Homeostasis

Question 1

What is homeostasis?

Answer 1

A dynamic process that maintains internal conditions within a narrow, healthy range.

Question 2

Why is homeostasis important in pharmacy?

Answer 2

All medical conditions can be traced to failures in homeostatic control; restoring it is a core healthcare goal.

Question 3

What are the three levels where homeostasis can occur?

Answer 3

Cellular, Organ/Tissue, and Whole-body levels.

Question 4

Name seven regulated homeostatic factors.

Answer 4

[Glucose], Body temperature, Blood pressure/volume, [Waste products], pH, [Water], [Salts], [Electrolytes], [O₂], [CO₂].

Question 5

What is a set point?

Answer 5

The optimal physiological value the body tries to maintain, e.g., 4–6 mmol/L for blood glucose.

Question 6

What is negative feedback?

Answer 6

A feedback mechanism that counters deviations from the set point to restore homeostasis.

Question 7

What is positive feedback?

Answer 7

A mechanism that amplifies changes and moves the system further from the starting point.

Question 8

Give an example of negative feedback.

Answer 8

Thermoregulation (sweating, shivering).

Question 9

Give an example of positive feedback.

Answer 9

Blood clotting cascade via thrombin activation.

Question 10

What are the three components of a homeostatic system?

Answer 10

Sensor, Control Centre, Effector.

Question 11

What does the sensor do?

Answer 11

Detects deviations from the normal range.

Question 12

What does the control centre do?

Answer 12

Receives information from the sensor and determines the response.

Question 13

What does the effector do?

Answer 13

Executes the response to restore homeostasis.

Question 14

What is intrinsic regulation?

Answer 14

Local, automatic adjustments in response to environmental changes.

Question 15

Give an example of intrinsic regulation.

Answer 15

↓ O₂ → NO release → vasodilation → ↑ O₂ delivery.

Question 16

What is extrinsic regulation?

Answer 16

Systemic, coordinated responses involving nervous and endocrine systems.

Question 17

Give an example of extrinsic regulation.

Answer 17

↓ body temp → nervous system causes shivering, endocrine releases thyroid hormone.

Question 18

What organ regulates blood glucose?

Answer 18

The pancreas.

Question 19

What do beta (β) cells secrete?

Answer 19

Insulin, to lower blood glucose.

Question 20

What do alpha (α) cells secrete?

Answer 20

Glucagon, to raise blood glucose.

Question 21

What are insulin’s target organs?

Answer 21

Fat, muscle, and liver.

Question 22

What does insulin do in the liver?

Answer 22

Increases glycogen synthesis, decreases gluconeogenesis.

Question 23

What does glucagon do in the liver?

Answer 23

Increases glycogen breakdown and gluconeogenesis.

Question 24

What is homeostatic variability?

Answer 24

Normal fluctuation around the set point within a safe range.

Question 25

What tool shows real-time glucose variability?

Answer 25

Continuous glucose monitors (e.g., Dexcom).

Question 26

What is the normal blood glucose set point range?

Answer 26

4–6 mmol/L.

Question 27

What is a real-life example of set point change?

Answer 27

Fever raises the body temperature set point.

Question 28

Why is glucose variability monitored?

Answer 28

To detect deviations and prevent hyper/hypoglycemia.

Question 29

Which feedback loop is most common in the body?

Answer 29

Negative feedback.

Question 30

Which system is a rare example of positive feedback?

Answer 30

Blood clotting.

Question 31

What happens in thermoregulation when temperature rises?

Answer 31

Vasodilation and sweating lower the temperature.

Question 32

What happens in thermoregulation when temperature drops?

Answer 32

Vasoconstriction and shivering increase temperature.