Exam 2 Flashcards
Villi
Finger like protrusions or the lining of the small intestine that participate in digestion and absorption of nutrients
Microvilli or brush border
Brush like projections on the mucosal cell membrane that increase the absorptive surface area in the small intestine
Lacteal
Tubular component of the lymphatic system that carries fluid away from body tissues
Lymph vessels in the intestine are known as lacteals and can transport large particles such as the products of fat digestion
Cholectcytokinin
Released by the duodenum that stimulates the release of pancreatic kids rich in digestive enzymes and causes gallbladder to contract and release bile into th duodenum
Hepatic portal circulation
Blood vessels collecting nutrient rich blood from digestive organs and deliver them to the liver
Lymphatic system
Vessels organs and tissues that drains excess fluid from spaced in between cells, transports fat soluble substances and contributes to immune function
Cytosol
Liquid found within cells
Organelles
Cellular organs that carry out specific metabolic functions
Mitochondria
Providing energy
AMDR for carbs
45-65
No more than ————— of carbs should come from sugars
20%
DV for fibre
28g
Natural vs refine sugar
…
Carbs in whole foods
Natural state
Fruit
Dairy
Whole grains
Refined carbs
Sperate carbs from vitamin minerals and fibre
Fruit has good fibre
Kcal consumed come from added sugars in desserts beverages and prepared snacks
15%
Whole/unrefined grains contain
Bran layers
Good source of vitamin and fibre
Germ
Veggie oil and vitamin e
Endosperm
Get energy from
Refined grains are largely made from the
Endosperm
Mostly made of starch
Refined grains sold in canada may be enriched with
Thiamin riboflavin
Niacin
Iron
Fortified with folate
They do not contain magnesium, vitamin e, b6, or a number of other nutrients lost during processing
Free sugars
Sugars added to food during processing
Added sugar
Sugars added to food during processing
Empty kcals
Food that contribute to energy but fewer other nutrients
Monosaccharide
Basic unit of carbs
Most common monosaccharides
Glucose
Galactose
Fructose
Glucose is known as blood sugar is the most important carb fuel for the body
Disaccharide
Simple made of 2 mono linked together
Sucrose
Disaccharide
Glucose and fructose
Hydrolysis reaction
Braak sugars apart
Condensation reaction
Links two sugars together
Oligosaccharide
Short chains of less than ten mono
Polysaccharide
Long chains of mono
Includes glycogen found in animals and starch and fibre found in plants
Functional fibre
Extracted from starchy foods
Shown to have health benefits
Soluble fibre
Dissolves in water
Oats
Beans
Apples
Insoluble fibre
Does not dissolve in water
Wheat brain
Fruit
Veggies
Digestion and absorption of carbs
Mouth
Salivary amylase breaks down starch into shorter polysaccharide
Stomach
Salivary amylase is inactivated by acid so no carbs digest
Small intestine
Most starch digestion and breakdown of disaccharides occurs. Pancreatic amylase continue breaking down starch into mono, dis and olig
Enzymes attached to the brush border of the small intestine villi completes the digestion of carbs. Dis and olig are broken down into mono
Large intestine
Fibre and other indigestible carbs are partially broken down by bacteria to form short chain fatty acids and has. Some fibre is exerted in the feces
Glycemic response
How quickly and how high blood glucose rises after carbs are consumed
Glycemic index
Ranking of how a food affects the glycemic response
Insulin
Hormone secreted by the pancreas in response to a rise in blood glucose levels
Glucagon
Hormone secreted by the pancreas in response to decline in blood glucose levels
Enzyme lactase
Is needed to digest lactose the sugar found in milk
If lactose is not digested in the small intestine it passes through the large intestine absorbs water and is metabolized by bacteria
Undigested lactose in the small intestine can cause cramping abdominal distension and diarrhea
12 or older diagnosed with diabetes
7.3
Elevated glucose levels causes damage to blood vessels and leads to
Stroke and heart disease
Long term complications
Damage to heart and blood vessels Kidneys Eyes Nervous system Infections may lead to amputations
Complications of diabetes
Diabetic retinopathy
Leading cause of blindness
Diabetic nephropathy
Leading cause of end stage renal disease
Gestational diabetes
Occurs while pregnant
Greater chance of getting it later
Type 1 diabetes
Autoimmune disease in which the body’s own Immune system destroys insulin secreting cells, insulin is no longer made
Type 2
Cells have decreased sensitivity to insulin and there is a decrease in insulin production
Most common form of diabetes
Type 2
Usually found in adults
90-95%
Structure of small intestine
Contains large circular folds villi and microvilli which all increases the absorptive surface area
Factors that impact rate of stomach emptying
Chyme usually leaves the stomach in 2-6 hours
Determined by size and composition of meal
Higher fat meal will stay in stomach longer
More protein will leave more quickly
Mostly carbs will leave the fastest
Liquids leave fast
Solids don’t
Segmentation
Rhythmic local constrictions of the intestine that mix food together with digestive juices and speed absorption by repeatedly moving the food mass over the intestinal wall
Secretin
Released by duodenum that signals the release of pancreatic juice rich in bio carbonate ions and stimulates the liver to secrete bile into the gallbladder
Cholecystokinin
Released by duodenum that stimulates the release of pancreatic juice rich in digestive enzymes and causes gallbladder to contract and release bile into duodenum
What triggers the release of CCK and secretin
Food entering the duodenum
Mechanisms of absorption
Simple diffusion
High concentration to low concentration
No energy
Osmosis
Diffusion of water
Move from an area of low concentration
Want to equalize
Facilitated diffusion
High to low concentration
With the aid of a carrier molecule
No energy
Active transport
Aid of carrier
Need energy
May occur against concentration gradient
Large intestine contains
Colon and rectum
Water nutrients and fecal may spend
24 hours in large intestine
Overview of digestion and absorption
Some carbs digestion occurs in the mouth and some protein digeetion occurs in the stomach
But majority of the digestion occurs in the small intestine
Dental pain and lost of teeth
Tooth decay gum disease
Change consistency of foods consumed
Heartburn
GERD
Stomach acid leaking Due to overeating, anxiety, stress, pregnancy Ulcers increased cancer risk Avoid high fat foods Reduce meal size
Hiatal hernia
Pressure on abdomen from severe coughing or vomiting Heart burn GERD chest pain Reduce meal size Consume liquids Lose weight
Ulcers
Infection of stomach
Pain bleeding
Abdominal infection
Antibiotics to treat infection
Hepatic portal circulation
Carries blood from the stomach and intestines to the hepatic portal vein then to the liver
Selectively permeable
Describes a membrane or barrier that will allow some substances to pass freely but Will restrict the passage of others
Cytosol
Liquid found within cells
All human cells have
Cell membrane Nucleus Mitochondria Lysosome Endoplasmjc reticulum Ribosome Cytosol
Metabolic pathway
Series of chemical reactions inside of living organism that result in the transformation of one molecule to another
Catabolic pathways
Release energy trapped in chemical bonds
Break large molecules into smaller ones
ATP
Energy in Catabolic reactions is converted into atp
Anabolic pathways
Energy requiring process in which simpler molecules are combined to form more complex substances
Structure of ATP
Adenosine molecule is attached to three phosphate groups
Cellular respiration
Reactions that break down carbs fats and proteins in the presence of oxygen to produce carbon dioxide water and energy in the form of ATP
Cellular respiration uses
Oxygen to convert to glucose
Fatty acids and amino acids into carbon dioxide water and energy in form of ATP
Taking in nutrients and oxygen and eliminating waste
Digestive system takes in nutrients and the respiratory system takes in oxygen , which are then disturbed to all body cells by the circulatory system. The urinary system, respiratory, integumentary systems transfer metabolic wastes to the external environment
Soluble fibre in tract
Increases volume in intestine contents by absorbing water, these effects slow down aboosrtiom
Insoluble contents in intestine
More concentrated resulting in more rapid digestion and absorption
Effect of soluble fibre on blood glucose response
Rise in blood glucose is delayed and blunted after a high carb meal rich in soluble fibre. Blood glucos rises rapidly after a high carb, low soluble meal
Effect of GI on nutrient absorption
With low glycemic index food the digestion and absorption of glucose is slower than with a high glycemic index food
Blood glucose regulation
Immediwlty after eating blood glucose increases so insulin is then released Stimulating the uptake and storage of glucose
Several hours later blood glucose drops and glucagon is released from pancreas stimulating glycogen breakdown and gluconeogenesi
Glucose metabolism
Reactions of cellular respiration split bonds between carbon atoms in glucose releasing energy that is used to synthesize ATP.
Gluconeogenisis
Uses 3 carbon molecule and energy from atp to synthesize glucose.
Reduced sugar
25% less sugar than normal
Lower in sugar
25% less
High source vs very high source of fibre
4g per serving
6g per serving
