Fluid and Digestive System Review

These flashcards cover key concepts regarding body fluid compartments, water regulation, digestive processes, nutrient intake, and metabolic rates.

What is the primary composition of the body's fluid compartments?

65% Intracellular fluid (ICF), 35% Extracellular fluid (25% tissue fluid, 8% blood plasma & lymphatic fluid, 2% transcellular fluid).

What is sensible water loss and how much occurs daily?

Observable water loss: approximately 1,500 mL/day in urine, 200 mL/day in feces, and 100 mL/day in sweat.

Define insensible water loss and provide examples.

Unnoticed water loss: about 300 mL/day in breath and 400 mL/day in cutaneous transpiration.

What controls fluid intake in the body?

Thirst governed mainly by the hypothalamus in response to dehydration, which decreases blood volume and pressure.

How do osmoreceptors respond to increased plasma osmolarity?

They sense the rise in osmolarity and trigger thirst and secretion of ADH.

Differentiate between hypovolemia and dehydration.

Hypovolemia involves decreased Na+ and water with constant osmolarity; dehydration involves more water loss than Na+, raising osmolarity.

Why are infants more vulnerable to dehydration?

Infants have a high metabolic rate, greater body surface to mass ratio, and immature kidneys.

What is fluid sequestration?

Excess fluid accumulation in a specific location, commonly leading to edema.

List the five stages of digestion.

Ingestion, Digestion, Absorption, Compaction, Defecation.

What are the main functions of mechanical digestion?

Physical breakdown of food into smaller particles to increase surface area for enzymes.

What are the accessory organs of the digestive system?

Teeth, tongue, salivary glands, liver, gallbladder, and pancreas.

Describe the function of mucous cells in the stomach.

Mucous cells secrete mucus that protects the stomach lining.

What are the three phases of gastric motility?

Cephalic phase, Gastric phase, and Intestinal phase.

List the three ways the stomach protects itself from acidity.

Mucous coat, tight junctions, and epithelial cell replacement.

Define vomiting.

Forceful ejection of stomach contents from the mouth, coordinated by the emetic center in the medulla oblongata.

What is the role of hormones in the digestive system?

They stimulate digestion by acting via blood to influence distant parts of the digestive tract.

What are the major classes of nutritive molecules?

Carbohydrates, proteins, lipids, vitamins, and minerals.

How is obesity defined in terms of BMI?

Obesity is being more than 20% above the recommended weight for one's age, sex, and height.

Identify short-term regulators of appetite.

Ghrelin, PYY, and CCK.

What is the required daily intake of carbohydrates?

130g/day; less than 40g/day in sugars.

What is basal metabolic rate (BMR)?

The baseline metabolism rate at rest, typically around 2000 kcal/day for adults.

How do you calculate total metabolic rate (TMR)?

TMR = BMR adjusted for energy expenditure based on activity level.