Unit 4 Introduction…

Internal Systems and Regulation

The Vitruvian ManSymmetry 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

Da Vinci’s Anatomical Sketches

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…

The ‘Graham’ Cracker!

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!

HomeostasisAll of our organ systems work togetherto maintain Homeostasis

Homeostasis is a steady internal state, keeps conditions in the body constant.

Examples:1. Blood Pressure (circulatory

system)2. Respiration Rate (respiratory

system)3. Body Temperature (circulatory

system)4. 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)

Acid Reflux…OUCH!