7 - Human Nutrition Flashcards
Define ingestion
Food is taken in through the mouth, chewed, and swallowed
Mastication
Tongue and teeth cut up food and mix it
Bolus
Mucus and saliva take the products of mastication and help make a squishy food ball that goes down the esophagus
What’s in saliva?
Water, mucus, amylase to start chemical digestion
Transports food from mouth to stomach
Esophagus
Muscular organ that does peristalsis
Esophagus
Peristalsis
Longitudinal and circular muscle contractions - mechanical digestion, also helps transport the food from the mouth to the stomach
Makes bile to emulsify fats and neutralize chyme
Liver
Makes cholesterol
Liver
Does a ton of stuff including detoxifying the body
Liver
Stomach digestion
Mixes food with gastric juices with digestive enzymes - chemical digestion. Muscles (it’s a muscular organ) churn and break down food - mechanical digestion.
What’s in the stomach and why?
Pepsin - a type of protease.
HCl - kills pathogens, good ph for Pepsin
Chyme - the food mixed with the gastric juices
Stores bile
Gallbladder
Releases bile into duodenum through bile duct
Gallbladder
Makes insulin and glucagon
Pancreas
Delivers amylase, protease, lipase, and sodium hydrogen carbonate to small intestine
Pancreas
Helps neutralize chyme with HCO3
Pancreas
1st section of small intestine
Duodenum
Pancreatic juices mix with chyme to digest food so it can be absorbed
Duodenum
Bile is delivered to the…
Duodenum
2nd (and final) section of small intestine
Ileum
Food mixed with digestive enzymes and blood
Ileum
Most water is absorbed in the…
Ileum
Nutrients are absorbed into the bloodstream
Ileum
Churns food to keep it touching the villi
Illeum
Assimilation happens in the
Ileum
Large intestine
Water reabsorption happens here (though not as much as in the ileum) to prevent loss of ions, dehydration, and diarrhea
Feces are stored in the
Rectum
Feces are egested through the…
Anus
Mechanical digestion
Physically breaks down food, no chemical change, increases surface area
Chemical digestion
Enzymes help break bonds, chemical changes happen
Digestion
Nutrients as large insoluble molecules —> small soluble molecules (keep in mind that this is mainly chemical digestion, as mechanical digestion doesn’t actually change any of the chemical properties)
Absorption
Nutrients pass from the digestive system into the bloodstream
Assimilation
Body cells take in biomolecules for cell processes (eg glucose for respiration)
Egestion
Removal of undigested waste
Excretion
Removal of byproducts of metabolism (pee)
Trypsin
Protease that likes alkaline conditions - in the small intestine
1st stage of starch digestion
Amylase breaks starch down into maltose
2nd stage of starch digestion
Maltase breaks maltose down into glucose
Maltase is secreted in the ____ and acts on the ____
Small intestine, membranes of epithelium lining small intestine
Lipids are broken down into
Glycerol and 3 fatty acid tails
Lipid function
Triglyceride in body, makes up cell membranes, insulation
Parts of a balanced diet
Carbs, vitamins, fats, water, proteins, mineral ions like calcium & iron, fiber
Carbohydrate function and main sources in diet
Fruit, vegetables, pasta, bread, potates
Provide short term energy
Fats function and main sources in diet
Avocado, nuts, olive oil, oily fish
Provide long term energy
Protein sources and function in diet
Meat, fish, eggs, beans, pulses, nuts
Growth and repair
Vitamin function in diet
C - Healthy blood vessels, skin, cartilage, bones, and wound healing
D - Calcium and phosphate regulation
A - Immune system and vision
Calcium and Iron function in diet
Calcium - strengthens bones and teeth, helps with muscle contraction and clotting of wounds
Iron - produces haemoglobin for red blood cells
Fiber function in diet
Helps digestion, helps move food and feces along the gut, associated with lower risks of coronary heart disease, type 2 diabetes, and bowel cancer
Water function in diet (the source of water is water)
About 60% of body mass is water - needed for almost everything
Deficiency disease
Illness caused by insufficient intake of a nutrient in the diet or the inability to absorb it efficiently
Rickets - cause and symptoms
Vitamin D deficiency - bone pain, weak muscles, bone loss with increased risk of fractures/skeletal deformities
Scurvy - cause and symptoms
Vitamin C deficiency - severe leg/joint pain, tiredness, weakness, blue or red spots on skin which bruise easily, swollen/bleeding gums
Alimentary canal
The canal down which food travels - mouth to esophagus to stomach to duodenum to ileum to large intestine to rectum to anus - does the physical digestion (though mouth and stomach do do some enzymes) and organs provide most of the enzymes
Molar and premolar function
Chew, crush, grind food
Canine function
Hold and tear food
Incisors function
Cut and slice food
Stages of tooth decay
Healthy tooth with plaque - Bacteria anaerobically respire with food, make acid which wears down teeth
Decay in enamel - acid wears out surface - takes time, no pain
Decay in dentine - Erosion is faster in dentine bc softer - pain
Decay in pulp - Erosion hits pulp with its nerves and blood vessels - EXTRA PAIN
Enamel
Hardest tissue in body, made by tooth forming cells - outer layer of tooth
Dentine
Major part of tooth. Hard. Made of calcium salts on collagen fibers. Canals -> pulp cavity. Under the enamel
Pulp
Full of nerves and blood vessels, goes down into root
Gum
Acts as junction between enamel and cement
Cement
Like dentine but no canals. Anchors jaw
Crown
Top part of tooth, above gum
Root
Bottom part of tooth, below gum
Bile function
Emulsifies fats into small droplets, allows lipase to chemically digest fats into tiny fat droplets
Villi function
Increase surface area for absorption of digested food molecules and water into the bloodstream, constant movement to mix food, enzyme secretion, capillaries for blood supply, CONCENTRATION GRADIENT
Epithelium
Had epithelial and goblet cells, thin so short diffusion pathway
Capillary network
Transports glucose and amino acids, IS THE BLOODSTREAM
Lacteal
transports fatty acids and glycerol
Nerve
Wrapped around lacteal with the capillaries
Gland
Makes digestive enzymes, probably spurts them out?
Goblet cell
Makes mucus to protect body from its own digestive enzymes
Epithelial cell
Covered in microvilli, part of epithelium
