Section: Coach Water — Water as System
This section covers Chapter 3, Lessons 3.1 through 3.4.
Part A — Vocabulary (20 points, 2 points each)
Select the best answer for each question.
1. Plasma volume is:
A) The total blood volume B) The volume of the liquid portion of blood; expands with heat acclimatization and aerobic training, contracts with dehydration C) Red blood cell count D) Plasma protein concentration
2. Cardiac output refers to:
A) The volume of blood pumped per beat B) The volume of blood the heart pumps per minute, equal to heart rate × stroke volume C) Heart muscle thickness D) Pulse strength
3. Stroke volume is:
A) Total daily blood pumped B) The volume of blood pumped per heartbeat, depending partly on how full the chambers are C) Stroke risk D) Cardiac rhythm
4. Cardiovascular drift refers to:
A) Heart valve issues B) The progressive increase in heart rate during sustained exercise at constant workload, partly from declining plasma volume C) Atrial fibrillation D) Resting heart rate
5. Sarcoplasm is:
A) Cell wall material B) The fluid inside a muscle fiber, where the contractile machinery is bathed and many metabolic reactions occur C) Connective tissue D) Bone marrow
6. Cerebrospinal fluid (CSF) is:
A) Blood plasma B) The clear fluid surrounding the brain and spinal cord, providing cushion and chemical regulation C) Lymph fluid D) Saliva
7. Trans-Epidermal Water Loss (TEWL) refers to:
A) Sweating B) Continuous water loss from the skin through evaporation, independent of sweating C) Urination D) Insensible fluid loss only at night
8. The stratum corneum is:
A) A muscle layer B) The outermost epidermal layer of dead corneocytes in a lipid matrix; the body's main water-retention barrier C) The deepest skin layer D) A blood vessel layer
9. Mucus is:
A) A waste product B) A sticky water-based secretion produced by mucous membranes; traps particles, lubricates, contains antimicrobial molecules, keeps tissue moist C) A solid D) Stomach acid
10. Nocturia is:
A) A dream B) Waking from sleep to urinate; occasional is normal, frequent warrants attention C) Night sweats D) Sleep paralysis
Part B — Concept Comprehension (20 points, 2 points each)
Select the best answer for each question.
11. Approximately what percentage of skeletal muscle is water?
A) 30-40% B) 50-60% C) 70-75% D) 90-95%
12. Cardiovascular drift during long exercise refers to:
A) A drop in heart rate as the body adapts B) A progressive rise in heart rate at constant workload, partly due to falling plasma volume C) A shift from aerobic to anaerobic energy D) Cooldown blood pressure change
13. At what general level of body-mass fluid loss does endurance performance in heat begin to show clear decrements?
A) 0.2% B) 1-2% C) 8-10% D) 15-20%
14. Research on mild dehydration and cognition in adolescents most consistently shows effects on:
A) Long-term memory and complex reasoning B) Mood and perceived effort C) IQ test performance D) Reading comprehension over a year
15. The brain is approximately what percentage water?
A) 25% B) 50% C) 75-78% D) Nearly 100%
16. During the night, vasopressin (ADH):
A) Decreases, increasing urine output B) Increases, reducing urine volume and concentrating overnight urine C) Stops entirely D) Is converted to insulin
17. Typical total overnight fluid loss for an adolescent is approximately:
A) 50-100 mL B) 400-700 mL C) 1.5-2 L D) 4-5 L
18. The stratum corneum is:
A) The deepest skin layer B) The outermost skin layer of dead cells in a lipid matrix, the main water-retention barrier C) Subcutaneous fat D) The middle dermis
19. Trans-epidermal water loss (TEWL) refers to:
A) Sweat through eccrine glands B) Continuous water loss from the skin through evaporation, independent of sweating C) Water lost in saliva D) Water lost in urine
20. Which of the following has the largest effect on day-to-day skin hydration in adolescents according to current research?
A) Total daily water intake B) Number of glasses at breakfast C) Local conditions (humidity, soap, weather) and skin-care practice D) Fasting status
Part C — Application (30 points, 6 points each)
Write 2-4 complete sentences for each question. Show your reasoning.
21. Explain how plasma volume connects exercise performance, thermoregulation, and cardiovascular function. Why does fluid loss matter more in heat than in cool conditions?
22. Summarize what research has and has not established about mild dehydration and adolescent cognition. Why is it inaccurate to say "drink water for sharper thinking" without qualification?
23. Describe the tension between adequate evening hydration and minimizing nocturia. What is the Elephant's suggested approach to navigating this tension?
24. Explain the role of the stratum corneum and trans-epidermal water loss (TEWL). Why is local skin care often more important than total water intake for everyday skin hydration?
25. This chapter emphasizes that water is the medium every other body system runs in. Choose one Coach (Move, Brain, Sleep, Hot, Cold, Light, Food, or Breath) and write 3-4 sentences explaining how the work of that Coach depends on water.
Continue to the next section.