HSCI 4050 Final Exam
alpha-linolenic acid
18C Omega-3 Essential Fatty Acid • Is a polyunsaturated fatty acid • Food sources - walnuts, flax seed (oil) • Can transform into 20C EPA and 22C DHA through process called elongation (adding 2C at a time)
Body Mass Index (BMI)
A calculation using a person's height and weight to define obesity. • Weight (lbs) * 703 / Height (in)2 • Is not a body composition technique, but rather provides an estimate of health. • Method utilized to determine population overweight/obese statistics...obesity is BMI > 30.
hepatic portal vein
Blood vessel that conducts blood from the GI tract to the liver. The small intestine is drained by two systems - the portal system and the lymphatic system. The portal system takes digested CHOs (monosaccharides), PROs (AAs), and short & medium chain FAs to the liver.
Osteoclasts
Bone cells that enzymatically break down bone during bone remodeling, and also when blood calcium is low - this calcium will be delivered into the blood to raise blood calcium back into the proper range. • Activity of osteoclasts is stimulated by PTH and active vitamin D (1,25(OH)2D)
What is the prevalence of severe obesity and what are the risks faced by the severely obese population?
By 2010, the prevalence of severe obesity had increased to over 10% in the U.S. Severely obese individuals face a two- to twelve-fold increase in mortality with increasing BMI above 30 kg/m2 and a greatly increased risk of disease (diabetes, heart disease, certain cancers, etc.) and a markedly reduced quality of life.
calbindin
Calcium binding PRO in the small intestine...active vitamin D (1,25(OH)2D) upregulates synthesis and activity of calbindin...increases Ca absorption.
sarcoplasmic reticulum
Intracellular storage organelle in the muscle fiber - stores Ca • Inside the muscle fiber, Ca is released from here during muscle contraction and actively pumped back into here during muscle relaxation.
Chylomicrons
Lipoprotein (lipid transport vehicle in the body) that transports dietary TGs (with LCFAs, via the lymphatic system) to your cells (FAT, muscle...with LPL) - this lipoprotein is formed in the small intestine.
antrum
Lower part of the stomach - contains thicker smooth muscle for churning and mixing of stomach chyme. • When pyloric sphincter closes, it propels stomach chyme back into this portion of the stomach for further mixing and churning.
DXA scan
Measures the degree of attenuation (measures the reduction in intensity of the x-ray beam b/w the source and the detector) of the x-ray beam - this is different for bone, lean mass, and body fat. • DXA scan is the gold standard for diagnosing osteoporosis
Angina
chest pains; usually occurs during a strenuous activity - i.e.- weekend warrior, shoveling snow.
Gastrin
A hormone that is released (from the stomach) when you see food or smell food • Gastrin (hormone) stimulates the release of pepsinogen from the chief cells in the stomach • Pepsinogen is converted to pepsin by the acid in the stomach • Pepsin (a protease enzyme produced in the stomach) breaks down proteins into smaller poly- and/or oligopeptide fragments
motor unit
A motor neuron and all the muscle fibers it innervates. • All muscle fibers are the same type within a motor unit
A) List three (3) major characteristics of a public health approach to a health problem and (B) provide four examples of such an approach
A) A public health approach to a health problem is characterized by the following: a. It devises population-wide strategies to prevent disease, illness or injury rather than strategies that target the individual b. It relies on surveillance - the collection of data - to monitor and document the magnitude or scope of a public health problem c. It focuses on prevention, rather than treatment, although for obesity, treatment can be a prevention strategy, for example, to avert type 2 diabetes or further weight gain (B) Examples of a public health approach to a health problem include: • Laws requiring seat belt use • Vaccination programs to control infectious diseases • The establishment of rigorous safety standards for automobile construction • Laws to prevent driving while under the influence of alcohol or drugs • Laws to prevent underage drinking • Well-organized garbage collection and disposal systems • Food safety standards • Regulation of tobacco sales • Enforcement of smoke free zones in public places • Community zoning to insure the inclusion of (a) greenspace; (b) sidewalks; (c) bike lanes • Hand washing programs to prevent the spread of disease • Water and sewage treatment programs • Fluoridation of water to prevent dental caries
Pepsin
Active protease enzyme in the stomach • The acidic environment of the stomach stimulates formation of pepsin from the inactive protease enzyme pepsinogen. • Begins initial PRO digestion, breaking down larger polypeptides into shorter polypeptides.
right atrium
Blood flow (deoxygenated blood) returning to the heart via the superior & inferior vena cava return blood to this chamber of the heart first.
trabecular bone
• The inner matrix of bone which provides a Ca storage bank - give up Ca to the blood when Ca in the diet is deficient.
Expressed in terms of "initial body weight", what is the smallest amount of weight loss that is considered clinically meaningful?
Clinically meaningful or beneficial weight loss can be as small as 5% - 10% of initial body weight.
Actin
Contactile protein...known as the "thin filament" • Regulatory PROs (troponin & tropomyosin) are located on actin filament
smooth muscle cells
In atherosclerosis, these cells migrate into the intima to make a fibrous cap (body's attempt to repair the lesion (fatty streak)). • In atherosclerosis, these cells deposit calcium near area of endothelial dysfunction (decreases compliance of vessel).
What are the four major diseases that are more common in the obese?
Diabetes mellitus, cardiovascular disease, cancer, and stroke are major diseases associated with obesity. Hypertension and metabolic syndrome are also increased.
In terms of the energy balance equation, how do obesity drugs work.
Energy balance is achieved when energy intake consistently equals energy expenditure. Weight loss occurs when energy intake consistently is less than energy expenditure. Obesity drugs act through a variety of mechanisms that relate to energy balance. They can reduce energy intake by reducing energy absorption, or by decreasing hunger or increasing satiety; some drugs can increase energy expenditure by increasing metabolic rate or physical activity.
What are 3 environmental factors that shape appetitive traits?
Environmental factors that interact with appetitive traits to favor increased food or calorie intake and increased body weight include: a. Constant availability of inexpensive food and sugar-sweetened beverages b. Energy dense foods and beverages that are engineered to be highly palatable c. Large portion sizes
pepsinogen
Inactive protease enzyme produced in the stomach • Release is stimulated by the hormone gastrin
Multiple factors contribute to chronic energy imbalance and obesity, thus a wide variety of strategies to promote reduced calorie intake, reduced sedentary behaviors and increased physical activity can be considered by public health activists. Provide four examples of public health strategies that may help stem obesity.
Examples range from zoning for recreational greenspace, sidewalks and bike lanes when a new community is built, siting schools to insure children can walk or bike to school, establishing zoning restrictions on the siting of fast food restaurants, curbing marketing to children, adopting "complete streets" policies that facilitate walking and biking, promoting farmers markets, advocating for healthier school meals, insuring daily physical education is taught in schools by a qualified professional, establishing limits on TV viewing in the home, removing TVs from bedrooms, insuring that fresh fruit and vegetables are always available for snacks and meals at home, etc.
GLUT 4
Glucose transporter protein inside of muscle cells • Activity is insulin induced - when insulin attaches to its receptor on the outside of a muscle cell, (GLUT 4) migrates out to the plasma membrane → glucose uptake
Glucagon
Hormone released from the alpha-cells of the pancreas in response to low blood glucose. Glucagon is active during the Postabsorptive and Fasting State. • The result of the release of this hormone is glycogenolysis and gluconeogenesis.
What are some of the beneficial health changes that occur when an obese person loses a modest amount of weight?
Modest weight loss reduces progression to type 2 diabetes in those with impaired glucose tolerance, and lowers blood pressure. It also improves health in those with metabolic syndrome. The LookAHEAD trial has shown improved insulin resistance, fitness, and blood pressure and lipids as a result of significant weight loss. Blood chemistries can normalize. Weight loss may also lower cancer risk.
micelle
Molecule formed from bile + amino acid that is utilized to emulsify dietary fat (hydrolyzed TG - monoglyceride + FFAs). Insulates dietary fat on the inside and allows diffusion across absorptive cell - absorption!
Type 1 muscle fibers
Muscle fiber type (Type I - Slow Twitch Oxidative) that has the highest # of mitochondria and the smallest amount of glycogen stores. • Type I muscle fibers are always recruited first during an activity, and then if the activity becomes more intense, Type II muscle fibers are also recruited.
DRIs
Nutrient recommendations for diet planning and to prevent chronic disease. • Include RDAs, AIs, and ULs • Gender and age specific
What characterizes a "comorbidity" of obesity?
Obesity comorbidities are those disease conditions that develop or worsen as weight increases and that improve with weight loss.
Kidneys
Organ that controls fluid balance • Active form of vitamin D (1,25(OH)2D) is formed here
Macrophages
Part of the body's inflammatory response during atherosclerosis process - these cells engulf oxidized LDL on the endothelium and then become foam cells.
For the purpose of estimating the prevalence of obesity in a population, how is obesity defined in adults?
Rather than using direct measures of body fat (which are costly and impractical) in epidemiology and vital statistics, researchers have relied upon simple measurements of weight and height, and the use of these measures to calculate a value known as the body mass index, or BMI, to define obesity. BMI is calculated as the weight, expressed in kilograms, divided by the square of height, expressed in meters (i.e., kg/m2). Obesity is defined as a BMI of 30.0 or above.
Troponin
Regulatory PRO - during muscle contraction, Ca that is released from the SR attaches to troponin (creating a Ca-Troponin complex)...this moves tropomyosin out of the way of the myosin binding site on actin...cross-bridge cycle.
Tropomyosin
Regulatory PRO - during muscle relaxation, occupies a "blocking position"...blocking the myosin binding site on actin. During muscle contraction, Ca-Troponin complex moves tropomyosin out of the way, allowing the cross-bridge cycle...muscle contraction.
parathyroid hormone
Released from parathyroid gland in response to low blood Ca • Hormone that activates vitamin D in kidneys (from 25(OH)D to 1,25(OH)2D • PTH and 1,25(OH)2D increase Ca reabsorption in the kidneys, increase Ca absorption in the small intestine, and increase bone resorption (↑ osteoclast activity which enzymatically breaks down bone to release calcium into the blood)...all of these activities increase blood Ca back into normal range which then turns off PTH activity (negative feedback inhibition).
Monosaccharides
Simple sugars that include glucose, fructose, & galactose • When CHOs are absorbed, they must be in this form (monosaccharides)
Collagen
Structural PRO that makes up the initial matrix of bone. Bone is built (minerals are added onto) on a matrix of collagen.
Disaccharides
Sucrose (Glu & Fru), Lactose (Glu & Gal), and Maltose (Glu & Glu) • Enzymes for these are synthesized by the enterocytes and located in the microvilli and complete the last step of CHO digestion, forming monosaccharides (remember - only monosaccharides are absorbed!)
According to the FDA, weight loss drugs may be appropriate for persons with a BMI in what range?
The Food and Drug Administration (FDA) recommends using obesity drugs in patients with a BMI of 30 kg/m2 or more, or in persons with a BMI as low as 27 kg/m2 or more in those with an obesity-related comorbid condition.
Epimysium
The connective tissue that surrounds the entire muscle.
Describe the benefits of modest weight loss and compare those benefits to the typical weight loss achieved with commonly used weight loss drugs that have been approved by the Food and Drug Administration (FDA).
The health benefits of modest weight loss, defined as 5%-10% of initial body weight, include reduction of blood pressure and blood lipid levels (cholesterol and triglycerides), improved control of blood glucose, improved sleep apnea and reduced risk or pain of osteoarthritis. For people with impaired glucose tolerance or type 2 diabetes, weight loss can resolve symptoms and/or reduce medication requirements. For most people, FDA-approved weight loss drugs, when paired with improvements in both eating and exercise habits, can help produce clinically meaningful weight loss. Although obesity medications used alone have only small effects on weight and all have side effects, the rationale for their use is that they help more patients achieve clinically meaningful weight loss (when those patients are already making lifestyle changes to reduce weight) at least doubling the chances of achieving 5%-10% loss of initial body weight.
hypertrophy
The increase in size - for instance, of a muscle fiber or a FAT cell. Muscle fibers can only undergo hypertrophy (and not hyperplasia - divide and create new muscle fibers), whereas during weight gain FAT cells first undergo hypertrophy and then can undergo hyperplasia (once a FAT cell reaches its size limit, and you continue to gain weight, the fat cell will split, divide, and new FAT cells will be created).
sarcopenia
The loss of muscle mass and function with aging • This condition, especially in the lower body, combined with osteoporosis, dramatically increases risk of falls and fractures. • This is not a disease - it happens to everyone, but can be delayed with optimal nutrition and resistance training.
Sarcolemma
The plasma membrane of the muscle fiber. • Has specific receptors for the neurotransmitter acetylcholine, which is released from synaptic vesicles at the terminal end of the motor neuron and travel across the synaptic cleft and attach to these receptors on the sarcolemma...allow action potential to continue.
basal metabolic rate
The rate of energy use by the body when at rest and awake in a warm, quiet environment. Basal metabolism accounts for 60-70% of total energy use by the body. Processes involved include beating of the heart, respiration, circulation, maintenance of body temperature • Lean body mass is the factor that most influences basal metabolism - thus in general males will have a higher BMR than females
What is responsible for the majority of health care costs? How does this relate to obesity?
The treatment of chronic diseases accounts for the majority (approximately 75%) of health care costs. Obesity contributes to most chronic diseases (e.g., hypertension, dyslipidemias, heart disease, diabetes, certain cancers, etc.) and thus is contributing to escalating health care costs.
cortical bone
The very dense outer shell of the bone
metabolic syndrome
Three of the five following conditions are indicative of metabolic syndrome: large waist circumference, abnormal glucose metabolism with high fasting glucose or type-2 diabetes, high blood pressure, high blood triglycerides, low HDL-cholesterol. A variety of abnormalities of other blood components may also co-occur.
fundus
• The uppermost part of the stomach. This contains a thinner layer of smooth muscle which is important for expansion after a meal for initial storage.
What are the characteristics that define the metabolic syndrome? 3. How can metabolic syndrome be managed?
Three of the five following conditions are indicative of metabolic syndrome: large waist circumference, abnormal glucose metabolism with high fasting glucose or type-2 diabetes, high blood pressure, high blood triglycerides, low HDL-cholesterol. A variety of abnormalities of other blood components may also co-occur. 3. Weight loss, even if modest, can improve the condition; life-style changes to promote weight loss are used. These changes can include dieting, increasing exercise/physical activity, and behavior modification.
trans fat
Type of fat that is created during the hydrogenation process • Type of fat you will find in a food product when you see "partially hydrogenated oil" in the ingredient list • Hydrogenation creates these type of fats, which now have the hydrogens on opposite sides of the C=C. Normally hydrogens are on the same side of the C=C (cis conformation) • This type of fat downregulates the activity of the B-100 cells (LDL receptor cells) in the liver, leading to less efficient clearance of LDL, increased LDL accumulation in the blood, and increased risk of atherosclerosis.
High blood urea
Urea is the body's principle vehicle for excreting unused nitrogen (if PRO is used for energy or turned into body fat). • Condition seen with kidney disease • Urea (which is made in the liver) is not able to be filtered properly out of the blood for excretion in the urine by the kidneys, thus it accumulates in the blood. Urea levels can be measured in the blood to test kidney function.
myocardial infarction
heart attack) (3 words: dead heart tissue) death of some heart muscle tissue due to a complete lack of blood flow
AMDR
• Acceptable Macronutrient Distribution Range • Tells you what % of your total kcals for the day should come from each energy yielding nutrient (CHO, PRO, FAT). • CHO: 45-65% ; PRO: 10-35%; FAT: 20-35%
Liver
• An accessory organ of the GI tract • Glucose is stored here (Liver Glycogen) • VLDL and HDL are synthesized here (in this accessory organ) • B-100 cells (LDL receptor cells) function here - help clear LDL and keep LDL levels within normal, healthy range. • Bile is synthesized here • The major circulating form of Vitamin D (25(OH)D) is synthesized here.
Gallbladder
• An accessory organ of the GI tract. Bile is stored here • When FAT is sensed by the duodenum, the hormone CCK travels here (to the gallbladder), and stimulates release of bile to emulsify the FAT.
bone remodeling
• Bone is very metabolically active, continually being broken down and rebuilt (bone remodeling) throughout your life. Starting in your 30's, you begin to break down more bone than is rebuilt, and this remodeling process tilts toward a gradual loss of bone density and increased fragility as you age.
pulmonary artery
• Carries blood (deoxygenated) to the lungs ("A" for away from the heart to the lungs) to pick up oxygen and get rid of carbon dioxide.
Myosin
• Contractile protein...known as the "thick filament" • Has a binding site for 1) ATP and 2) Actin
Bile
• Emulsifiers synthesized by the liver and released into the small intestine by the gallbladder during digestion of dietary fat • Viscous Gel Forming/Soluble fiber latches onto bile acids and increases excretion. Bile is very cholesterol rich - so the liver takes cholesterol from the bloodstream to make new bile, thus lowering blood cholesterol levels • CCK, a hormone released from the duodenum during FAT digestion, travels to the gallbladder (makes it contract) and bile is released to emulsify the FAT (break down to more manageable size and increase surface area for more efficient enzymatic breakdown)
pancreatic lipase
• Enzyme released from the pancreas during FAT digestion • Lipase released in response to CCK during FAT digestion • Enzyme utilized to hydrolyze dietary TGs in small intestine - cleaves the two outside FAs (creating FFAs) and leaves the middle FA still attached to the glycerol (monoglyceride).
CCK (cholecystokinin)
• Hormone released from the duodenum - major stimulator of release of this hormone is fatty acids. • This hormone is released from the duodenum and travels to the gallbladder and pancreas during FAT digestion.
long chain fatty acids
• Most common length/type of dietary FAs - 18C • Must be packaged up into chylomicrons and sent via the lymphatic system to your fat cells.
type two muscle fibers
• Muscle fiber type (Type IIa - Fast Twitch Oxidative Glycolytic and Type IIx - Fast Twitch Glycolytic) that has the largest amount of glycogen stores. • Larger, more powerful muscle fiber type.
Insulin
• Peptide hormone released from the β-cells of the pancreas in response to high blood glucose. • Attaches to insulin receptor on surface of muscle cell, which prompts migration of GLUT-4 (glucose transport PRO) to plasma membrane for glucose uptake. • This hormone is a strong inhibitor of lipolysis (FAT breakdown)
Endomysium
• The connective tissue that surrounds each muscle fiber is called the...
7-DHC
• Vitamin D precursor with a cholesterol backbone • In the skin (epidermis), 7-DHC interacts with UVB rays from the sun to make pre-vitamin D...isomerizes to vitamin D (inactive) in the skin...leaves skin and attaches to vitamin D binding PRO (DBP) in the circulation to travel to liver (25 (OH)D) and eventually kidneys (1,25(OH)2D).
Ischemia
• insufficient blood flow and thus insufficient oxygen delivery to heart tissue
osteomalacia
• the weakening of the bones that occurs in adults as a result of poor bone mineralization linked to inadequate vitamin D status • "Soft bones" - characterized by poor calcification of newly synthesized bone. These "soft bones" press against the nerve endings surrounding the bone - osteomalacia is painful. When you press down on the bones of someone with osteomalacia, it is very painful.