30 Questions
What is the primary function of buffers in the maintenance of normal cellular pH?
To bind excess H+ ions
Which of the following is an example of a negative feedback mechanism?
Control of blood pressure
What is the set point of normal cellular pH?
7.4
Which component of the homeostatic control mechanism determines the appropriate response to a stimulus?
Control centre
What is the result of a marked change in [H+]?
Decrease in enzymatic activity
What is the primary goal of homeostasis in the body?
To maintain a relatively constant internal environment despite changes in the external environment
Which of the following is an example of a positive feedback mechanism?
Childbirth
What is the term for the internal environment of the body?
Milieu Interieur
What percentage of the body is made up of water in an average young male?
60%
What is the main function of homeostasis in regulating the body's metabolic rate?
To maintain a constant metabolic rate despite changes in the external environment
What is the term for the ability of cells to regulate their volume?
Volume regulation
What is the term for the relatively constant temperature of the body?
Body temperature
What is the normal plasma ion concentration range in terms of osmolarity?
180-290
What happens to the osmolarity of the external environment during exercise?
It increases
What is the effect of a decrease in glucose 6 dehydrogenase on NADPH production?
It decreases NADPH production
What type of solution is 0.45% saline compared to 0.9% saline?
Hypotonic
What is the primary mechanism of water movement across a membrane?
Passive diffusion
What is the name of the protein involved in water transport across a membrane?
Aquaporin 1
What percentage of body weight is composed of total body water?
60%
What is the osmolarity of the extracellular fluid (ECF) and intracellular fluid (ICF)?
290-300 mOsm/kg
What happens to the movement of water when the ion concentration outside the cell increases?
Water moves out of the cell
What is the approximate volume of plasma in the body?
3.5 L
What is the primary function of the equilibrium between the extracellular and intracellular fluid spaces?
To maintain cellular homeostasis
What is the approximate percentage of body weight composed of interstitial fluid?
15%
What drives the movement of H2O into the extracellular space?
Hydrostatic pressure
What is the net result of Na+/K+ ATPase activity?
Decreased sodium and increased potassium inside the cell
What is the response of cells to cell shrinking?
Regulatory volume increase
What is the consequence of rapid fluid replacement during dehydration?
Cell swelling and oedema
What is the term for the process by which cells respond to an increase in extracellular osmolarity?
Regulatory volume increase
What is the primary function of Na+/K+ ATPase?
To regulate electrolyte composition
Learn about the principles of homeostasis at the cellular level, including the regulation of cell volume, electrolyte composition, pH, and metabolic rate. Understand how cells maintain a constant environment, as described by Claude Bernard's 'Milieu Interieur' concept.
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