Puberty
Intermediary Metabolism
Regulation of Appetite
Anorexia Nervosa
Weight Management
100
When puberty occurs.
What is after peak height velocity?
100
What are the two stages of intermediary metabolism?
Metabolism and oxidative phosphorylation
100
Appetite is generally controlled by a balance between _________, which stimulates eating, and __________, which supresses it.
Ghrelin; Leptin
100
What are some of the personality characteristics associated with anorexia nervosa (name 2)?
Perfectionism, Obsessive/compulsive, tend to be socially withdrawn and increasingly committed to work/study, dieting and exercise
100
What is the formula for calculating BMI? What are some of the limitations in using BMI to assess obesity and health?
BMI = (Weight in kg)/(Height in m^2) BMI does not account for fat distribution – fat distribution, especially if visceral and around the abdomen, is the key risk factor for comorbidities It also does not account for duration of obesity, it is inaccurate at extremes of height and with extremes of lean body mass (e.g. athletes, weightlifters, elderly).
200
Name 4 physical changes associated with puberty in males and 4 in females.
Females: Menstruation; Curvier body (breasts and wider hips); Vaginal discharge; Oestrogen production Males: Voice becomes deeper; Longer, wider penises; Shoulders become wider; More muscular; Erections and wet dreams; Testosterone and sperm production Both: Pubic hair; Acne (due to oilier skin); Body odour
200
Name the two energy storage forms in the body.
Fat and glycogen
200
What area of the brain is most important in regulating appetite? Name the three components of this brain center as described by the Dual Center Model of Food Intake.
Hypothalamus Lateral hypothalamic area: feeding centre Ventromedial hypothalamic nucleus: satiety centre Arcuate nucleus integrates these feeding signals
200
Name 3 laboratory abnormalities associated with anorexia nervosa.
1. Mild normochromic, normocytic anemia, mild to moderate leukopenia (low white cell count) 2. Increased levels of blood urea nitrogen and creatinine (-> dehydration) 3. Blood sugar may be low 4. Serum cholesterol may be moderately high 5. Hypokalaemia (low blood potassium), often with alkalosis, suggests self induced vomiting or use of diuretics 6. Hyponatremia (low serum sodium concentration)
200
Name 3 weight control strategies that have been shown to be successful in adolescent weight loss and management.
1. Increase exercise levels 2. Drink less soft-drink 3. Walk more/climb stairs 4. Self-weigh (as a motivational tool) 5. Limit TV viewing - TV viewing is associated with higher fat and body size in both adolescents and children 6. Try not to skip meals, especially breakfast
300
What is the cause of menarche?
An increase in the frequency of the gonadotropin releasing hormone (GnRH) pulse generation in the hypothalamus
300
Name the 3 main steps of cellular respiration and where do they take place?
1. Glycolysis; cytoplasm 2. Citric Acid Cycle; mitochondrial matrix 3. Oxidative Phosphorylation; inner mitochondrial membrane
300
Ghrelin is released from _________ and _________. Leptin is released from _________.
Ghrelin is released from the fundus of the stomach and from epsilon cells in the pancreas. Leptin is released from adipose tissue.
300
In a patient with anorexia nervosa, decreased GnRH may lead to ___________.
Amenorrhea
300
When measuring a waist-hip ratio (WHR), where should the waist circumference be measured for optimal accuracy? WHR (in both males and females) greater than what value(s) are considered unhealthy?
Measurement of the waist circumstance should be performed in the horizontal plane above the iliac crest. Unhealthy WHR are indicated as >0.9 in males and >0.8 in females
400
Name 3 factors that influence menarche.
Fat distribution, skeletal growth, hip circumference.
400
Which 2 molecules combine to initiate the citric acid cycle?
2-carbon acetyl CoA enters the citric acid cycle at 4-carbon oxaloacetate to form 6-carbon citrate
400
Name 2 types of leptin resistance (leading to obesity).
1. Congenital leptin deficiency 2. Defect in the JAC/STAT pathway in hypothalamus 3. Impaired transport into the cerebrospinal fluid (Blockage transporting leptin from blood to cerebrospinal fluid; Hypothalamus receptors have less contact with leptin)
400
Describe some typical changes seen in GI and cardiac function of a patient with prolonged anorexia nervosa.
Decrease in GI motility leading to reduced gastric emptying and constipation Bradycardic and hypotensive
400
Name and describe the 2 most common surgical procedures used to achieve weight loss goals currently?
1. Gastric bypass surgery - involves construction of a small pouch in the proximal part of the stomach that is then connected to the jejunum with a section of small bowel of varying lengths; the pouch is separated from the remaining part of the stomach with staples. 2. Gastric banding surgery - involves placing an adjustable band around the stomach near its upper end; this also creates a small stomach pouch that restricts the amount of food that can be eaten at each meal.
500
Describe leptin's involvement in inducing menarche.
Leptin is responsible for stimulating the pulse generator for GnRH in the hypothalamus. Increased amounts of gluteofemoral fat deposition are associated with puberty in females. The more gluteofemoral fat produced, the more total and free leptin in the body which will increase the GnRH pulse frequency and the likelihood of menarche.
500
Name the 6 electron carrier proteins of the electron transport chain.
The four stationary membrane spanning proteins (Complexes I-IV) and two mobile electron carriers, cytochrome (c) and ubiquinone (CoQ)
500
Name 3 types of drugs used in the treatment of obesity.
1. 5-HT (serotonin)/Noradrenaline Reuptake Inhibitor 2. Fat absorption inhibitors 3. Ciliary neurotrophic factor (CNTF) – usually used to treat amyotrophic lateral sclerosis 4. MC4-receptor agonist
500
What is the soft, downy hair growth that sometimes develops in patients with long term anorexia nervosa called?
Lanugo
500
Briefly describe the 3 phases of protein depletion during starvation (including basic summary of ketone body formation and utilization).
1. Initial rapid protein depletion - caused by the use of easily mobilized protein for direct metabolism or for conversion to glucose and then metabolism of glucose mainly by the brain. 2. Greatly slowed protein depletion - after the readily mobilized protein stores have been depleted during the early phase of starvation, the remaining protein is not so easily removed. At this time, the rate of gluconeogenesis decreases to ~1/4 its previous rate, and the rate of depletion of protein becomes greatly decreased. (*Ketone Bodies - The lessened availability of glucose then initiates a series of events that leads to excessive fat utilization and conversion of some of the fat breakdown products to ketone bodies, producing the state of ketosis. The ketone bodies, like glucose, can cross the blood-brain barrier and can be used by the brain cells for energy. Therefore, about two thirds of the brain's energy is now derived from these ketone bodies, principally from beta-hydroxybutyrate. This sequence of events leads to at least partial preservation of the protein stores of the body.) 3. Final (pre-death) rapid protein depletion - when the fat stores are almost depleted, and the only remaining source of energy is protein, the protein stores once again enter a stage of rapid depletion. Because proteins are also essential for the maintenance of cellular function, death ordinarily ensues when the proteins of the body have been depleted to about half their normal level.
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