D3.3 Homeostasis

Question 1

True or false?

Organisms aim to maintain internal conditions within a preset range.

Answer 1

T

Question 2

A feedback response acting against the change of a factor is called negative feedback.
T or F?

Answer 2

T

Question 3

________ feedback mechanisms aim to keep conditions fluctuating within a preset range.

Answer 3

negative

Question 4

Identify the best definition for the term homeostasis.

Answer 4

Regulation of internal conditions within a range

Question 5

Identify which of the following is an example of negative feedback.

Answer 5

Beta cells of pancreatic islets release the hormone
insulin into the bloodstream when glucose is high in blood.

Question 6

Early signs of diabetes are excessive urination and excessive thirst.

T or F?

Answer 6

T

Question 7

Identify the role of pancreatic hormones.

Answer 7

Regulating blood glucose

Question 8

Identify how the release of pancreatic hormones would change during fasting (a period of time where no food is consumed).

Answer 8

Insulin decreases, glucagon increases

Question 9

Identify which of the following is one of the major symptoms of type 2 diabetes.

Answer 9

Increase secretion of insulin in blood

Question 10

In cold environments, the body’s blood vessels _____ in order to conserve heat. This process is called ________.

Answer 10

contrict, vasoconstriction

Question 11

___________ is the homeostatic mechanism by which the body maintains a stable internal temperature.

Answer 11

thermoregulation

Question 12

Identify which of the following parts of the human body are involved with thermoregulation.

Answer 12

Hypothalamus, pituitary gland and thyroid gland

Question 13

Identify how muscles contribute to thermoregulation.

Answer 13

shivering

Question 14

Identify which of the following is a way in which the body can conserve heat in cold environments.

Answer 14

Rising hair on the skin

Question 15

Osmoregulation is the regulation of _______ concentration.

Answer 15

osmotic

Question 16

Identify the name of the process by which the components of the blood move out from the glomerulus to the Bowman’s capsule.

Answer 16

Ultrafiltration

Question 17

Determine the effect of increased blood pressure on the filtration rate of the nephron.

Answer 17

Filtration rate increases

Question 18

Explain why the filtrate in Bowman’s capsule of a healthy person does not contain any blood cells.

Answer 18

The pores of the capillaries in the glomerulus are smaller than the cells

Question 19

True or false?

The descending limb of the loop of Henle is permeable to water.

Answer 19

True

Question 20

The loop of Henle is a part of the _______ in the mammalian kidney.

Answer 20

nephron

Question 21

Identify the factor that decreases the secretion of ADH.

Answer 21

Consumption of water

Question 22

The collecting ducts _____ water based on the body’s hydration status.

Answer 22

reabsorb

Question 23

During exercise blood _______ dilate, blood flow ________.

Answer 23

vessels, increases

Question 24

Define homeostasis.

Answer 24

Homeostasis is the tendency of an organism to maintain a stable internal state.

Question 25

List examples of variables that are maintained by homeostasis by humans.​​

Answer 25

• heart rate
• ventilation rate
• blood glucose
• body temp.
• blood osmolarity
• blood pH

Question 26

Compare consequences of negative and positive feedback.

Answer 26

negative - counteract the change, bring the system back to stable state
positive - amplifies the change, pushing the system further away from its original state.

Question 27

Explain how negative feedback loops maintain homeostasis.

Answer 27

-

Question 28

Explain the control of blood glucose concentration, including the roles of glucagon, insulin and the endocrine cells in the pancreatic islets.