Bolognese Biology

• what are hormones


  Hormones are chemical messengers. Hormones are released by glands.
• what does the pituitary gland do

  The pituitary gland releases many hormones, including growth hormone.
• what does the thyroid gland produce


  The thyroid gland produces several hormones, including thyroxine.
• what does the pancreas produce

  insulin
• what do the ovaries produce


  estrogen and progesterone the sex hormones
• what do the testes produce


  The testes release the sex hormone testosterone.
• what do the adrenal glands produce


  several hormones including adrenaline
• what is a target organ

  an organ affected by a specific hormone
• how do hormones travel around the body

  in the blood
• what does the hormonal system cause


  The hormonal system causes slower responses than the nervous system because the hormones take time to travel to the target organs in the blood.
• what is the metabolic rate


  Metabolic rate is the rate at which the energy stored in your food is transferred by all the reactions that take place in your body to keep you alive.
• how is resting metabolic rate measured


  Resting metabolic rate is measured with the body at rest, in a warm room and long after the person last had a meal.
• what is thyroxine


  a hormone that affects metabolic rate
• what does throxine cause


  Thyroxine causes heart cells to contract more rapidly and strongly, it also increases the rate at which proteins and carbohydrates are broken down inside cells.
• what is negaqtive feeback


  Negative feedback is a control mechanism that reacts to a change in condition by trying to bring the condition back to a normal level.
• what is the control of throxine an example of


  The control of thyroxine is an example of negative feedback because an increase in thyroxine concentration directly causes changes that bring about a decrease in the amount of thyroxine released into the blood and vice versa
• what is adrenaline


  a hormone released in large amounts by the adrenal glands in frieghtening or exciting situations
• what effects are caused by adrenaline


  o Heart muscles contract - increasing blood pressure and heart rate. o Diameter of blood vessels leading to muscles gets wider increasing blood flow. o Diameter of blood vessels to other organs narrow, reducing blood flow and lowering blood pressure. o Liver changes glycogen to glucose to increase blood sugar concentration.
• what is the menstrual cycle


  The menstrual cycle is cycle of changes in a woman's reproductive system that takes about 28 days.
• when does the menstrual cycle continue on from


  puberty to menopause
• what does the menstrual cycle prepare the womans body for


  the fertilisation of an egg cell, leading to pregnancy.
• what is day 1-5 of the menstrual cycle


  Day 1-5 of the menstrual cycle is menstruation - when the uterus lining and an unfertilised egg cell are lost during a 'bleed'.
• what happens when the menstruation ends

  When menstruation ends, the uterus lining starts to thicken again until the cycle starts again.
• what day is ovulation

  day 14 when the ovary releases an egg
• what is the menstrual cycle controlled by


  the sex hormones oestrogen and progesterone
• whem does fertilisation occur


  when the male gamete nucleus fuses with the female gamete nucleus
• what is contraception


  the prevention of fertilisation
• what are the main methods of contraception


  Barrier methods, stopping the sperm reaching the egg (male condom, the diaphragm) o Hormonal methods, preventing the release of the egg
• what does the hormonal pill or implant do


  The hormone pill or implant releases hormones to prevent ovulation and thickens mucus at the cervix, making it difficult for sperm to enter the vagina
• where are the FSH and LH hormones released from

  FSH (follicle stimulating hormone and LH (luteinising hormone) are released from the pituitary gland.
• what is the release of FSH AND LH controlled by

  the concentration of oestrogen and progesterone
• what happens when the levels of progesterone are low

  FSH is released
• what happens when the levels of progesterone are high


  FSH and LH release is inhibited
• what happens when the levels of oestrogen are high

  more LH is released
• what does FSH stimulate

  FSH stimulates growth and maturation of egg follicle.
• what does LH trigger

  ovulation
• what does oestrogen cause

  thickening of the walls
• what does progesterone maintain

  the lining of the uterus walls
• what do falling oestrogen and progesterone levels cause

  menstruation
• what does hormonal contraception use


  Hormonal contraception uses a progesterone-like hormone that prevents the natural fall of concentrations at the end of the menstrual cycle.