Chapter 4: Water

Question 1

Water

- explain structure

Answer 1

Polar nature gives it a v shape; positive hydrogen atoms and negative oxygen atoms

Question 2

Describe the water content of the human body

Answer 2

• 60-70% of the body is water by weight
  intracellular: 2/3
• A cell’s cytoplasm is 80% water; water in cytoplasm accounts for the majority of the body’s water
  extracellular: 1/3
• blood, around joints, lining tissues around lungs, lymph, between cells

Question 3

fill in the blank: blood is ___ water

Answer 3

90%

Question 4

Explain how water is exchanged between the extracellular space and the blood (2)

Answer 4

• Osmosis: movement of water across semi permeable membranes to even out concentration differences
• blood pressure: force pushes water out of blood and into the extracellular space

Question 5

List the functions of water (6)

Answer 5

• structure
• solvent
• hydrolysis
• defence from infection
• protection from injury
• temperature regulation

Question 6

Explain how water provides structure

Answer 6

• Gives cells 3 dimensional shape to function properly with water pressure
• Synovial fluid in sacs between joints promote joint structure and allow bones to glide by each other more fluidly
• Fluid in eye gives it structure

Question 7

Explain how water serves as a solvent

Answer 7

• Dissolves polar substances allowing them to be more easily transported around body through a medium into passageways (digestive tract or blood vessels)
• Compatible reactants dissolved in water have an increased chance of them colliding and undergoing a chemical reaction

Question 8

Explain water’s role in hydrolysis

Answer 8

• Process of splitting larger molecules into smaller ones using water
• Example: maltose → 2 glucose molecules

Question 9

Explain water’s role in defence from infection (2)

Answer 9

• Infectious agents are moved to the lymph where immune cells act on them
• Mucus traps and gathers pathogens for removal

Question 10

Explain water’s role in injury protection

Answer 10

• Reduces the friction and damage from movement or trauma
• Water in synovial fluid prevents bones from scraping against each other
• Mucus protects tissues from injuries
• Cerebrospinal fluid protects brain from various forces

Question 11

Explain water’s role in temperature regulation

Answer 11

• Internal temperature for proper function: 37degC
• Body opens blood vessels near skin to allow blood to shunt heat from the body’s core to the skins surface . This triggers the sweat response. Also contributes to the observable redness of our skin when exercising
• Sweating: released water on skins surface cools our bodies and skin as it evaporates

Question 12

What are ways we lose water (3) and gain water (3)

Answer 12

lose: urine, feces, evaporation
gain: beverages, foods, metabolic processes (hydrolysis)

Question 13

What 2 mechanisms come to play when blood volume decreases

Answer 13

• Thirst increases
• Kidneys gatekeep what stays in blood and is excreted in urine
  (High blood volume → excess water is excreted in kidneys)
  (Low blood volume + pressure → kidneys decrease urine production)

Question 14

Dehydration

• symptoms
• what does chronic dehydration put you at risk for?

Answer 14

• symptoms: increased thirst, dry mouth, headaches, fatigue, dizziness, irritability, dark urine
• kidney disease, seizures, hypovolemic shock

Question 15

Water intoxication

• what
• hyponatremia
• symptoms

Answer 15

• Content of water in body is too high with respect to the level of electrolytes
• Occurs when you consume too much water too fast or when you lose alot of water from sweating, diarrhea or vomiting and only replace it with more water (need electrolytes!)
• Hyponatremia: too much water in relation to sodium in the body
• Symptoms: headache, confusion, personality changes, irritability, drowsiness, malfunction of the CNS, increased risk for seizures, brain damage, coma, death

Question 16

Fill in the blank: Water loss of _____ of body weight can lead to death

Answer 16

10-20%

Question 17

List some diuretics

Answer 17

• water pills
• caffeine
• alcohol

Question 18

Explain how water pills are a diuretic and when they’re prescribed

Answer 18

• Aka water pills; prescribed for high blood pressure, kidney stones, tissue swelling
• Promote sodium excretion and therefore water excretion

Question 19

Caffeine

• effects
• diuretic effect risk
• benefits

Answer 19

• Promotes alertness, reduce fatigue and drowsiness
• Diuretic side effect of caffeine may increase risk for miscarriage and kidney problems
• Contains antioxidant and anti-inflammatory properties
• Meta analysis review found that coffee probably reduced to decreased risk of cardiovascular disease, parkinson’s disease, type 2 diabetes, and some cancers

Question 20

Alcohol

• risks
• benefits
• kcal/g

Answer 20

• Risks: increases risk of liver cirrhosis, liver cancers, digestive cancers, confusion, dementia
• Drinking alcohol impairs the absorption of several micronutrients
• Light to moderate consumption of alcohol may reduce risk of cardiovascular disease
• Provides 7kcal/g

Question 21

Factors that affect level of intoxication

Answer 21

• How much consumed
• How quickly the alcohol is absorbed (fizzy drinks and empty stomachs)
• Size of the individual
• Gender
• Genetic factors
• Type of alcohol consumed
• Menstruation cycle

Question 22

How is alcohol metabolized? list the pathway

Answer 22

• 90% of alcohol is metabolized and eliminated at the liver; enzymes at play: alcohol dehydrogenase and aldehyde dehydrogenase
• see google doc

Question 23

Hangovers

• symptoms
• how

Answer 23

• Symptoms: vomiting, tiredness, decreased attention, decreased concentration, stomach pain, disturbed sleep
• Presence of congeners, acetaldehyde buildup, and the direct effect of alcohol are likely the cause of hangover symptoms
• congeners (substance added during fermentation process)

Question 24

What are some water recommendations (3)

- AI

Answer 24

• Adequate intake (AI): women 2.7L/day and men 3.7L/day
• Look for signs of dehydration: thirst, headache, dark yellow urine
• Replenish water and electrolytes when excessive water is lost through sweating, vomiting, and/or diarrhea

Question 25

Describe the western and indigenous lens on water

Answer 25

``` Western lens - Important natural resource - Commodity - Used for industry, agriculture - Used by humans as a nutrient Indigenous lens - Tied to our existence - Part of who we are - Has a life of its own - Mother life’s blood ```

Question 26

What happened with the Whanganui River

Answer 26

140 year long lobbying effort resulted in the New Zealand river given the same legal rights as humans

Question 27

How is Canada decolonizing water?

Answer 27

- Aim: create a community based water governance system led by indigenous individuals and rooted in Indigenous law - Example: indigenous led collection of water samples along the Yukon River