Study guide… - PowerPoint PPT Presentation

• Match the layers of the GI tract to their location and type of tissue they contain.
• Identify the enzymes that digest each nutrient and their location.
• Describe the role of pH in digestion.
• List the parts of the small and large intestine in order.
• Describe how villi aids in absorption in the small intestine.

• Describe the digestive role of the pancreas and liver.
• Describe how the nervous and endocrine systems regulate digestion.
• Apply the nutritional guidelines for carbohydrates, lipids and proteins.

ACCESSORY ORGANS:

ORGANS:

Mouth

Pharynx

Salivaryglands

Esophagus

Stomach

Liver

Smallintestine

Gallbladder

Pancreas

Largeintestine

Appendix

Sigmoidcolon

Rectum

Anus

Figure 14.1

• Mucous membrane
• Connective, nervous, blood vessels
• Smooth muscle
• Serous membrane

• Secretes mucus, digestive enzymes, acid; absorbs
• Carries nutrients
• Movement from esophagus to anus
• Secretes lubricating fluid

Vein

Lymph vessel

Artery

Nerve

Serosa

Muscularis

Lumen

Submucosa

Mucosa

Figure 14.2

• Saliva
• Salivary glands
• Parotid
• Submandibular
• Sublingual
• What enzyme digests carbohydrates in the mouth?
• The tongue forms a bolus and moves it into the pharynx.

Figure 14.3a

What cells line the pits?

Figure 14.7a–b

• Specific cells secrete gastric juice
• Hydrochloric acid
• Produces a pH of about 2; activates pepsinogen
• Mucus
• Protects stomach lining from acid
• Pepsinogen
• What activated enzyme begins protein digestion?
• Helicobacter pylori
• Chyme enters the small intestine after 2-6 hours.

What muscles are involuntarily churning your food?

Figure 14.8

• Functions
• Digestion
• Neutralizes acid from stomach
• Adds digestive enzymes and bile
• Breaks proteins, carbohydrates, and lipids to absorbable materials
• Absorption
• 95% of food absorbed in small intestine

• Structure
• Duodenum
• Jejunum
• Ileum
• Mucosa adaptations
• Villi containing blood and lacteal capillaries

• Liver
• Produces bile (What stores it?)
• Hepatic portal
• Drains blood from digestive tract to liver

Figure 14.11

• Pancreas
• Exocrine functions
• Secretes digestive enzymes and sodium bicarbonate
• Which enzyme acts on carbohydrates?
• Proteins?
• Fats?

Figure 14.13

Figure 14.14

• Functions
• Absorbs water and vitamins
• Eliminates waste
• Structure
• Cecum, appendix
• Colon
• Rectum, anus

• Regulation dependent on volume and content of food
• Nervous system
• Stretch receptors in stomach
• Hormones
• Gastrin
• Secretin
• Cholecystokinin (CCK)

• Digested into glucose
• Pancreas secretes insulin
• Insulin binds to receptors on cells
• Glucose can now enter cells to make ATP
• What if your insulin receptors become less sensitive?
• Cells scream at pancreas to release more insulin
• High insulin leads to higher blood pressure, high cholesterol and fat deposition
• Increased risk of type 2 diabetes, heart disease and liver problems

• Exercise-helps insulin attach to receptors
• Get lean-Fat cells sabotage muscle cells
• Eat original, whole grain vs. refined, processed
• Insulin receptors work best if you keep your blood sugar steady
• Eat fiber
• Slows down sugar absorption process
• Friend to your digestive tract
• Aim for 25-35 grams per day

• Made of amino acids
• 9 essential amino acids can not be made by the body
• 11 nonessential amino acids can be made by the body if the building blocks are there
• Come from plant and animal sources
• Animal sources and soy provide all 9 essential amino acids
• Empties stomach slowly and leaves you feeling full longer
• What if you eat more protein that what you need?
• Deposited as body fat

• Eat 0.8grams of protein per kg of body weight.
• Choose wisely
• Fish, shellfish, skinless (white meat) poultry
• Lean beef (>85%) with visible fat removed
• Beans, lentils, tofu, peanut butter, seeds
• Grill, bake, broil, roast, poach, stir fry

• Fats help to maintain healthy skin, hairand transports vitamins (ADEK)
• Saturated vs. Unsaturated
• Trans-fatty acids
• reduce the ability of cells to clear cholesterol from the bloodstream
• High density lipoproteins (HDL) cholesterol
• carries cholesterol to the liver where it is converted to bile salts
• Low density lipoproteins (LDL) cholesterol
• Deposits within walls of arteries and increases risk of heart attacks and stroke

Limit saturated fats

• Found in animals and processed snack food
• Avoid trans fats
• Ingredient list will say hydrogenated
• Limit cholesterol to 300 mg per day

• Choose unsaturated fats
• Found in most plants, nuts, seeds and fish
• Choose polys and monos
• Include omega fatty acids
• Don’t smoke…it will increase your LDLs and lower your HDLs