Malnutrition Flashcards
What are the essential components of diet?
- Carbs
- Proteins
- Fats
- Minerals
- Water
- Roughage
Function of Carbs?
- Energy
- Protein Sparer
- Can be stored in times of exces
Function of Fats?
- Heat and energy
- Transporting fat soluble vitamins
- Myelin Sheathe
- Bile
What is the difference between essential and non-essential amino acids?
Essential amino acids must be derived from diet, whereas non-essential can be produced in the body
What foods contain all of the essential amino acids?
- Meat
- Fish
- Eggs
- Soya
What foods do not contain all of the essential amino acids?
- Peas
- Beans
- Lentils
What is the function of dietary intake of water?
- Assists in regulation of body temp
- Major component of blood and tissue fluid
- Component of urine and faeces
What is the function of dietary intake of roughage?
-Stimulates peristalsis and bowel movements
What are the types of protein energy malnutrition?
- Kwashiorkor
- Cachexia
- Phthisis
- Marasmus
What is Kwashiorkor?
Malnutrition due to diet deficient in protein
What is Cachexia?
Condition of abnormally low weight associated with chronic disease like cancer or AIDS
What is Phthisis?
any disease resulting in wasting of tissue
What is marasmus?
Severe wasting of infants
What are the symptoms of Kwashiorkor?
- Oedema
(Pitting) - Diarrhoea
- Potbelly
(Hepatomegaly) - Change in Hair and Nail
- Desquamating Skin Rash
- Decrease in linear growth
What are the two different categorisations Oedema can be split into?
- Pitting/Non-pitting
- Local/General
What is the difference between local and general oedema?
- Local is injury or inflammation
- General is heart or kidney failure
What is the difference between pitting and non-pitting oedema?
- Pitting, when pressed indentation does not reform quickly
- Non-pitting, indentation reforms quickly
Where can general oedema occur?
- Chest Cavity (Pleural Effusion)
- Abdomen (Ascites)
- Air Spaces (Pulmonary Oedema)
What is the mechanism of oedema?
- Less protein means less amino acids means less albumin in the liver
- Albumin is a carrier for fatty acids and maintains osmotic pressure
What are the three types of diarrhoea?
- Osmotic
- Secretory
- Malabsorptive
What is osmotic diarrhoea?
Retaining water in lumen on GI tract
What is secretory diarrhoea?
Entereotoxin released by bacteria draws water into the lumen from cells
What is malabsorptive diarrhoea?
Reduced ability to digest and absorb nutrients
What type of diarrhoea is symptomatic of Kwashiorkor?
Malabsorptive
Why does Kwashiorkor cause malabsorptive diarrhoea?
-Decreased digestive enzymes and reduction in absorption in the pancreas and intensines, lowering the water potential in the lumen so water diffuses in by osmosis
What types of cells are there in the intestines and what do they secrete?
- Goblet (Mucous)
- Enteroendocrine cells (GLP-1)
- Enterocytes (Absorptive cells)
- Paneth cells (Bactericidal)
What 2 categories can the pancreas be divided into?
Endocrine and exocrine
What hormones are secreted by the endocrine structure of the pancreas? (Islet of Langerhans)
- Insulin
- Glucagon
- Somatostatin
- Pancreatic Polypeptide
- Ghrelin
What are the exocrine structures in the pancreas?
- Ductal Cells
- Acinar Cells
What do acinar cells in the pancreas produce?
Digestive enzymes:
- Lipase
- Amylase, etc.
What do the ductal cells of the pancreas do?
Connect to the pancreatic duct to pass the enzymes secreted by the acinar cells into the intestine
What changes in hair occur in kwashiorkor?
Banded hair pattern of good/poor growth. Poor growth will be grey/blonde
What changes in nails occur in kwashiorkor?
Finger clubbing, bloated fingernails/tips
How does the desquamating skin rash work in kwashiorkor?
The stratum corneum layer of the epidermis is lost
What is the mechanism of cachexia?
Hypercatabolism of fat and protein, mediated by cytokines which cause protein breakdown vie the Proteasome
How do cytokines mediate protein breakdown via the Proteasome in Cachexia?
Proteins are tagged by Ubiquitin which are then sent to the proteasome for degradation
What is Obesity?
Excessive accumulation of fat. BMI above 25.
What is BMI formula?
Bodymass(kg)/Height(m)^2
What are the causes of obesity?
- higher food intake than energy expenditure
- Genetic
- Pathological
What are cytokines?
Hormone-like substances that act in a paracrine fashion to mediate immune response
What hormone is deficient in genetic obesity that is responsible for appetite control?
Leptin
Why does a deficiency in Leptin lead to increased food intake?
Leptin inhibits NPY which reduces appetite and increases energy expenditure, so appetite/food intake increases while energy expenditure goes down
What is genetic obesity caused by?
Homozygous mutation in the ob gene (ob/ob) causing no leptin to be produced
What are the symptoms of Cushing’s Disease?
- Moon Face
- Thin Limbs
- Truncal Obesity
- Buffalo Hump
- Stretch Marks
- Muscle Wasting
- Diabetes Mellitus
What are the two causes of Cushing’s Disease?
- Pituitary Adenoma
- Adrenal Tumour
What is the function of the anterior pituitary gland?
- Basophilic Cells secrete FSH, LH, ACTH and TSH
- Acidophilic cells secrete GH and prolactin
What is the function of the posterior pituitary gland?
Release of Oxytocin and Vasopressin
What does FSH do?
Females: Graafian follicle development
Males: Sperm production
What does LH do?
Females: Stimulates ovulation
Males: Androgen production
What does ACTH (Adrenocorticotropic Hormone) do?
Controls cortisol secretion in the adrenals
What does TSH do?
Controls the thyroid gland
What does prolactin do?
Stimulates milk production in females
What does oxytocin do?
Stimulates uterine contraction
What does vasopressin do?
Reabsorption of water into the kidney
What are the two sections of the adrenal gland?
the Cortex and Medulla
What is the cortex of the adrenal gland split into?
- Zona Glomerulosa
- Zona Fasiculata
- Zona Reticularisa
what hormones are secreted by the adrenal cortex?
- Glucocorticoid
- Mineralocorticoid
- Sex Steroids
What hormones are secreted by the adrenal medulla?
Epinephrine and Norepinephrine
How does ACTH typically interact with the adrenal gland in healthy people?
Causes adrenal cortex to release cortisol (glucocorticoid), which causes negative feedback decreasing the rate of secretion of ACTH
How does a pituitary adenoma cause cushings disease?
Increases ACTH, which increases cortisol, which cannot inhibit ACTH due to the tumour cells not being able to sense cortisol, causing constantly high cortisol (Hypercortisolaemia)
How does increased cortisol from having an adrenal adenoma cause cushing’s disease?
- Increased gluconeogenesis causing diabetes
- Muscle wasting
- Redistribution of fat to centre of body
What is the clinical presentation of Cushing’s disease?
- Obesity
- Headaches due to stretching of dura matter in brain and spinal cord
- Visual field defects due to adenoma pressing on optic chiasma
- Hypercortisolaemia
What are the health risks of obesity?
- Increased risk of death from surgery
- Insulin resistance and diabetes
- Coronary heart disease
- Gallstones
- Arthritis
- Varicose Veins and Haemorrhoids
Why does obesity lead to increased risk of death from surgery?
- Takes longer
- Difficult to control anaesthesia
- Reduced lung function due to fat in thoracic cavity
Why does obesity lead to an increase in diabetes?
increased Fatty acids cause decrease in glucose uptake/utilisation in muscle
Why does obesity lead to increased risk of arthritis?
Increased weight puts more stress on load bearing joints
How does obesity increase haemorrhoid risk?
Increased intraabdominal pressure and decreased fibre intake leading to more straining during defecation
