open energy balance part2 Flashcards
Calories consumed through eating and drinking
Energy In
– provides moisture to allow taste buds to function
– contain enzymes that digest starch
salivary glands
food lubricated by saliva, formed into soft lump/swallowed and passes thru the pharynx and esophagus to stomach
bolus
____ is rhythmic contraction and relaxation of
the circular muscles of the digestive system that
propels the food through
peristalsis
Bolus enters stomach
– Stomach secretes the enzyme pepsin that starts protein digestion
– Little absorption of nutrients occurs in the stomach(Only alcohol, aspirin, & fat-soluble drugs are absorbed)
– Major function is to mix food particles with gastric juices to prepare for absorption in the small intestine (duodenum)
Digestive Process
secreted by the pancreas into the
duodenum to decrease acidity and help in digesting carbohydrates and fats
– Pancreas produces insulin facilitating entry of glucose into bodily
tissues
pancreatic juices
primarily in small intestine (duodenum) • Starch finished from saliva • Proteins finished from stomach • Carbohydrates and fat • 90% of water (allows absorption of vitamins & electrolytes)
absorption of food
____produces bile salts that are stored in the gall bladder and are released into the duodenum to break down fats that are further broken down by pancreatic enzymes
liver
Peristalsis propels food mixture from duodenum to the large intestine(colon)
- peristalsis is more sluggish and irregular in colon
- bacteria inhabit the colon and produce vitamins
typically absorbs only water, a few minerals, and the vitamins proudced by its bacteria
(feces left over after digestion)peristalsis carries feces thru colon, rectum, and then anus when
eliminated
– Stomach flu (norovirus - 50% of all gastroenteritis around the world )
– Inflammation of lining of stomach & small intestine
– Vomiting, diarrhea, abdominal cramps, & nausea
– Excessive food or water, contaminated food or water, or food
poisoning
gastroenteritis
– Watery & frequent BMs
– Lining of intestines can’t properly absorb water & food
– Chronic may result in serious fluid & electrolyte disturbances
diarrhea
– Like diarrhea except mucus, pus, & blood are also excreted
– Protozoan attacks large intestine or a bacterial organism
– Common cause of death in less developed countries
dysentery
• Open sore in the stomach or duodenum lining
• Cause
– Hypersecretion of hydrochloric acid
– Pepsin (enzyme) digests part of the lining
– H. pylori bacterium contributes to development
– Stress aggravates ulcers but is not necessary
Peptic Ulcer
• 20% of the US population has weekly reflux
• Muscle between the esophagus and the
stomach does not work properly
• Stomach acid flows back up and irritates the
esophagus
• This backward flow is reflux or heartburn
Gastroesophageal Reflux Disease
GERD
• Cholecystis
– Infection & inflammation of gallbladder
• Gallstones – Made up of cholesterol, calcium, bile, & inorganic salts – Move into duct of gallbladder – Cause painful spasms
Gallbladder
• Bacterial infection in appendix caused by
obstruction due to wastes and bacteria
• Pain, increased peristalsis, nausea
• If appendix ruptures, bacteria are released into
abdomen or peritoneum & further infection &
death can occur
Appendicitis
Viral inflammation & damage to liver=
hepatitis
– Contagious & serious
– Transmitted thru food & water
– Bilirubin can’t pass thru ducts & collects in blood (jaundice)
– Fatigue, fever, pain, nausea, vomiting, & diarrhea
heptatitis A
– Similar to Hep A but more serious
– Spread by blood, needles, sexual contact, mother-to-infant
hepatitis B
– Spread by blood & needles
hepatitis C
– IV drug users
– Must have Hep B infection first
hepatitis D
– Like Hep A but caused by different virus
hepatitis E
– Protein hormone secreted by fat (adipose) cells
– Signals hypothalamus about stores of fat
– Inhibits neurons that stimulate appetite
– Activates neurons that suppress appetite
Leptin
– Hormone produced by beta cells in the pancreas
– Allows body cells to take in glucose for their use
– High insulin leads to intake of more glucose than the cells can use and the excess is converted into fat
– Therefore, the higher the insulin levels, the more fat
– Receptors in the hypothalamus detect insulin levels
Insulin
– Peptide hormone secreted by cells in the stomach
– Spikes just before meals, drops afterwards
– When given ghrelin injections, people feel extremely hungry
– Acts in the hypothalamus to activate production of other neurochemicals
involved in the regulation of eating, such as neuropeptide Y (that stimulates Agouti-related peptide) and the orexins
– Melanin-concentrating hormone is another brain peptide that increases
food intake and interacts with ghrelin
Ghrelin
– Peptide hormone produced by intestines
– Acts on the brain and produces feelings of satiation
– Short-term use is to tell us to stop eating
– Other peptide hormones produced by the intestines to produce satiation are glucagon-like peptide 1 and peptide Y
Cholecystokinin (CCK)
– Large role in controlling eating
– Ventromedial hypothalamus
• When damaged, rats eat excessively
• May play a role in some cases of human obesity
hypothalamus
excessive body fat
– Women: fat should be 20% to 27% of body tissue
– Men: fat should be 15% to 22% of body tissue
Obesity
Create tables of weight based on height, frame
size, and mortality rates (Met Life)
• Calculate an index of weight and height (BMI)
– Body Mass Index (BMI) = kg/m2
– Overweight = 25-29.9
– Obese ≥ 30
• Determine percentage and distribution of body fat
– Imaging (computer tomography, ultrasound, magnetic
resonance imaging, and PET scanning)
– Skinfold test
– Bioelectrical impedance measurement
• Fat distribution as ratio of waist to hip size
– Particular risk to “apples” rather than “pears” (fat
localized in abdomen)
• More psychologically reactive to stress
• Greater cardiovascular reactivity
• Risk factor for metabolic syndrome
How we measure obesity