Homostasis And Response

• What are the three main components of ACS's?

  -Receptor

  -co-ordination centres

  -effectors
• what does the human edocrine system do?

  it sends hormones arounf the body
• What is PNS


  Peripheral nervous system (PNS) – all of the nerves in the body
• what is the endocrine system made up of ?

  made up of glands which secrete hormones directly into the bloodstream
• What do homostasis controls?

  -Blood glucose concentration

  -Body temperature

  -Water levels
• What is the function of pitutiary gland?


  it is the master gland which secretes hormones into the blood to either have an effect on the body or act on the other glands to stimulate them to produce different hormones
• What do effectors respond to?

  Nervous impulses
• what organ controls the blood glucose concentration

  the pancreas
• What do effectors do?

  Produce a responseWhat do effectors do?
• why is glucose needed for the body?

  it is needed by cells for respiration
• What are some types of receptors?

  Taste,sound,light,heat,blood sugar
• what happens when the glucose levels are too high?

  the pancreas creates the hormone insulin
• What is homeostasis?


  The regulation of the conditions inside the body
• what happens when insulin is produced in the body?

  insulin binds to cell in target organs causing:

  -glucose to move from the blood into muscle cells for respiration

  -excess glucose to be converted into glycogen which is stored in the liver
• How do muscles react to an impulse?

  They contract
• what happens when the glucose levels are too low?

  the pancreas produces glucogen,which can be turned in to glucoseGlucose is realsed into the blood which increases the blood glucose concentration
• What are effectors?


  Muscles and glands
• how is the blood concetration kept constant?

  using the hormones glucogen and glucose
• What is the structure of the nervous system?

  -Information from receptors passes along cells (neurones) as electrical impulses to the central nervous system (CNS)

  -The CNS is the brain and spinal cord

  -The CNS coordinates the response of effectors which may be muscles contracting or glands secreting hormones

  -The pathway through the nervous system is: stimulus → receptor → coordinator → effector → response
• What is type 1 diabetes?

  -the pancreas can't produce enough insulin-glucose is excreted with urine which makes them thirsty
• negative feedback


  counteracting a change automatically
• What is CNS


  -Central nervous system (CNS) – the brain and spinal cord
• What do receptors do?

  Detect a stimulus
• How homeostasis works


  responds to change with negative feedback cycle.
• What do co-ordination centres do?

  Receives and processes information to organise a response
• What are the adaptations of the nervous system

  -Neurones have a cell body (where the nucleus and main organelles are found) and cytoplasmic extensions from this body called axons and dendrites-Some human neurones have axons over a metre in length (but only 1 - 4 micrometres wide)-This is far more efficient than having multiple neurones to convey information from the CNS to effectors – less time is wasted transferring electrical impulses from one cell to another-The axon is insulated by a fatty myelin sheath with small uninsulated sections along it (called nodes) which the impulse jumps along
• what happens when the glucose levels are too high?

  the pancreas creates the hormone insulin
• how is the blood concetration kept constant?

  using the hormones glucogen and glucose
• What is type 2 diabetes


  is when the body stops responding to insulin
• What are the risk factors  and how can they be reduced of type 2

  -obesity-reducing the number of simple carbs-there are drugas to make insulin more effective on body cells
• What hormones do males produce

  testosterone which stimulates sperm production
• What hormones do females produce

  oestrogen which is involved in the mesntrual cycle
• What is a mestrual cycle

  -it begins with the lining of the uterus breaking down and the woman has her period

  -the layer builds up until ovulation-ann egg is released from the ovary and moves to the uterus via fallopian tube
• What is the 4 hormones

  -follicle stimulating hormone-causes the maturation of the egg

  -produce in pituitary gland which results in the stimulation of the ovary to produce oestrogen
• What does oestrogen do 

  causes lining of the uterus to grown again

  -produced in the ovaries

  -results in follicle stimulating hormone

  -production of lutenising hormone
• What does the lutenising hormone do

  -in the pitutiary gland

  -which results in the hormone of oestrogen
• What does progesterone do

  in the ovaries

  -maintains the lining of the uterus

  -release both follicle stimulating and lutenising hormone
• What does a contraceptive patch contain 

  contains oestrogen and progestogen

  -lasts for a week
• What does a contraceptive implant do

  releases a continous amount of progesterone-lasts for 3 years
• what do a contraceptive injection do

  lasts for 2-3 months