EXAM 1 - intro to nutriton & digestion Flashcards
1
Q
What is nutrition?
A
the science of how living organisms obtain and use food to support processes required for life
2
Q
What is a nutritional scientist?
A
a scientist in a research setting whose main focus is learning the science of food and nutrition
3
Q
dietitian
A
someone who specializes in nutrition in a clinical setting; can diagnose and help provide food plans to those wanting to eat healthier
4
Q
Describe what is meant when a food is identified as “organic”.
A
Certified Organic foods promote and enhance biodiversity; they are produced, grown, and harvested WITHOUT (a) conventional pesticides, (b) fertilizer, (c) bioengineering, and (d) ionizing radiation
5
Q
What is the Environmental Working Group (EWG)?
A
an American activist group that specializes in research and advocacy in the areas of agricultural subsidies, toxic chemicals, drinking water pollutants, and corporate accountability
6
Q
What are the two lists that the EWG release annually?
A
- Clean Fifteen
- Dirty Dozen
7
Q
Clean Fifteen
A
list of the 15 fruits and vegetables that are LEAST likely to have pesticide residue; can be bought non-organic
8
Q
Dirty Dozen
A
a list of 12 fruits and vegetables that are MOST likely to have high levels of pesticide residue, and are therefore best to be bought organic
9
Q
phytochemicals
A
health-promoting substances found in plants that have a pigment to them; the darker the pigment, the more nutrients there are; helped to prevent disease and decreases risk of cancer
10
Q
zoonutrients
A
substances found in animal foods presumed to be health-promoting
11
Q
functional foods
A
foods w/ enhanced amounts of nutrients; promote optimal health above and beyond simply helping the body meet its basic nutritional needs
12
Q
What are the three main functions of nutrition?
A
- structure
- energy
- chemical processes
13
Q
nutrients
A
substances that provide nourishment essential for the growth and the maintenance of life; chemical compounds in food that are used by the body to function properly and maintain health
14
Q
micronutrients
A
nutrients of which we need small amounts (<1g/day) to help bodily functions; divided into vitamins and minerals
15
Q
macronutrients
A
nutrients of which we need large amounts (>1g/day) to help maintain bodily functions/nutritional functions; divided into carbohydrates, proteins, and lipids (fats and oils)
16
Q
How many kcals per gram - PROTEIN?
A
4 kcals/g
17
Q
How many kcals per gram - CARBOHYDRATES?
A
4 kcals/gram
18
Q
How many kcals per gram - LIPIDS?
A
9 kcals/gram
19
Q
What elements comprise CARBOHYDRATES?
A
literally “hydrate of carbon”
CH2O (carbon, hydrogen, oxygen)
20
Q
What are the types of carbohydrates?
A
- starches (aka complex carbohydrates)
- sugars
- fiber
21
Q
What are the general functions of carbohydrates?
A
- act as an energy source
- help control blood glucose/insulin metabolism
- participation in cholesterol & triglyceride metabolism
- help w/ fermentation
22
Q
What elements comprise lipids?
A
hydrogen and oxygen mostly; in some cases, phosphorus, nitrogen, sulfur, and other elements
23
Q
general functions - lipids
A
used for metabolic processes; help w/ moving and storing energy, absorbing vitamins, making hormones
24
Q
types of lipids?
A
fatty acids, glucose
25
What are the general functions of protein?
- repairing and building body’s tissues
- drives metabolic reactions
- keeps immune system strong
- transports and stores nutrients
- can act as energy source
26
What elements comprise proteins?
carbon, oxygen, hydrogen, nitrogen
27
vitamins
type of micronutrient
28
Which vitamins are FAT-soluble?
Vitamins A, K, E and D
29
Which vitamins are WATER-soluble?
Vitamin C and all B vitamins
30
What are some of the roles that water play in nutrition?
- waste functions
- hydration
- regulation of body temperature
31
What is the role of minerals?
involved in energy production; provide structures and are naturally recurring in life
32
What role do vitamins play?
- building and maintaining tissue
- use energy to protect the body from harmful ingredients (Vitamin C w/ the sun, e.g.)
- regulate chemical reactions
33
What IS energy?
the capacity of a physical system to do work
34
What is the role of energy from ATP in the body?
- fuels all types of chemical reactions
- moves things inside cells
- transports molecules across cell membranes
35
What IS ATP?
Adenosine Triphosphate; the most important compound that cells use to store and release energy; the energy currency for all forms of life that powers nearly every process in all living things (like a tiny, rechargeable battery); one of the building blocks of RNA
36
calorie
the amount of energy it takes for 1 gram of water to have a temperature change of 1 degree Celsius
37
ADMR
Acceptable Macronutrients Daily Range; one of the many ways to estimate food calories/distribution of nutrients for energy
38
essential vs. non-essential vs. conditionally essential nutrients
essential - have to be obtained thru our diet b/c our body doesn't make it or doesn't make enough
non-essential - nutrients your body can make in enough amounts when needed
conditionally essential - needing different amounts at various points of development
39
What is true about intervention studies?
- test for causality
- there is a control group
- controlling for biases
- examples: animal and cell culture studies
40
What are the advantages to intervention studies?
minimizes effect of confounding variables, controlling/avoiding biases
41
What are the limitations to intervention studies?
time-consuming, expensive, need to represent actual populations
42
How do you control for bias (intervention)?
1. random assignment of the treatments
2. controlling for any confounding variables
43
What is the IDEAL nutrition intervention study?
randomized, double-blind, placebo-controlled study
44
epidemiological studies
study or analysis of distribution and/or patterns of determinants of disease in population groups; CORRELATIONAL RELATIONSHIPS ONLY
45
What is true about the relationship b/w exp. design and hypothesis?
the choice of experimental design depends on the hypothesis
46
simple relationship
the effect of Factor A on Factor X is not influences by anything else
47
complex relationship
the effect of Factor A on Factor X is influenced by Factor B
48
How is nutrition research conducted?
STEP 1 - making an observation that is appropriate and accurate
STEP 2 - proposing a hypothesis (causative & correlational)
STEP 3 - determine experimental design
STEP 4 - collect and analyze data
STEP 5 - draw conclusions
49
What does it mean to have a "reductionist approach" to nutrition?
= everything is broken down into the parts, foods narrowed down into only single purpose
50
digestion
the physical and chemical processes of breaking down food from large, insoluble pieces into smaller, soluble ones
51
gallstones
crystalized cholesterol that develops in the gallblatter, causing bile ducts to be blocked
52
GERD
a condition caused by the weakening of the gastroesophageal sphincter, which enables gastric juices to reflux into the esophagus, causing irritation to the mucosal lining
53
Irritable Bowel Syndrome
a condition that typically affects the lower part of the GI tract, causing abdominal pain, muscle spasms, diarrhea, and constipation
54
Ulcerative Colitis
an inflammatory bowel disease that causes inflammation and ulcers in the colon
55
Crohn's Disease
an inflammatory bowel disease that causes inflammation of the digestive tract, especially in the colon and the ileum
56
Celiac disease
an autoimmune response to the protein gluten that damages the absorptive surface of the small intestine
57
Small Intestinal Bacterial Overgrowth
a digestive disorder characterized by an excessive amount of bacteria in the small intestine, usually implicated by diarrhea or malabsorption
58
Chronic pancreatitis
an advanced inflammatory disorder that leads to the irreversible destruction of exocrine and endocrine pancreatic parenchyma caused by atrophy and replacement w/ fibrotic tissue
59
segmentation
a muscular movement in the GI tract that moves the contents back and forth within a small region
60
peristalsis
WAVES of muscular contractions that move materials in the GI tract in a forward direction
61
chemoreceptors
a type of sensory receptor that responds to a chemical stimulus
62
mechanoreceptors
a type of sensory receptor that responds to pressure, stretching, or mechanical stimulus
63
What are the three phases of digestion?
1. cephalic phase
2. gastric phase
3. intestinal phase
64
peptic ulcers
an irritation or erosion of the mucosal lining of the esophagus, stomach, or duodenum
65
gastroparesis
a condition that affects gastric motility and gastric emptying that slows the movement of food from the stomach to the small intestine
66
hemorrhoids
swollen / dilated veins of the anus or rectum
67
anal fissures
tears of the sensitive mucosal lining of the anus
68
diverticulitis
chronic inflammation of the pouches (diverticula) that develop in the walls of the intestines
69
mortality rate
the number of deaths in a given period of time
70
infant mortality rate
the number of infant deaths (<1 year of age) per 1,000 live births in a year
71
morbidity rates
the number of illnesses in a given time
72
life expectancy
a statistical prediction of the average number of years remaining to a person at specific age
73
incidence
the number of people who are newly diagnosed with a condition in a given period of time
73
prevalence
the TOTAL number of people who have a condition in a given period of time
74
Differences in the leading causes of death in 20th century vs. 21st century?
20th cent. - infectious diseases (pneumonia, influenza, malaria, etc.) and diseases caused by a deficiency (scurvy, e.g.)
21st cent. - chronic diseases
75
nutrition transition
the shift from undernutrition to overnutrition or unbalanced nutrition that often occurs simultaneously with the industrialization of a society
76
risk factor
a lifestyle, environmental, or genetic factor related to a person's chance of developing a disease
77
What should be considered when evaluating nutrition information and claims?
- determine the source of info (peer-reviewed journals = ideal)
- look at who conducted the research/their credibility
- consider who funded the research
- evaluate experimental design
78
sphincter
a muscular band that narrows an opening between organs in the GI tract
79
How do GI motility and secretions facilitate digestion?
- GI motility movements mix and propel food and then churn it
- secretions provide necessary enzymes to further break down food/provide for efficient digestion
80
What are the major organs of the digestive system?
- mouth
- pharynx
- esophagus
- stomach
- small intestine
- large intestine
81
What are the accessory organs of the digestive system?
- salivary glands
- liver
- gallbladder
- pancreas
82
What are the secretions produced in the stomach?
gastrin and ghelin
83
What are the secretions produced in the small intestine?
secretin and CCK
84
hydrolysis
a chemical reaction that breaks chemical bonds by the addition of water
85
How do enzymes affect the rate of digestion?
they are biological catalysts that facilitate chemical reactions that break down complex food particles; speed up digestion
86
How do hormones control digestion?
acting as chemical messengers and communicate w/ organs about food entering the system; control movement of GI tract, transit time, and secretions
87
How are nutrients absorbed into the body?
passive, active, facilitated absorption into intestinal absorptive cells
88
Which organ plays the largest role in digestion of nutrients?
small intestine
89
Which organ plays the largest role in absorption of nutrients?
small intestine
90
How is digestion regulated?
w/ the help of hormones, feedback mechanisms, and parts of the nervous system like the vagus nerve
91
gastrin
hormone released by endocrine cells in stomach; stimulates exocrine cells in stomach to release HCl, intrinsic factor from parietal cells and pepsinogen from chief cells
92
secretin
hormone released by the small intestine that stimulates the release of pancreatic juice
93
CCK
stands for Cholecystokinin; hormone of the small intestine that stimulates the gallbladder to contract and release bile AND stimulates the release of pancreatic enzymes
94
ghrelin
hormone released by the stomach that stimulates appetite
95
What role does the esophagus play in digestion?
directing the food toward the stomach
96
lower esophageal sphincter
a barrier between the esophagus and the stomach made of muscle, forming a juncture b/w the two organs
97
structure of the stomach
large J-shaped organ that is divided into three parts: (from uppermost to lowermost) fundus, body, and antrum
98
What happens to food in the stomach?
food is stored, digested, and transformed into chyme
99
rugae
folds and pleats that form the lining of the stomach; are structured this way in order for the stomach to expand at the sight of food until mechanoreceptors send messages to the brain = "I'm full"
100
What is the role of the stomach in digestion?
temporary storage of food; producing gastric secretions; mixing of food with gastric secretions
101
pyloric sphincter
circular muscle at the base of the antrum (lower stomach)
102
What happens to food at the pyloric sphincter?
the flow of food continues/is regulated b/w stomach and the duodenum (start of small intestine)
103
What are the 3 regions of the small intestine?
1. duodenum
2. jejunum
3. ileum
104
What is the role of the small intestine in digestion?
nutrient absorption (and further digestion)
105
Describe the cells and basic organization of tissues in the small intestine.
the surface area is large and made up of circular folds (PILCA CIRCULARES). these folds are covered in finger-like projections (VILLI), and those projections are covered in specialized cells (ENTEROCYTES). those specialized cells are covered in hair-like projections that are at the outermost absorptive surface (MICROVILLI)
106
structure of the large intestine
last segment of the gastrointestinal tract; inverted U-shape that frames the small intestine on three sides
107
What does the large intestine secrete?
mucus
108
What happens to food in the large intestine?
final parts are digested and then carried into the accessory organs/rectum
109
What role does the large intestine play in digestion?
1. nutrient absorption and reabsorption
2. microbial action
3. formation + storage + elimination of solid waste
110
What role do the internal + external sphincters play in digestion?
helps control levels of elimination/defection from rectum
111
What role does the pancreas play in digestion?
- neutralizes acidic chyme coming from stomach
- gives enzymes needed to break down carbs, lipids, and proteins chemically
112
What role does the gallbladder play in digestion?
stores bile that helps us digest fat
113
What role does liver play in digestion?
make and secrete bile and processes it; purifies bloodstream containing newly absorbed nutrients from small intestine
114
infectious vs. non-infectious diseases
infectious - caused by viruses/bacteria coming from the outside of your body in
non-infectious - caused by genetics, anatomical differences, environment, age, lifestyle, etc.
115
How and where are water-soluble nutrients taken into the body?
in absorptive cells of the small intestine; enter cell - > capillaries -> hepatic portal vein -> liver
116
Where do fat-soluble nutrients enter?
absorptive cell and then lacteal to lymphatic system
