Physiological Fluids Flashcards
What are physiological fluids?
Weak solutions of salts in water essential to cellular function, including intracellular and extracellular fluids.
Which fluids are excluded from the definition of physiological fluids?
Urine, gut contents, and hormones.
Why are physiological fluids important?
They maintain osmotic balance, transport nutrients, and support cellular activities.
What percentage of body weight is water in vertebrates?
~60%.
How is water distributed in the body?
Intracellular Fluid: 67%.
Tissue Fluid (Interstitial): 26%.
Plasma: 7%.
What is the role of blood plasma?
It is vital for transporting nutrients, hormones, and waste products.
What are the main solutes in extracellular fluids?
Sodium (Na⁺) and chloride (Cl⁻).
What are the main solutes in intracellular fluids?
Potassium (K⁺) and phosphate (HPO₄²⁻).
How does water enter the body?
Through ingestion (food and drink) and metabolic water production (~10%).
What are the main ways water is lost from the body?
Urine, respiration, sweat, and feces.
What hormone regulates water retention in the kidneys?
Antidiuretic hormone (ADH/AVP).
Why is water important for biochemical processes?
It provides the medium for biochemical reactions and reflects the ionic composition of ancient seas.
What process controls water movement between fluid compartments?
Osmosis.
What is the role of aquaporins?
They are water channels that facilitate the movement of water across cell membranes.
What evolutionary adaptations help animals maintain water balance?
Waterproof coverings, specialized water intake and excretion systems, and internal regulation mechanisms.
