Unit 8: The Human Body- BIO Flashcards
Nutrients
-Usable parts of food
-Provide our bodies with chemicals and energy
Why do we eat?
-Nutrients
-Energy
-Flavor Satisfaction
-Social
-Bored
Nutrition
-Life activity by which your body gets food and changes it into a usable form
6 major groups of nutrients
- Carbohydrates
- Lipids
- Proteins
- Vitamins
- Minerals
- Water
Carbohydrates
-A primary source of energy
-Provides roughage- not digestible material
Lipids (Fats and Oils)
-A source of stored energy
-Yield more energy per gram than carbohydrates
Proteins
-Build and repair body tissue
-Source of energy
Vitamins
-Work as coenzymes to allow proper enzyme function
Minerals
-Build body parts
-Involved in muscle and nerve action
-Regulate body functions
Water
-Dissolve and transport materials
-Makes up approximately 65% of our body weight
Obesity
-The #2 preventable death in the world
-60% of americans are overweight/obsese
BMI
-Body Mass Index
-A number calculated from a persons weight and height
-A reliable indicator of body fatness
-A screen for weight problems that may lead to health problems
Digestion
-A process that changes food into a form that can be used by your body cells
How do we take in food?
Ingestion
Two forms of digestion
-Mechanical
-Chemical
Mechanical DIgestion
-The physical breakdown of food into smaller pieces in order to increase the surface area
Chemical DIgestion
-Chemical changes of complex food molecules into simpler molecules
Gastrointestinal Tract
-Continuous one way tube
-Starts at the mouth and ends at the anus
Peristalsis
-Slow, rhythmic muscular contractions used to move food through the GI tract
Mouth
-Teeth and jaws use mechanical digestion (mastication)
-Salvary glands produce saliva to start chemical digestion and to help moisten food
Amylases
Enzymes that break down carbs
Tongue
-Helps with the swallowing and tasting of food
Once food is swallowed it enters the..
-Esophagus
-This tube moves food from the mouth to the stomach
-Esophagus produces mucus which lubricates food so that it slides down easier
Stomach
-Mechanically churns and mashes food
Hydrochloric acid destroys bacteria and provides the proper PH for enzyme action
-Turns food into a think mixture called Chyme
Pepsin in the stomach
-Chemically digests proteins
-Gastric juices contain this
-What do glands in the stomach lining secrete?
-Gastric juice and hydrochloric acid
What 4 things does the pancreas digest?
- Pancreatic juice
- Nucleases
- Insulin
- Glucagon
Pancreatic juice
Digests carbs
Nucleases
Splits DNA and RNA into nucleotides
Insulin
-Converts excess glucose in the blood into glycogen for storage
Glucagon
-Counteracts insulin by telling the liver and the small intestines to increase blood glucose levels
Small Intestine
-Most chemical digestion takes place here
-Lined by tiny finger-like projections called villi
-Food broken down into simple molecules like monosaccharides, amino acids, fatty acids, and glycerol
Villi
-Villi line the small intestine
-Increase the surface area of the small intestine for the absorption of digested food through diffusion
The liver’s role in digestion
- Carbohydrate metabolism
- Protein metabolism
- Fat metabolism: Bile (emulsifies fat = breaking it into very small particles) stored in gallbladder
- Filters toxins
Hepatic portal vein
-Connects small intestines to Liver before going to the heart
Food travel
- Swallowed
- Mouth to stomach in 5-7 seconds
- Stomach 2-6 hours
Digestive enzyme in the mouth
Amylases- digests carbs into Maltose
Digestive enzyme in the stomach
Pepsin: Digest protein into amino acid
Lipase: Digest Lipids into fatty acids and glycerol
Small Intestine digestive enzymes
Maltase- digests maltose into glucose
Lactase- digests lactose into glucose and galactose
Sucrase: Digests sucrose into glucose and fructose
Rectum
-Lower end of the large intestine that stores undigested substances called feces
Feces is eliminated from the body through the anus in a process called …
Egestion
Feces is eliminated from the body through the anus in a process called …
Egestion
Large Intestine
-Receives indigestible foods from the small intestine
-Water and some vitamins/ minerals absorbed (sodium and potassium)
Nutrient absorption in the stomach
-Alcohol