ANIMAL COORDINATION

• what are hormones

  chemical substance in gland that is carried in the bloodstream
• what is the human endocrine system

  network of organs and glands that produces hormones
• what is the difference between the endocrine and nervous system

  the effects of hormones are much slower but they last for longer
• What are the glands in the endocrine system

  Pituitary gland

  thyroid gland

  pancreas

  adrenal glands

  testes

  ovaries
• what are the features of the pituitary gland


  The master gland, at the base of the brain

  produces ADH (anti diuretic hormone)

  Targets the kidneys

  Controls the water content of the blood

  Increases reabsorption of water by the collecting ducts

  Hypothalamus detects changes in hormone levels and releases hormones that the pituitary controls. They act on other glands to stimulate the reease of different types of hormones
• what are the features of the thyroid glands

  Produces thyroxine to stimulate the metabolic rate that controls the speed in which oxygen and food products react to release energy
• what happens when there is low thyroxine levels in the bloodstream

  stimulates the hypothalamus to release TRH and the pituitary to release TSH, so the thyroid releases more thyroxine and return to normal
• what are the features of the pancreas

  produces Insulin hormone

  Targets the liver

  Controls blood glucose levels

  Increases the conversion of glucose to glycogen for storage
• why is glucose important

  simple sugars used by cells for respiration
• what are the features of the adrenal glands

  Produces adrenaline

  Targets several organs in the respiratory and circulatory system

  Preparation for 'fight or flight' where a quick response is needed

  Increases breathing rate, heart rate, flow of blood to muscles, conversion of glycogen to glucose in respiration
• what are the features for the testes

  produces testosterone
• what are the features of ovaries

  produces oestrogen
• what is homeostatic control

  regulation of internal conditions inside organisms
• what must be kept as constant as possible in animals

  water concentration

  temperature

  glucose concentration
• what is a negative feedback mechanism

  if the level of something rises, control systems reduce it again (and vice versa)
• what is an example of negative feedback

  sweating to reduce body temperature/shivering to raise body temperature
• what is diabetes

  a condition where blood glucose levels cannot be controlled by the body
• what is type 1 diabetes

  where the pancreas fails to produce enough insulin

  uncontrolled high blood glucose levels

  controlled by injecting insulin

  controlled by having a controlled diet with foods that increase blood sugar levels

  controlled by exercising as it lowers blood glucose levels due to increased respiration
• what is type 2 diabetes

  where body cells no longer respond to insulin produced by the pancreas

  controlled by exercise

  controlled by a controlled diet that restricts carbohydrates since they are digested into glucose and raises blood sugar

  common in older people and obese people
• how is high levels of glucose regulated

  insulin is secreted into the blood

  liver converts glucose into glycogen

  glucose goes down
• how is low levels of glucose regulated

  glucagon (not insulin) is secreted into the blood

  liver does not convert glucose into glycogen

  glucose levels goes up
• negative feedback with the role of glucagon in control of blood sugar levels


  consuming sugary food

  high blood sugar - insulin is released

  glucose taken into cells and used or stored as glycogen

  optimal blood sugar levels

  at the same time!

  exercising or not eating for a while

  low blood sugar - glucagon is released from the pancreas

  glycogen turned back into glucose in the liver and released into the blood stream

  optimal blood sugar levels
• what is the menstrual cycle

  28 day process where the lining of the uterus is preparing for pregnancy. if implantation of the fertilised egg into the uterus lining does not happen, the lining is then shed in menstruation
• what hormones are involved in the menstrual cycle

  FSH - causes the maturation of an egg in the ovary

  LH - stimulates the release of the egg

  oestrogen - repairing and thickening the uterus lining

  progesterone - maintains the uterus lining
• how do the hormones involved in the menstrual cycle interact with each other

  The pituitary gland produce FSH

  the egg develops inside the follicle (fluid filled ball of cells) which produces oestrogen

  oestrogen rebuilds the uterus lining and inhibits FSH

  when oestrogen levels are high, it causes a surge of LH and causes ovulation

  the follicle becomes corpus luteum and produces oestrogen and progesterone that also inhibits FSH and LH

  if the egg hasn't been fertilised, the corpus luteum dies and progesterone levels drop to cause menstruation
• what are the features of FSH

  follicle stimulating hormone

  comes from the pituitary gland

  Causes the egg to mature and stimulates the ovaries to release oestrogen
• what are the features of oestrogen

  comes from the overies

  stops FSH being produced and repairs the uterus lining while stimulating the pituitary gland to release LH
• what are the features of LH

  luteinising hormone

  comes from the pituitary gland

  triggers ovulation
• what are the features of progesterone

  comes from ovaries

  maintains the lining during the menstrual cycle and pregnancy
• what is the role of a placenta

  an organ in the uterus of a pregnant woman that allows the transfer of nutrients to the fetus in the umbilical cord. produces progesterone to maintain the uterus lining
• hormonal contraception

  The pill

  • contains oestrogen or progesterone that produces FSH
  • high levels of oestrogen doesnt allow the egg to mature
  • 99% effective
  • reduces risks of certain cancers
  • side effects of changes in weight, mood and blood pressure
• non hormonal contraception

  physical barriers

  • condoms and diaphragms prevent the sperm reaching the egg
  • condoms prevents stds but could be ripped

  IUD

  • prevents the implantation of an embryo or releases of hormones
  • remains for 10 years, small risks of pregnancy

  vasectomy

  • where the sperm ducts are cut and tied
  • cannot be reversed
• what is ART

  assisted reproductive technology, used when women have difficulty becoming pregnant

  Can be expensive and lead to premature or underweight babies

  IVF

  • involves giving a mother FSH and LH to stimulate the maturation of several eggs
  • Eggs and sperm are collected from the parents to be fertilised in a lab
  • fertilised eggs develop embryos

  Clomifene

  • fertility drug to stimulate ovulation
  • blocks the action of oestrogen negative feedback oh LH