Human Health and Disease

Health - complete physical, mental and social well-being.

Disease - ill-health with a set of symptoms.

Malfunction of the mind/body leading to a departure from good health.

Multifactorial.

Acute - Sudden onset with rapid changes lasting for a short time.

Chronic - months/years.

• Physical - Damage to the body

• Mental - Psychological Disorder

• Social - Disease from environment

• Infectious - Caused by pathogens

• Non-Infectious - Not caused by pathogens

• Degenerative - Gradual decline in bodily functions

Genes, mutation, parents to child via gametes, parents = carriers or sufferers, caused by recessive/dominant alleles.

• Self-inflicted - Person's own lifestyle put them at risk

• Deficiency - Lack of energy/nutrients

Identifies human genes and what each one codes for. Genome = all genetic material

Advantages:

• Link between genes and disease
• Reliable DNA tests
• Blood sample
• Screening unborn child
• Post natal screening for diseases

As a result:

• Targeting treatment
• Targeting preventative measures
• Drugs
• Gene therapy

Disavantages:

• Results from gene tests not always clear cut
• FX on psychological health knowing harmful allele
• Employers discrimination
• Insurance discrimination
• Copyright of genetic info

Epidemiology - study of patterns of disease.

Epidemiologists collect data on morbidity and mortality for a population.

Compare different places using 'per 100,000' to make fair comparisons.

Incidence - no. ppl diagnosed

Prevalence - no. ppl with a disease

Mortality - no. ppl who die

Use of statistics

• Which diseases are most common
• Priorities for health care
• Comparing populations in diff parts of countries
• Comparing populations in diff countries
  

Endemic - infectious disease always in population

Epidemic - diseases spreads rapidly

Pandemic - disease spreads over a continent/internationally.

Infectious diseases in LEDCs -

• Limited control programmes
  
• Remote areas
• Poor health care
• Sanitation
• Water supply
• Cholera
• Overcrowding
• TB
• Poor control of HIV spread
• ref Antibiotics
• ref vaccination
• ref nutrition
• ref housing
• ref education
• ref cost

Macronutrients - supply enrgy for growth, repair, movement and organ functioning.

• Proteins; amino acids. Essential amino acids must be in diet.
• Fats; long term energy store. Essential fatty acids must be in diet. Make phosopholipids for cell membranes from fatty acids and glycogen.
  
• Carbohydrates; Energy for respiration. Stored as glycogen in the liver.

Micronutrients - vitamins and minerals

Fat-soluable Vitamins;

• A - (retinol) - retina functioning in eye and epithelial tissue.
• D - Stimulates Ca uptake from gut, deposits in bone.
• K - Substances promoting blood clotting.

Water-soluable Vitamins;

• B - respiration, protein synth, nucleic acid synth, RBC synth, nerve function.
• C - aids wound healing.

Age - young = more protein, old = more Ca

Gender - females need more iron

Pregnancy - more Folic Acid (vit.B)to protect against spina bifida

Physical Activity - Active = more protein for muscle development and carbs for energy.

RDA - US 1940s Military

DRVs -

1) Estimated Average Requirement (EAR)

• Energy and Nutrients
• Average for population

2) Reference Nutrient Intake (RNI)

• More than adequate
• Nutrients

3) LRNI

• Low needs
• Nutrients

4) Safe Intakes; nutrients without statistical data

Proteins

• Provide amino acids to make proteins
• 8 a.as can't be made - essential!!
• Can change some a.as into others
• Essential - heal wounds and stop hair loss.

Essential Fatty Acids

• Linoleic and Linolenic Acids
• Linolenic Acid - makes phospholipids and lowers cholesterol

Vit A

• Meat and Veg
• Good eyesight
• Epitheial cells in good nic.

Vit D

• Oily fish and eggs
• Control Ca absorption, helps absorb phosphorus for ATP

Metabolism slows

Protein energy malnutrition

Kwashiorkor

• underweight
• odema (lack of plasma protein...more h2o potential..no osmosis into caps from tissue fluid..tissues swell)
  
• moon face
• dry, thin, reddish hair
• fatty enlarged liver
• bloated
• apathetic
• no appetite

Marasmus (general starvation and Anorexia)

• v. underweight
• no odema
• old man's face
• muslce wasting
• little change to hair
• wrinkled skin
• mentally alert
• no loss of appetite

• Wasting - mjr weight loss (reversible)
• Stunting - poor growth (irreversible)
  

Vit D Deficiency

• Sunlight
• In muslces and fat
• Fat soluable
• Eggs, Oil
• Active form - Stimulates intestine to absorb Ca.
• Symtoms - Rickets (weak bones, bowed legs), Osteomalacia (bone softening)

Vit A Deficiency

• Retinol
• Fat Soluable
• Carotenoids > Retinal
• In liver
• Symptoms; xeropthlamia, night blindness, epithelia infections

energy intake > energy usage

risks;

• CHD (high BP and cholesterol)
  
• Diabetes
• Colon, rectum, prostate, uterus, cervix and breast cancer
• Arthritis
• Hernias
• Varicose Veins
• Gallstones