Digestive System

Digestive system

• Used for breaking down food into nutrients to be sent throughout the body

Macronutrients

1. Carbs

• your body’s main source of short-term energy

• 50-60% of your diet

2. Protein

• Helps build muscles

• building blocks of your body

• 15-30% of your diet

• fights infection

• biomolecules made up of amino acids joined by pepticle bonds

• Amino acids are the building blocks of protein

• helps cells divide

3. fat

• your body’s source of long term energy

• 20-30% of your diet

4. Carbohydrates

• organic molecules containing carbon, hydrogen and oxygen

4. Lipids

• reserved after yoou use short-term energy

• absorbs vitamins

• component of cell and tissue

• main source of elemetns

• converted into other molecules

Micronutrients

1. water

• transports nutrients and oxygen into cell

• protects and moisturizes our joint

• detoxifies our body

• moisturizes air in our lungs, helps with metabolisim

• protects our organs

• brain consists of 90% water

Process of digestion

1. Ingestion- entry of food

2. Digestion- breaking down of food

3. absorbtion- villi passing nutrients to blood

4. assimilation- nutrients become parts of the cell

5. excretion- removal of waste and indigested material

Digestive Parts

1. Digestive Tract- A long tube of organs where food passes through

2. Accessory organs- Organs that aid in digestion by releasing substances that break down food

Mouth

• Receiver of food

• has salivary glands

• the tongue moves the food around until it forms a ball called a bolus

• the bolus has the same color as the food being eaten, and the saliva gives it an alkaline pH

• The bolus passes through the Pharynx and then goes to the esophagus

Esophagus

• No mechanical/Chemical digestion

• passageway of the bolus from the mouth down to the stomach

• The bolus passes down the esophagus by peristalsis

Stomach

• Acid kills off any invading bacteria/viruses

• mucus protects the lining of the stomach from the acid

• bolus exits the stomach as a CHYME

• Mechanical (churning)

• Chemical (releases acidic gastric juices)

Small Intestine

• most absorption occurs here

• the liver and pancreas help the small intestine maximize absorption

Large Intestine

• The large intestine/colon is used to absorb water from the waste material

• site of Vitamin K and B production by bacteria

• All leftover waste is compacted and stored at the end called rectum

• when full the anal sphincter looses and the waste called feces passes out of the body through the anus

Teeth

• Aids digestion using mastication

• Incisors: used for cutting food

• Canines: Chisel shape, fang-like, and is adapted for tearing and piercing

• Premdars (bicuspid) and Molars: broad crowns with rounded cusps for grinding

Salivary glands

• empty their secretions to the mouth

• releases saliva

• contains any lase that breaks down carbohydrates

• saliva contains lyzone and igA

Pancreas

• A triangular gland that extends across the abdomen

• releases enzymes that breaks all kinds of digestible food including fats, proteins and carbohydrates

Liver

• the largest gland in the body that produces bile

• bile salt aids the digestive process because it emulsifies fats

Gallbladder

• stores bile and releases it when needed. located below the liver

Mechanical Digestion

• breakdown of food into smaller pieces so it increases the surface area of the substance for enzyme action

Chemical Digestion

• Enzymes breakdown food into simple chemical substances for absorption

• Amylase breaks starch into glucose, Protease breaks protein into amino acids, lipase breaks fat into fatty acids, and glycerol

• Digestive enzymes - The chemicals that break large insoluble food molecules into smaller soluble molecules for absorption

The main nutrients the body needs

• carbohydrates for energy

• proteins for growth and repair

• fats to store energy

• vitamins and minerals to keep the body healthy