Nutritional Disorders Flashcards
State the two protein compartments of the body and give a brief description of each.
(1) Somatic protein compartment
☛ Primarily found in skeletal muscles.
☛ Provides structural support and is involved in movement and physical activity.
☛ This compartment is relatively homogenous, meaning it consists mostly of similar types of proteins.
(2) Visceral protein compartment
☛ Found within the organs (such as the liver, pancreas, and kidneys), as well as in blood cells (like granulocytes and lymphocytes) and serum proteins.
☛ Plays a crucial role in metabolic processes, immune function, and maintaining homeostasis.
☛ This compartment is more heterogeneous, containing a wide variety of proteins that serve different structural and functional roles.
Briefly discuss primary and secondary causes of malnutrition.
Primary causes are related to diet. Secondary causes are due to nutrient malabsorption, impaired nutrient utilization or storage, excess nutrient losses and increased need for nutrients.
What are two main clinical syndromes brought about by protein-energy malnutrition?
Marasmus, Kwashiokor
clinical features of marasmus
clinical presentation of Kwashiokor
Edema: Swelling with fluid, especially in the ankles and feet
Ascites: build-up of fluid in the abdominal cavity
Hair changes: Dry, brittle hair, hair loss, and loss of pigment in hair
Dermatitis: Dry, peeling skin, scaly patches, or red patches
Enlarged liver: Often a symptom of fatty liver disease
Depleted muscle mass: Despite retaining subcutaneous fat (under the skin)
Dehydration: Due to poor intake and loss of fluids
[Image 1] [Image 2]
Discuss protein-energy malnutrition in the developed world. [vulnerable populations, signs]
✓ This type of PEM develops in chronically ill, older and bed-ridden patients and people with eating disorders.
✓ Obvious signs of secondary PEM include:
☛ depletion of subcutaneous fat in arms, chest wall, shoulders or metacarpal regions.
☛ wasting of quadriceps and deltoid muscles
☛ ankle or sacral edema
discuss cachexia
✓ This is a type of PEM in patients with chronic diseases such as AIDS, advanced cancer, congestive heart failure, chronic obstruction pulmonary disease (COPD) and chronic kidney disease.
✓ It is characterized by extreme weight loss, fatigue, muscle atrophy, anemia, anorexia and edema.
discuss anorexia nervosa
🍔 Self induced starvation resulting in marked weight loss.
🍔 Clinical features are similar to severe PEM and they include:
✓ extreme weight loss and thin appearance
✓ fatigue and insomnia
✓ amenorrhea (GnRH secretion decreases)
✓ symptoms of hypothyroidism
✓ bone density decreases [osteoporosis]
✓ dehydration and electrolyte abnormalities
✓ cardiac arrhythmias and hypokalemia
Discuss bulimia nervosa.
📝 Bulimia nervosa is an eating disorder characterized by episodes of binge eating followed by compensatory behaviors such as vomiting, excessive exercise, or the use of laxatives to prevent weight gain.
📝Clinical features:
- recurrent episodes of binge eating
- self-induced vomiting, misuse of laxatives
- preoccupation with body shape and weight
- normal or slightly above normal body weight
What is obesity?
Obesity is defined as an accumulation of adipose tissue that is of sufficient magnitude to impair health.
Define:
(a) orexigenic factors
(b) anorexigenic factors
(a) orexigenic factors: Factors which increase appetite and stimulate food intake.
(b) anorexigenic factors: Factors that decrease appetite and reduce food intake.
Pathophysiology of Obesity, Afferent system of energy homeostasis
Briefly explain the role of each of the following in energy homeostasis [also state where they are produced]:
(a) leptin
(b) ghrelin
(a) leptin
Leptin is a hormone produced by adipose (fat) tissue. It plays a crucial role in regulating energy balance by inhibiting hunger, which in turn reduces food intake and promotes energy expenditure. Leptin signals the hypothalamus in the brain about the amount of energy stored in fat cells. When fat stores are sufficient, leptin levels increase, signaling the brain to reduce appetite and increase energy expenditure.
[Diagram 1] [Diagram 2] [Diagram 3]
(b) ghrelin
Ghrelin is known as the “hunger hormone” because it stimulates appetite. It is produced mainly in the stomach and signals the hypothalamus to increase food intake. Ghrelin levels rise before meals and fall after eating. It also promotes the release of growth hormone and plays a role in regulating energy balance by increasing food intake and reducing energy expenditure.
[Diagram 4] [Diagram 5] [Diagram 6] [Diagram 7]
Pathophysiology of Obesity, Afferent system of energy homeostasis
Briefly explain the role of each of the following in energy homeostasis:
(a) peptide YY
(b) glucagon-like peptide
(c) insulin
(a) Peptide YY
Peptide YY is a hormone released by the cells in the ileum and colon in response to eating. It helps to reduce appetite and inhibit gastric motility. PYY acts on the hypothalamus to decrease food intake and increase satiety. It is part of the body’s mechanism to signal fullness and reduce further food intake after a meal.
(b) Glucagon-Like Peptide-1 (GLP-1)
GLP-1 is an incretin hormone produced in the gut in response to food intake. It enhances insulin secretion, inhibits glucagon release, and slows gastric emptying, which helps to regulate blood glucose levels. GLP-1 also acts on the brain to promote satiety and reduce food intake, playing a significant role in energy homeostasis.
(c) Insulin
Insulin is a hormone produced by the pancreas that regulates blood glucose levels. It facilitates the uptake of glucose into cells for energy production and storage as glycogen in the liver and muscle. Insulin also inhibits the breakdown of fat and protein. In the brain, insulin signals the hypothalamus to reduce food intake and increase energy expenditure, thus playing a key role in maintaining energy balance.
Pathophysiology of Obesity, CPS of Energy Homeostasis
Where is the central processing system for energy homeostasis located?
Pathophysiology of Obesity, CPS of Energy Homeostasis
What is the function of the central processing system in energy homeostasis?
The central processing system integrates neurohumoral signals from the periphery to generate efferent signals that regulate food intake and energy expenditure.
Further notes:
Neurohumoral refers to the interaction between the nervous system and the endocrine system, particularly involving the release of hormones or neurotransmitters.
