Anorexia

• Symptoms of Anorexia Nervosa To be diagnosed with anorexia nervosa accarding to DSM 5 a patient needs to meet 3 different critería Criterlon A: Restriction of food Intake ·Deliberate weight loss so that weight is below what is expected for age and height (eg. in an adult a BMI bebw 17.5 with less than 15 being an extreme case Weighing less than 85% of 'normal weight Avoiding food and drink Criterion B: Intense fear of gaining weight Obsession with checking the calorie values of all foods Tendency to lie about how much they eat Frightened of the consequences of eating food Excessive exercise to stop weight gain Criterion C: Distorted body image Do not perceive themselves in the same way as others Cannot accept the severity of their low body weight Grossly overestimate their own body weight Low self-esteem as body weight is used as a way to evaluate themselves
• What is one function of the hypothalamus?

  Regulates eating
• How does a malfunction in the hypothalamus relate to anorexia nervosa (AN)?

  It can cause avoidance of food and binge eating
• What role does the hypothalamus play in appetite control?

  It sends signals indicating hunger
• What hormone is produced in the stomach when hungry?

  Ghrelin
• What happens to ghrelin levels before and after a meal?

  They rise before a meal and decrease afterwards
• Why are ghrelin levels elevated in anorexic patients?

  Because they are starving
• What occurs to ghrelin levels when an AN patient eats?

  Ghrelin levels drop significantly
• How does the malfunction of ghrelin binding to receptors affect anorexia patients?

  It causes the brain to interpret no hunger
• Where is leptin produced?

  In adipose (fatty) tissue
• What does leptin signal to the hypothalamus?

  That we are full
• Why do anorexic patients have high levels of leptin despite low fat tissue?

  They produce high leptin after small meals
• What faulty signal does high leptin send to the hypothalamus in AN patients?

  That they are full, reducing the need to eat
• What did Anand et al (51) find regarding the lateral hypothalamus?

  Damage led to patients not feeling hunger
• What did Kaye (2015) discover about anorexic brains?

  They show greater activity linked to self-control
• What did Quade (1971) find about lesions to the lateral hypothalamus in obese patients?

  It reduced eating behavior
• What happened when the lateral hypothalamus was electrically stimulated in Quade's study?

  Patients reported feeling hungry
• What did Becker (2002) find about Fijian girls and vomiting to control weight?

  0% in 1995, increased to 11.3% by 1995
• What does Becker's study suggest about the causes of AN?

  It may be caused by social learning theory (SLT)
• What are the strengths and weaknesses of the biological explanation of AN?

  Strengths:

  • Reductionist approach simplifies AN causes
  • Predicts likelihood of developing AN based on hypothalamus activity

  
  

  Weaknesses:

  • Ignores individual differences
  • Overlooks social media's impact on AN symptoms
• How does the biological explanation of AN simplify understanding its causes?

  By attributing it to hypothalamus malfunction
• Why might the biological explanation of AN be considered reductionist?

  It simplifies complex behaviors to brain functions