diseases

what is a disease

a condition in which the health of an organism is damaged

name the four types of diseases

pathogens

deficiency

hereditary

physiological

what is a pathogen

a parasitic organism which causes diseases in its host.

name the 5 groups of pathogens

viruses

bacteria

fungi

protozoans

parasitic worms

viruses

minute particles composed of DNA enclosed in a protein coat. they are all parasites which can't reproduce outside living cells. they inhibit cellular activity and destroy cell structure

polio,influenza, yellow fever, aids, herpes

mosaic disease of tobacco

bunchy top of paw paw

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bacteria

single cells lacking a true nucleus, DNA is spread throughout the cytoplasm. produces enzymes which destroys hosts cells or releases toxins into the body

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fungi

body consists of a network of hyphae which make up a mycelium. destroy the hours tissues by extracellular digestion

ringworm,athletes foot

rust and smut of rice coffee and sugar cane

protozoans

single cells with a true nucleus. digest hosts tissues or release toxins into the hosts body

malaria, sleeping sickness, amoebic dysentery

parasitic roundworms and Flatworms

tape worm, liver fluke, blood fluke, hookworm, threadworm

rootknot nematode of tomato corn and carrots

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name the 6 ways pathogenic diseases can be spread

airborne droplets- droplets containing pathogens

direct contact- bodily contact or handling objects by an infected person( contagious)

dust- pathogens stick to dust

faeces- pathogens in faeces of an infected person

spores- reproductive spores spread by fungal disease

animals- spread pathogens by carrying them on or in their bodies(vectors)

describe the body's line of defense against pathogenic diseases in a cut

if bleeding and clot formation fails to prevent entry of bacteria then the blood vessels around the cut dilate. this increases blood flow and brings a large number of ohagocytes to the area. they destroy the bacteria while it produces toxins to kill the phagocytes. this results in the formation of pus which are the dead cells. when all the bacteria is destroyed the pus is absorbed and a scab forms

describe the body's line of defense in the bloodstream

if large numbers of bacteria or viruses enter the bloodstream, swimming phagocytes in the blood and stationary phagocytes in lymph nodes engulf and destroy the. lymphocytes produce antibodies against them.

immunity

the permanent or temporary resistance to a disease.

name the 2 types of immunity

natural and artificial

natural immunity-actively acquired

different bacteria and viruses have specific proteins in their walls called antigens. when a pathogen enters the blood lymphocytes make specific antibodies against the antigens.

they cause the pathogens to clump together which prevents reproduction and results in death or

cause pathogens to disintegrate or

antitoxins neutralize toxins produced by pathogens.

the pathogens would have produced symptoms of disease before being destroyed or neutralize. over time the antibodies disappear from the blood.

however if the pathogen appears a second time lymphocytes immediately recognize the antigens and rapidly make large amounts of antibodies to destroy or neutralize the pathogen before symptoms develop granting immunity. immunity can vary based off the disease

natural immunity- passively acquired

antibodies are passed through the placenta providing newborns with immunity against certain diseases.

breast milk contains antibodies which gives protection. the antibodies disappear because the baby's lymphocytes were not involved in making the antibodies.

artificial immunity- active

the vaccine contains weakened, inactivated or dead pathogens which can not allow diseases. however it still allows the the lymphocytes to learn the antigens and create antibodies the next time this pathogen enters the body. the second time antibodies will be made immediately destroying the pathogen before the disease develops.

artificial immunity- passive

vaccine contains antibodies, usually antitoxins which provides an immediate source of antibodies. because the lymphocytes have not learned to make them, immunity is short lived.

sexually transmitted diseases

stds are transmitted through sexual intercourse. this includes aids, gonorrhoea, syphilis and genital herpes

describe a treatment for hiv( human immunodeficiency virus)

triple therapy can be used where the patient would take 3 antiviral agents, two of which prevent reproduction of the virus and 1 protease inhibitor. this reduces measurable virus to immeasurable levels

social consequences of aids( acquired immune deficiency syndrome)

increased pressure on health service

short life expectancies

Neglect by relatives and friends

primary host

cause the disease

secondary host

they reproduce but cause no harm . vectors are the secondary hosts.

what are some measures to control the anopheles mosquito

spraying adults with insecticide

draining breeding areas to kill larvae and pupae/ spraying with insecticide

introducing fish like tilapia into breeding areas to eat larvae and pupae

what are deficiency diseases?

diseases caused by the shortage of a particular nutrient in the diet

anaemia

lack of iron reducing hemoglobin production

shortness of breath,increased heart beat, weakness, pale appearance

take iron tablets or green leafy vegetables and red meat

kwashiokor or protein energy malnutrition

deficiency of protein

discolored and blotchy skin, distended stomach due to fluid retention

rickets

deficiency of vitamin c or calcium, insufficient exposure to uv light

disorder in growing bones, they are soft weak and abnormally formed with swollen ends at joints mainly affecting leg bones causing bow legs. tooth development is poor

diet rich in vitamin d calium and phosphorus

xerophthalmia

permanent blindness, poor vision or night blindness, dry unhealthy skin or cornea, lack of vitamin a

eat animal fats

keeps skin and mucous membranes healthy

beri beri

weak and painful muscles nervous disorders, paralysis back of b1

eat unpolished rice, cereals and yeast extract

assists in respiration

pellagra

digestive nervous system and skin disorders, lack of vitamin b3

liver,yeast extract, wholemeal flour

assists in respiration

scurvy

bleeding from gums and other membranes, loss of teeth,wounds do not heal,painful muscles and joints, lack of vitamin c

eat citrus foods and raw green vegetables

this keeps tissue healthy especially skin and connective tissue

Goitre in adults

swelling of thyroid gland in neck, reduced membrane rate, lack of iodine

eat sea food

helps with formation of thyroxine

cretinism in children

physical and mental retardation, lack of iodine

eat more seafood

formation of thyroxine

what is a physiological disease

these diseases are caused by the malfunction of a body organ

hypertension

stress,obesity,conditions leading to narrowing of arteries, kidney or adrenal gland disease, sedentary lifestyle

no symptoms but can later cause heart failure, kidneys or strokes

reduce stress,obesity,diet low in salt and fat, stop smoking, reduce consumption of alcohol,moderate excercise

diabetes

inability of islets of langerhans to produce enough insulin( type 1)

inability of body cells to respond efficiently to insulin(type 11) often as a result of overweight

increased blood sugar levels, excretion of sugar in urine, increase urination,continual thirst ,weight loss,tiredness,sweet smelling breath

control carbohydrate intake, consume foods containing polysaccharides, reduce obesity for type 11, tablets to lower glucose type 11, daily injections of insulin type 1

what are hereditary diseases

passed on from one generation to another by genes

name the 2 forms of sickle cells disease

sickle cell anaemia