Chapter 22:Homeostasis

Question 1

Flashcard 1:
- Q: What is homeostasis?

Answer 1

• A: The maintenance of a constant internal environment.

Question 2

Flashcard 2:
- Q: What are the two environments in living organisms?

Answer 2

• A: External environment (the surroundings) and internal environment (space inside the body filled with tissue fluid).

Question 3

Flashcard 3:
- Q: How does homeostasis help enzymes work effectively?

Answer 3

• A: By maintaining a constant internal body temperature around 37˚C.

Question 4

Flashcard 4:
- Q: Why is maintaining a constant amount of water important for the body?

Answer 4

• A: To prevent damage to body cells or losing too much water by osmosis.

Question 5

Flashcard 5:
- Q: What is the importance of maintaining constant blood glucose levels?

Answer 5

• A: To ensure there is always enough fuel for respiration.

Question 6

Flashcard 6:
- Q: Why must blood pH be kept constant at about 7.4?

Answer 6

• A: Because variations in pH can lead to denaturation of enzymes.

Question 7

Flashcard 7:
- Q: What does negative feedback do in homeostasis?

Answer 7

• A: It automatically brings about a correction to return a condition to its normal state.

Question 8

Flashcard 8:
- Q: How does negative feedback work?

Answer 8

• A: Receptor cells detect changes and send messages to the brain, which issues instructions to effectors to correct the change.

Question 9

Flashcard 9:
- Q: What happens if a factor is within its normal range after correction?

Answer 9

• A: Nothing more happens.

Question 10

Flashcard 10:
- Q: What happens if a factor is still out of limits after initial correction?

Answer 10

• A: The receptor cells send another message to the brain, and the effector responds again.

Question 11

Flashcard 11:
- Q: How does the body prevent overcorrection in negative feedback?

Answer 11

• A: By sending a negative message from the receptor to the effector to stop its corrective action.

Question 12

Flashcard 12:
- Q: What are ectothermic animals?

Answer 12

• A: Animals that cannot generate sufficient heat inside the body and rely on external sources such as the sun for body heat.

Question 13

Flashcard 13:
- Q: Give examples of ectothermic animals.

Answer 13

• A: Reptiles and insects.

Question 14

Flashcard 14:
- Q: How do ectothermic animals regulate temperature in cold weather?

Answer 14

• A: By basking in the sun, darkening their skin, and hibernating.

Question 15

Flashcard 15:
- Q: How do ectothermic animals regulate temperature in warm weather?

Answer 15

• A: By seeking shade, panting, and aestivating.

Question 16

Flashcard 16:
- Q: What are endothermic animals?

Answer 16

• A: Animals that rely on heat produced within their bodies by metabolic reactions to control their body temperature.

Question 17

Flashcard 17:
- Q: Give examples of endothermic animals.

Answer 17

• A: Mammals and birds.

Question 18

Flashcard 18:
- Q: How do endothermic animals generate heat when it is cold?

Answer 18

• A: Through cellular respiration and increased metabolic rates due to adrenaline.

Question 19

Flashcard 19:
- Q: How do endothermic animals lose heat when it is hot?

Answer 19

• A: Through radiation, evaporation, convection, and conduction.

Question 20

Flashcard 20:
- Q: What is the role of insulation in temperature regulation?

Answer 20

• A: To prevent heat loss from the body; fats under the skin act as insulation.

Question 21

Flashcard 21:
- Q: What happens to hair erector muscles in cold temperatures?

Answer 21

• A: They contract, making hairs stand upright to trap a layer of air for insulation.

Question 22

Flashcard 22:
- Q: What happens to hair erector muscles in hot temperatures?

Answer 22

• A: They relax, making hairs lie flat and preventing insulation.

Question 23

Flashcard 23:
- Q: How does sweating help regulate body temperature?

Answer 23

• A: By increasing evaporation of sweat from the skin surface, which leads to heat loss.

Question 24

Flashcard 24:
- Q: What is vasoconstriction and its effect?

Answer 24

• A: Narrowing of blood vessels, reducing blood flow to the skin, and decreasing heat loss.

Question 25

Flashcard 25:
- Q: What is vasodilation and its effect?

Answer 25

• A: Widening of blood vessels, increasing blood flow to the skin, and enhancing heat loss.

Question 26

Flashcard 26:
- Q: What happens to blood glucose levels after a meal rich in carbohydrates?

Answer 26

• A: They may rise to 150mg.

Question 27

Flashcard 27:
- Q: What hormone is secreted when blood glucose levels are high?

Answer 27

• A: Insulin.

Question 28

Flashcard 28:
- Q: What is the role of insulin in blood glucose regulation?

Answer 28

• A: It stimulates glucose uptake by cells and conversion of excess glucose to glycogen.

Question 29

Flashcard 29:
- Q: What hormone is secreted when blood glucose levels are low?

Answer 29

• A: Glucagon.

Question 30

Flashcard 30:
- Q: What is the role of glucagon in blood glucose regulation?

Answer 30

• A: It instructs the liver to convert glycogen back to glucose.

Question 31

Flashcard 31:
- Q: What are the symptoms of Type 1 diabetes?

Answer 31

• A: Extreme thirst, frequent urination, unintended weight loss, extreme hunger, irritability, fatigue, blurry vision, and in females, vaginal yeast infection.

Question 32

Flashcard 32:
- Q: How is Type 1 diabetes treated?

Answer 32

• A: By frequent blood sugar monitoring, daily insulin injections, dietary changes, and regular exercise.

Question 33

Flashcard 33:
- Q: What materials were used in the insulation experiment?

Answer 33

• A: Foil, cotton cloth, woolen sock, and newspaper.

Question 34

Flashcard 34:
- Q: What indicates the best insulator in the experiment?

Answer 34

• A: The material that keeps the water warmest.

Question 35

Flashcard 35:
- Q: Why might a woolen sock be the best insulator?

Answer 35

• A: It traps air and reduces heat loss, similar to fur or feathers.