Hydration Flashcards
Intracellular Fluid (ICF)
The water contained within a cell’s membrane, makes up approximately 2/3 of total body water.
Extracellular Fluid (ECF)
The water found outside of the body’s cells – ECF is found between cells and transported throughout the body via arteries, veins, and capillaries.
Osmolality
Describes the concentration of solutes in a liquid – various compartments hold fluids but the primary regulator of hydration status is the osmolality of ECF, specifically plasma osmolality. Multiple sites in the body house osmoreceptors that detect shifts in osmolality and generate responses to return the body to fluid and sodium homeostasis.
The regulatory mechanism that describes the processes that dictate total body water levels and water compartment movement in the body is called
osmolality
Dipsogenic Signal
Physiological factors such as high osmolality or low blood pressure, which prompt sodium and water appetite.
Baroreceptors
Specialized nerves that can sense changes in pressure in the heart or blood vessels.
primary ECF solute
sodium
the concentration of ____________ is a primary factor in determining the amount of water that will enter a cell body
sodium
sodium intake is a pivotal _____________ when attempting to restore total body water after training.
dipsogenic signal
When large quantities of sodium are ingested without a similar increase in water, plasma osmolality ___________ and __________ thirst drive follows
increases. increased
the most significant influence to thirst for water is regulated by ___________________
ECF osmolality
Loss of body water comes in the form of sweating or urine production, both ________________, which results in decreased blood pressure due to a loss in total blood volume, or ______________
hypo-osmotic, hypovolemia
physical activity in warm environments can result in sweat rates up to and exceeding _____ liters per hour
3 liters per hour
Hypo-Osmotic
A solution with a lesser concentration of solute (i.e., fresh water compared to salt water).
Gastric Emptying Rate (GER)
The rate at which fluids and their contents pass through the stomach via the pyloric sphincter and into the small intestine – the faster and more complete the GER, the more quickly carbohydrates and electrolytes can be absorbed into the mesentery system, where they feed the liver first and then the rest of the body via the vascular system.
the primary reason for the sodium-diluted sweat is that water …………….
shifts out of the ICF to the vascular ECF space.
This movement of ________________ keeps total blood volume from decreasing and serves to maintain blood pressure but also limits the increase of plasma osmolality, the major dipsogenic stimulus.
fluid from the ICF space
What is the most significant influence-to-thirst for water?
ECF osmolaity
Increased body water can also reduce heat generation related to elevated cardiovascular strain due to …………………
a less efficient venous return associated with decreased total blood volume
Convection
The movement or flow of air over an object.
euhydration
A normal hydration status.
Ad Libitum
Translates to “as desired” and refers to eating or drinking as you are normally driven to (i.e., not purposely overeating or undereating).
Exertional rhabdomyolysis (ER) (often referred to as rhabdo)
a condition in which muscle cell membranes rupture and leak high amounts of proteins, such as myoglobin and creatine kinase, into the extracellular fluid after abnormally hard or new exercise routines
key symptoms of exertional rhabdomyolysis
-dark urine
-puffiness
-stiff, swollen joints
-abnormal muscle soreness
the primary medical concern for exertional rhabdomyolysis is ________________ because
renal dysfunction, Because the kidneys must handle the excess nitrogen/amino acids loads released from the increased circulating proteins
dehydration
change in total body water in the field versus plasma osmolality status
calculating sweat loss
Initial weight _______________ kg
minus (-) post-weight in _______________ kg
+ fluid consumption between weigh-ins _______________ kg
minus (-) urine volume _______________ kg
Sweat-loss volume _______________ kg (L)
fluid intake should not exceed sweat-loss volume and a fluid deficit should be limited to less than ___% of body mass
less than 2% of body mass
Exercise Associated Hyponatremia (EAH)
A potentially serious medical condition in which the plasma sodium falls below 135 mmol/L, usually the result of fluid intake greatly exceeding sweat losses during prolonged exercise.
Urine-Specific Gravity (USG) measures
the ratio of solutes in the urine versus distilled water.
Urine-Specific Gravity (USG)
a scale that represents the ratio in which the pathway of light is bent (or refracted) after traveling through a liquid in comparison to light passing through water that has no solute content.
Which of the following responses occurs during exercise associated hyponatremia?
Extracellular fluid shifts inside cells.
Where is approximately 2/3 of body water found?
intracellular fluid
A client has repeatedly exhibited a pre-exercise USG range between 1.028 and 1.032. How would a Nutrition Coach interpret this finding?
The client needs to increase their fluid intake between training bouts.
