topic 5 biology health disease and medicine full deck PMT

What is a communicable disease

Diseases that can be transferred between people

what is a non communicable disease

Diseases which can’t be transferred between individuals

What does HIV do

Leaves your immune system impaired leaving you at risk to other diseases

What’s a pathogen

A microorganism that causes disease

What are the types of pathogens

Virus

bacteria

fungi

protists

Describe viruses

Very small,

move into host cells to make copies of themselves,

leading to cell bursting and spreading virus

Describe bacteria

Small,

multiply quickly through binary fission,

produce toxins that damage cells

Describe fungi

Produce spores that spread to other organisms

Describe protists

Some are parasitic meaning they use humans and animals as their hosts

What type of disease is cholera

Bacteria

What type of disease is Tuberculosis

Bacterial

What type of disease is Chalara ash die back

Fungi

What type of disease is Malaria

Protist

What type of disease is hiv

Virus

What type of disease is Ebola

Virus

What are the effects of cholera

Diarrhoea

What are the effects of Tuberculosis

Lung damage, coughing

What are the effects of Chalara ash die back?

Leaf loss , bark lesions

What are the effects of Malaria?

Damage to blood and liver

What are the effects of hiv?

Destroys white blood cells, leads to onset of AIDs

What are the effects of Ebola?

Causes haemorrhaging fever (fever accompanied by severe bleeding)

How is Ebola spread

Water

How is tuberculosis spread

Through air/airborne

How does cholera ash die back spread

through air / airborne

How’s malaria spread?

Animal vector (mosquito )

How is HIV spread

Through bodily fluids

How’s Ebola spread?

Through bodily fluids

What are some ways pathogens are spread?

Through:

• direct contact = touching contaminated surfaces, kissing, direct skin to skin

• By water = drinking or coming into contact with dirty water

• By air = pathogens can be carried in the air and then breathe in (for example droplet infection)

How can we reduce the spread of pathogens?

• improving hygiene: Hand washing, using disinfectant, isolating raw meat

• Reducing contact with infected individuals

• Removing vectors: using pesticides or insecticides and removing their habitat

• Vaccinations: by injecting antigens from a ded or inactive pathogen into an individual’s body, they can become immune.

What is an STI?

Sexually transmitted infections that can be spread through sexual contact, including oral and vaginal sex. They are carried in bodily fluid.

What is chlamydia?

An STI and bacterial pathogen that can create painful urination and pelvic pain and can lead to infertility.

What is HIV?

An STI and viral pathogen, that leads to increased susceptibility to other infections, severe illness and death if untreated.

How can STI spread be reduced?

Barrier methods of contraception

Abstaining from sexual activity

What are some physical barriers against disease humans have?

• mucus

• cillia

• Skin

What are some chemical barriers against disease humans have?

• lysozymes

• Hydrochloric acid

How does mucus prevent disease?

• produced by goblet cells in the airway

• Mucus traps bacteria and pathogens

• Before they can reach the lungs and cause infection

How does cilia prevent disease?

• cilliated epithelial cells waft away mucus that has trapped pathogens to be killed by stomach acid

How does skin prevent disease?

Provides a physical barrier against pathogens

Protecting the tissues and cells beneath from infection

How do lysozymes preovent disease

• are found in tears, saliva, mucus

• Break down bacteria cell walls

• To destroy bacteria

How does hydrochloric stomach acid prevent disease?

Used to kill bacteria in food reaching the stomach

To prevent infections

The specific immune response:

What are phagocytes?

White blood cells engulfing and consuming pathogens

The specific immune response:

How does phagocytosis protect you?

Destroys pathogens preventing spread of disease.

The specific immune response:

How does producing antibodies Protect you?

• each pathogen has an antigen on their surface which a specific complementary antibody binds to

• Antibodies bind to the pathogen causing the pathogens to clump together

• Making it easier for phagocytes to locate and engulf them

The specific immune response:

How do antibodies protect you after an illness?

• antigens trigger production of memory lymphocytes

• If you become infected again the specific complementary antibodies will be produced faster

• The individual wont feel the symptoms of illness (become immune)

The specific immune response:

How do antitoxins protect you?

Neutralise toxins released by pathogen by binding to them

What is herd immunity?

The immunisation of a large proportion of the population causing the spread of pathogen to be reduced as there are fewer susceptible individuals

Why don’t you feel ill on secondary infection to the same disease?

Antibodies are produced much faster due to memory lymphocytes so pathogen is destroyed faster

How do vaccines work?

• they contain a dead or inactive form of the pathogen

• Which stimulates white bloods Cells to produce antibodies complementary to the antigens on the pathogens

What do antibiotics treat?

Bacterial infections

Why do antibiotics kill bacteria?

• bacteria are susceptible to antibiotics inhibit bacteria cell wall synthesis or protein synthesis

Why are viruses and other pathogens unaffected by antibiotics?

Viruses and pathogens often use cell machinery in host cells to reproduce

How does bacterial resistance arise?

Through natural selection when mutations allow some bacteria to survive antibiotics. These resistant bacteria reproduce, increasing the resist population.

What do drugs needs to be tested for?

• toxicity

• Efficacy (how well they carry out their role)

• Dose

How do chemists test drugs?

In preclinical and clinical trials

How are plants used in medicine?

The chemicals that plants use to kill pests and pathogens can be used to treat symptoms or human diseases

For example, aspirin (originates from willow)

how was penicillin found?

Alexander Fleming was growing bacteria on plates

And found mould with clear rings around it, indicating there was no longer any bacteria there

He found mould was producing penicillin which killed bacteria

What does preclinical testing use?

Cells

Tissues

Live animals

What does clinical testing involve?

• volunteer and patients

How does clinical testing work?

• First it’s tested on healthy volunteers and patients with a low dose to ensure there aren’t harmful side affects

• The drugs are then tested in patients to find the most effective dose

• To test how it works they use placebos and single and double blind trials.

How is a placebo used in clinical trials?

Patients are split into two groups with one group receiving the drug and one recieving a placebo so the affect if the drug can be observed

These can be single or double blind

What is a single blind trial

only the patient doesn’t know whether they are receiving the drug or placebo

What is a double blind trial ?

Neither the patient or doctor knows if they are reciting the drug or placebo

Why may one choose to use a double blind trial?

Removes biases the doctors may have when recording results

Why must results from trials be peer reviewed by other scientists?

To check for bias and repeatability

What is a non communicable disease?

A disease that can’t be spread

What can play a large factor in determining whether people will develop non communicable diseases

Life style factors such as diet and exercise

How can cardiovascular diseases be caused?

High dietary intake of saturated fat combined with sendetary (inactive) lifestyle

How can chance of cancer be increased

Smoking (lung)

Age and genetics (such as breast)

How are chances of lung and liver diseases increased

Smoking

High alcohol intake

Age

Genetics

How are chances of vitamin and nutritional deficiencies increased?

Anorexia

People who can’t absorb or use nutrients properly (coeliac disease or anaemia)

What is obesity

Eating more calories than you burn from physical activity causing weight gain

What can obesity cause ?

Cardiovascular disease, high blood pressure, type 2 diabetes

What is malnutrition?

Eating significantly fewer calories than we use meaning the body doesn’t receive adaquete nutrients and vitamins

What is BMI and how’s it calculated?

Body mass index

BMI = mass (kg) / height squared (m)

\frac{mass}{height^2}

What does BMI indicate

If someone is underweight , healthy weight, obese or morbidly obese

If bmi is <30 is obese

What is waist hip ratio?

\frac{waist.circumference}{hip.circumference}

Obesity =

< 0.85 for women

< 1 for men

What is liver disease and how to reduce chances?

Due to high alcohol intake

Can lead to liver cancer

Recommended weekly alcohol allowance is 14 units per week

Reducing drinking intake of alchohol

What is lung disease cause by?

Smoking

Cigarettes contain over 7000 chemicals such as tar and nicotine

Treatments for cardiovascular diseases

What is life long meidication?

Several medications reduce cholesterol or blood pressure

Taken for life

Treatments for cardiovascular diseases

What surgical procedures are there?

Coronary artery bypasses where blocked sections of the artery is bypassed

Stents - a metal stent widens arteries narrowed by fat deposits

Treatments for cardiovascular diseases

What Lifestyle changes can you make?

Changes to exercise, diet etc

• reducing fat reduces high cholesterol and heart issues

• Maintaining good BMI can reduce strain on heart

• Regular exercise ensures we remain a healthy weight

• Reducing salt in diet and managing stress levels prevents high blood pressure