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Flashcards in Unit 2: Food and Health Deck (130)
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What is a balanced diet?

Provides all nutrients and energy needed to sustain life


What are nutrients needed for?

Better health
Stronger immune system
Learn more effectively
To increase productivity


What are the 7 main food groups and what do they provide for the body?

Carbohydrate-main source of energy
Proteins-growth and repair of muscle and tissues
Fats-biggest source of energy, cell membranes, waterproofing, absorption of fat soluble vitamins
Vitamins-roles in chemical processes
Minerals- inorganic elements essential to normal functions
Water-transporting substances around body
Fibre-essential for healthy functioning of digestive system


What does changes to weight show about energy in the diet?

Losing weight= too little energy in diet
Gaining weight= too much energy in diet


What are the body categories for BMI?

Less than 18.5 = underweight
18.5-25= healthy
25-30= overweight
30-35=obese (class 1)
35-40= obese (class 2)
Over 40= morbidly/ severely obese (class 3)


Why is BMI not an accurate measure of body mass?

Person may be pregnant
Person may have lots of muscle-make them heavier than average person
BMI not suitable for children


What is obesity?

When the body weight of a person is 20% or more above the weight recommended for your height


Why is obesity classed as a form of malnutrition?

The person is not getting the right amounts of each food group

Increased amounts of fatty foods
Little exercise
Social and economic stress lead to comfort eating
Physiological problems eg underactive thyroid gland


What diseases are so societies with obesity?

Coronary heart disease
High blood pressure
Angina (sufficient blood flow to heart but coronary arteries can't cope with exercise, results in chest pains)
Varicose veins
Type 2 diabetes
Gall stones


How is salt linked to heart disease?

Salt-excess salt levels decrease water potential of blood=high diastolic pressure
-> hypertension
-> damage to artery walls, starting atheroscerlosis leading to HD


How is fat linked to heart disease?

Balance of fats needed (sat fats and unsat fats)
An excess of sat fats can lead to atheroscerlosis, leading to HD


What is the difference between low density lipoproteins and high density lipoproteins?

LDL= sat fat, cholesterol and protein
HDL= unsat fat, cholesterol and protein


How are polyunsaturated fats and monounsaturated fats useful to us?

Polyunsaturated fats=increase the number of receptors available for LDLs so more cholesterol enters tissues

Monounsaturated fats=remove LDLs from blood


Short term effects of tar? (4)

Settles in airway and alveoli linings- increases diffusion distance for gaseous exchange

Chemicals in tar can cause allergic reactions-causes smooth muscle contract

Tar paralyses/destroys cilia and stimulates goblet cell production

Trapped bacteria in mucus means lungs more susceptible to infection


Long effects of tar? (3)

Smokers cough

Frequent infections

Lung cancer


What does a smokers cough do to the airways?

Caused by tar irritating the airways and the need to clear blocked airways
-> Cough damages airway and alveoli lining which gets replaced with scar tissue=thicker and less flexible
-> layer of smooth muscle in bronchioles thickens, lumen narrows and flow of air permanently restricted


How do frequent infections, caused by smoking, result in damage to lining and layer of epithelium?

Infections attract WBC to deal which pathogens
-WBC have to enter airways
-to enter airways, enzyme used to break through lining walls (elastase), damaging elastic tissue of lining of lungs


How does smoking cause lung cancer?

Cigarettes contain carcinogenic compounds which cause cancer-found in tar lying on surface of lungs
Carcinogens enter lung tissue cells, enter nucleus and mutate the genetic material
-> if mutation affects genes for cell division, leads to uncontrollable cell division


Where does lung cancer often start developing?

At the entrance to the bronchi as this is where smoke deposits tar in the airways


Why are cancers difficult to detect?

Lung cancer can take 20-30 years to develop, meaning it might be years before the cancer is actually discovered


Name 4 diseases associated with smoking

Chronic bronchitis
Chronic obstructive pulmonary disease
Lung cancer


What are the causes and symptoms of chronic bronchitis?

Causes= inflammation of airways with damage to cilia and overproduction of mucus lead to mucus collecting in lungs

Symptoms= lung irritation, continued coughing, coughing up mucus with bacteria and WBC


What are the causes and symptoms of emphysema?

Causes=loss of elasticity in alveoli causing alveoli to burst -> decreases SA for gaseous exchange

Symptoms=shortness of breath especially when exerting themselves, in extreme cases breathing is shallow and rapid leading to fatigue


What is chronic obstructive pulmonary disease?

Combination of chronic bronchitis emphysema and asthma


What are the symptoms of lung cancer?

Continual coughing, shortness of breath, chest pain and blood coughed up in sputum


What effect does nicotine have on smokers?

It's the addictive chemical. The smoker gets used to the effects and becomes addicted.


What are the specific effects of nicotine on a smoker and why?

Increased sensitivity, feel more alert-nicotine mimics action of transmitter substances at synapses between nerves

Increased blood pressure-nicotine releases adrenaline, increased heart rate and constriction of arterioles

Restricted blood flow to extremities-nicotine causes constriction of arterioles=decreased blood flow and oxygen delivery

Increased risk of blood clot or thrombus-nicotine makes platelets more sticky


What effect does carbon monoxide have on smokers?

Decreases affinity for oxygen
Forms carboxyhaemoglobin (more stable and combines more readily than oxygen)
Lower oxygen levels may cause heart rate to rise

Can also damage lining of arteries


Name 4 problems caused by changes to blood system

Coronary heart disease


How des athersclerosis occur?

Carbon monoxide can damage the inner lining of the arteries, this is worsened by high blood pressure
Movement of WBC plus high blood pressure causes deposition of LDLs in arteries
Deposits (atheromas) May include fibres, dead BCs, platelets- this process is called atherosclerosis