Well done Holly, really good page!

Bile

Bile is a green liquid produced by the liver and stored in the gallbladder. It contains bile salts which aid lipid digestion by increasing the surface area for lipase to work on.

Prolactin

Prolactin stimulates breast milk production in mothers during and after pregnancy until the mother stops breastfeeding.

The Lymphatic system

Lymph is excess fluid carried through the body in the lymphatic system before being eventually returned to the blood stream by the lymphatic ducts.Lymph is moved through the lymphatic transport system by muscular contractions. Each villi in the small intestine contains a lymphatic vessel called a lacteal which allows the lymphatic system to absorb droplets of fat which then pass into the blood stream. Lymph nodes act as lymphatic filters, they remove any unwanted materials. During infection, the nodes become infected and swell. The lymph nodes are where antibodies and lymphocytes are formed,making them esseltial for the immune system to function. Conditions such as oedema can devepol when the immune system does not function adequately.

Hypertension


High blood pressure is a fairly common condition that can increase a person's risk of heart disease. high blood pressure is a blood pressure of higher than 140/90 mmHg this can be just high diastolic pressure, just high systolic pressure or both. In the Uk half of those over 65 suffer from the condition.Those who have diabetes or who have recently suffered a stroke or a heart attack are at higher risk.

Essay question from textbook

5.i. The follicular phase of the menstrual cycle is the first half of the cycle. In this phase Follicle Stimulating Hormone from the pituitary gland (1) stimulates the development and maturation of a graafian follicle in the ovary (1) and the production of oestrogen by ovarian tissues (1) . The increasing concentration of oestrogen triggers proliferation and repair of the endometrium (1). At around day 14, the high concentration of oestrogen causes the pituitary to produce Luteinising Hormone, this LH causes the graafian follicle to rupture, releasing the ovum. This is ovulation (1). (5)
ii. The luteal phase is the second half of the cycle. In which, LH stimulates the graafian follicle to develop into the corpus luteum after ovulation (1). The corpus luteum secretes progesterone and oestrogen (1). The rise in the hormone progesterone stimulates the further development of the endometrium which becomes thick and rich in blood vessels (1). The high levels of oestrogen and progesterone during the luteal phase inhibit the pituitary from secreting LH or FSH due to negative feedback. This means no new graafian follicles can be produced during this time (1). At around day 22, the corpus luteum degenerates, causing a rapid drop in progesterone and oestrogen (1) . by day 28, these hormones are so low that the endometrium can no longer be maintained and menstruation causes the loss of the inner layer of the endometrium and some blood (1).(5)

Excellent Holly, full marks!!

Male infertility

A man can be classified as infertile after a year of trying to conceive a child with no success.

Causes


The most common cause of male infertility is poor semen quality. Other possible causes are :-
  • hormone disorders
  • reproductive organ trauma/obstruction
  • sexual dysfunction.
  • General lifestyle due to factors such as abuse of drugs or alcohol and obesity.
  • Over-use of saunas or hot tubs can over-heat the testes causing impaired sperm production.
  • varicocele
  • genetic disorders
  • blockages in the sperm duct

external image hrinfert_05.gif

http://library.med.utah.edu/kw/human_reprod/mml/hrinfert_05.gif
Treatments

If caused by infection, male infertility can be treated by antibiotics.Surgery can remove a duct obstruction causing infertility. Fertility drugs can be taken to increase sperm production. Leading a healthy lifestyle by avoiding toxins such as drugs, alcohol and nicotine and eating a balanced diet can impact fertility. Avoiding stress can also prove beneficial.

If these treatments are unsuccessful, fertility treatments such as IUI or IVF may be successful methods of fertilisation. If these fail,using a sperm donor may work as a last resort.

external image fcgcpmalepic.jpg
http://www.cancer.med.umich.edu/images/fcgcpmalepic.jpg

Female infertility

A woman is infertile after a year of trying to conceive a child unsuccessfully.
there are two types of infertility
  • primary - in 40% of cases infertility is primary meaning no child has ever been conceived
  • secondary - 60% of infertility is secondary meaning fertilisation ha occurred in the past but not for over a year


Causes
a possible cause of female infertility is age. After 30, chances of conception decrease 3-5% a year.
other causes include
  • damage to oviducts - surgery,infection or endometriosis may lead to scarring and damage to the oviducts
  • hormone problems - problems with the synchronisation of the hormones needed during ovulation
  • cervical problems - a small minority of female infertility is due to mucus blocking the cervix so sperm cannot pass through
  • ovarian causes - some examples are polycystic ovary syndrome, menopause, luteal disfunction or ovarian cancer.
  • sexually transmitted infections
  • general risk factors - smoking harms ovaries and oestrogen production, it increases a woman's chance of infertility by 60%.chemotherapy brings follicle stimulating hormone to menopausal levels after 4 series.weight extremes and eating disorders such as obesity and anorexia affect infertility greatly.
  • stress
  • alcohol or drug abuse
  • previous ectopic pregnancy
  • polyps in uterus

Treatments

  • fertility drugs to stimulate hormone production
  • fertility treatments such as IUI or IVF
  • antibiotics to treat infection
  • surgery to remove blockage or scar tissue
  • if all treatments are unsuccessful, egg donation or using a surrogate mother ma be considered
  • generally living a healthy lifestyle and avoiding anything that could possibly affect fertility is also beneficial

Contraception

contraception can be used be either a male or a female to protect against unwanted pregnancy and/or sexually transmitted infection.
Male contraceptives
  • male condom - 98% effective, prevents both pregnancy and sexually transmitted infections.

  • vasectomy- extremely effective, permanent, not always reversible. minor surgery is done to block, sever or seal the perm duct, preventing sperm from leaving the male body.
female contraceptives
  • Combined pill - over 99% effective when taken every day. Oestrogen and Progesterone present in the pill prevent ovulation.


  • Progesterone only pill - 99% effective. Progesterone thickens mucus making sperm unable to get to egg, also thins lining of the uterus so an egg can't implant itself there. It must be taken at the same time every day.


  • diaphragms - 92-96% effective, inserted into vagina before sex.


  • Cap - 92-96% effective, like diaphragm but smaller.


  • female condoms - 95% effective, also prevent sexually transmitted infections.


  • Implant - contains progesterone and is implanted into the skin where it can work as a contraceptive for three years. It can be removed at any time and normal fertility will return. more than 99.9% effective.


  • Injection - there are two types of contraceptive injection, Depo-Provera,which lasts for 12 weeks and Noristerat, which lasts for 8 weeks.They are both more than 99% effective.


  • Patch - more than 99% effective.Each patch lasts a week. Works in the same way as the combined pill.


  • Intrauterine Device - more than 99% effective and can last for 3-10 years depending on the type used. Inserted into uterus to prevent sperm from reaching fallopian tubes.


  • intrauterine System - more than 99% effective, releases progesterone into womb, lasts for 5 years.


  • Natural family planning - 98% effective when used accurately. Use natural body signals such as temperature and records of previous menstrual cycles to reduce risk of pregnancy without using contraception.


  • vaginal ring - more than 99% effective. continually releases progesterone and oestrogen for 21 days.

  • female sterilisation - not as effective as male sterilisation as blocked fallopian tubes can rejoin after the surgery. Permanent and not always reversible. If the operation fails, chances of ectopic pregnancy increase.


Heart Disease

heart disease is a term that refers to diseases that affect the heart. It is more common in the western world due to a common cause of it being poor diet.
myocardial infarction - also known as heart attack. Caused by a blocked coronary artery, stopping blood flow to the heart. If the cells are deprived of oxygen long enough, they begin to die. Symptoms include severe chest pain, sweating, fainting, feeling out of breath. Men tend to have stronger symptoms than women.
atherosclerosis - build up of atheromas/fatty plaque(fat, cholesterol, calcium, and other substances) that hardens and reduces the flow of blood to the heart. Some possible end results of this condition are the cells deprived of oxygen for so long that they die or the a blood clot can occur and block the blood supply completely. There are no noticable symptoms until the condition gets more severe. It is more common over 40 as the arteries naturally harden with age.
angina - Mainly caused by atherosclerosis. Severe chest pain commonly brought on by stress or excercise as these lead to the heart needing to pump blood faster,which is made complicated by the blockage in the arteries. Usually lasts no more that 15 minutes and is treated with medication or rest.
coronary thrombosis - caused by atherosclerosis, the uneven surface of the artery can cause the valve to develop into a clot, which can be carried in the blood until it blocks a smaller vessel. This blockage, oxygen deprivation and increasing pressure causes a heart attack.
causes - smoking, excercise, diabetes, high cholesterol, high blood pressure, obesity, stress
treatments -
coronary bypass surgery
aspirin - blood thinner
medicine - glyceryl trinitrate, betablocker drug, angiotensin-converting enzyme inhibitor drug
angioplasty - wire inserted into space in blocked artery to prevent it from closing.
lifestyle changes