Homeostasis

What is homeostasis?

The maintenance of a stable internal environment within the body.

Why is homeostasis crucial?

It ensures optimal cellular function.

What do body cells thrive under?

Correct temperature, water levels, and glucose concentration.

What mechanisms does the body use to maintain homeostasis?

Mechanisms that ensure cells remain in a constant environment conducive to function.

What percentage of the human body weight is body fluid?

Approximately 70%.

What are the two main compartments of body fluids?

Intracellular fluid (ICF) and Extracellular fluid (ECF).

Where is intracellular fluid found?

Within the cells.

How much of the total body water does ICF constitute?

Around 55%.

Where is extracellular fluid found?

Outside the cells.

How much of the total body water does ECF constitute?

Approximately 45%.

What are the components of extracellular fluid?

Interstitial fluid, plasma, lymph.

Where is interstitial fluid located?

Between cells.

What percentage of ECF is interstitial fluid?

About 80%.

What are the functions of interstitial fluid?

Delivers nutrients to cells, facilitates communication, removes waste.

What is plasma?

The fluid component of blood.

What are the functions of plasma?

Transports oxygen and CO₂, carries nutrients from the digestive tract.

What is lymph?

A clear fluid containing 96% water and 4% solids like proteins, lipids, carbohydrates, and electrolytes.

What fluids are included in lymph?

Synovial, cerebrospinal, pleural, pericardial, and peritoneal fluids.

What is water balance?

A state when water intake equals water output.

What percentage of daily water intake comes from drinking?

About 60%.

What percentage comes from moist foods?

Approximately 30%.

What percentage comes from metabolic water?

Roughly 10%.

What regulates water intake?

The thirst mechanism.

What triggers the thirst mechanism?

Osmotic pressure of extracellular fluids and hypothalamus signals.

What inhibits the thirst response?

Stomach distention after drinking.

How is water lost from the body?

Through urine, feces, perspiration, insensible perspiration, and breathing.

What affects water loss rate?

Temperature, humidity, physical activity.

What are electrolytes?

Charged ions present in all body fluids.

Why is electrolyte balance important?

It is critical for normal bodily functions.

What do electrolytes help maintain?

Fluid balance within cells and blood.

How do electrolytes assist with acid-base regulation?

They help maintain pH balance vital for cellular activity.

What role do electrolytes play in enzyme reactions?

They facilitate necessary metabolic processes.

How do electrolytes support neuromuscular function?

They enable muscle contractions and nerve signals.

How are electrolytes usually taken in?

Through food consumption.

What can salt cravings indicate?

An underlying electrolyte deficiency.

How are electrolytes lost?

Through sweat, urine, and feces.

What is homeostasis in terms of feedback?

The ability to maintain internal conditions by responding to changes.

What maintains homeostasis?

Feedback loops.

What is a negative feedback mechanism?

A response that reduces or counteracts the original stimulus.

What are the components of a negative feedback mechanism?

Stimulus, Sensor/Receptor, Control Center, Effector.

What does the stimulus do in a feedback loop?

Prompts a response in the body.

What does the sensor/receptor do?

Detects the change and sends information to the control center.

What does the control center do?

Evaluates input and determines a response.

What does the effector do?

Executes the control center's response to restore stability.

What is a positive feedback mechanism?

A response that amplifies the change and moves the system away from its original state.

When is a positive feedback mechanism essential?

During processes like childbirth.