Unit 1 - 3.3 Fluid Compartment & Homeostasis Flashcards

This set of flashcards covers key concepts from the lecture notes on Fluid Compartments and Homeostasis, including body fluid distribution, ion concentrations, the definition of homeostasis, and the mechanisms of negative and positive feedback.

What are the two major categories of body fluid compartments?

Intracellular Fluid (ICF) and Extracellular Fluid (ECF)

What percentage of total body mass in an average lean adult male is fluid?

60%

What percentage of total body mass in an average lean adult female is fluid?

55%

How is total body fluid distributed between intracellular and extracellular compartments?

Two-thirds (2/3) is Intracellular Fluid (ICF) and one-third (1/3) is Extracellular Fluid (ECF)

What are the three components of Extracellular Fluid (ECF)?

Interstitial fluid, Plasma, and Transcellular fluid

For a 70 kg adult, approximately what is the total body water volume?

42 liters

For a 70 kg adult, what is the approximate volume of Intracellular Fluid (ICF)?

25 liters

For a 70 kg adult, what is the approximate volume of Extracellular Fluid (ECF)?

17 liters

Which major ion has a high concentration in the Extracellular Fluid (ECF)?

Sodium (Na+)

Which major ion has a high concentration in the Intracellular Fluid (ICF)?

Potassium (K+)

What is homeostasis?

The maintenance of nearly constant conditions in the internal environment, referring to a state of equilibrium with respect to bodily functions and chemical compositions.

What is the extracellular fluid (ECF) often called in the context of homeostasis?

The internal environment

Through what mechanism is homeostasis primarily maintained?

Feedback mechanisms

What are the two main types of feedback mechanisms for maintaining homeostasis?

Negative feedback and Positive feedback

What are the four basic steps in a negative feedback mechanism?

1) Senses parameter using sensor/receptor, 2) Compares parameter to set-point, 3) Sensor sends signal to control center, 4) Control center activates effector to bring parameter closer to set-point.

Which component of the feedback system senses a parameter and needs a stimulus?

Sensor/Receptor

Which component of the feedback system receives an output signal from the control center to bring a parameter closer to the set-point?

Effector

What type of feedback mechanism counteracts the initial stimulus, shutting off the response loop?

Negative feedback

What type of feedback mechanism reinforces the initial stimulus, sending the variable farther from the set-point, and requires an outside factor to shut off?

Positive feedback

Give an example of a positive feedback loop in the human body.

The onset of labor (cervical stretching leading to oxytocin secretion and stronger uterine contractions)

Which internal organs help maintain homeostasis by filtering electrolytes and fluid balance?

Kidneys

Which structure within the feedback system provides input to the control center?

Receptor

What condition is NOT regulated by a negative feedback loop among the given options?

Childbirth (it is a positive feedback loop)

What is the major electrolyte normally found in high concentration in your blood plasma (ECF)?

Na+

The set-point of a biological parameter related to maintaining homeostasis is usually set within what?

A range of normal operating values