Infection Treatment

Cholera bacterium is ingested and enters the small intestine.

Oral rehydration solution (ORS) is given to the infected patient.

Cholera bacterium secretes enterotoxin subunit B.

ORS contains glucose and sodium, and also bicarbonate and potassium ions.

Enterotoxin subunit B attaches to a receptor on the cell membrane of the

small intestine microvilli.

The presence of glucose and sodium in the small intestine causes the carrier protein to co-transport these into the

small intestine cell.

This causes the release of enterotoxin subunit A inside the small intestine cell

This changes the water potential and water flows back into the small intestine

cell by osmosis.

This causes ion channels to open and sodium ions flow back from the

bloodstream into the small intestine lumen.

Water, glucose, sodium and the other ions now diffuse into the bloodstream.

Water also flows back into the small intestine lumen by osmosis, causing rice

water (diarrhoea).

The patient is cured! However, the bacterium has been known to survive upto 50 days in faeces, so Colin the

cholera and co. may now have infected someone else…

HomeworkHomework

• Answer the past exam questions on coronary heart disease and cancer.

(We will be learning about these two topics today)

Due in: Friday 3Due in: Friday 3rdrd October October (Day 3, Period 5)

• BHF animation

Play your cards right!Play your cards right!

http://www.youtube.com/watch?v=ThMIAHxdawI&feature=related

For each picture that appears, say whether it would HIGHERHIGHER or LOWERLOWER your risk of developing

CHD or cancer

You have been warned!You have been warned!

Cancer and CHDCancer and CHD

• Aims:

• To know how lifestyle can affect your risk of developing some diseases

- In particular, cancer and coronary heart disease (CHD)

• To understand how specific risk factors can contribute to (not cause!!) cancer and CHD

How much do you already know…?How much do you already know…?

• What are the differences between meiosis and mitosis?

• Which of these two types of cell division do you think is involved in cancer?

• What is the name given to an agent that causes cancer?

• Name the two types of tumour caused by cancer.• How many cancer treatments do you know of?

http://www.cancerquest.org/images/Documentary/English/DocInterfaceEng.swf

Cancer TreatmentCancer Treatment

• Chemotherapy – stops the cancer cells from replicating themselves

• Radiotherapy – damages DNA so that the cell destroys itself

• Surgery – removal of the tumour and surrounding tissue.

On a lighter note!On a lighter note!

• 80% of most cancers are curable if diagnosed early

• Science has already made vast improvements already in treating cancer, and continue to do so

• You are now aware of the risk factors which make you more susceptible to getting cancer (and CHD), so YOU have the choice to change your bad habitats now!

CVD – cardiovascular diseaseCVD – cardiovascular disease

• Most common form is Coronary Heart Disease (CHD)

• In economically developed countries, the main cause of CHD is atherosclerosis.

• http://uk.youtube.com/watch?v=fLonh7ZesKs

• http://uk.youtube.com/watch?v=EQVEdFSlUGU

• Complete the following activity on atherosclerosis…

 The deposit builds

up further and hardens causing arteriosclerosis

Blood flow is restricted and blood pressure

increases

White blood cells, lipids, dead cells and connective

tissue are deposited 

This causes fatty streaks

Healthy arteryAn aneurysm or thrombosis can then develop

The inner lining of the artery

(endothelium) is damaged

This partially blocks the lumen

of the artery

This deposition is called an atheroma

(fibrous plaque)

Re-arrange the following steps into a flow-charts, detailing how an atheroma is formed. Then draw pictures next to certain steps showing what a cross-section of the artery would look like.  

AneurysmAneurysm ThrombosisThrombosis

A burst blood vessel associated with an aneurysm, blood clot or

head injury can cause a …

StrokeStroke

(make your own notes here from my explanation)

Blockage or severe narrowing of one of the coronary arteries that supply the heart can lead to angina pectorisangina pectoris, or more severely,

a ‘‘myocardial infarction’myocardial infarction’

Atherosclerosis

CholesterolCholesterol• Diet high in saturated fats causes excess cholesterol in blood• Part of the fatty deposits in atheromas• Accelerates atherosclerosis

High Blood PressureHigh Blood Pressure• Hypertension

• Excessive salt intake, saturated fats, lack of exercise, stress, smoking, high alcohol consumption

• Increased risk of damage to the artery wall through increased pressure

• Heart has to work harder to pump blood around the body – could cause a myocardial infarction

Smoking and CHDSmoking and CHD

COCO NicotineNicotine

Carboxyhaemoglobin Stimulates adrenaline(reduced O2 capacity)

Increased heart rate b.p., reduces arteries ability to dilate

Increased risk of CHD &stroke

RBC ‘sticky’

Increased risk of thrombosis

Heart pumps faster

HypertensionAngina during exercise

Stroke/myocardial infarction

True or FalseTrue or False

In the UK, one person has a heart attack every two minutes