Nurtition-exam 2- Body Fluids and Major Materials Flashcards
Most of water is in….
Lean muscle/ tissue about 75% water
Less lean tissue=less water
Who generally has a lower percentage of water in their body?
Females, obese people and elderly
Ion
Charged atom
Extracellular
Outside cell
Interstitial
Between cell
Intracellular
Inside cells
Aka: same as intercellular
Thirst mechanism :high salt concentration
10% decrease in blood plasma volume . 1-2% increase in blood plasma particle
Pituitary in the hypothalamus controls water retention by releasing ADH (vasopressin) which triggers the kidney to reabsorb water
Thirst response lacks behind the body’s need for water
Even when your body needs water you won’t feel thirsty until later. Once you are thirsty you already in need of water importance of drinking H2O even when you don’t want to
How the body Regulates blood volume with the kidneys.
The kidneys respond to reduced blood flow releasing the enzymes renin.
Renin initiates the activation of the protein angiostensin.
Angiostensin signals the adrenal glands to secrete aldosterone. Angiostensin causes the blood vessels to constrict raising blood pressure.
Aldosterone and ADH signals the kidneys to retain sodium and water, respectively, thus increasing blood volume
How the body Regulates blood volume by the brain.
The hypothalamus responding to high salt concentration in the blood by stimulating the pituitary gland.
The pituitary gland releases Antidiuretic hormone.
Aldosterone and ADH signals the kidneys to retain sodium water, respectively, thus increasing blood volume.
Water losses
Obligatory water loss:
Urine, vapor from lungs, sweat from skin, loss in feces
Dehydration
Excessive water loss
Causes: Too little intake, diarrhea, vomiting
S/S :
Thirst, weakness, delirium, exhaustion
Water intoxicated
Excessive with water intake or kidney disorders
Hyponatremia - endurance athletes
S/S : confusion, Convulsions, death
Recommendation for fluid intake
1 to 1.5 liter per hour
Osmosis
Movement of water
High to low water concentration
- a selectively permeable membrane is required
Cation
Positive ion
Anion
Negative ion
Electrolytes
Salts that break apart in water and conduct electricity
Acidosis
Blood pH below 7.35
Depresses the nervous system: coma death
Alkalosis
Blood pH above 7.45
Over excites the nervous system: nervousness, Convulsions
Bicarbonate buffer system (chemical process)
Acid base balance
Carbon dioxide (CO2) is a volatile gas the quickly dissolves in H2O forming carbonic acid (H2CO3).
Carbonic acid readily dissociation to a hydrogen ion (H+) and a bicarbonate ion (HCO3-)
Two main keys: carbonic acid, bicarbonate ion
Bicarbonate buffer system function
Regulars by the lungs
• too much carbonic acid: respiration rate increase (expel more carbon which means less carbonic acid is produced)
• CO2 exhales increase, less carbonic acid formed, less H+
Regulation in the kidneys
(Complex. Requires different electrolytes and metabolic means)
• reabsorbing or excreting bicarbonate: complex regulation
• the body’s total acid remains constant, acidity of urine fluctuates
Sodium roles
Humans tend to like sweet and salty and stay away from bitter and sour.
Enhances other flavors, suppressing bitter flavors
Muscle concentration, nerve transmission, regulations of extracellular volume.
Sodium deficiencies
Deficiencies are very unlikely b/c
Body adapts by reducing sodium loss
S/S:
Nausea, vomiting, headache, confusion, lethargy, fatigue, loss of appetite, irritability, muscles weakness, cramps, seizures, coma
