2.11 - Diet and Nutrition Flashcards
Where is ghrelin produced
Epsilon cells in pancreas
Where is ghrelin released
Stomach lining
What stimulates and inhibits ghrelin release
Stimulated - empty stomach via vagus nerve
Inhibited - full stomach
What is the function of ghrelin
Stimulates excitatory primary neurones, stimulate appetite in the arcuate nucleus
Where is PYY secreted, and by which cells
L cells in the ileum
What stimulates the release of PYY
Presence of lipids, amino acids, glucose, bile in ileum
What is the function of PYY
Inhibition of excitatory primary neurones in arcuate nucleus -> appetite suppression
Name 2 hormones secreted into the ileum which are involved in appetite suppression
PYY
GLP-1
Where is CCK secreted from
I cells in duodenum
What stimulates CCK release
Lipids and proteins entering duodenum
What are the functions of CCK (4)
Gallbladder contraction
Pancreatic enzyme release
Inhibits gastric emptying
Reduces appetite
Were is GLP-1 secreted from
L Cells in ileum
What stimulates GLP-1 release
presence of lipids, glucose, amino acids in ileum
What are the functions of GLP-1 (4)
Reduces gastric emptying
Increases upper intestinal mobility
Decreases gastric acid secretion
Reduces appetite
Where is leptin released from
white adipocytes in bloodstream
What stimulates leptin release
high fat stores
What are the functions of leptin (3)
stimulates inhibitory neurones and inhibits excitatory neurones in arcuate nucleus
Suppresses appetite
Increases basal metabolic rate
Where is insulin released from
beta cells in pancreas
What stimulates insulin release
Hyperglycaemia
What is the function of insulin (in terms of appetite)
Appetite suppressor
What is the fancy word for a hormone that suppresses appetite
Anorexigenic
What factors influence satiety (2)
Rate of gastric emptying
Volume and type of food
What factors can increase rate of gastric emptying (6)
High volume food
Low pH
Cholinergic drugs
Gastrin
Motilin
Distension
What factors can decrease the rate of gastric emptying (6)
High osmolarity foods
Anti-cholinergics
Secretin
CCK
Glucagon
Stress, fear, depression
What is the main function of Vitamin A, and what can deficiency cause
Synthesis of photoreceptors in the eye
Deficiency -> Night blindness
What is the main function of vitamin B1 (thiamine), and what can deficiency cause
Carbohydrate and amino acid metabolism
Deficiency -> neuropathy, wernicke-korsakoff syndrome, heart failure
What is the main function of vitamin B3 (Niacin) and what can deficiency cause
Energy metabolism and cholesterol regulation
Deficiency -> 4 Ds (Dermatitis, Diarrhoea, Dementia, Death)
What can vitamin B6 (Pyridoxine) deficiency cause
Anaemia, irritability, seizures
What can vitamin B7 (Biotin) deficiency cause
Dermatitis
What is the main function of vitamin B9 (folic acid) and what can deficiency cause
DNA synthesis
Deficiency -> Megaloblastic anaemia, neural tube defects (during pregnancy)
What is the main function of vitamin B12 (cyanocobalamin) and what can deficiency cause
Myelination
Deficiency -> Megaloblastic anaemia, peripheral neuropathy
What is the main function of vitamin C (asorbic acid) and what can deficiency cause
Immune system function
Deficiency -> Scurvy (arr)
What is the main function of vitamin D and what can deficiency cause
Synthesis of Calbindin D -> Calcium absorption
Deficiency -> rickets, osteomalacia
What is the main function of vitamin E and what can deficiency cause
antioxidant - prevents free radical damage to RBCs
Deficiency -> haemolytic anaemia in newborns, ataxia, peripheral neuropathy
What is the main function of vitamin K and what can deficiency cause
Synthesis of vitK dependent clotting factors (X, IX, VII, II)
Deficiency -> haemorrhagic disease of the newborn, bleeding diathesis
What are the main functions of sodium
Maintain fluid balance
Nerve function
Muscle function
What are the symptoms of sodium deficiency
Dizziness
Muscle weakness
Seizures
What are the main functions of potassium
Maintain fluid balance
Nerve and muscle functions
What are the symptoms of potassium deficiency
Cramping
Muscle weakness
Mood changes
Arrhythmias
What are the main functions of calcium
Bone protection
Muscle function
What are the symptoms of calcium deficiency
Osteoporosis
Muscle cramps
What is the function of phosphate
Required for ATP production
What are the symptoms of phosphate deficiency
Sore bones
Anxiety
Changes in body weight
What are the main functions of magnesium
Energy metabolism
Release of neurotransmitters
What are the symptoms of magnesium deficiency
Irritability
Muscle weakness
Arrhythmias
What is the main function of iron
Haemoglobin synthesis
What are the symptoms of iron deficiency
Anaemia
fatigue
shortness of breath
Having one or more of these factors puts you at a high risk of refeeding syndrome (4)
BMI <16
Unintentional loss of >15% of body weight over last 3-6 months
Little or no nutritional intake for >10 days
Low potassium, phosphate, or magnesium
Having 2 or more of these factors puts you at a high risk of refeeding syndrome (5)
BMI <18.5
Unintentional loss of >10% body weight over last 3-6 months
Little or no nutritional intake for >5 days
History of alcohol abuse
Certain medications
What are the clinical features of refeeding syndrome (4)
Hypophosphataemia (Pi deficiency)
Hypomagnesaemia (Mg deficiency)
Hypokalaemia (K deficiency)
Increased sodium and water retention
What are the complications of refeeding syndrome (3)
Cardiac arrhythmias
Cardiac failure
Respiratory failure
