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Unit 4 Introduction…. Internal Systems and Regulation. The Vitruvian Man. Symmetry of the human body…and the Universe! a man's height is four cubits (and thus 24 palms) the length of a man's outspread arms is equal to his height
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Unit 4 Introduction… Internal Systems and Regulation
The Vitruvian Man Symmetry of the human body…and the Universe! • a man's height is four cubits (and thus 24 palms) • the length of a man's outspread arms is equal to his height • the distance from the hairline to the bottom of the chin is one-tenth of a man's height • the distance from the top of the head to the bottom of the chin is one-eighth of a man's height • the maximum width of the shoulders is a quarter of a man's height • the distance from the elbow to the armpit is one-eighth of a man's height • the length of the hand is one-tenth of a man's height • the length of the ear is one-third of the length of the face
A Little Food History! • 400 BC: Hippocrates said that food was medicine…but couldn’t tell people which foods to eat. • 1800’s – Salem, NJ: Sam Johnson ate a tomato in public to prove that they were not poisonous.
Dr. NO! • 1800’s – Minister Sylvester Graham told everyone not to: • Eat meat (It leads to sex) • Use spices • Drink Caffeine • Drink Alcohol • Go to the Doctor (They bleed you out!) • An unhealthy diet simulated sexual desire which irritated the body and led to disease. • His followers were called “Grahamites” • His substitute for sex was…
To Eat or Not to Eat… • Our food is full of chemicals…an apple contains over 300 different compounds • We are skeptical about food because technology has allowed us to measure in parts per trillion! • 1 pp trillion is the same as 1 second in 32 000 years! • “Paralysis by analysis”
Who do you trust? • Harvey and Marilyn Diamond • Claimed that enzymes are “life force” • Women shouldn’t have sex when pregnant because it would cut off oxygen to the fetus • Lots of bad/unscientific advice out there!
Homeostasis All of our organ systems work together to maintain Homeostasis Homeostasis is a steady internal state, keeps conditions in the body constant. Examples: • Blood Pressure (circulatory system) • Respiration Rate (respiratory system) • Body Temperature (circulatory system) • Blood Sugar (digestive and circulatory) The brain and the adrenal system (hormones) do most of the regulating.
The Digestive System Just Eat It!
Betcha didn’t know that… • Your intestines are 7.5 metres long! • A horse’s intestines are 27 metres long! • Digestion from mouth to anus takes ~72 hrs! • In your lifetime, your digestive system may handle about 50 tons o’ food! • The average person eats about 1.4 kg of food per day! • 1.5 litres of saliva are produced each day! • An adult’s stomach can hold about 1.5 litres! • Each day 11.5 litres of digested food, liquids and digestive juices flow through the digestive system…but only 100mLs are lost in faeces!
Nutrition Basics Remember the ‘big three’? • Carbohydrates (glucose needed for cellular resp.) • Proteins (amino acids are building blocks) • Lipids (long term E storage) There are three more players that are vital to our survival…
Vitamins • Individual Units…not long chains • They assist in the release of energy form Carbs, Fats and PRO’s (coenzymes) • Measured in milligrams (mg) • 13 different vitamins Examples: • Vitamin C…infection resistance and prevention of scurvy (oranges). • Vitamin A…helps us to see better (found in carrots) • Vitamin D…bone mineralization (if not enough…Rickets!)
Minerals • Inorganic elements • They do not yield energy • 16 are known to be essential to humans Examples: • Calcium (bones), Iron (blood cells), Zinc (enzymes), Fluorine (nice teeth!)
Water • Provides the environment in which nearly all the body’s activities are conducted. • Helps with metabolic reactions • Transporter of vital materials and waste products
Healthy Eating & Exercise • Canada’s Food Guide • Government recommendations
Regular Exercise Builds muscle Increases metabolism (body’s ‘burning’ of energy) Decreases body fat
“24 Hour Food Challenge” • How did you do? • Daily Calorie Requirements
Anorexia Nervosa • Significant weight loss resulting from excessive dieting. • Motivated by the strong desire to be thin and a fear of becoming obese. • Anorexics usually strive for perfection.
Signs and Symptoms • Noticeable weight loss • Becoming withdrawn • Excessive exercise • Always being cold • Muscle weakness • Obsession with food, calories, recipes • Excuses for not eating meals (ie. ate earlier, not feeling well)
Physical/Medical Complications • Fatigue and lack of energy • Amenorrhea (loss of menstruation) • Skin problems • Dizziness and headaches • Dehydration • Shortness of breath • Irregular heartbeats, cardiac failure…death.
Bulimia • A cycle of binge eating followed by purging to try and rid the body of unwanted calories. • A binge is different for all individuals.
Signs and Symptoms • Binge eating • Secretive eating (food missing) • Bathroom visits after eating • Vomiting • Laxative, diet pill or diuretic abuse • Weight fluctuations (usually with 10-15 lb range)
Physical/Medical Complications • Fatigue and lack of energy • Amenorrhea (loss of menstruation) and irregular menstruation • Dizziness • Headaches • Dehydration
Types of Digestion • As food travels down the alimentary canal it must be broken down into monomers so that our cells can use them. • They need to be small enough to pass through the villi and into the bloodstream.
Mechanical Digestion • Chewing, Mixing, Emulsifying • Done with the teeth • Peristalsis: Muscular contractions move the bolus (food ball) along the digestive tract.
Chemical Digestion • Performed by enzymes • Uses the process of hydrolysis to break down polymers into monomers.
Question: HOW DO WE KEEP FROM DIGESTING OURSELVES??
Answer: • Line the entire system with mucus!! • Lined from the cardiac sphincter to the anus. • Where is there no mucus? • Esophagus…Acid reflux (heartburn)
