Q: According to the law of mass balance, if a person consumes 2 L of water and loses 1.5 L through urine and 0.3 L through sweat, how much water must be lost or gained to maintain homeostasis?

$$2.0\ \text{L} - (1.5\ \text{L} + 0.3\ \text{L}) = 0.2\ \text{L}$$ must be lost or gained

Q: Which of the following best describes the difference between osmolarity and tonicity?

Osmolarity can be measured in $$\text{mOsm/L}$$, while tonicity is a comparative term that describes what happens to a cell placed in a solution.

Question 1

Which of the following best describes the concept of 'emergent properties' as it applies to physiology?

Accepted Answer

Properties that arise from the interaction of system components and cannot be explained by knowledge of the individual parts alone.

Question 2

A patient is experiencing a drop in blood pressure. Which of the following best describes the baroreceptor reflex response to restore homeostasis?

Accepted Answer

Baroreceptors decrease their firing rate, leading to increased heart rate and vasoconstriction.

Question 3

Which of the following is an example of a negative feedback loop in human physiology?

Accepted Answer

Regulation of blood glucose by insulin and glucagon.

Question 4

According to the law of mass balance, if a person consumes 2 L of water and loses 1.5 L through urine and 0.3 L through sweat, how much water must be lost or gained to maintain homeostasis?

Accepted Answer

$$2.0\ 	ext{L} - (1.5\ 	ext{L} + 0.3\ 	ext{L}) = 0.2\ 	ext{L}$$ must be lost or gained

Question 5

Which of the following statements about homeostasis is TRUE?

Accepted Answer

Homeostasis is the maintenance of a dynamic steady state, not equilibrium.

Question 6

A cell is placed in a solution and swells. Which of the following best describes the tonicity and osmolarity of the solution relative to the cell?

Accepted Answer

The solution is isosmotic and hypotonic.

Question 7

Which of the following best explains why cholesterol is important in the cell membrane?

Accepted Answer

It increases viscosity and decreases permeability.

Question 8

A researcher is studying a membrane protein that spans the entire lipid bilayer and acts as a channel for sodium ions. This protein is best classified as:

Accepted Answer

An integral (transmembrane) protein

Question 9

Which of the following is a correct sequence for a reflex control pathway?

Accepted Answer

Stimulus $$\rightarrow$$ Sensor $$\rightarrow$$ Input signal $$\rightarrow$$ Integrating center $$\rightarrow$$ Output signal $$\rightarrow$$ Target $$\rightarrow$$ Response

Question 10

Which of the following best describes the difference between osmolarity and tonicity?

Accepted Answer

Osmolarity can be measured in $$	ext{mOsm/L}$$, while tonicity is a comparative term that describes what happens to a cell placed in a solution.

Question 11

A solution contains 300 mOsm/L of non-penetrating solutes. A cell with an internal osmolarity of 300 mOsm/L is placed in this solution. What will happen to the cell?

Accepted Answer

The cell will not change in volume because the solution is isotonic.

Question 12

Which of the following is a function of integral membrane proteins?

Accepted Answer

Acting as receptors, enzymes, and channels for ions and minerals

Question 13

A patient with a genetic disorder has a defect in their GLUT transporter. Which process is most likely to be directly affected?

Accepted Answer

Facilitated diffusion of glucose across the cell membrane

Question 14

Which of the following best describes the role of feedforward control in physiological systems?

Accepted Answer

It anticipates change and initiates a response before the variable is altered.

Question 15

Which of the following is TRUE regarding the composition of the cell membrane?

Accepted Answer

It is composed of approximately 55% proteins, 45% lipids, and trace amounts of carbohydrates.

Question 16

Which of the following best explains why phospholipids are considered amphipathic molecules?

Accepted Answer

They contain both a hydrophilic polar head and hydrophobic fatty acid tails.

Question 17

A cell is placed in a solution with a lower concentration of non-penetrating solutes than the cell's cytoplasm. What will happen to the cell and why?

Accepted Answer

The cell will swell because water will move in.

Question 18

Which of the following is a correct example of primary active transport?

Accepted Answer

Sodium-potassium pump using ATP to move ions against their concentration gradients

Question 19

Which of the following best describes the function of the extracellular fluid (ECF)?

Accepted Answer

It acts as a buffer between cells and the external environment.

Foundations of Physiology and Cell Membranes: Homeostasis, Control Systems, and Membrane Structure

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