Final Exam Review Notes

Final Exam Review

Exam Overview

• The final exam will primarily cover chapters 24, 25, and 26, with some questions from chapter 27.
• Chapter 27: Focus on identifying structures with red underlines indicated in the PowerPoint slides posted on Blackboard.
• Questions related to the reproductive systems from homework assignments may also appear.
• Approximately 80 out of 100 questions will come from chapters 24, 25, and 26.
• Exam includes bonus questions related to missed questions from exam four; refer to the study guide on Blackboard.
• The remaining 20% of the exam questions will address topics missed in previous lecture exams. Consult the study guides folder on Blackboard for these topics.

Chapter 24: Nutrients and Metabolism

Nutrients

• Definition: Substances required for growth, health, normal cell function, and repair.
• Two main categories:
  • Major Nutrients:
    • Organic compounds needed for cell structure and function.
    • Include: Carbohydrates, Proteins, and Lipids.
  • Other Nutrients:
    • Needed in smaller amounts but still essential.
    • Vitamins:
      • Function as coenzymes, aiding enzyme function.
      • Some act as antioxidants.
      • Important to know which are water-soluble vs. lipid-soluble and how the body processes them.
      • Know which vitamins are made by the body and which must be obtained from diet.
    • Minerals:
      • Examples: Calcium, Sodium, Potassium, and Chloride.
      • Seven minerals are needed in moderate amounts.
      • Their balance is crucial for proper function; imbalances can lead to pathological conditions.
      • Will be revisited in chapter 26.
      • Functions of minerals will be discussed.
    • Water: Also considered a nutrient.

Significance of Major Nutrients

• Characterize each major nutrient in terms of:
  • Functions in the body.
  • Regulation mechanisms.
  • Metabolic processes.

Lipid Metabolism

• The liver plays a central role in the metabolism of all major nutrients.
• Regulatory processes and mechanisms are critical.

Metabolism

• Definition: All chemical reactions in the body.
• Anabolic vs. Catabolic Reactions:
  • Anabolic: Building up.
  • Catabolic: Breaking down.
  • The body maintains balance between these processes based on its needs.
• Absorptive State:
  • Metabolic state during and right after a meal.
  • Characterize what happens after nutrient absorption.
• Post-Absorptive State:
  • Occurs hours after eating when nutrient levels are low.
  • Characterize this state in terms of nutrient levels and hormonal responses.
• Hormonal Responses:
  • Hormones are secreted in response to fluctuations in nutrient levels.
  • Understand the main metabolic reactions taking place for each nutrient.

Feeding Behavior (Control of Food Intake)

• Hypothalamus: The organ that controls feeding behavior.
  • Processes signals from:
    • Sensory receptors.
    • Nutrient content in the blood.
    • Hormone signals.
    • Temperature.
    • Psychological mood.
  • Acts as the main visceral control center.
  • Generates a response to activate or inhibit the hunger center.

Hypothalamus and Hormones Interactions

• Low Carbohydrate Levels: Hypothalamus secretes neuropeptide Y, increasing appetite for carbohydrates.
• Low Lipid Levels: Hypothalamus stimulates galanin secretion, increasing craving for fats.
• Hunger: Low levels of all nutrients lead to orexin secretion, increasing appetite.
• Fullness: Hypothalamus responds to hormones like leptin (released from adipose tissue), inhibiting neuropeptide Y secretion.
• Leptin signals that there is plenty of food, crucial for regulating appetite through feedback inhibition.

Other Factors Influencing Feeding Behavior

• Signals from the digestive viscera (GI tract sensory information).
• Temperature.
• Psychological mood.

Metabolic Rate

• Basal Metabolic Rate (BMR): The amount of energy needed for essential body functions.
• Total Metabolic Rate: The amount of energy needed for all functions.

Body Temperature Regulation

• Mechanisms include:
  • Radiation.
  • Conduction.
  • Convection.
  • Evaporation.

Summary of Chapter 24

• Major nutrients and their significance.
• How nutrients are processed in the body.
• Continue with carbohydrates, proteins, and lipids.
• Metabolic pathways and the importance of maintaining homeostatic levels of glucose and other nutrients.