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Natural sciences

Grade 9

Life processes: healthy life

Module 10

Nerves and sensitivity

  • Sensitivity involves your capacity to react to your changing (internal and external) environment.

1. Indicate the stimulus-reactor path for the process that follows when a bee stings you on the hand.

2. Add the captions to the illustrations of the brain and the neuron.

  1. Write down the functions of the following:

Brain, spinal cord, motor neuron, sensor neuron

  1. Write down the stimulus and sensation of each sense organ:
  • Light rays penetrate the lens to fall on the retina
  • Image is formed
  • Cones and rods stimulated
  • Impulse transmitted to brain via optic nerve
  • Sound waves stimulate receptors in cochlea
  • Impulse to brain via auditory nerve
  • Gas molecule dissolves in mucus membrane
  • Olfactory nerve transmits impulse to the brain
  • Taste buds on the tongue sense only bitter, sweet, sour or salty (other tastes are perceived by the sense of smell)
  • Impulse to brain
  • Receptors in skin pick up mechanical, heat, touch, cold or pain stimuli.
  • Impulses to brain

5. FIND OUT:

  • Why :

a) you blink your eyes:

b) your nose runs when you have been crying:

c) your pupils dilate in a dark room:

d) food has no taste when your nose is blocked:

The effects of drugs and alcohol on the brain

When your body is in pain, painkillers mask the pain. You can control the nervous system’s capacity to feel. This means that medication can be applied usefully, but also that it can be misused.

Drugs are used in this way to provide excitement, but this is dangerous because it can lead to DEPENDENCY and result in TOLERANCE for particular levels of the drug. When this happens, more and stronger drugs are needed.

PAIN KILLERS :Morphine and heroin

  • suppress pain

deaden the senses

STIMULANTS :Caffeine, nicotine, ecstasy anti-depressants

  • enhance brain activity
  • anxiety (it causes)

lead to depression

TRANQUILLISERS :Alcohol and sleeping tablets

  • slow down brain activity
  • willpower, judgement and self-control affected

Sluggishness and disturbances of the vision

HALLUCINOGENICS :Dagga and LSD

  • feelings of wellbeing
  • experiencing things that are not real

Schizophrenia

  • Why do young people turn to drugs?

Assessment: APPLICATION

Could you apply your existing knowledge?

LO 2.4

Assessment

Learning Outcomes 2 : Constructing Science knowledge

The learner will know and be able to interpret and apply scientific, technological and environmental knowledge.

We know this when the learner:

2.4 applies knowledge.

Memorandum

1. impulse/stimulus – receptor – impulse – cns – impulse – effector

2. labels: sketch brain + neurone

4. Complete the table on the senses:

5 a) reflex action to lubricate the eye with a lubricant

b) Tears drain the tear duct that opens at the back of the throat cavity – which is also the back of the nasal cavity

c) opening enlarges to allow more light

d) nasal receptors temporarily out of action; tongue only recognises sweetness, saltiness, acidity, and bitterness

Questions & Answers

how environment affect demand and supply of commodity ?
Amos Reply
Wht at the criteria for market ?
Amos
what is difference between monitory policy and fiscal policy?
Malik Reply
monetary policy is a policy thrust by National Govt(CBN) to influence government spending, purchase &taxes
Frank
necessity of economics
Pamela Reply
I will say want,choice,opportunity cost,scarcity,scale of preference
Alao
what is monopoly market.How price output are determined under monopoly market
bisham
b) Monopoly market is an impecfect market where s single firm having the innovation to produce a particular commodity.Prices are determined through output since there are no other competitive.
Frank
Monopoly market:firm has market power & does not respond to market price
Frank
Explain the process of price determination under perfect competition market with suitable diagram
bisham Reply
Price determination under perfect competition via this process :firms have no market power to influence price rather firms respond to market price.
Frank
price is different from demand- demand is amount of commodity
Effah Reply
demand is amount /quantity of commodity a potential buyer is willing to buy at a given price at market
Frank
demand is a desire of customer on commodity with the ability to pay it and willing to buy it at given price of commodity
Harika
demand is price of what
Faith Reply
show that shortrun average cost
Baby Reply
what is economics
Mbah Reply
what is money
Mbah
what is money
Mbah
Difine macro economics
agaba
money is a medium of exchange between goods and services,maybe inform of currency.
Wesonga
Economics is study of how human beings strive to satisfy numerous wants using limited available resources.
Wesonga
how do you find the maximum number of workers the firms should employ order to produce where there are increasing returns
Jane
what are implications of computing national income?.
agaba
pl
MUDASIRU
what is the formulae for calculating national income
MUDASIRU
it calculated by value added method
Praveen
classify the production units like agriculture, banking, transport etc
Praveen
money is anything that is generally acceptetable for human
Ogbaji
Estimate the net value added(NVA) at fixed cost by each industrial structure
Praveen
definition of unemployment
Adam Reply
what are the causes of unemployment?
Mbubi Reply
The main causes of unemployment are listed below. 1. Frictional unemployment 2. Cyclical unemployment 3. Structural unemployment
assani
We can also categorize the causes on a broader sense as: 1. Political and 2. Social cause As unemployeement root causes are embaded in this two.
Yonathan
would opportunity cost exist if there was no scarcity?
assani
yes just because the opportunity cost arose when there is Alternative to choose among the alternatives.
BADAMASIU
I am thinking that, if our resources were unlimited, then there wouldn't be any need to forgo some wants. Hence the inexistence if opportunity cost
assani
Politics
Job
politics has done what?
assani
consider time assani
Mary
I'm Emmanuel,...I taught the main cause is the change in gov't.
Emmanuel
...Lack of capital to set up a firm respectively
Emmanuel
🙈
Emmanuel
I would like to bring in Educational levels can also be the cause the cause of the problem respectively
Emmanuel
I think the main causes of unemployment is lack of INFRASTRUCTURAL DEVELOPMENT OVER POPULATION OVER DEPENDENT ON GOVERNMENT LACK OF SELF EMPOWERMENT...
ananti
lack of skills among the new generation is the serious issue.
Vishal
Where I come from , I don't see why education or personal aspects seem to do with unimployment, technically the motivation and eigerness in all works of live is there , dispite the cultural influence and physical bearriors;the thing we lacking is Government Support and open market ethics.
Joe
sorry about that-(repation). We have a over powering ethical political system that's displacing the marketing asspects of economy and causing large scale unemployment right across the board...
Joe
can someone Explain Expansionary Monetary Policy and Contractionary Monetary Policy Using one of the instrument of Monetary Policy? Please am kinda lost here?. ta
Emmanuel Reply
using a graph show the case of substitute and compliment goods
Ade Reply
can anyone give me a simple explanation to Five Sector Macroeconomics?
Emmanuel
Can someone please define what economics is
jason Reply
economics simply is a social science subject that study human behavior.
dajan
economics is a social science which studies human behaviour as a relationship between ends and scarce means that has alternative uses
Alao
Can someone please tell me how to calculate GDP
Emmanuel
emmanual kapal to calculate GDP (Gross Domestic Product) has three method in calculating it (1)income approach (2) expenditure approach (3) value added method
Alao
thanks Alae
Emmanuel
u are welcome
Alao
in basic terms economics is revered to as battery system, it date back to when Men sees the need to exchange sapless goods and produce to gain , either wealth , basic necessities or to establish trading ties for personal benefit or social asspects in terms of coexistence and continuity, future .
Joe
what is the law of demand
Berlinda Reply
keep other thing constant, when the price increases demand decrease when the price decreases demand increases of the commodity.
sj
all things being equal,quantity demanded decrease as price increase and increase as price decrease
Seth
there's practial joke to it ..." the higher the demand ; scarcity, increase in production and drop in quality"... quite the controversy - for example China vs Europe, United States and we are all boxed up in between somewhere...
Joe
Other thing remain constant the low price of commodity the high quantity of commodity and vice versa is true
Baraka
Explain Effective demand
Anita Reply
What is effective demand
Anita
like Modi is in demand...best example of effective demand
Pranav
Don't get you
Anita
Anita you mean you don't get me or who?
Onyeking
level of demand that represents a real intention to purchase by people with the means to pay
Pranav
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Source:  OpenStax, Natural sciences grade 9. OpenStax CNX. Sep 15, 2009 Download for free at http://cnx.org/content/col11069/1.1
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