Nutrition and Health Part 2

Vocabulary flashcards summarising major concepts from the lecture: Australian dietary policy tools, digestion processes, key enzymes, absorption structures, bioavailability, and common micronutrient deficiencies with their clinical features.

Australian Guide to Healthy Eating

A population tool that visually depicts the recommended proportions of the five food groups for a balanced daily diet in Australia.

Five Food Groups

Vegetables & legumes, fruits, grains/cereals, lean meats & alternatives, and milk & milk products – the core groups promoted for dietary variety and health.

Dietary Guidelines (Australian)

Five evidence-based recommendations covering healthy weight, variety, limitation of saturated fat/salt/sugar/alcohol, breastfeeding, and safe food handling.

Nutrient Reference Values (NRV)

Scientific recommendations that specify the daily amounts of individual nutrients needed to meet physiological requirements and prevent chronic disease.

Discretionary Foods

Energy-dense items high in saturated fat, added sugars, salt or alcohol that are non-essential and should be consumed only occasionally.

Bioavailability

The proportion of an ingested nutrient that is absorbed, enters the circulation, and is available for physiological use.

Peristalsis

Wave-like muscular contractions that propel food through the digestive tract.

Brush Border

Microvilli-covered surface of intestinal epithelial cells where final digestion and nutrient absorption occur.

Villus (plural Villi)

Finger-like projections lining the small intestine that increase surface area for absorption.

Duodenum

The first section of the small intestine where acidic chyme is neutralised and mixing with bile and pancreatic juice begins.

Jejunum

Middle segment of the small intestine; principal site for absorption of most nutrients, including lipids.

Ileum

Final portion of the small intestine; absorbs vitamin B12, bile salts and remaining nutrients.

Portal Vein

Blood vessel that carries nutrient-rich blood from the gastrointestinal tract to the liver for first-pass metabolism.

Pepsin

Stomach protease that initiates protein digestion in an acidic environment.

Rennin (Chymosin)

Milk-coagulating enzyme active in infants’ stomachs, aiding digestion of milk proteins.

Ptyalin (Salivary Amylase)

Enzyme in saliva that begins starch breakdown in the mouth.

Pancreatic Amylase

Carbohydrate-digesting enzyme secreted into the small intestine to complete starch hydrolysis.

Lingual Lipase

Fat-digesting enzyme secreted from glands under the tongue; suspected minor role in oral lipid digestion.

Bile

Liver-derived fluid stored in the gallbladder that emulsifies dietary fats for enzymatic digestion.

Fat Emulsion

Oil-in-water dispersion formed in the stomach that enables efficient action of pancreatic lipase on lipids.

Triglyceride

The main dietary lipid; three fatty acids esterified to glycerol, hydrolysed by lipases during digestion.

Australian Dietary Guideline 1

Encourage healthy weight, physical activity and proper food portions for growth and wellbeing.

Polyunsaturated Vegetable Oil

Recommended cooking fat source owing to its beneficial fatty-acid profile compared with saturated fats.

Iron Deficiency

Insufficient body iron stores leading to reduced haemoglobin synthesis and possible anaemia.

Microcytic Hypochromic Anaemia

Anaemia characterised by small, pale red blood cells commonly caused by iron deficiency.

Iodine Deficiency Disorder (IDD)

Collective term for adverse effects of inadequate iodine, including goitre, hypothyroidism and impaired neurodevelopment.

Goitre

Visible enlargement of the thyroid gland resulting from chronic iodine deficiency.

Thyroxine (T4)

Iodine-containing thyroid hormone essential for growth, development and metabolic regulation.

Iodised Salt

Table salt fortified with iodine to prevent iodine deficiency in the population.

Folate (Folic Acid)

Water-soluble B-vitamin required for DNA synthesis and one-carbon (methylation) reactions.

Megaloblastic (Macrocytic) Anaemia

Anaemia with large, immature red cells caused by folate or vitamin B12 deficiency.

Neural Tube Defects (NTD)

Congenital malformations (e.g., spina bifida, anencephalus) arising from failure of the fetal neural tube to close; linked to inadequate maternal folate.

Spina Bifida

Type of neural tube defect where the spinal column fails to close, leaving nerves exposed at birth.

Anencephalus

Severe neural tube defect in which major portions of the brain and skull are absent.

Vitamin A Deficiency

Inadequate vitamin A intake leading to visual and epithelial disorders.

Night Blindness

Early symptom of vitamin A deficiency marked by impaired vision in low light.

Conjunctival Xerosis

Dryness and inflammation of the eye’s conjunctiva due to vitamin A deficiency; reversible stage.

Bittot’s Spots

Foamy, whitish accumulations on the conjunctiva indicating prolonged vitamin A deficiency.

Xerophthalmia

Progressive ocular changes from vitamin A deficiency culminating in irreversible corneal damage and blindness.

Electrolytes

Minerals such as sodium and potassium that conduct electrical impulses and maintain fluid balance; lost in sweat and replaced in sports drinks.

Energy-Yielding Nutrients

Macronutrients (carbohydrate, protein, fat, alcohol) that provide calories; fat yields the most energy per gram (≈9 kcal).

Per Capita Water Recommendation

Guideline to drink roughly 2–2.5 litres of water daily for adequate hydration.

Peristaltic Loss Concept

Recognition that at each stage—digestion, absorption, utilisation—some nutrient quantity is lost, lowering eventual bioavailability.

Body Mass Index (BMI)

Weight-for-height metric used to classify underweight, healthy weight, overweight and obesity; obesity class I begins at BMI 30 kg/m².