B1 Flashcards
Name the two stages of heart pumping.
- Heart relaxes to fill with blood
2. Heart contracts to squeeze blood out in arteries
What is the job of the circulatory system?
- To carry oxygen and glucose in blood to all bodily cells
* So that energy can be released through aerobic respiration
Why is blood under such high pressure when it’s pumped out of the heart?
- To ensure that the blood reaches all parts of the body supplying cells with glucose and oxygen for respiration
- Blood in arteries is always under high pressure
- This surge of blood is the heart beat or pulse
What is blood pressure and how is it measured?
- Blood pressure is as measure of the force of blood per unit area as it flows through the arteries
- It’s measured in mm Hg (millimetres of mercury)
What is systolic blood pressure?
• The first number is the pressure in your arteries when your heart contracts i.e. the highest number
What is diastolic blood pressure?
- The second number
* The pressure in your arteries when your heart relaxes
What is the average, healthy reading for systolic and diastolic blood pressure?
120 over 80 mm Hg
But this is affected by lifestyle factors and age
How can you reduce high blood pressure?
- By doing regular aerobic exercise to strengthen your heart
* Also a healthy diet can also help by maintaining a steady weight
What factors can lead to high blood pressure and how do they do it?
• Excess weight - the circulatory system has to work harder to pump blood around the body of a person is overweight
• High stress levels
• Excess alcohol
• A diet which is high in sat fat, sugar and or salt. Too much salt can raise blood pressure, whilst too much sat fat can lead to build-up of cholesterol in the arteries forming plaque. The amount of cholesterol in the arteries can be linked to the amount of saturated fat eaten. This plaque bulges into the lumen, restricting or blocking blood flow through the arteries, increasing the risk of heart attack
• Smoking - carbon monoxide produced reduces the oxygen-carrying capacity of the blood so the heart rate and pressure increases in order to compensate. Plus, nicotine increase the heart rate.
HT - carbon monoxide takes the place of oxygen in the haemoglobin so the oxygen-carrying capacity of the blood is greatly reduced
What are the long term risks of high blood pressure?
- Blood vessels can weaken and eventually burst
- If a blood vessel bursts in the brain it may lead to brain damage/stroke
- in the kidneys it could cause kidney damage
What effects does low blood pressure have on the body?
- Blood doesn’t circulate efficiently
- Some part of the body are deprived of glucose and oxygen
- This can lead to dizziness, fainting, and cold hands and feet
- Also pressure may drop in the kidneys leading to kidney failure
What factors increase the risk of heart disease?
- High blood pressure
- Smoking - carbon monoxide combines with red blood cells, preventing them from carrying as much oxygen
- Too much salt
- High-fat diets - block arteries + cause heart attacks. Heart attacks are more likely with narrowed coronary arteries and thrombosis
Define: healthy
• Being free from infection - no coughs, colds or diseases
Define: fit
- How much physical activity you are capable of doing and how quickly your body recovers afterwards
Define: cardiovascular efficiency
• How well your heart copes with aerobic exercise and how quickly it recovers afterwards - is often used as a measure of general fitness
What three things should a balanced diet contain?
- Carbohydrates
- Fats
- Protein
What are carbohydrates, fats and proteins made up of?
- Carbohydrates are made from simple sugars such as glucose
- Fats are made up of fatty acids and glycerol
- Proteins are made up of amino acids
How are carbohydrates, fats and protein stored?
- Carbohydrates are stored in the liver as glycogen or can be converted to fats
- Fats are stored under akin and around organs as adipose tissue
- Proteins are not stored
Although they don’t provide energy what other substances do you need in your diet to keep your body healthy?
- Minerals - e.g. iron to make haemoglobin in red blood cells
- Vitamins - e.g. Vitamin C to prevent scurvy
- Fibre - to prevent constipation and to maintain healthy bowels
- Water - to prevent dehydration and to help remove waste
Why might someone alter their diet?
- Beliefs - about animal welfare (vegetarians/vegans)
- Religious beliefs - for example Muslim and Jewish faiths prohibit eating pig
- Medical issues - such as allergies or intolerances
- Age - more/less calories and protein
- Sex - males need more calories dope to being larger and having more muscle
- Activity levels - someone with a more active profession would need more calories
- Personal choice
How can you maintain a healthy body mass?
What happens if you don’t?
- You must balance the amino if energy you consume the amount of energy you use up through daily activity
- If you consume more food than you need you will become overweight/obese
- Obesity is a major problem in the developed world. It can lead to arthritis (swollen and painful joints), heart disease, type II diabetes and breast cancer
Protein molecules are made from long chains of ….?
• Amino acids
Where are essential/non essential amino acids found?
- Essential - taken in by eating food (the body can’t make them)
- Non-essential - can be made in the body
Why is it so important for teenagers to have a high-protein diet?
• Protein supplies enable you to grow!
Why might people have protein deficiencies?
Where might people have these especially?
Name a disease that occurs because of protein deficiency.
- People that don’t have access to protein or enough food to live healthily
- Developing countries (LEDC’s)
- Kwashiorkor
Formula for calculating your estimated average daily requirement for protein (EAR)
What can make an EAR vary?
EAR = 0.6 x body mass in kg
• Whether someone is pregnant or lactating and their age
When is protein used as an energy source?
• When carbohydrates or fats aren’t available
What factors may lead to poor diet?
- Poor self-image
- Low self-esteem
- Desire for perfection
Name two eating disorders and explain why they are so damaging to the body?
- Anorexia nervosa
- Bulimia nervose
• The body does not get the balance of energy and nutrients to function properly.
• The reproduction system may be affected as well as bone damage
Define: non-infectious disease
- A disease which cannot be caught from another person
- Not caught/passes on
- No pathogens involved
What can cause a non-infectious disease?
- Poor diet - e.g. Lack of vitamin C causes scurvy
- Organ malfunction - e.g. the pancreas stops producing insulin causing diabetes
- Generic inheritance - e.g. People inherit genes for particular diseases like red-green colour blindness
- Cells mutate - causing cancer
What is cancer?
• Cancer is a non-infectious disease where cells grow out of control and form tumours
How can you reduce the likelihood of developing cancer?
- Don’t smoke - chemicals in cigarettes cause lung cancer + other cancers like throat cancer
- Don’t drink excess alcohol - alcohol is linked to cancer of the liver, gut and mouth
- Avoid getting sunburn - skin cells damaged by the sun can mutate and become cancerous
- Eat a healthy diet - a high-fibre diet can reduce the risk of bowel cancer
Describe the division of cancerous cells.
• Cancerous cells divide in an abnormal and uncontrollable way, forming lump cells called tumours
• A tumour that grows in one place is called benign
• If it breaks off and spreads to other areas of the body it becomes malignant
•
What affects a person’s chances of surviving cancer?
- Type of cancer
- Time of diagnosis
- Age of the person
- Whether it is benign
Describe the characteristics of infectious diseases
- Spread from one person to another
* Caused by pathogens (microorganisms that attack and invade the body)
Give examples of infectious diseases and their causes.
- Athlete’s foot - fungus
- Flu - virus
- Cholera - bacterium
- Malaria - protozoan
Describe the stages of mosquitos (vector) spreading.
- A mosquito sucks blood from the human (host)
- If there are malaria parasites in the blood, they mate and move from the mosquito’s gut to its salivary gland
- The mosquito then bites another person and passes the malaria parasites into their bloodstream.
- The malaria parasites move to the liver, where they mature and reproduce
- The new generation of malaria parasites migrates to the blood and replicates in red blood cells, bursting them open. This damage leads to characteristic malaria fever and can sometimes result it death
How can the risk of the spread of malaria be reduced?
- Sleeping under a mosquito nets
- Using insect repellent
- Killing Mosquitos with pesticide
What defences does the body have against pathogens getting in?
- The skin acts as a barrier against microorgansims
- Blood clots in wounds to prevent microorganisms from entering the bloodstream
- The respiratory system is lines with cells that produce a sticky, liquid mucus that forms a mucus membrane to trap microorganisms
- The stomach produces hydrochloric acid which kills microorganisms in the food we eat
Name the two ways the two types of white blood cells deal with pathogens.
- By engulfing and digesting pathogens they find in the bloodstream
- By making antibodies to attack pathogens. They recognise the markers on pathogens and produce antibodies which lock onto the markers (antigens) killing the pathogens
Describe the stages of a vaccination.
- A person is injected with a weakened or dead strain of the pathogen, which is incapable of multiplying. It’s harmless.
- Even though the pathogens are harmless, the antigens (markers) trigger the production of specific antibodies by the white blood cells
- Long after the pathogen has been dealt with, the white blood cells remain in the blood (memory cells are produced). This means more antibodies can be produced very quickly if the pathogen is detected again