BIO1100 Dr. Morris Troy University Exam 3 - Module 4, Human Biology

Digestive System purpose

Sustaining the body

4 stages of food processing:

1. Ingestion (/eating)

2. Digestion (/breaking down)

3. Absorption (of nutrients)

4. Elimination (of anything that can’t be processed)

Peristalsis (what & where)

= wave-like contractions of smooth muscle, spands from esophugas to intestines

2 types of smooth muscle fibers (& what they do):

• Vertical— temporarily shorten distance btwn. food and next organ

• Horizontal— squeeze behind food

8 organs of the Digestive System:

1. Oral Cavity

2. Pharynx

3. Esophogas (+ Epiglottis)

4. Stomach

5. Small Intestine

6. Large Intestine

7. Rectum

8. Anus

Oral Cavity (where, kinds of breakdown, what begins digestion here)

• = the mouth

• Physical breakdown: tongue manipulates food & teeth initiate mechanical breakdown → bolus

• Chemical breakdown: salivary glands create saliva that initiates chemical breakdown of carbs

• Carb digestion starts here

Bolus

= undigested food

Pharynx (where, shared?)

• = (opening to) throat

• Shared organ btwn digestive & respiratory system

Esophogas (what)

= food pipe; connects Pharynx to Stomach

Epiglottis (what it does, what it’s made of)

= flap of cartilage (connective tissue) that controls what goes down Trachea vs Esophogas

Stomach (what it is, what it’s made of, what starts digestion here)

• = muscular bag

• 3 kinds of tissue;

• Protein digestion starts here

2 natural protein digestors

Pineapple & papaya

3 kinds of tissue in Stomach:

1. Muscular

2. Connective

3. Epithelial

What does muscular tissue do in the Stomach?

churns food

What does connective tissue do in the Stomach?

holds organ in place

What does epithelial tissue do in the Stomach?

• highly folded to increase surface area

• 3 purposes;

Rugae

Highly folded folds of epithelial tissue

3 purposes of epithelial tissue in the Stomach (hint- secretion):

1. Secretes HCl acid (3 purposes)

2. Secretes enzymes for protein breakdown

3. Secretes mucus to protect stomach from being digested

3 things HCl acid does:

• Chemical digestion

• Kills germs that don’t get killed by bacteria

• Protein digestion

Stomach Acid (where it goes, what it’s made of)

• Duct connects stomach to small intestine, valve controls how much drips into s.i. (drop by drop, or else small intestine would get burned up)

• Either Pepsinogen or Pepsin

Pepsinogen

Inactive; there when NOT eating food

Pepsin

Active; there when eating food, absent when NOT (otherwise stomach would digest itself)

Small intestine (measurements, what it does, what starts digestion here)

• 18ft long, ½ diameter of large intestine, SA size of baseball diamond

• Nutrient absorption, chemical digestion

• Lipid digestion starts here

Villi & Microvilli in Small Intestine

• Villi = finger-like projections

• Microvilli = hair-like projections; increases SA the most, infections/viruses (ex. stomach bug) can break these off and must be regrown

Large Intestine (aka, measurements, 3 things it does, connected to what)

• aka the Colon

• 5ft long, 2x diameter of small intestine, SA much smaller

• Water & water-soluble vitamin reabsorption

• Helps eliminate undigested food

• Synthesizes Vitamin K (essential for proper blood clotting)

• Connected to Appendix

Appendix

• houses white blood cells → help immune system concerning food germs

• Prone to infection as white blood cells fight germs

• **Appendicitis

• CAN be lived without

Rectum

= temporary storage of feces

Feces (what, made up of)

= “solid waste”; made up of mostly water, fiber, & dead bacteria

Anus

= where waste leaves body

4 Accessory Glands

1. Salivary Glands

2. Liver

3. Gallbladder

4. Pancreas

Salivary Glands (what they do)

Secrete saliva

4 roles of Saliva:

1. Lubricates (abrasive foods; ex. almonds, popcorn, etc.)

2. Neutralizes (acidic foods; ex. orange juice) to protect teeth

3. Kills germs

4. Enzymes to start carb digestion

Liver (size vs. rest of glands, connected to what)

• Biggest gland in body

• Connected to gallbladder by duct

• Multiple roles;

(3) roles of Liver:

• Remove toxins

• Regenerates blood cells

• Secretes bile;

Role of bile

Performs process of emulsification

Emulsification

= increasing SA of fats to make easier dissolvably by enzymes (lipases)

Lipases

= enzymes that break down lipids

Gallbladder (stores what, makes anything?, helps digest what, can be lived without?)

• Stores excess bile that liver makes

• Doesn’t make anything itself

• Helps lipid digestion

• CAN be lived without, but must watch fat intake

Pancreas (where, connected to what)

• Critical but small organ located just below stomach

• Connected to small intestine by duct

• 3 major roles in digestion;

3 major roles of Pancreas in digestion:

1. Makes insulin for healthy blood sugar levels in circulatory system — also important to nervous system (high blood sugar / diabetes correlated w/dementia)

2. Secretes alkaline (high pH) fluid to neutralize stomach acid (low pH) — keeps small intestine from being burned up by HCl

3. Secretes enzymes that break down ALL nutrient types )carbs, lipids, & proteins)

5 medical conditions associated w/the digestive system:

• Acid Reflux

• Gastric Ulcer

• Colon Cancer

• Pancreatic Cancer

• Appendicitis

Acid Reflux (what it is, caused by what, treatments, can turn into what)

• = backflow of stomach acid into lower part of esophagus

• Happens when stomach valve doesn’t close all the way

• Treatments: antacids like Tums, Pepto

• If not treated, can lead to Esophageal Cancer

Gastric Ulcer (what it is, caused by what, what happens in body, treatments)

• = ulcer in stomach

• Caused by bacteria that can survive in harsh environment of stomach — “Helicobacter pylori”

• Shuts mucus away, makes wall prone to being digesting

• Treatment: powerful antibiotics

Colon Cancer (what it is, ways to reduce risk)

• = cancer in colon / small intestine

• Reduce risk by exercising eating less saturated fats, and eating more fiber

Pancreatic Cancer (what it is, why it’s dangerous)

• = cancer in pancreas

• very dangerous because pancreas completes so many functions (poses threat to circulatory system, nervous system, digestive system, etc.)

Appendicitis (what it is, treatment)

• = appendix becomes infected

• Often removed

3 diff. functions of Nutrients:

• Sources of energy

• Building up own tissues & biochemistry

• Regulators — controlling body processes, making sure they happen smoothly & efficiently

6 classes of nutrients:

1. Carbohydrates

2. Lipids

3. Proteins

4. Vitamins

5. Minerals

6. Water

Carbohydrates (main function, digested where to where)

• Quick energy

• Digested oral cavity → small intestine

Lipids (main function, digested where to where)

• Stored energy

• Digested small intestine → small intestine

Proteins (main function, digested where to where)

• Building up own tissues & biochemistry

• Digested stomach → small intestine

Organic

HAS Carbon

Inorganic

DOES NOT have Carbon

Vitamins (funct., calories?, size vs. minerals, organic?)

• Regulators; assist enzymes in speeding up chemical reactions

• No calories

• Larger than minerals

• Organic (have Carbon)

2 kinds of Vitamins:

1. Water-soluble

2. Fat-soluble

Water Soluble vitamins (ingestion, 2 kinds)

• must be ingested DAILY

• Vitamin C

• B-Complex

Vitamin C (what it does, found in what)

• Immune system “booster” → anti-cancer vitamin

• Found in citrus fruit, tomatoes, white potatoes

B-Complex (what it does, found in what)

• Guards the nervous system → longer life expectancy (correlated w/brain sharpness)

• Found in dairy products, meats, veggies

4 types of B-Complex:

• Folic Acid

• Vitamin B12

• Vitamin B6

• Pantophinic Acid

Folic Acid (aka)

Anti-birth defect vitamin

Vitamin B12 (deficiencies found in who?)

Deficiencies found in those w/type-2 diabetes, clinical depression, multiple sclerosis

Vitamin B6 (deficiencies found in who?)

Deficiencies found in some ppl w/autism

Pantophinic Acid (aka)

Anti-stress vitamin

Fat Soluble vitamins (stored in what)

Stored in fat tissue (not as regularly flushed out)

4 kinds of fat-soluble vitamins:

• Vitamin A

• Vitamin D

• Vitamin E

• Vitamin K

Vitamin A (helps do what, 2 kinds)

• Helps build up immune system

• Helps nervous system → better vision

• Can help skin as well

• Plant derived or Animal derived;

Plant-derived fat soluble vitamin (name, found in what)

Beta-carotine — found in orange plants (carrots, mangoes, sweet potatoes, etc.)

Animal-derived fat soluble vitamin (found in what, overdose?)

Found in a variety of meats, CAN be overdosed on (eskimos)

Vitamin D (helps what, activated by what?)

• Strong skeletal system

• Helps immune system

• Activated by sunlight

  • ≥20 mins daily

  • deficiency possible;

Condition associated w/Vitamin D deficiency (name, what it does)

Rickets — weak & porous bones, bow-legged

Vitamin E (aka, found in what)

• Powerful antioxidant

• Found in nuts (almonds)

Antioxidant

= material that guards the DNA → prevents mutations → guards humans against cancer

Vitamin K (does what, found where)

• Proper blood clotting

• Made by bacteria in small intestine

Minerals (funct., calories?, size vs. vitamins, organic?)

• Regulators; assist enzymes in speeding up chemical reactions

• No calories

• Smaller than vitamins

• Inorganic (no Carbon)

2 types of Minerals:

1. Major

2. Trace

Major minerals

= needed in LARGE amt.s

4 examples of major minerals:

**CaK NaP

1. Calcium (Ca)

2. Potassium (K)

3. Sodium (Na)

4. Phosphorus (P)

Calcium (element, helps what 3 things, found in what)

• Ca

• Skeletal system, teeth (Calcium Phosphate makes teeth hardest bone)

• Cell-to-cell communication

• Muscle contraction

• Found in dairy products

Potassium (element, helps what, found in what)

• K

• Very important in cell-to-cell communication

• Found in bananas, potatoes

Sodium (element, helps what, found in what)

• Na

• Maintaining proper water balance

• Cell-to-cell communication

• Found in salt

Phosphorous (element, 3 places found in)

• P

• Cell membrane — phospholipids

• DNA — phosphate

• ATP — tri-phosphate

Trace minerals

= needed in SMALL amounts

2 examples of trace minerals:

• Iron (Fe)

• Iodine (I)

Iron (element, where, helps what, found in what)

• Fe

• Part of hemoglobin in red blood cells

• Oxygen transport

• Found in leaky greens (spinach)

• Deficiency;

Deficiency associated w/Iron (name, what it is)

“Iron-deficient anemia” — fatigue

Iodine (element, needed for/does what, found in what)

• I

• Critical for proper thyroid funct.

• Sets pace for entire metabolism

• Found in iodized salt, seafood

• Deficiency;

Deficiency associated w/Iodine (name, what it is, found in who)

“Goiter” = issues w/thyroid — historically, found in ppl in mountains bcuz far from ocean

H₂O (funct., processes involved w/)

• Regulator

• Dehydration Synthesis

• Hydrolysis (used in digestion!!!)

Calorie

= unit to measure energy content in food

1 calorie listed on food packaging is actually…

1 kilocalorie

Respiratory System purpose

To breathe; exchange of O₂ and CO₂

Cartilage (where, what it does)

= lining trachea & other respiratory passageways; makes it so you can breathe while eating

Cilia (what, where, what they do)

= fine hair-like projections that line respiratory passageways from trachea → bronchioles; filter remaining foreign substances (dust, pollen, spores, etc.) to keep from reaching lungs

Chronic smoking effect on Cilia

Destroys them → more prine to respiratory conditions/infections

Smoker’s Cough

= body’s backup defense mechanism; physically forces foreign particles out of lungs

8 organs of the Respiratory System

1. Nose / Oral Cavity

2. Pharynx

3. Larynx

4. Trachea

5. Bronchi

6. Bronchioles

7. Alveoli

8. Capillaries

Nose / Oral Cavity (where, 3 things it does)

• = nose/mouth; how air enters body

• Warms air (so it travels faster)

• Moistens air (it’s easier to exchange O₂ & CO₂ across a moist surface, as compared to a dry one)

• Traps germs (prevents them from reaching lungs)

Pharynx (what it is, shared?, connected to what)

• = throat

• Shared organ — also part of Digestive System

• Epiglottis;

Epiglottis (what it is/made of, 2 settings)

• = flap of cartilage tissue

• When breathing, flap = UP

• When eating, flap = down (covering trachea)

Larynx (what it is, contains what)

• = voice box

• Contains Vocal chords;