Excellent! Really well done for keeping this page up to date and complete!

Hormone Prolactin

The hormone prolactin is produced by mothers during and after pregnancy. It stimulates the production of breast milk, which is fed to the new born baby, containing antibodies and nutrients/glucose to aid the child's growth.


Bile (or gall) is green/brown fluid that is produced by the liver and stored in the gall bladder. Bile aids the digestion of lipids that occurs in the small intestine. It is composed of water, bile salts, mucus, fats and cholesterin.

external image lymphnodes.jpg

Lymphatic System

Just as blood flows around the body, there is a secondary system containing lymph, excess fluid that leaves and enters the blood through lymphatic vessels. The lymph is moved through the lymphatic system by muscular contractions, allowing it to reach different areas in the blood to absorb and release the lymph. The lymphatic system not only filters and removes excess fluid from the blood, but also helps to fight infection in the body.
The lymphatic system also absorbs lipids from in the small intestine. This is absorbed into the lacteal in the villi, then eventually reaches the bloodstream.
Also in the lymphatic are lymph nodes, which filters the lymph, clearing it of all unwanted materials such as micro-organisms. These nodes are in the groin, neck chest, as well as other areas. Macrophages go to the lymph nodes and destroy these substances, causing them to swell up when an infection is being fought in the body. The lymph nodes are also where lymphocytes and antibodies are produced, making the nodes essential for the immune system to function.
When the lymphatic system doesn't work efficiently, conditions such oedema and elephantitis develop, both involving the swelling up of limbs.




Hypertensionexternal image 166404055_3a32887233.jpg

Hypertension, or high blood pressure, is an illness that effects 1 in 5 of Britain's population. It is calculated by measuring the pressure of the blood when it is contracting, over the pressure of the blood when the heart is relaxed. e.g 120/80 mm Hg. This number is not only due to the overall pressure of the patient's blood, but the width of the arteries. This can be influenced by atheromas or a coronary thrombosis.
Blood pressure is classified as high is either 160 mm Hg when contracting (systolic) or 100 mm Hg when relaxed (diastolic). The unit used to measure blood pressure is the height of mercury (chemical symbol - Hg) affected in the blood pressure cuff or sphygmomanometer.
The blood pressure cuff is the doctor's method of measuring blood pressure. Air is pumped into a inflatable cuff to restrict the blood flow that reaches your arm. Manual sphygmomanometers are used with a stethoscope, but many now can tell when the heart is in systole or diastole, eliminating the need to listen manually.
Around 90% of sufferers have a form of the illness called primary hypertension, where the cause of the increased pressure is not apparent or revealed through testing. For those with secindary hypertension, however, the causes can be as follows;
  • endocrine tumours
  • severe kidney diseases
  • hormonal imbalances
  • damage to the ateries suppling the kidneys
There are some factors that contribute to the likeliness to develop hypertension, including obesity, smoking, diabetes, high salt or alcohol intake and lack of exercise. Those in the demograpic that is most susceptible to having hypertension should look out for the following symptoms:
  • fatigue
  • headache
  • confusion
A doctor can prescribe medication to lower blood pressure, but usually the main difference is made by the patients themselves. Losing weight, exercising regularly and having a healthy, balanced diet is the basic advice of any doctor, but if the patient smokes they are advised to quit and any excessive alcohol consumption should cease. Also, a primary problem affecting blood pressure levels is a stressful lifestyle, so all stressful situations should be avoided.

Net Doctor .co.uk
Angry Doc .com

Heart Disease

The term refers to any illness that causes a vessel/vein to become restricted or even blocked. There are many forms that this can take, each, if untreated, having catastrophic consequences. It is a medical problem of developed countries, due to one of the main causes being due to an excessive diet and lack of exercise.
  • Myocardial Infarction
This is technical term for what is commonly refered to as a heart attack. It is a general term for any kind of blocked vessel in the heart, leading to lack of blood to the coronary arteries. As the heart is constantly under strain to provide the body with oxygenated blood, it is essential that it receives oxygen itself in order for organisms to function healthily. If the muscles of the heart continue to be deprived of oxygen, cells will eventually die and cause a heart attack.external image coronary+bypass.jpg?version=2&modificationDate=1232381907993
Acute heart attacks can display a number of symptoms. For men - a pain in the chest, nausea, anxiety, sweating and shortness of breath. Women, on the other hand, have been found to experience fewer symptoms, in the form of shortness of breath, fatigue and a feeling of indigestion. Although this is the norm, some AMIs (acute myocardial infarctions) can occur 'silently', with no obvious discomfort.
  • Atheroscelorsis
This is a form of MI that is caused by a build up of fatty plaque due to fatty materials such as cholesterol. This, with the addition of calcium, hardens to been known biologically as atheromas. This means that the artery becomes narrower causing lack of oxygen to places that need it. The restriction of blood flow leads to many medical complications, including angina and coronary thrombosis.
  • Angina
One of the aforementioned consequences of atheroscelorsis. Symptoms that alert people to this problem only occur when the heart is under stress, whether through exercise or choronic anxiety. Due to lack of oxygen reaching the heart because of narrowed arteries, the sufferer experiences pain in the chest, jaw, neck and left arm.
  • Coronary Thrombosis
The uneven surface of the arteries due to atheroscelorsis often causes the valve to develop a blood clot. This can be carried along in the blood stream until it blocks a smaller opening of a capillery or vessel. This blockage, deprivation of oxygen and built up pressure goes on to cause a heart attack.

Firstly, the diet and lifestyle choices that caused any myocardial infarction need to be changed inorder for the heart to function normally. If the damage is extensive, a coronary bypass can be effective. This is an operation that takes a vein from the patient's leg to provide a 'way around' the blocked artery, allowing blood and therefore oxygen to the originally isolated area of the organ.
Text Book
National University of Singapore


9/10 Fantastic! This essay is clear, concise and very well written. You only lost 1 mark for repeating what you said at the end of stage 1 and the start of stage two. As usual, great work!

Question 5

(i) During the follicular phase of a woman's menstrual cycle, the graafian follicle is developing and therefore the egg (1). This is all caused by the hormone FSH, the follicle stimulating hormone (1). The graafian follicle also secretes the hormone oestrogen (1), which stimulates the endometrium and causes it to develop a lining (1). Oestrogen also stimulates the pituitary gland to release LH (lutenising hormone), which goes on to trigger ovulation (1). (5)
(ii) The luteal phase starts when ovulation occurs. The egg is released from the graafian follicle and ovary, by the release of LH from the pituitary gland. This hormone also causes the graafian follicle to develop into the corpus luteum (1) and oestrogen and progesterone is released. The progesterone to causes the lining of the endometrium to thicken (1), ready to accept a fertilised egg. LH and FSH drop as a result of this (1) , and therefore the corpus luteum degenerates and the lining breaks down as menstruation (1). (4)

Catriona, this page is excellent. The information is first class and the diagrams are relevant, really well done!

If you complete the work I have set out on GLOW and this site then please get in touch via the homepage or the Higher Human Biology GLOW discussion page so that I can direct you as to what to do next.

Once again, well done!

Contraceptionexternal image 2189839.jpg

Unplanned pregnancies have become more and more uncommon in the UK, due to the wide range of contraception available. There are methods which target the male or female reproductive tract.


  • Condom
This is one of the most common forms of protection, acting as a protection from sexually transmitted infections (STIs).
  • Vasectomy
This is a minor operation which prevents sperm entering the semen. The sperm duct is severed and tied, meaning that it can be reversed if needed.

Femaleexternal image FC_Condom_hres(1).jpg

  • Female Condom (Femidom)
Similar to the male condom, this is inserted into the vagina to prevent sperm from entering the cervix.
  • The Contraceptive Pill
The single most popular form of birth control. This pill is taken by the female, which contains oestrogen and progesterone, preventing her from ovulating.
The success rate is near 100%, as long as the pill is taken every day.
  • Female Sterilisation
Female equivelant of the vasectomy in which the fallopian tubes are cut/blocked, preventing the eggs from reaching the sperm.
  • Intra-Uterine Device (IUD)
A device around the size of a matchstick which is inserted into the uterus to prevent sperm from reaching the fallopian tubes.
  • Conceptive Injection
This is an injection of the hormone progesterone to provide short to long term birth control.
  • Intra-Uterine System (IUS)
Same as the IUD but containing the hormone progestogen, adding to its effectiveness.external image M860302-Contraceptive_patch_377x171.jpg
  • Skin Patch
A patch to be worn on the skin, releasing oestrogen and progesterone, making its effects similar to that of the pill.
  • Diaphragm
A 'cap' to be placed in the vagina or on the opening of the cervix acting as a barrier against sperm.


Net Doctor .co.uk
Wikipedia .co.uk

Female Infertilityexternal image female.jpg

Women who are trying to conceive may find that they are inable to get pregnant. This could be due to the partner or themselves being infertile.


Infertility in women can be due to a large number of problems.
  • Blocked/damaged fallopian tubes
  • Polycystic ovaries
  • Ovulation problems or failure
  • Endometriosis (endometrial cells affecting the ovaries)
  • Cevical mucus problem
  • Fibroids
Also, unfortunately, there can be no found medical explanation for why a woman cannot get pregnant, being labelled 'unexplained infertility'.


There are many treatments known to help a woman with fertility problems, both medical and through self help. Unfortunately there are some conditions that can't be solved, despite such huge improvements in medicines and treatments available.
Clomifene tablets are given to women who have ovulation problems but have normal levels of oestrogen. They have been shown to be fairly successful, as well as a slight increase in your chance of having twins.
If clomifene tablets are unsuccessful, gonadotrophin can be offered. This treatment is where many different hormones can be injected into the system to aid ovulation/fertilisation.
Another treatment which is not as widely offered is assisted conception techniques. These include IVF treatment (the test-tube baby) and Intra-Cytoplasmic Sperm Injection (ICSI). ICSI is similar to IVF, but where a single sperm is injected into a single egg, and still has the same chance of results as In Vitro Fertilisation.
If no treatments are successful, egg donation may considered as a final option. This is when another woman's egg is combined with the client's partner's sperm and then implanted into the infertile woman's uterus.
A woman undergoing medical treatment for infertility, or who is simply having trouble getting pregnant, will urged to try to improve their lifestyle to aid conception.
These include
  • No smoking
  • Not drinking excessively
  • Losing any excess weight
Success rates of fertility treatments have risen over the last decade, female treatment rising by 6%. Patients can hope for a positive outcome, as treatment becomes more and more advanced.


Net Doctor .co.uk
Fertility Expert .co.uk
Guardian - Science .co.uk
Wikipedia .co.uk
Bupa .co.uk



Male Infertility

You can usually be classified as infertile or sterile when you have been trying have a child for over a year with no success. A test will then be scheduled to confir
Picture of Human Penis
Picture of Human Penis
m or disprove the diagnosis. Though infertility is fairly uncommon, sterility in the male can account for 15% of couples' reasons for not being able to conceive.


  • Blockages in the sperm duct
  • Testicular disease or injury
  • Genetic disorders
  • Sperm disorders
  • Hormonal disfunction
  • Environmental toxins
  • Varicocele - a swelling of the veins in the scrotum
  • Drugs causing infertility
  • Problems with erection or ejaculation


There are treatments through the doctor or through self-help that are proven to have an effect.
Surgery can be useful if the cause is a blockage in the sperm duct, through a the reversal of a vasectomy. However, there it is not guaranteed that you see an effect through the surgery, and there is always a risk when being put under anaesthetic.
Another treatment which is not as widely offered is assisted conception techniques, ranging from IVF treatment (test-tube baby) to Intra-Cytoplasmic Sperm Injection (ICSI), similar to IVF, but where a single sperm is injected into a single egg with the same chance of results as In Vitro Fertilisation.
If the case is not so major as to need surgery or IVF, there are things a man can do to help the situation. Men can be advised to eat a healthy balanced diet, do regular exercise and to avoid nicotine, alcohol and drug use as all will have an effect on their sperm count. Stress can also have a massive affect on couples trying to conceive, so stressfully situations should be avoided.
Unfortunately, for many men, nothing can be done to remedy the situation. Sperm donation has been successful in many cases, where treatments were unaffective.


Net Doctor .co.uk
Fertility Expert .co.uk
Web MD .com
Wikipedia .com (for picture only)
EXCELLENT!! Exactly what I was looking for, well done!