 37

a detectable change in the internal or external environment

Question 38

What does a receptor do? (14)

Answer 38

detects the change

Question 39

What is the afferent pathway? (14)

Answer 39

brings stimulus to integrating center

Question 40

What does the integrating center do? (14)

Answer 40

decides to respond to stimulus

Question 41

What is the efferent pathway? (14)

Answer 41

takes stimulus away from the integrating center

Question 42

What does an effect do? (14)

Answer 42

produces response, commanded by the integrating center

Question 43

What are the two types of effectors? (14)

Answer 43

glands and muscles

Question 44

Do all reflexes follow the same pathway? (14)

Answer 44

Yes

Question 45

Practice slide 15 about the patellar reflex pathways

Answer 45

yay slide 15

Question 46

What are the two types of homeostatic responses? (17)

Answer 46

reflexes and local responses

Question 47

What is the difference between reflexes and local responses? (17)

Answer 47

Reflexes: - long range - can stimulate muscles and glands Local Response: - restricted to the location of the stimulus

Question 48

What can reflexes stimulate? (17)

Answer 48

muscles and glands

Question 49

What do glands do? (17)

Answer 49

secrete stuff

Question 50

What do endocrine glands do? (17)

Answer 50

secrete hormones

Question 51

What do exocrine glands do? (17)

Answer 51

secrete sweat and oil

Question 52

What is an example of a local response? (17)

Answer 52

when cells are metabolically active, they secrete substances that cause nearby blood vessels to dilate (no signal to the brain or hormone coming from somewhere)

Question 53

What is an adaptation? (18)

Answer 53

a characteristic that favors survival in a specific environment

Question 54

Are adaptations inherited or learned?

Answer 54

inherited

Question 55

What is an example of an adaptation? (18)

Answer 55

the ability of raising body temperature by shivering

Question 56

What is acclimation? (18)

Answer 56

improved functioning of an already existing homeostatic system based on an environmental stress.

Question 57

Can acclimation occur in an individual or only inherited? (18)

Answer 57

it can change in an individual

Question 58

What is an example if acclimatization? (18)

Answer 58

some wearing shorts in the cold vs sweaters in the cold due to where they have lived

Question 59

Can acclimatization be reversible? (18)

Answer 59

Not always

Question 60

What are biological rhythms? (19)

Answer 60

regular, periodic programmed changes in the set point value

Question 60

What are biological rhythms? (19)

Answer 60

regular, periodic programmed changes in the set point value

Question 61

What are examples of biological rhythms? (19)

Answer 61

Variation in alertness, body temp, hormone concentrations, urinary and digestive activity

Question 62

What is entrainment? (20)

Answer 62

biological rhythms are internally driven, but may cue on environmental factors to adjust timing (JET LAG)

Question 63

What are ontogenetic shifts? (20)

Answer 63

developmental changes in set point values - may or may not be desirable - not reversible or cyclic