Chap. 9 Digestive System & Nutrition

Stomach

- 1 Liter capacity A muscular and elastic sac that serves mainly to store food, break it up mechanically, and begin chemical digestion of proteins and fat.

mucosa

- inner mucous membrane layer modified according to the digestive organ

Polyunsaturated:

- linoleic and linolenic acid - healthy insulin signal -above foods, also corn and safflower oil

The Large Intestine

18 - 24 hours for food to pass through structure - absorb water, vitamins B and K - form feces

Teeth

20 deciduous, 32 adult

oblique layer

3rd layer of smooth muscle allowing for extremely forceful contractions

epiglottis

A flap of tissue that seals off the windpipe and prevents food from entering.

secretin

A hormone secreted by the small intestine (duodenum) in response to low pH (e.g., from stomach acid). It promotes the release of bicarbonate from the pancreas to act as a buffer.

cholecystokinin

A hormone that stimulates contraction of the gallbladder which releases bile, stimulates the pancreas to secrete enzymes to help break down fat.

pH level

A measure of the relative amounts of H+ it contains; expressed between 0 and 14.

anus

A muscular opening at the end of the rectum through which waste material is eliminated from the body

esophagus

A muscular tube that connects the mouth to the stomach.... passes from the pharynx down the neck between the trachea and the spinal column and behind the left bronchus where it pierces the diaphragm slightly to the left of the middle line and joins the cardiac end of the stomach.

Pharynx

A passageway leading from behind the nasal cavity to the trachea. The throat

rectum

A short tube at the end of the large intestine where waste material is compressed into a solid form before being eliminated

appendix

A small, fingerlike extension of the vertebrate cecum; contains a mass of white blood cells that contribute to immunity.

bile

A substance produced by the liver that breaks up fat particles. ( a dark green to yellowish brown fluid, produced by the liver of most vertebrates, that aids the digestion of lipids in the small intestine. In humans, bile is produced continuously by the liver (liver bile), and stored and concentrated in the gallbladder (gallbladder bile). After eating, this stored bile is discharged into the duodenum.)

The liver has all of the following functions except: A. produce insulin B. regulate cholesterol C. store glucose as glycogen D. produce bile E. remove and store vitamins

A. produce insulin (pancreas produced insulin)

trachea

Allows air to pass to and from lungs

Essential amino acids

Amino acids that are needed, but cannot be made by the body; they must be eatin in foods

Diarrhea

An abnormal, frequent discharge of fluid fecal matter from the bowel

Anorexia Nervosa

An eating disorder characterized by an obstinate and willful refusal to eat, a distorted body image, and an intense fear of being fat

Bulimia Nervosa

An eating disorder characterized by episodes of overeating, usually of high-calorie foods, followed by vomiting, laxative use, fasting, or excessive exercise.

lipase

An enzyme secreted in the digestive tract that catalyzes the breakdown of fats into individual fatty acids that can be absorbed into the bloodstream

amylase

An enzyme that digests starch into disaccharides. Amylase is secreted by salivary glands and by the pancreas.

gall bladder

An organ that stores bile and releases it as needed into the small intestine

Match the organ with its description or function. beginning of the large intestine has ducts for enzyme secretion end of the large intestine A. duodenum B. cecum C. rectum

B. cecum A. duodenum C. rectum

Match the list of organs with their description or function where digestion is completed where water and vitamins are absorbed where protein digestion begins A. stomach B. small intestine C. large intestine

B. sm intestine C. lg intestine A. stomach

Body Mass Index

BMI a measure of body weight relative to height

hard palate

Bone supported anterosuperior boundary of the oral cavity

Digestion

Breakdown of food substances into simpler forms that can be absorbed and used

Carbohydrates

Broken down to glucose to provide energy.

cholesterol

Carried in the blood by high and low density lipoproteins (transport mechanisms)

Antioxidants

Chemical compounds that nullify the effects of oxygen free radicals by forming a bond with their unattached oxygen electron.

hormones

Chemical messengers, mostly those manufactured by the endocrine glands, that are produced in one tissue and affect another

nutrient

Component of food that has a physiological effect on the body: Energy, growth, regulation of metabolism

Digestive System

Composed of the alimentary canal and accessory structures. Mouth, esophagus, stomach, small intestine (duodenum, jejunum, and ileum), large intestine (colon), and anus, Breaks down food into absorbable units that enter the blood for distribution to body cells.

diverticulosis

Condition of having small pouches in the lining of the colon, or large intestine that bulge outward through weak spots. (Can be asymptomatic)

All of these are secreted by the pancreas except A. trypsin to digest protein B. lipases to digest fat C. pancreatic amalyse to digest carbohydrates D. saliva to digest carbohydrates E. sodium bicarbonate to neutralize acid

D. saliva to digest carbohydrates

gastrin

Digestive hormone that stimulates sustained secretion of gastric juice from the stomach

Small Intestine

Digestive organ where most chemical digestion and absorption of food takes place

salivary amylase

Enzyme in saliva that breaks down starch

pepsin

Enzyme that breaks down proteins into smaller polypeptide fragments

Lipids

Fats, oils, cholesterol

Monounsaturated

Fatty acids that have only one double bond. protect heart and brain - olive, canola, peanut oil, flax seed, fish oil

cecum

First part of the large intestine

duodenum

First part of the small intestine

GI

Gastrointestinal

salivary glands

Glands of the mouth that produce saliva, a digestive secretion

Constipation

Hard, slow stools that are difficult to eliminate; often a result of too little fiber in the diet

Obesity

Having an excessive amount of body fat

Diabetes

Inability of cells to take up glucose

periodontitis

Inflammatory disease of the supporting tissues of the teeth.

Peristalsis

Involuntary waves of muscle contraction that keep food moving along in one direction through the digestive system.

diaphragm

Large, flat muscle at the bottom of the chest cavity that helps with breathing

trace Minerals

Less than 100mg needed/day - copper, fluoride, iodine, iron, and zinc- 1000 mg/day - Vitamin D needed along with it

First Part of the Digestive Tract

Mouth

digestion mechanical

Mouth: chewing, moistens the food and mechanically breaks it down into pieces small enough to swallow.

4 layers of GI tract

Mucosa, submucosa, muscularis, serosa lumen

sphincters

Muscles arranged in circles that are able to decrease the diameter of tubes. Examples are found within the rectum, bladder, and blood vessels.

Define sphincter. Give the name of 2 and tell where they are located in the digestive system

Muscles arranged in circles that are able to decrease the diameter of tubes. lower esophageal sphincter located at the top of the stomach and at the bottom of the esophagus. the pyloric sphincter located at the bottom of the stomach,

Nutrition

Obtained from food and used by our bodies for growth and maintaining good health.

chyme

Partially digested, semiliquid food mixed with digestive enzymes and acids in the stomach.

Chemical digestion

Process by which enzymes break down food into small molecules that the body can use

lactose intolerance

The inability to completely digest the milk sugar lactose

Nutrient absorption small intestine has surface area of a tennis court due to

The process of absorbing or assimilating substances into cells or across the tissues and organs through diffusion or osmosis, as in absorption of nutrients by the digestive system

glycemic index

The relative ability of a food to raise blood sugar. Related to the ease with which a food is digested and absorbed. High simple sugars = high

villi

Tiny finger-shaped structures that cover the inner surface of the small intestine and provide a large surface area through which digested food is absorbed

Vitamin D

Vitamin given with calcium to ensure proper absorption

Irritable bowel syndrome

a common condition of unknown cause with symptoms that can include intermittent cramping, abdominal pain, bloating, constipation, and/or diarrhea

lacteal

a lymph tubule located in the villus that absorbs fatty acids

Minerals

a major part of cells, structural component of tissues and body fluids

soft palate

a muscular flap that closes off the nasopharynx during swallowing or speaking

Muscle dysmorphia

a preoccupation with ones by size and a perception that, though one is very muscular, one actually looks small

bolus

a small rounded mass of a substance, especially of chewed food at the moment of swallowing.

Hepatitis A

acquired from sewage contaminated water

dental caries

an infectious disease caused by bacteria that destroy the enamel and dentin of the tooth; also known as tooth decay or a cavity

Omega 3 fatty acids

an unsaturated fatty acid, mostly in fish, they can lower triglyceride levels

Antioxidants

are vitamins C,D, A & E that defend against these ( bind with the free radicals) Abundant in fruits and vegetables

pancreatic juice

breaks down fats (lipase), carbs (amylase) and proteins (trypsin)

submucosa

broad band of loose connective tissue that contains nerves, blood, and lymphatic vessels

Proteins

broken down into 20 amino acids body uses to synthesize thousands of proteins 9 are essential, must be eaten a.a. are not stored so a daily supply is needed

major Minerals

calcium, chloride, magnesium, phosphorus, potassium, sodium, sulfur Required in large amounts.

lumen

central space containing food being digested

CCK

cholecystokinin

Pancreas

digestive organ and endocrine gland in the back of abdomen secretes through a duct into the duodenum An organ of the digestive system that produces a fluid that neutralizes stomach acid and chemicals that help finish digestion.

pancreatic amylase

digests carbohydrates

pancreatic lipase

digests fat

Trypsin

digests protein

defecation

elimination of feces from the digestive tract through the anus

protease

enzyme that digests protein

deciduous

falling off at a specific season or stage of growth as of leaves; Ex. deciduous tree/teeth

movement

food passing between organs

hormone insulin

hormone that sends glucose into cells and stores excess as Glucagon

Glucagon

hormone that stimulates liver to break glycogen down, back into glucose when are low

Colitis

inflammation of the colon

hepatitis

inflammation of the liver caused by a virus

Structure

large in diameter, 6.5 cm, just under 2 M long

Liver

largest metabolic organ, made of 100,000 globules *Functions: - largest metabolic organ - many functions filters blood from GI tract Removes and stores vitamins Stores glucose as glycogen Makes plasma proteins, regulates cholesterol Breaks down hemoglobin Makes bile - emulsifies fat

essential fatty acids

linoleic and linolenic acids are

cirrhosis

liver becomes fatty and replaced by scar tissue, seen in alcoholics and obese- Liver can regenerate and transplants are getting more common

tongue

manipulates food for chewing and swallowing; a taste organ

glottis

mouth of windpipe.. in mammals, the slitlike opening formed by the vocal folds in the larynx

Sodium bicarbonate

neutralize acidic chyme

absorption

nutrients pass from GI tract to blood to all cells

unsaturated

oils, usually form plants

Vitamins

organic compounds used for metabolism, but aren't produced by body , many are coenzymes

Type I Diabetes

pancreas does not produce insulin, metabolizes fat, ketones buildup, acidosis of blood occurs: coma or death- injections of insulin necessary

elimination

removal of indigestible material

rugae

ridges on the hard palate and the wall of the stomach

gastric glands

secrete a fluid called gastric juice into the stomach

Binge-eating Disorder

significant binge-eating episodes, followed by distress, disgust, or guilt, but without the compensatory purging, fasting, or excessive exercise that marks bulimia nervosa

Polyps and cancer

small growths in the epithelial lining that can be benign or cancerous. Dietary fat may increase colon cancer odds.

saturated fat

solid, usually animal fat: meat, butter, contributes to atherosclerosis

Hepatitis B

spread by sexual contact, blood, needles

Hepatitis C

spread like B, no vaccine

Carbohydrates simple

sugar and refined grains • Raise blood sugar level sharply • High on glycemic index

Hemorrhoids

swollen, twisted, varicose veins in the rectal region

ingestion

taking in food

serosa

thin, outermost tissue that is the visceral peritoneum

How can proteins be harmful ?

too much protein makes the kidneys work over time to get it out of the system.... If proteins form aggregates (clumps) they can be very harmful. Prions, mid-folded proteins, etc can interfere with normal cell processes. Many times the mis-folding causes the hydrophobic portions to be exposed which then interferes with the cell membrane or causes other proteins to aggregate with it.

Muscalaris

two layers of smooth muscle

Type 2 Diabetes

unhealthy diet triggers excess insulin, cell membranes become resistant to it. - can be controlled through diet and exercise

Carbohydrates complex

whole grains, fruit, veg, beans Take longer to digest Low on glycemic index (remember, low and slow)

jaundice

yellowing of the skin and the whites of the eyes caused by an accumulation of bile pigment (bilirubin) in the blood