nutrition exam 3

What does ECF stand for and what is its proportion in the body water?

ECF stands for Extracellular Fluid, and it constitutes 1/3 of body water.

What is the percentage of body weight contributed by ECF?

ECF contributes 20% of body weight.

What are the two components of ECF and their respective percentages?

Interstitial fluid makes up 75% and plasma makes up 25% of ECF.

What does ICF stand for and what is its proportion in body water?

ICF stands for Intracellular Fluid, and it constitutes 2/3 of body water.

What percentage of body weight does ICF constitute?

ICF constitutes 40% of body weight.

What is an isotonic solution of NaCl?

An isotonic solution of NaCl is 0.9% NaCl.

How does water move in relation to electrolytes?

Water follows the movement of electrolytes by diffusion.

What is the role of ATPase in the exchange of Na and K ions?

Na and K constantly use energy via ATPase to exchange, consuming 30% of total energy for cells.

Which two substances act as pH buffers for body fluid?

Bicarbonate and proteins act as pH buffers for body fluid.

How is fluid pH affected in the body?

Fluid pH is affected by lung respiration and the excretion of bicarbonate in kidneys.

What is the function of capillaries in plasma-interstitial space exchange?

Capillaries facilitate fluid and solute exchange due to their large surface area.

What happens to hydrostatic pressure from the heart to veins?

Hydrostatic pressure is high when leaving the heart but drops going through arteries to capillaries to veins.

Define capillary hydrostatic pressure. What is its relationship with oncotic pressure on arterial and venous sides?

Capillary hydrostatic pressure is blood pressure; on the arterial side, hydrostatic pressure > oncotic pressure; on the venous side, oncotic pressure > hydrostatic pressure.

What condition can reduce plasma oncotic pressure?

Liver disease or low serum albumin can reduce plasma oncotic pressure.

What impact does pregnancy have on plasma oncotic pressure?

Pregnancy increases hydrostatic pressure.

What is edema?

Edema is the buildup of fluid in the interstitial space.

What contributes to edema due to capillary hydrostatic pressure?

Heart failure can elevate capillary hydrostatic pressure leading to edema.

How is water regulation partially managed?

Water regulation is partially managed by the kidneys.

What are the two types of water loss and examples of each?

Insensible water loss (respiration, skin) and sensible water loss (sweat, urine).

How much water intake should one aim for based on calorie expenditure?

One should intake about 1 mL of water per kcal expended.

What is the minimum urine output required to eliminate waste products?

At least 500 mL of urine must be excreted to eliminate waste products.

What is a risk associated with consistently concentrated urine?

Consistently concentrated urine poses a risk for kidney stones.

What does dehydration trigger in the body?

Dehydration can lead to an increase in ECF osmolarity (hyperosmolarity).

What is hyperosmolarity and what can it cause?

Hyperosmolarity can lead to water intoxication, brain swelling, and symptoms like nausea, malaise, and seizures.

What influences the thirst sensation?

A water loss as small as 2% will activate neural centers in the hypothalamus to produce thirst.

Which individuals may have impaired thirst sensations?

Infants, elderly, or individuals in diseased/vigorous states may have impaired thirst sensations.

What are the kidneys responsible for regulating?

Kidneys regulate body fluid osmolarity, volume, and electrolyte balance.

How do kidneys contribute to acid/base balance?

Kidneys regulate acid/base balance as well as excreting metabolic waste products.

What is the nephron's role in kidney function?

The nephron is the functional unit of the kidney that filters blood and forms urine.

What does filtration in the nephron involve?

Filtration involves the initial removal of solutes and water from blood, excluding large proteins.

What is the process of reabsorption in the nephron?

Reabsorption is the selective removal of water and solutes from the glomerular filtrate back into the blood, regulated by hormones.

Describe secretion in the nephron.

Secretion involves the selective removal of certain solutes from the plasma into the tubular compartment.

What characterizes the excretion phase in nephron function?

Excretion is the removal of final urine to the bladder.

What is the role of coenzymes in enzyme activity?

Coenzymes combine with inactive enzymes to form active enzymes for catalyzing reactions.

What is the process of glycolysis?

Glycolysis occurs in the cytosol and is where glucose is broken down to pyruvate.

What is the primary site for ATP synthesis in cells?

The mitochondria are the primary site for ATP synthesis via the electron transport chain.

What is the effect of ADH on the kidneys?

ADH increases water reabsorption in the kidneys in response to increased ECF osmolarity or decreased blood volume.

How does alcohol affect ADH?

Alcohol inhibits ADH secretion, leading to dehydration.

What is the role of renin released from the kidneys?

Renin is released in response to decreased blood pressure and acts on angiotensinogen to produce angiotensin 1.

What is angiotensin 2 and its effects?

Angiotensin 2 is a powerful vasoconstrictor that increases blood pressure and promotes the release of aldosterone.

What is the recommended daily allowance (RDA) for sodium intake?

There is no specific RDA for sodium; a minimum of ~500 mg/day is suggested.

How is sodium typically obtained in the diet?

Sodium is primarily obtained from processed foods, often in forms other than NaCl.

What complications can arise from sodium deficiency?

Sodium deficiency can lead to symptoms like muscle cramps, mental apathy, and loss of appetite.

What are signs of sodium toxicity?

Acute sodium toxicity can cause edema and hypertension.

What is the principal cation inside cells?

Potassium (K+) is the principal cation inside cells.

What role does potassium play in the body?

Potassium is crucial for fluid and electrolyte balance, nerve and muscle function, and fundamental cellular processes.

What is the minimum daily intake requirement for potassium?

The minimum daily intake for potassium is 2000 mg.

Which foods are major sources of potassium in the diet?

Major sources include fresh unprocessed foods like fruits and vegetables, as well as coffee, tea, and milk.

What can cause hypokalemia?

Hypokalemia can occur due to diarrhea, vomiting, and severe dehydration.

What can severe potassium toxicity cause?

Severe potassium toxicity (hyperkalemia) can cause muscle weakness, vomiting, and heart failure.

What nutritional factors influence metabolic pathways?

All energy-yielding nutrients can be broken down into acetyl CoA, which enters the TCA cycle or forms fat.

How is nitrogen eliminated from amino acids?

Nitrogen is eliminated by converting toxic ammonia into urea through the urea cycle.

What causes ketoacidosis?

Ketoacidosis is caused by increased ketone production, leading to lowered blood pH.

What is the normal functioning of insulin related to blood glucose levels?

Insulin is released in response to elevated blood glucose levels to regulate glucose metabolism.

What are the two main states concerning insulin and glucagon levels?

The fed state has higher insulin than glucagon, while the fasting state has higher glucagon than insulin.