Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
GCSE Homeostasis
GCSE AQA Biology: Homeostasis and Response (Topic 5)
| Question | Answer |
|---|---|
| What is homeostasis? | Maintenance of a constant internal environment in order to maintain optimum conditions for enzyme and cellular function |
| Give examples of conditions maintained by homeostasis in the body | Blood glucose levels Body temperature Water concentration |
| What two types of responses are used in body control systems? | Nervous and chemical |
| What three components do all control systems have? | Receptors Coordination centres Effectors |
| What is the function of a receptor? | detect stimuli (changes in the environment) |
| What is the function of a coordination centre? | obtain and process information from receptors |
| What is the function of an effector | bring about responses to stimuli |
| Synapse | the connection between 2 neurones . A nerve signal is transferred across a synapse by the diffusion of chemicals |
| 5 steps in a reflex arc | Stimulation of pain receptor Impulses travel along sensory neurone Impulses passed along relay neurone Impulses travel along motor neurone Muscle contracts and the arm moves |
| 2 differences between the nervous system and the endocrine system | Nervous system uses electrical impulses which travel down neurones Whereas endocrine system secrets hormones which are carried in the bloodstream to target organs. Nervous system signalling is extremely fast Whereas endocrine system is much slower |
| Pancreas secretes which hormone and what is its function | Insulin - controls concentration of glucose in blood |
| Testes secretes which hormone and what is its function | Testosterone - involved in puberty and reproduction |
| Ovaries secretes which hormone and what is its function | Oestrogen - involved in puberty and reproduction |
| Thyroid gland secretes which hormone and what is its function | Thyroxine - involved in protein synthesis (for growth and development) and in regulating the body's basal metabolic rate |
| Adrenal gland secretes which hormone and what is its function | Adrenaline - released in response to fear or stress - increases heart rate - increases supply of oxygen and glucose to muscles and brain - prepares body for fight or flight response |
| Pituitary gland (Master Gland) function: | secrets a number of different hormones into blood depending on conditions. They act on other glands and cause other hormones to be released, the pituitary gland can trigger lots of different effects. |
| How is blood glucose reduced | Pancreas detects high blood glucose so secretes insulin - insulin causes glucose to move into cells - insulin makes the liver turn glucose into glycogen. Therefore blood glucose levels are reduced. |
| How is blood glucose increased | Pancreas detects low blood glucose so secretes glucagon - glucagon makes the liver turn glycogen into glucose which is stored in the liver and muscles. Therefore blood glucose is increased. |
| Cause of type 1 diabetes, effect and treatment | Pancreas produces little or no insulin - blood glucose can rise to dangerously high levels. Treated by insulin injections |
| Cause of type 2 diabetes, effect and treatment | Cells no longer respond properly to insulin - blood glucose can rise to dangerously high levels. Treated by controlled carbohydrate diet and regular exercise. |
| Stage 1 of menstrual cycle | Menstruation starts - uterus lining breaks down |
| Stage 2 of menstrual cycle | Uterus lining builds back up into a thick spony layer full of blood vessels ready to recieve a fertilised egg |
| Stage 3 of menstrual cycle | Egg develops and is released from ovary - ovulation |
| Stage 4 of menstrual cycle | Wall is maintained. If no fertilised egg lands on the wall, lining breaks down and cycle starts again. |
| FSH (follicle simulation hormone) | Causes an egg to mature in ovary |
| Oestrogen | causes uterus lining to grow |
| LH (lutenising hormone) | stimulates ovulation |
| 3 Hormonal methods of contraception | Oral contraceptive pills containing hormones that inhibit FSH Contraceptive implant - release progesterone continuously to stop maturation/release of eggs Injections or skin patches |
| 3 Non-hormonal methods of contraception | Condons and diaphrgams - prevent sperm reaching egg Sterilisation - stops a man/woman from being fertile Spermicides - kill sperm Abstaining from sexual intercourse |
| Women who cant get pregnant are given a fertility drug containing which 2 hormones? | FSH and LH |
| 3 Negatives of IVF | Its emotionally and physically stressful Low success rate Can lead to multiple births, which can be dangerous for mother and baby |
Created by:
Jascelectronic
Popular Biology sets