Biology 1A - Summary One

What is a Sense Organ?

What is a Sense Organ?

What is a Receptor?

A sense organ is the organ which detects the stimulus these are:

- EYES

- EARS

- NOSE

- TONGUE

- SKIN

What is a Stimulus?

Receptors are groups of cells which are sensitive to a stimulus - they change stimulus energy into electrical impulses.

- EYES: Light receptors

- EARS: Sound and 'balance' receptors

- NOSE: Smell receptors (chemical stimuli)

- TONGUE: Taste receptors

- SKIN: Receptors sensitive to touch, pressure and temperature change

A stimulus is a change in your environment, which you may need to react to (e.g. a recently pounced tiger).

A sense organ is the organ which detects the stimulus these are:

- EYES

- EARS

- NOSE

- TONGUE

- SKIN

What is a Sensory Neurone?

Sensory neurones are the nerve cells that carry signals as electrical impulses from the receptors in the sense organs to the CNS (central nervous system).

A stimulus is a change in your environment, which you may need to react to (e.g. a recently pounced tiger).

What is a Motor Neurone?

What is a Sensory Neurone?

Motor Neurones are the nerve cells that carry signals from the CNS to the effector (muscle or gland).

Sensory neurones are the nerve cells that carry signals as electrical impulses from the receptors in the sense organs to the CNS (central nervous system).

What is the Central Nervous System?

What is a Motor Neurone?

The Central Nervous System (CNS), is where all the information from the sense organs is sent, and where reflexes and actions are coordinated. The CNS consists of the brain and spinal cord only.

Motor Neurones are the nerve cells that carry signals from the CNS to the effector (muscle or gland).

What is a Synapse?

What is the Central Nervous System?

A Synapse is the 'junction' between two neurones. The nerve signal is transferred by chemicals which diffuse (move) across the gap - which then set off a new electrical signal in the next neurone.

The Central Nervous System (CNS), is where all the information from the sense organs is sent, and where reflexes and actions are coordinated. The CNS consists of the brain and spinal cord only.

What is a Reflex Arc?

The reflex arc is the passage of information in a reflex action (from receptor to effector). We have reflex actions because sometimes waiting for your brain to make a decision is too slow, therefore we have automatic responses to certain stimuli - and they reduce the risks of us being injured.

Here is a diagram to display a reflex arc:

Stimuli>Receptor>Sensory Neurone>Relay Neurone>Motor Neurone>Effector>Response

What is a Synapse?

What is a hormone?

A Synapse is the 'junction' between two neurones. The nerve signal is transferred by chemicals which diffuse (move) across the gap - which then set off a new electrical signal in the next neurone.

What is a Reflex Arc?

Hormones are chemical messengers which travel in the blood to activate target cells.

The reflex arc is the passage of information in a reflex action (from receptor to effector). We have reflex actions because sometimes waiting for your brain to make a decision is too slow, therefore we have automatic responses to certain stimuli - and they reduce the risks of us being injured.

Here is a diagram to display a reflex arc:

Stimuli>Receptor>Sensory Neurone>Relay Neurone>Motor Neurone>Effector>Response

What is the Pituitary Gland?

What is a hormone?

The pituitary gland is located just below the brain, and produces many important hormones including LH (luteinising hormone), FSH (follicle-stimulating hormone) and ADH (controls water content).

Hormones are chemical messengers which travel in the blood to activate target cells.

What is the Pancreas?

What is the Pituitary Gland?

The Pancreas is located just infront of the kidneys, and produces insulin for the control of the blood sugar levels in the body.

The pituitary gland is located just below the brain, and produces many important hormones including LH (luteinising hormone), FSH (follicle-stimulating hormone) and ADH (controls water content).

What are the Ovaries?

What is a Receptor?

Ovaries are within females only, and they produce Oestrogen which controls the Menstrual Cycle. Ovaries also promote all female secondary characteristics such as extra body hair, and widening of the hips.

The Pancreas is located just infront of the kidneys, and produces insulin for the control of the blood sugar levels in the body.

What are the Testes?

What are the Ovaries?

Testes appear in men only, and they produce testosterone which promotes all male secondary sexual characteristics at puberty e.g. extra body hair.

Ovaries are within females only, and they produce Oestrogen which controls the Menstrual Cycle. Ovaries also promote all female secondary characteristics such as extra body hair, and widening of the hips.

What is FSH?

What are the Testes?

FSH (Follice-stimulating hormone), is produced by the pituitary gland, and causes an egg to mature in one of the ovaries, as well as stimulating the ovaries to produce Oestrogen.

Testes appear in men only, and they produce testosterone which promotes all male secondary sexual characteristics at puberty e.g. extra body hair.

How can FSH increase the chances of pregnancy?

What is FSH?

Low levels of FSH mean that there is not enough of the hormone to mature the eggs in the ovaries. Consequently, no eggs are released at the middle of the Menstrual Cycle, and this means that the woman can not get pregnant. Therefore, this hormone can be taken by women to stimulate the production of eggs in the ovaries.

Increased levels of FSH also mean that ovaries are stimulated to produce LH (luteinising hormone), which means your ovaries are stimulated to release eggs.

ADVANATGES - Help women get pregnant

DISADVANTAGES - This process does not always work. Also, sometimes, too many eggs could be stimulated - increasing the chances of multiple births.

FSH (Follice-stimulating hormone), is produced by the pituitary gland, and causes an egg to mature in one of the ovaries, as well as stimulating the ovaries to produce Oestrogen.

What is Oestrogen?

How can FSH increase the chances of pregnancy?

Oestrogen is produced in the ovaries, and causes the pituitary gland to produced LH (luteinising hormone), as well as inhibiting any further release of FSH (follicle-stimulating hormone).

Low levels of FSH mean that there is not enough of the hormone to mature the eggs in the ovaries. Consequently, no eggs are released at the middle of the Menstrual Cycle, and this means that the woman can not get pregnant. Therefore, this hormone can be taken by women to stimulate the production of eggs in the ovaries.

Increased levels of FSH also mean that ovaries are stimulated to produce LH (luteinising hormone), which means your ovaries are stimulated to release eggs.

ADVANATGES - Help women get pregnant

DISADVANTAGES - This process does not always work. Also, sometimes, too many eggs could be stimulated - increasing the chances of multiple births.

What is LH?

What is Oestrogen?

LH, is the hormone produced in the pituitary gland, and it stimulates the release of an egg at around the middle of the Menstrual Cycle.

Oestrogen is produced in the ovaries, and causes the pituitary gland to produced LH (luteinising hormone), as well as inhibiting any further release of FSH (follicle-stimulating hormone).

What is the Pill?

What is LH?

The Pill is an oral contraceptive, which contains Oestrogen. It works by ihibiting the release of FSH, and if the levels of Oestrogen are kept permanatly high, after a while, egg development and production stops and stays stopped.

ADVANTAGES: Over 99% effective, and it reduces the risk of getting some types of cancer.

DISADVANTAGES: Side effects include headaches, nausea and irregular bleeding, and The Pill doesn't protect again sexually transmitted diseases (STDs).

LH, is the hormone produced in the pituitary gland, and it stimulates the release of an egg at around the middle of the Menstrual Cycle.

What is IVF?

Receptors are groups of cells which are sensitive to a stimulus - they change stimulus energy into electrical impulses.

- EYES: Light receptors

- EARS: Sound and 'balance' receptors

- NOSE: Smell receptors (chemical stimuli)

- TONGUE: Taste receptors

- SKIN: Receptors sensitive to touch, pressure and temperature change

Also known as 'in vitro fertilisation', IVF is a method used to help women get pregnant. It involves collecting eggs from the woman's ovaries, and fertilising them in a lab with the man's sperm. These are then grown into embryos, and implanted into the uterus.

- Hormones are given before egg collection to stimulate egg production.

- Oestrgen and Progesterone are also given before implantation to increase the chances of the process succeeding.

The Pill is an oral contraceptive, which contains Oestrogen. It works by ihibiting the release of FSH, and if the levels of Oestrogen are kept permanatly high, after a while, egg development and production stops and stays stopped.

ADVANTAGES: Over 99% effective, and it reduces the risk of getting some types of cancer.

DISADVANTAGES: Side effects include headaches, nausea and irregular bleeding, and The Pill doesn't protect again sexually transmitted diseases (STDs).

What is Homeostasis?

What is IVF?

Homeostasis is the process in which all the functions of the body try to maintain a 'constant internal environment'. The bodily levels which need to be controlled are:

- Ion Content

- Water Content

- Sugar Content

- Temperature

Also known as 'in vitro fertilisation', IVF is a method used to help women get pregnant. It involves collecting eggs from the woman's ovaries, and fertilising them in a lab with the man's sperm. These are then grown into embryos, and implanted into the uterus.

- Hormones are given before egg collection to stimulate egg production.

- Oestrgen and Progesterone are also given before implantation to increase the chances of the process succeeding.

Why is it important to regulate the ion content?

What is Homeostasis?

Ion content is regulated by the kidneys. Ions (e.g. sodium) is taken into the body through food. If the food contains too much of any kind of ion, then the excess ions need to be removed. Ions are lost in sweat, as well as removed by the kidneys in urin.

Homeostasis is the process in which all the functions of the body try to maintain a 'constant internal environment'. The bodily levels which need to be controlled are:

- Ion Content

- Water Content

- Sugar Content

- Temperature

Why is it important to regulate the water content in the body?

Why is it important to regulate the ion content?

Water is taken into the body with food and drink, and is lost from the body in these ways:

- Through the skin as sweat

- Via the lungs in breath

- Via the kidneys as urine

Ion content is regulated by the kidneys. Ions (e.g. sodium) is taken into the body through food. If the food contains too much of any kind of ion, then the excess ions need to be removed. Ions are lost in sweat, as well as removed by the kidneys in urin.

Why is it important to regulate the body temperature?

What is the Pill?

All enzymes work best at 37 degrees, and therefore your body aims to maintain this temperature. A part of your brain acts as your own personal thermostat, and is sensitive to the blood temperature.

Water is taken into the body with food and drink, and is lost from the body in these ways:

- Through the skin as sweat

- Via the lungs in breath

- Via the kidneys as urine

Why is it important to regulate the blood sugar levels?

Why is it important to regulate the body temperature?

Sugar is taken into the body through carbohydrate foods. Metabolism of cells removes glucose from the blood, and so does a balanced daily amount of exercise. However, to maintain the right level, we have the hormone insulin - which removes sugar from our blood. Diabetes (Type 1) is an illness at which your body doesn't produce enough insulin to maintain the correct blood sugar level.

All enzymes work best at 37 degrees, and therefore your body aims to maintain this temperature. A part of your brain acts as your own personal thermostat, and is sensitive to the blood temperature.

What are the five groups, and their roles?

Why is it important to regulate the blood sugar levels?

- Carbohydrates and fats: Keep you warm and provide energy

- Protein: For growth, cell repair and cell replacement

- Fibre: Keep everything moving smoothly in your digestive system

- Vitamins and minerals: Maintain the healthiness of the blood, skin and bones

Sugar is taken into the body through carbohydrate foods. Metabolism of cells removes glucose from the blood, and so does a balanced daily amount of exercise. However, to maintain the right level, we have the hormone insulin - which removes sugar from our blood. Diabetes (Type 1) is an illness at which your body doesn't produce enough insulin to maintain the correct blood sugar level.

What is the Metabolism?

What are the five groups, and their roles?

The Metabolism is the chemical reactions which happen within the body to keep you alive. The Metabolic Rate is the speed at which these reactions occur. People with higher proportions of muscle to fat, will have a higher Metabolic Rate.

Regular exercise can boost your resting Metabolic Rate.

- Carbohydrates and fats: Keep you warm and provide energy

- Protein: For growth, cell repair and cell replacement

- Fibre: Keep everything moving smoothly in your digestive system

- Vitamins and minerals: Maintain the healthiness of the blood, skin and bones

What is Obesity and what are its effects?

What is the Metabolism?

Obesity is the condition at which people become severely overweight, and this can happen because of bad diet, overeating, lack of exercise, or even hormonal problems.

Health problems caused because of obesity include:

- Arthritis (inflamation of the joints)

- Diabetes (inability to control blood sugar levels)

- High blood pressure

- Heart Disease

- Some types of cancer

The Metabolism is the chemical reactions which happen within the body to keep you alive. The Metabolic Rate is the speed at which these reactions occur. People with higher proportions of muscle to fat, will have a higher Metabolic Rate.

Regular exercise can boost your resting Metabolic Rate.

What is Malnutrition/Starvation, and what are the effects of each of them?

What is Obesity and what are its effects?

What is a Stimulus?

Obesity is the condition at which people become severely overweight, and this can happen because of bad diet, overeating, lack of exercise, or even hormonal problems.

Health problems caused because of obesity include:

- Arthritis (inflamation of the joints)

- Diabetes (inability to control blood sugar levels)

- High blood pressure

- Heart Disease

- Some types of cancer

What is Cholesterol?

What is Malnutrition/Starvation, and what are the effects of each of them?

What is a Sense Organ?

Malnutrition, is the condition of a person when they are given a lack of one of more types of foods.

Starvation is the condition of a person when they are not given enough food of any sort.

The effects of Malnutrition /Starvation include:

- Slow growth

- Fatigue

- Poor resistance to infection

- Irregular periods (in women)

Why is it important to regulate the water content in the body?

A sense organ is the organ which detects the stimulus these are:

- EYES

- EARS

- NOSE

- TONGUE

- SKIN

What are HDLs (High Density lipo-proteins) and LDLs (Low Density lip-proteins)?

What is Cholesterol?

What is a Receptor?

Cholesterol is a fatty substance that's essential for good health - and it is found in every cell of the body.

However, a high cholesterol level is bad for your health, because blood vessels get clogged with fatty cholesterol deposits, and this reduces the blood flow to the heart. Reduced blood flow can lead to angina (chest pain) or even a heart attack!

The liver makes and removes this substance into and from the blood, however the amount it makes and removes depends on your health...

Cholesterol is transported around the body in blood by lipoproteins.

High Density lipo-proteins (HDLs), carry cholesterol that isn't needed from the body cells back to the liver for removal from the body - so they're called 'good cholesterol'.

Low Density lipo-proteins (LDLs), carry cholesterol from the liver to the body cells - they're known as 'bad cholesterol' because any excess can build up in the arteries.

Receptors are groups of cells which are sensitive to a stimulus - they change stimulus energy into electrical impulses.

- EYES: Light receptors

- EARS: Sound and 'balance' receptors

- NOSE: Smell receptors (chemical stimuli)

- TONGUE: Taste receptors

- SKIN: Receptors sensitive to touch, pressure and temperature change

What are HDLs (High Density lipo-proteins) and LDLs (Low Density lip-proteins)?

What are Saturated Fats, Polyunsaturated Fats, and Monounsaturated Fats?

What is a Stimulus?

Saturated Fats: These fats contain no double carbon bond - they raise cholesterol in the blood, by increasing the amount the blood makes, and decreasing the amount it gets rid of (should be eaten in moderation).

Polyunsaturated Fats: These fats contain more than one double carbon bond - they tend to lower blood cholesterol, by increasing its removal from the body, and improving the LDL/HDL balance.

Monounsaturated Fats: These fats contain exactly one double carbon bond - they are considered as 'neutral' as far as health is concerned. However, recent evidence has suggested that they can help to lower blood cholesterol and improve the LDL/HDL balance.

Cholesterol is transported around the body in blood by lipoproteins.

High Density lipo-proteins (HDLs), carry cholesterol that isn't needed from the body cells back to the liver for removal from the body - so they're called 'good cholesterol'.

Low Density lipo-proteins (LDLs), carry cholesterol from the liver to the body cells - they're known as 'bad cholesterol' because any excess can build up in the arteries.

A stimulus is a change in your environment, which you may need to react to (e.g. a recently pounced tiger).

What are Saturated Fats, Polyunsaturated Fats, and Monounsaturated Fats?

What is a Sensory Neurone?

A drug is a chemical or substance which alters the way the body or mind function, they are derived from natural substances found in plants. Some of the chemical changes which happen because of a drug can cause the person to become addicted. If this drug isn't taken reguarly, the addict can suffer withdrawal symptoms.

Medical drugs have to be thoroughly tested, and go through a thorough testing procedure of four stages:

- First step: Computer models (they stimulate a human's response to a drug).

- Second step: The drug is then developed further by testing on human tissue in the lab.

- Third step: To develop and test the drug using live mammals.

- Fourth step: To finally test the drug on human volunteers.

Saturated Fats: These fats contain no double carbon bond - they raise cholesterol in the blood, by increasing the amount the blood makes, and decreasing the amount it gets rid of (should be eaten in moderation).

Polyunsaturated Fats: These fats contain more than one double carbon bond - they tend to lower blood cholesterol, by increasing its removal from the body, and improving the LDL/HDL balance.

Monounsaturated Fats: These fats contain exactly one double carbon bond - they are considered as 'neutral' as far as health is concerned. However, recent evidence has suggested that they can help to lower blood cholesterol and improve the LDL/HDL balance.

What is Thalidomide and what were the problems with it?

Sensory neurones are the nerve cells that carry signals as electrical impulses from the receptors in the sense organs to the CNS (central nervous system).

What are drugs, and what is done to make sure they are safe?

Thalidomide was a drug developed in the 1950s, and was intended as a sleeping pill. But later it was seen as an effective drug in relieving sickness in pregnant women.

However, Thalidomide had not been tested as a drug for morning sickness, and consequently, people did not know the effects as a drug on pregnant women.

10,000 babies were affected by Thalidomide, and only about half of them survived - Thalidomide was later realised that it could pass through the placenta and affect the fetus, cauding stunted growth of the fetus' arms and legs.

The drug was banned, and rigorous testing procedures were introduced, it has now been re-introduced as treatment for leprosy, AIDS, and certain cancers, but can not be used on pregnant women.

What is a Motor Neurone?

A drug is a chemical or substance which alters the way the body or mind function, they are derived from natural substances found in plants. Some of the chemical changes which happen because of a drug can cause the person to become addicted. If this drug isn't taken reguarly, the addict can suffer withdrawal symptoms.

Medical drugs have to be thoroughly tested, and go through a thorough testing procedure of four stages:

- First step: Computer models (they stimulate a human's response to a drug).

- Second step: The drug is then developed further by testing on human tissue in the lab.

- Third step: To develop and test the drug using live mammals.

- Fourth step: To finally test the drug on human volunteers.

What are the effects of Tobacco on the human body?

Motor Neurones are the nerve cells that carry signals from the CNS to the effector (muscle or gland).

What is Thalidomide and what were the problems with it?

TOBACCO:

- Carbon Monoxide: Cobines with Haemoglobin in blood cells - body deprived of Oxygen.

- Tobacco smoke contains carcinogens - chemicals that cause cancer.

- Smoking causes disease of the heart and blood vessels - leading to heart attacks and strokes. This leads to diseases like emphysema and bronchitis.

- The tar in cigarettes damages the cilia (little hairs) in your lunngs and windpipe. These hairs, along with mucus, catch a load of dust and bacteria before they reach the lungs, without them, chest infections are more likely.

- Smoking tobacco is also addictive - due to the nicotine in tobacco smoke.

What is the Central Nervous System?

Thalidomide was a drug developed in the 1950s, and was intended as a sleeping pill. But later it was seen as an effective drug in relieving sickness in pregnant women.

However, Thalidomide had not been tested as a drug for morning sickness, and consequently, people did not know the effects as a drug on pregnant women.

10,000 babies were affected by Thalidomide, and only about half of them survived - Thalidomide was later realised that it could pass through the placenta and affect the fetus, cauding stunted growth of the fetus' arms and legs.

The drug was banned, and rigorous testing procedures were introduced, it has now been re-introduced as treatment for leprosy, AIDS, and certain cancers, but can not be used on pregnant women.

What are the effects of Alcohol on the human body?

The Central Nervous System (CNS), is where all the information from the sense organs is sent, and where reflexes and actions are coordinated. The CNS consists of the brain and spinal cord only.

What are the effects of Tobacco on the human body?

ALCOHOL:

- The main affect of alcohol is that it reduces the activity of the nervous system -slowing down your reactions.

- It also makes you feel less inhibited - helping you to socialise and relax.

- Too much tobacco can lead to impaired judgement, poor balance and coordination, lack of self-control, unconsciousness and even coma.

- Excess alcohol can also cause dehydration - this can damage brain cells.

- There are also social costs too, alcohol is linked with way more than half of murders, stabbings and domestic assaults.

What is a Synapse?

TOBACCO:

- Carbon Monoxide: Cobines with Haemoglobin in blood cells - body deprived of Oxygen.

- Tobacco smoke contains carcinogens - chemicals that cause cancer.

- Smoking causes disease of the heart and blood vessels - leading to heart attacks and strokes. This leads to diseases like emphysema and bronchitis.

- The tar in cigarettes damages the cilia (little hairs) in your lunngs and windpipe. These hairs, along with mucus, catch a load of dust and bacteria before they reach the lungs, without them, chest infections are more likely.

- Smoking tobacco is also addictive - due to the nicotine in tobacco smoke.

What is bacteria and virus, and what does it do?

A Synapse is the 'junction' between two neurones. The nerve signal is transferred by chemicals which diffuse (move) across the gap - which then set off a new electrical signal in the next neurone.

What are the effects of Alcohol on the human body?

Bacteria:

Bacteria are very small living cells, which can reproduce rapidly inside your body.

Bacteria makes you feel ill by doing two things; a) Damaging your cells b) Producing toxins

Virus:

Viruses are not cells, they're about 100 times smaller than a bacteria cell. They're no more than a coat of protein around some genetic material.

Viruses replicate themselves by invading your cells and using the cells' machinery to produce many copies of themselves. The cell will then burst, releasing the virus into the body.

The cell damage is what makes you feel ill.

What is a Reflex Arc?

Malnutrition, is the condition of a person when they are given a lack of one of more types of foods.

Starvation is the condition of a person when they are not given enough food of any sort.

The effects of Malnutrition /Starvation include:

- Slow growth

- Fatigue

- Poor resistance to infection

- Irregular periods (in women)

The reflex arc is the passage of information in a reflex action (from receptor to effector). We have reflex actions because sometimes waiting for your brain to make a decision is too slow, therefore we have automatic responses to certain stimuli - and they reduce the risks of us being injured.

Here is a diagram to display a reflex arc:

Stimuli>Receptor>Sensory Neurone>Relay Neurone>Motor Neurone>Effector>Response

What is bacteria and virus, and what does it do?

What is a hormone?

Bacteria:

Bacteria are very small living cells, which can reproduce rapidly inside your body.

Bacteria makes you feel ill by doing two things; a) Damaging your cells b) Producing toxins

Virus:

Viruses are not cells, they're about 100 times smaller than a bacteria cell. They're no more than a coat of protein around some genetic material.

Viruses replicate themselves by invading your cells and using the cells' machinery to produce many copies of themselves. The cell will then burst, releasing the virus into the body.

The cell damage is what makes you feel ill.

Hormones are chemical messengers which travel in the blood to activate target cells.

Cholesterol is a fatty substance that's essential for good health - and it is found in every cell of the body.

However, a high cholesterol level is bad for your health, because blood vessels get clogged with fatty cholesterol deposits, and this reduces the blood flow to the heart. Reduced blood flow can lead to angina (chest pain) or even a heart attack!

The liver makes and removes this substance into and from the blood, however the amount it makes and removes depends on your health...

The pituitary gland is located just below the brain, and produces many important hormones including LH (luteinising hormone), FSH (follicle-stimulating hormone) and ADH (controls water content).

What is the Pancreas?

The Pancreas is located just infront of the kidneys, and produces insulin for the control of the blood sugar levels in the body.

What are the Ovaries?

Ovaries are within females only, and they produce Oestrogen which controls the Menstrual Cycle. Ovaries also promote all female secondary characteristics such as extra body hair, and widening of the hips.

What are the Testes?

Testes appear in men only, and they produce testosterone which promotes all male secondary sexual characteristics at puberty e.g. extra body hair.

What is FSH?

FSH (Follice-stimulating hormone), is produced by the pituitary gland, and causes an egg to mature in one of the ovaries, as well as stimulating the ovaries to produce Oestrogen.

How can FSH increase the chances of pregnancy?

Low levels of FSH mean that there is not enough of the hormone to mature the eggs in the ovaries. Consequently, no eggs are released at the middle of the Menstrual Cycle, and this means that the woman can not get pregnant. Therefore, this hormone can be taken by women to stimulate the production of eggs in the ovaries.

Increased levels of FSH also mean that ovaries are stimulated to produce LH (luteinising hormone), which means your ovaries are stimulated to release eggs.

ADVANATGES - Help women get pregnant

DISADVANTAGES - This process does not always work. Also, sometimes, too many eggs could be stimulated - increasing the chances of multiple births.

What is Oestrogen?

Oestrogen is produced in the ovaries, and causes the pituitary gland to produced LH (luteinising hormone), as well as inhibiting any further release of FSH (follicle-stimulating hormone).

What is LH?

LH, is the hormone produced in the pituitary gland, and it stimulates the release of an egg at around the middle of the Menstrual Cycle.

What is the Pill?

The Pill is an oral contraceptive, which contains Oestrogen. It works by ihibiting the release of FSH, and if the levels of Oestrogen are kept permanatly high, after a while, egg development and production stops and stays stopped.

ADVANTAGES: Over 99% effective, and it reduces the risk of getting some types of cancer.

DISADVANTAGES: Side effects include headaches, nausea and irregular bleeding, and The Pill doesn't protect again sexually transmitted diseases (STDs).

What is IVF?

What is a Sensory Neurone?

What is Homeostasis?

Homeostasis is the process in which all the functions of the body try to maintain a 'constant internal environment'. The bodily levels which need to be controlled are:

- Ion Content

- Water Content

- Sugar Content

- Temperature

Why is it important to regulate the ion content?

Ion content is regulated by the kidneys. Ions (e.g. sodium) is taken into the body through food. If the food contains too much of any kind of ion, then the excess ions need to be removed. Ions are lost in sweat, as well as removed by the kidneys in urin.

Why is it important to regulate the water content in the body?

Water is taken into the body with food and drink, and is lost from the body in these ways:

- Through the skin as sweat

- Via the lungs in breath

- Via the kidneys as urine

Why is it important to regulate the body temperature?

All enzymes work best at 37 degrees, and therefore your body aims to maintain this temperature. A part of your brain acts as your own personal thermostat, and is sensitive to the blood temperature.

Why is it important to regulate the blood sugar levels?

Sugar is taken into the body through carbohydrate foods. Metabolism of cells removes glucose from the blood, and so does a balanced daily amount of exercise. However, to maintain the right level, we have the hormone insulin - which removes sugar from our blood. Diabetes (Type 1) is an illness at which your body doesn't produce enough insulin to maintain the correct blood sugar level.

What are the five groups, and their roles?

- Carbohydrates and fats: Keep you warm and provide energy

- Protein: For growth, cell repair and cell replacement

- Fibre: Keep everything moving smoothly in your digestive system

- Vitamins and minerals: Maintain the healthiness of the blood, skin and bones

What is the Metabolism?

The Metabolism is the chemical reactions which happen within the body to keep you alive. The Metabolic Rate is the speed at which these reactions occur. People with higher proportions of muscle to fat, will have a higher Metabolic Rate.

Regular exercise can boost your resting Metabolic Rate.

What is Obesity and what are its effects?

Obesity is the condition at which people become severely overweight, and this can happen because of bad diet, overeating, lack of exercise, or even hormonal problems.

Health problems caused because of obesity include:

- Arthritis (inflamation of the joints)

- Diabetes (inability to control blood sugar levels)

- High blood pressure

- Heart Disease

- Some types of cancer

What is Malnutrition/Starvation, and what are the effects of each of them?

Malnutrition, is the condition of a person when they are given a lack of one of more types of foods.

Starvation is the condition of a person when they are not given enough food of any sort.

The effects of Malnutrition /Starvation include:

- Slow growth

- Fatigue

- Poor resistance to infection

- Irregular periods (in women)

ALCOHOL:

- The main affect of alcohol is that it reduces the activity of the nervous system -slowing down your reactions.

- It also makes you feel less inhibited - helping you to socialise and relax.

- Too much tobacco can lead to impaired judgement, poor balance and coordination, lack of self-control, unconsciousness and even coma.

- Excess alcohol can also cause dehydration - this can damage brain cells.

- There are also social costs too, alcohol is linked with way more than half of murders, stabbings and domestic assaults.

Cholesterol is a fatty substance that's essential for good health - and it is found in every cell of the body.

However, a high cholesterol level is bad for your health, because blood vessels get clogged with fatty cholesterol deposits, and this reduces the blood flow to the heart. Reduced blood flow can lead to angina (chest pain) or even a heart attack!

The liver makes and removes this substance into and from the blood, however the amount it makes and removes depends on your health...

What are HDLs (High Density lipo-proteins) and LDLs (Low Density lip-proteins)?

Cholesterol is transported around the body in blood by lipoproteins.

High Density lipo-proteins (HDLs), carry cholesterol that isn't needed from the body cells back to the liver for removal from the body - so they're called 'good cholesterol'.

Low Density lipo-proteins (LDLs), carry cholesterol from the liver to the body cells - they're known as 'bad cholesterol' because any excess can build up in the arteries.

What are Saturated Fats, Polyunsaturated Fats, and Monounsaturated Fats?

Saturated Fats: These fats contain no double carbon bond - they raise cholesterol in the blood, by increasing the amount the blood makes, and decreasing the amount it gets rid of (should be eaten in moderation).

Polyunsaturated Fats: These fats contain more than one double carbon bond - they tend to lower blood cholesterol, by increasing its removal from the body, and improving the LDL/HDL balance.

Monounsaturated Fats: These fats contain exactly one double carbon bond - they are considered as 'neutral' as far as health is concerned. However, recent evidence has suggested that they can help to lower blood cholesterol and improve the LDL/HDL balance.

What are drugs, and what is done to make sure they are safe?

A drug is a chemical or substance which alters the way the body or mind function, they are derived from natural substances found in plants. Some of the chemical changes which happen because of a drug can cause the person to become addicted. If this drug isn't taken reguarly, the addict can suffer withdrawal symptoms.

Medical drugs have to be thoroughly tested, and go through a thorough testing procedure of four stages:

- First step: Computer models (they stimulate a human's response to a drug).

- Second step: The drug is then developed further by testing on human tissue in the lab.

- Third step: To develop and test the drug using live mammals.

- Fourth step: To finally test the drug on human volunteers.

What is Thalidomide and what were the problems with it?

Thalidomide was a drug developed in the 1950s, and was intended as a sleeping pill. But later it was seen as an effective drug in relieving sickness in pregnant women.

However, Thalidomide had not been tested as a drug for morning sickness, and consequently, people did not know the effects as a drug on pregnant women.

10,000 babies were affected by Thalidomide, and only about half of them survived - Thalidomide was later realised that it could pass through the placenta and affect the fetus, cauding stunted growth of the fetus' arms and legs.

The drug was banned, and rigorous testing procedures were introduced, it has now been re-introduced as treatment for leprosy, AIDS, and certain cancers, but can not be used on pregnant women.

What are the effects of Tobacco on the human body?

TOBACCO:

- Carbon Monoxide: Cobines with Haemoglobin in blood cells - body deprived of Oxygen.

- Tobacco smoke contains carcinogens - chemicals that cause cancer.

- Smoking causes disease of the heart and blood vessels - leading to heart attacks and strokes. This leads to diseases like emphysema and bronchitis.

- The tar in cigarettes damages the cilia (little hairs) in your lunngs and windpipe. These hairs, along with mucus, catch a load of dust and bacteria before they reach the lungs, without them, chest infections are more likely.

- Smoking tobacco is also addictive - due to the nicotine in tobacco smoke.

What are the effects of Alcohol on the human body?

ALCOHOL:

- The main affect of alcohol is that it reduces the activity of the nervous system -slowing down your reactions.

- It also makes you feel less inhibited - helping you to socialise and relax.

- Too much tobacco can lead to impaired judgement, poor balance and coordination, lack of self-control, unconsciousness and even coma.

- Excess alcohol can also cause dehydration - this can damage brain cells.

- There are also social costs too, alcohol is linked with way more than half of murders, stabbings and domestic assaults.

What is bacteria and virus, and what does it do?

Bacteria:

Bacteria are very small living cells, which can reproduce rapidly inside your body.

Bacteria makes you feel ill by doing two things; a) Damaging your cells b) Producing toxins

Virus:

Viruses are not cells, they're about 100 times smaller than a bacteria cell. They're no more than a coat of protein around some genetic material.

Viruses replicate themselves by invading your cells and using the cells' machinery to produce many copies of themselves. The cell will then burst, releasing the virus into the body.

The cell damage is what makes you feel ill.