Chapter 3: The Remarkable Body Flashcards
How many cells is the body composed of?
Trillions
Red blood cells die after about
120 days
Digestive tract cells die after about
fairly hostile working environment
3 days
self-contained, living entities, dependent on one another
Cells
- Oxygen
- Water (an essential nutrient group)
- Nutrients (especially the essential nutrients // carbs, fats, proteins, vitamins, and minerals)
- Energy (supplied by carbs, fats, proteins)
Basic Needs of Body Cells
Why are nutrients needed?
growth, development, repair, maintenance, and replacement
- direct protein production
- provide instruction for structural components of cells
- affect how body handles nutrients
- complete set of genes in each cell
- gene variations (inborn error of metabolism; influence of nutrients)
Genes Control Functions / From DNA to Living Cells
Why are cells organized into tissues?
To perform specialized tasks
Why are tissues grouped together?
To form organs
- Cardiovascular System (focus on nutrient transport)
- Lymphatic System (focus on nutrient transport)
- Endocrine (Hormonal) System
- Nervous System
- Immune System (signs and symptoms of deficiencies are seen the quickest in this system and the digestive system)
Organs that work together as part of body systems
In Nutrition, what system is most focused on?
Digestive System
- Supply energy, oxygen, nutrients, and water
- Deliver fresh supplies and pick up wasts
Body Fluids
circulate around cells
fluid outside of cells
extracellular fluid
fluid inside of cells
- all cell reactions take place here
- holds cellular shape
intracellular fluid
Sweet, sour, bitter, salty, and umami (savory)
Five basic chemical tastes
- almost universally desired
- can lead to drastic overeating of these substances
sweet, salty, and fatty foods
- flexible, muscular tube
- extends from mouth to anus / total length: est. 26 ft
- GI tract is immature at birth and matures at about 6 months of age
- extensive surface area within the small intestine for nutrient absorption
The Digestive Tract
consists of:
- mouth, esophagus, stomach, small intestines, large intestines (colon), rectum, and anus
- accessory structures: salivary glands, pancreas, liver, and gallbladder
Gastrointestinal (GI) Tract
- break apart (digest) foods into smallest components
- absorb nutrients (and other substances such as phytochemicals)
- prevent numerous (but not all) microorganisms or other harmful compounds in food from entering tissues of the body
- excrete/expel from the body any substances which are not absorbed
Main functions of the GI tract
Often thought of as a tube or a tunnel with an opening at each end
Human body surrounds digestive canal
beginning in the mouth: the altering of the texture of foods by chewing, grinding, crushing foods and adding liquids to aid swallowing, create chyme, and chemical digestive processes
The Mechanical Aspect of Digestion
includes the mixing and moving of GI tract contents from the mouth to the anus using peristalsis, segmentation, and pendular movement
The Mechanical Aspect of Digestion
the forward, rhythmic muscular contractions that move food through digestive system from the initial swallow to the anus
Peristalsis
“sloshing motion”
mixes chyme with chemical secretions; seen predominantly in the small intestine
Segmentation
(constrictive draws together, compresses) wave moving chyme backward & forward; enhances nutrient absorption in small intestine
Pendular Movement
To move foods, liquids, and other swallowed substances (such as medicines) from the mouth to the stomach
Function of the Esophagus
To allow enzyme activity to continue if the activity began in the mouth (the esophagus itself cannot start or stop any enzyme activity)
Function of the Esophagus
Once started with a swallow, peristalsis (the dominant pattern of muscle contraction and relaxation) continues all the way to the anus
Function of the Esophagus
Peristalsis begins prior to birth as we swallow small amounts of amniotic fluid and never stops until our death. It may speed up or slow down but it never stops. Digestion is an on-going process 24 hours a day
Function of the Esophagus
- Powerful muscle sets within the stomach run vertically, horizontally, and diagonally.
- These muscles make the grinding, shredding, and crushing food pieces possible.
- A heavy thick layer of mucus (often shown as a white layer) coats the interior of the stomach; protecting the stomach’s interior surface from: hydrochloric acid, digestive enzymes, other substances
The Muscular Stomach
Beginning in the mouth: digestion starts; the process of breaking chemical bonds in ingested (consumed) foods and beverages into absorb-able substances such as glucose, amino acids, fatty acids
The Chemical Aspect of Digestion
actively used in the chemical digestion processes
water
- Salivary Glands: starch digesting enzymes and lipid digesting enzymes (Perk = supports tooth health)
Sources of digestive juices to assist with chemical digestion
Stomach - hydrochloric acid and protein digesting enzymes
Sources of digestive juices to assist with chemical digestion
Pancreas - bicarbonate ions and a variety of digestive enzymes released into the small intestine
Sources of digestive juices to assist with chemical digestion
Liver – produces and releases bile (needed to emulsify fats) into the small intestine
(bile may be stored by and released from the gallbladder)
Sources of digestive juices to assist with chemical digestion
Small Intestine - a variety of digestive enzymes
Sources of digestive juices to assist with chemical digestion
the moving of nutrients across the cell membranes and into the small intestine cells
initial transport of nutrients for distribution to body cells and tissues
absorption of nutrients
- Excess glucose and amino acids stored as glycogen and / or fat
- Modest amounts of most excess vitamins and minerals stored; the remaining excess vitamins and minerals excreted
- Excess amounts of vitamins A, D, E and the mineral iron are not excreted (may build to toxic amounts if intake is in excess of need)
storage forms
- Ferment many indigestible fibers
- Break down undigested protein and unabsorbed amino acids
- Break down bile
- Chemically alter certain drugs and phytochemicals
Digestive Tract Bacteria
- Adequate diet comprised of mostly whole or minimally processed foods
- Adequate intake of fiber and water
Diet to support beneficial colonies
- colon cancer
- choking
- constipation and diarrhea
- heartburn and GERD
- hernias
- Irritable Bowel Syndrome
- ulcers
- fiber and gas
- gallbladder disease and gall stones
Selected Common Digestive Problems
the epiglottis acts as a flap to seal the entrance to the lungs (trachea) and direct food to the stomach via the espohagus
Normal Swallow
person cannot speak or gasp because food lodged in the trachea blocks the passage of air.
Choking
- acid reflux
- or a more serious condition of GERD
Heartburn
common causes: certain foods, smoking drinking alcohol, being overweight/obese, tight-fitting clothes, pregnancy, laying down or reclining after eating
Heartburn
symptoms: nausea, bloating, belching, a burning sensation, uncomfortable feeling of fullness, unpleasant sour taste in the mouth
Heartburn
- Eat small meals
- If a smoker, try to stop smoking
- If over weight, try to lose weight to an appropriate weight
- wear loose fit clothing
- wait about 2 hours before laying down after eating
Suggested conservative treatments for Heartburn
seek medical attention if condition worsens
an irritated, inflamed defect or excavation of the organ/tissue surface by the acidic gastric juices
- probable causes: medications, alcohol, Helicobacter pylori (bacteria)
Ulcers
symptoms: abdominal pain, vomiting, fatigue, bleeding (minor to severe), general weakness
Ulcers
- medications
- limiting or avoiding alcohol, caffeine sources, spices, and acidic foods like citrus fruits, vinegar, and tomatoes
Suggested conservative treatments for Ulcers
- may become “sludgy” (filled with a thick, concentrated bile solution which begins to form crystals)
- as crystals form, they can lump together forming gallstones
Gallbladder Disease and Gallstones
possible causes: a diet low in fiber and chronically inadequate fluid intake resulting in abnormally thick – concentrated bile solution
Gallbladder Disease and Gallstones
symptoms: fever, nausea, vomiting, cramps
- Pain is unique: can range from no pain at all to mild pain
- Severe pain can be experienced which mimics an acute heart attack in progress
- Pain may be seen shortly after eating fried or fatty foods and “fade” away after a few hours
Gallbladder Disease and Gallstones
reduce dietary fat intake, medication to dissolve the stones, shockwave therapy, surgical removal of the gall bladder
Suggested treatments for formed stones
to gradually increase fiber to recommended amounts and to increase fluid intake to adequate hydration amounts
Preventive treatment
formed when an organ or part of an organ protrudes through the body chamber wall that contains the organ
Example of a Hernia
Transit time is too slow through large intestines
- Possible causes: Inadequate amounts of fiber and fluids; physical inactivity resulting in poor muscle tone which inhibit normal bowel reflexes; some illnesses like diabetes, depression, and stress; some medications such as pain medication and antacids; mineral supplements such as calcium or iron
Constipation
Symptoms:Difficult, painful, infrequent passage of hard, firm stools, headache, backache, nausea, vomiting
Constipation
Determine and address cause(s); add adequate fiber and fluids gradually into diet; and if needed, possibly add an over-the-counter stool softener
Suggested treatments for constipation
Transit time is too fast through small and large intestines
- Possible causes: Contaminated water, various microorganisms, stress, excessive fiber, some medications like antibiotics
Diarrhea
Symptoms: Passive of frequent, watery, loose stools resulting in loss of fluids and electrolytes; very serious if it lasts for extended period of time
Diarrhea
Fluid and electrolyte replacement -As acute and chronic malnutrition is of significant concern with this disorder, an attempt to identify the cause of the diarrhea is normally done.
Suggested treatments for diarrhea
Nutrient malabsorption is a significant concern if IBS is diagnosed. IBS is a functional disorder affecting intestinal rhythm and transit time of chyme and fecal materials
Irritable Bowel Syndrome (IBS)
symptoms: alternating patterns of constipation and diarrhea; Inflammation, pain, gas, abdominal cramping and bloating
Irritable Bowel Syndrome (IBS)
- low fiber diets, eating irritating foods
- physical inactivity, stress, inadequate sleep
- intestinal motility (spontaneous motion) disorders
Suspected Factors
possible causes are unknown
- small meals containing adequate fiber and water
- avoidance of irritating foods
- develop regular exercise habits, good sleep habits, stress management
- possibly medications
Suggested treatments for IBS
issue involving blood veins) are often formed when a person is trying to expel dry, hard fecal material by increasing pressure inside the colon, rectum, and anus areas. Greater pressures that occur during pregnancy, labor and delivery can cause hemorrhoid formation
Hemorrhoids
symptoms: itching, pain from minor to severe; swelling and inflammation in the rectum and anus veins which can tear, bleed and become infected
Hemorrhoids
- Internal hemorrhoids are close to the interior membrane surface of the rectum
- External hemorrhoids may have protruded just outside the anus
Hemorrhoid location
- Prevention is preferred. See Chapter 4 for prevention suggestions
- Treatment varies depending on the severity of the hemorrhoids
Treatment / Prevention
A leading form of cancer and the second leading cause of cancer deaths
Colon Cancer
Often no symptoms are seen or felt. If symptoms are seen they are often not associated with colon cancer initially. These signs and symptoms include weight loss, internal bleeding, iron-deficiency anemia, fatigue
Colon Cancer
surgery; dietary counseling may be offered after surgery
Suggested treatments if benign (Colon Cancer)
surgery; radiation therapy, chemotherapy, and dietary counseling
Suggested treatments if cancerous (Colon Cancer)
- develop inside of the colon
- size may be fairly small like a small button and up to the size of a mushroom or plum
- may or may not be benign
- developing within the large intestine (colon) may indicate an early stage of cancer developing
Polyps
