Nutrition

Nutrients

  • Provide energy

  • Need for growth, repair,  and maintenance of cells

  • Need for metabolism

  • Examples (why do we need each one)

    • Proteins - 

    • Carbs - 

    • Fats - 

    • Vitamins - 

    • Minerals - 

    • Water - 

Vitamins

  • Vitamin A

    • Vision

    • Fruits and Vegetables

  • Vitamin D

    • Bones

    • Dairy and skin exposed to sun

  • Vitamin K

    • Blood Clotting

    • Vegetables and rectal bacteria

  • Vitamin C

    • Bone, Cartilage, Gums

    • Fruits and Vegetables

  • Vitamin B12

    • Blood

    • Meat and Dairy

Minerals

  • Fe

    • Blood

  • F

    • Teeth

  • Mg

    • Coenzyme

  • Ca

    • Bone and Teeth

  • P

    • Bone and Teeth

  • I

    • Thyroid

  • Na, K

    • Water balance (Osmosis), Nerve Function

Essential Amino Acids

  • We can’t make 8 of the 20 amino acids

    • Need them to eat them from meat and dairy products to get them

Nutrient Acquisition

  • Autotrophic Nutrition

    • Phototrophs (plant, algae cyanobacteria)

      • Use sun to convert inorganics into organics

    • Chemotrophs (some bacteria)

      • Use carbon dioxide and hydrogen sulfide to create organics

  • Heterotrophs Nutrition

    • Ingest plants and/or animals for organics (animals, bacteria, fungi, some protozoa)

Energy in Food (ATP Potential)

  • calorie = The amount of heat needed to raise the temperature of one gram of water one degree centigrade

  • Calorie (kilocalorie [kcal]) (On side of food products) = 1000 calories

  • 1g of Carb or Protein = 4kcal

  • 1g of fat = 9 kcal

  • Measure with Calorimeter

Energy Needs

  • Humans - Just to live with no activity

    • 1,300-1,800 kcal/day

  • Unused Kcals

    • Stored in liver and muscles as glycogen

    • Stored as fat in adipose cells

Food Pyramid

  • There have been many food pyramids that have been sent by the government over the years

  • There have been many because people found them really confusing on how much of everything they should eat

Fiber

  • Indigestible materials

  • Fruits, vegetables, grains

  • Stimulates digestive system

  • Cleans out Colon and Rectal Cancer Cells

Nutrition

  • Ingestion

    • Take food into organism

  • Digestion

    • Break food down Mechanically and/or Chemically

    • Can happen inside of cells (Intracellular Digestion)

    • Can happen outside of cells (Extracellular Digestion)

  • Absorption

    • Breakdown products enter cells

  • Egestion

    • Elimination of indigestible food waste

Human Digestion

  • Digestion begins when you see, smell, hear, and touch anything that reminds of food

  • The brain will already start preparing to eat, even if you aren’t eating

Human Alimentary Canal

  • Mouth

  • Pharynk

  • Esophagus

  • Stomach

  • Small Intestine

  • Large Intestine

  • Rectum

  • Anus


Accessory Glands (Inject fluids into the alimentary canal)

  • Salivary Glands

  • Liver

  • Pancreas

  • Gall Bladder

Mouth

  • Ingestion

  • Mechanical Digestion (Increase food surface area)

  • Saliva

    • Mucin (Lubricant)

    • Salivary Amylase (Breaks down Carbs into Maltose)

  • Tongue

    • Taste Buds

    • Shapes food into a Bolus

Teeth

  • Incisors are for riping food

  • Canines are for griping and tearing bigger food into smaller food

  • Molars are for chewing thoroughly

  • The wisdom tooth was useful at sometime, but due to evolutionary changes, it is rendered useless

    • People often get their wisdom teeth removed

  • A tooth has three different layers: enamel, dentin, and pulp

    • When you get a cavity, the enamel has eroded away, so have to get a filling since enamel does grow back

      • Things like soda or any acidic drink erodes enamel

    • A root canal is when the dentist has to drill a hole into the tooth and scoop out the pulp, then fill the hole back up

Pharynx

  • Back of the throat

  • Swallowing reflex

  • Epiglottis closes trachea when swallowing

  • Three parts: nasopharynx, oropharynx, and laryngopharynx

Esophagus

  • “Foot Tube”

  • Line with smooth muscle (Involuntary)

  • Squeeze food down (Peristalisis)

Stomach

  • Entrance controlled by Cardiac Sphincter (“Heart Burn”, acid reflux)

    • If the cardiac sphincter is open for too long it will allow the stomach acid to rise up into wear the esophagus it

  • Stores and Churns food (Mechanical Breakdown)

  • Makes Gastric Juice (Chemical Digestion)

    • Mucous Cells = make protective mucus

    • Parietal Cells = Make HCl (Denatures Proteins)

    • Chief Cells = Make pepsinogen

      • Pepsinogen by itself is inactive and when it reacts with HCl, it becomes pepsin which is active

      • This breaks down proteins into small polypeptides

    • G Cells = Produce gastrin

  • Food, Sight, Thought, Smell, Empty Stomach

    • Brain stimulates stomach to make gastric juice

  • Food enters stomach cause more gastric juice production

  • Food mass stretches stomach walls

    • The stimulated stomach to make the hormone Gatrin

    • Gastrin simulates more Gastric Juice and contractions

    • When stretched to a point, Brain perceives “fullness”

  • Protein, Caffeine and Alcohol stimulate walls of stomach to release more Gastrin

  • Stomach feels more acidic after consuming them

  • Stomach converts food into White Paste Acid Chyme

  • Chyme exits through Pyloric Sphincter

Stomach Problems

  • Ulcer

    • Erosion of protective mucus

    • Acid eats through lining

    • Get hole

    • Helicobacter pylori

  • One stomach ache could be many things, which is what makes the job of physicians really hard


Small Intestine

  • Over 20 feet

  • It has three section: Duodenum, jejunum, and ileum

Duodenum

  • Mixing site of Chyme and Bile

  • HCL causes for Bicarbonate (basic) to come from pancreas

  • High pH (8)

  • Chyme causes for Gastrin production to stop

  • Bile (made by the liver), stored in gallbladder

  • Injected in Duodenum through the common bile duct

  • Bile (not an enzyme) emulsifies fats

  • Chyme mises with pancreatic juice injected by the pancreas through Pancreatic Duct

  • Pancreatic Juice/Intestinal Juice

    • Amylase

    • Trypsin and Chymotrypsin

    • Nucleasases

    • Lipases

    • Maltase, Sucrase, Lactase

    • Aminopeptidase

    • Carboxypeptidases

Gallbladder Problems

  • Hardened cholesterol deposits block bile exits

Small Intestine Lining

  • Villus = Fingerlike projection extending into tube lumen

    • Capillaries absorb monosaccharides, amino acids

    • Lacteals absorb glycerol and fatty acids

  • Small intestine pulled out has surface area of a tennis court 

  • On the villus, there are even more villus

Jejunum/Ileum

  • Primarily, absorption of nutrients

Appendix

  • Vestigial Organ

  • Prone to Infection and inflammation (appendicitis)

  • Long in herbivores

  • Very short in carnivores

  • Short in omnivores 

Large Intestine (Colon)

  • Not as long as small intestine!

  • 90% of water reabsorbed before elimination

  • Forms Feces = Fiber, water, bile salts, mucus

  • Have colony of E.coli bacteria that produce Vit.K (Antibiotics kill them)

Large Intestine Problems

  • Diarrhea = Feces moves out too quickly for water reabsorption

  • Constipation = Feces hangs around too long and we overly dry it

  • Flatulence = Poorly digested food in large intestine, bacteria digest it, produces hydrogen sulfide and methane gas

  • IBS = Probable nerve association

Rectum

  • Store Feces

  • Flow controlled by rectal sphincters

  • Then out the anus

Ruinant Animals

  • 4 chambered stomach

  • In Reticulum are bacteria and protozoa that can break cellulose

  • Regurgitate food

  • Chew Chud and re-swallow