homeostasis MINDMAP
- Created by: user101123
- Created on: 28-03-20 20:49
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- Homeostasis
- Homeostasis is maintaining a stable internal environment in response to changes in both internal and external conditions.
- Cells need right conditions for optimum enzyme action
- All control systems consist of: receptors, effectors and coordination centres (brain,spinal cord and pancreas).
- Control systems regulate internal environment. both nervous & hormonal
- Control systems maintain body temperature, blood glucose level and water content.
- Control systems regulate internal environment. both nervous & hormonal
- Negative feedback
- A mechanism used by control systems to keep internal environment constant
- N.F used when level of something is too low or too high
- Stimuli > receptor> sensory neurones > CNS > motor neurones > effectors > response
- A mechanism used by control systems to keep internal environment constant
- nervous system
- nervous system detects and reacts to stimuli
- nervous system is made up of different parts
- CNS: Central nervous system consists of spinal cord and brain. It is connected to body by sensory and motor neurones.
- Sensory neurones: carry info as electrical impulses fron receptors to CNS
- Motor neurones: carry electrical implises from CNS to effectors.
- Effectors: are muscles and glands that respond to nervous impulses
- CNS coordinates resposne.
- SYnapses and reflexes
- the connection between two neurones is a synapse
- nerve signal transferred by chemicals whcih diffuse across gap, then new electric signal set off in next neurone
- relfexes help prevent injury, rapid, automatic responses, doesnt involve the brain.
- reflex arc goes through the CNS
- stimuli>recedptor>sensory neurone>relay neurone>motor neurone>effector>response
- reflex arc goes through the CNS
- the connection between two neurones is a synapse
- endocrine system
- hormones are chemical messengers sent in the blood
- hormones are produced in endocrine glands - these galnds make up endocrine system.
- hormones have relatively long lasting effects
- examples of glands
- pituitary gland - master gland as it releases hormones which stimulate other hormones
- ovaries - female only. produce oestrogen for menstrual cycles
- testes - male only. produce testosterone wich produces puberty and sperm production
- thyroid - produces thyroxinregulates basal metabolic rate, heart rate and temperature
- adrenal gland - adrenaline, 'fight or flight'
- pancresa, insulin, regulates blood glucose level
- diference in nerves and hormone
- Nerves - fast acting , Hormones - slow acting
- Nerves - act for short time, Hormones - long-lasting efects.
- controlling blood glucose
- insulin and glucagon cntrol blood glucose level
- eating carbsputs glucose itno blood. nromal metabolism removes glucose form blood. exericse remoes glucose from blood
- excess glucose is stored as lgycogen
- Diabetes is a condition that affects your ability to control yoour blood sugar level.
- type2 diabetes when a person becomes resistant to their own insluin (still producing it though). obesity is major risk factr in development of this disease
- type 2 can be contrlled by eating a carb controllled diet and getting regular exercise
- type2 diabetes when a person becomes resistant to their own insluin (still producing it though). obesity is major risk factr in development of this disease
- insulin and glucagon cntrol blood glucose level
- hormones are chemical messengers sent in the blood
- puberty and menstrual cycle
- hormones promote sexual characterisrics at pubery
- in men, main reproductive hormone is testosterone, produced by testes and stimulates sperm production
- in women, main reproductive hormone is oestrogen, poduced by ovaries, brings physical changes as well as menstrual cycle
- Stage 1 - lining breaks down. stage 2 - lining builds up ready to receive fertilised egg Stage 3 ovulation. Stage 4 if no egg landed on uterus lining by day 28, lining breaks down, whole cycle repeats.
- hormones promote sexual characterisrics at pubery
- controlling fertility
- oestrpogen can be used to preent release of egg
- progesterone also reduces frtility; stimulates thick mucus production which prevents any sperm getting throughand reaching the egg
- contraceptive patch; contains oestrogen and progesterone, lasts for 1 week
- contracptive implant; inserted under skin of arm,lasts for 3 years. rekeases progesterone , prevents esperm reaching eggs
- contraeptive injection; contains progesterone, lasts from 2-3 months
- Intrauterine device (IUD) a T-shaped device inserted into uterus. Stop fertilised eggs from implanting in uterus wall.
- progesterone also reduces frtility; stimulates thick mucus production which prevents any sperm getting throughand reaching the egg
- barriers methods stop egg and sperm meeting (non hormonal form of contraception)
- More drastic ways to stop pregnancy
- Sterilisation: In females involves cutting/tying Fallopian tubes. In males it involves cutting/tying sperm ducts. It is permanent.
- Abstinence: Not having intercourse. This is called abstinence.
- Natural methods; Avoiding sexual intercourse when a women is at the stage of the menstrual cycle where she is most fertile.
- oestrpogen can be used to preent release of egg
- inreasing fertilityhormones can be used to increase fertillity.
- FSH and LH are given as fertility drugs to stimulate ovulation
- IVF - "In Vitro Fertilisation"
- involves cllecting eggs form the womans oaries and fertilising them in a lab using a mans sperm
- FSH and LH are given to the women prior egge collection to stimulate several eggs to mature
- cons of IVF;
- success rate of IVF ae low
- Multiple briths can happen if more than one embryo grows
- some women may have a strong reaction to the hormonal medication given
- IVF is controversial; unused embryos are unethical as potential human life
- geneti c testing of embryos means selecgtion of preferred characteristics - unethical
- involves cllecting eggs form the womans oaries and fertilising them in a lab using a mans sperm
- adrenaline anf thyrooxin
- adrenaline is produced by adrenal glands located abve kidneys
- prepares humans for fight or flight;
- increasing oxygen and glucose supply to cells in the brain and muscles, inreasing heart rate
- prepares humans for fight or flight;
- thyroxine is a hormone released by the thyroid gland which is in the neck
- regulates basal metabolic rate
- thyroxine also stimulates protein synthesis for growth and development
- thyroxine is released in esponse to TSH()thyroid stimulation hormone)
- negative feedback system keeps amoount of thyroxine in the blood at the rght level.
- adrenaline is produced by adrenal glands located abve kidneys
- Homeostasis is maintaining a stable internal environment in response to changes in both internal and external conditions.
- reaction time can be measured using a computer
- RP - investigating reaction time - ruler drop test
- caffeiene can speed up a persons reaction time
- reaction time is how quickly you respond to a stimulus
- RP - investigating reaction time - ruler drop test
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