Key area 3 - Control and communication. Nervous control Learning Intention: To investigate the CNS,...

Key area 3 - Control and communication

Nervous control

Learning Intention: To investigate the CNS, brain and nervous control.

Success Criteria: Identify the structures and functions of the CNS, brain and reflex arc

Nervous control

Learning Intention: To investigate the CNS, brain and nervous control.

Today’s Success Criteria: Identify the structures of the brain and their functions.

Videos- Intro’s and Info!

• The Brain• Watch and be able answer the following:-

• What protects the brain?• What percentage of energy is used by the brain?• What part of the brain controls balance?• What part of the brain controls speech?

• Skull• 20%• Cerebellum• Cerebrum

• The brain is made up of three main parts that do different jobs.

• These are:– The cerebrum (A)– The cerebellum (B)– The medulla oblongata (C)

– The Hypothalamus is also an important part used for controlling certain processes eg, body temperature.

A

CB

The Brain

Cerebrum

Cerebellum

Medulla

Hypothalamus

Pituitary gland

The Cerebrum• The cerebrum is the largest part of the brain which

split into two cerebral hemispheres.

• Both halves of the cerebrum are involved in conscious thought and decision making processes, as well as controlling your personality, emotions, sight and speech.

• The cerebellum controls subconscious activities associated with the fine motor control of muscles (co-ordination) and balance.

• Fact! The human cerebellum has more neurones in it than the rest of the brain, even though it is only 10% of the volume!!

The Cerebellum

• The medulla controls most of the basic bodily functions that we need to stay alive. If your medulla stops working, you are considered clinically dead.

• The functions of the medulla include:•Heart rate•Breathing rate•Digestion

The Medulla

Nervous control

Learning Intention: To investigate the CNS, brain and nervous control.

Today’s Success Criteria: Identify the structures of the brain and their functions.

Nervous control

Learning Intention: To investigate the CNS, brain and nervous control.

Today’s Success Criteria: Identify the function of the brain.

Starter

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A

Functions of the brain

• Your brain deals with large volumes of information or stimuli, all of the time. Sounds, smells, images etc.

• How do we know what to pay attention too and what to ignore?

• Our Cerebrum has two parts that help us deal with the information and then respond to it.

• These are the sensory strip and motor strip.

Front of cerebrum

Sensory stripMotor strip

Sensory Strip• The sensory strip is an area of the cerebrum that

deals with all incoming information from the senses; ears, eyes, nose, tongue and skin.

• This information is processed here and then you decided what to do.

• E.g. You hear a car coming around a bend, realise you cant cross in time and then decide to stop and wait for it to pass.

• Areas of the body which are more sensitive have a larger area of the sensory strip devoted to it.

Motor Strip

• The motor strip is an area of the cerebrum in front of the sensory strip.

• The motor strip sends information to muscles of the body that we control by conscious thought.

• If an area of the body has a greater degree of movement, such as the hands, then a larger area of the motor strip is devoted to the hands.

Nervous control

Learning Intention: To investigate the CNS, brain and nervous control.

Today’s Success Criteria: Identify the function of the brain.

Nervous control

Learning Intention: To investigate the CNS, brain and nervous control.

Today’s Success Criteria: Identify the structure and function of the nervous system and neurones.

Videos- Intro’s and Info!

• Nervous system• Watch and be able answer the following:-

• What makes up the Central Nervous System?• What detects stimuli?

• Brain and Spinal Cord• Sensory receptors

Nervous system

• The nervous system includes: brain, spinal cord and nerves.

• The central nervous system (CNS) includes: brain and spinal cord.

• The CNS controls the body by receiving information from sense organs and then responding to that information.

• Information from the CNS is carried by nerve cells, called neurons.

Nervous system

Brain- CNS

Spinal Cord- CNS

Nerves- PNS

PNS- Peripheral Nervous System

Videos- Intro’s and Info!

• Neurons• Watch and be able answer the following:-

• Nerve cells in the human brain are known as?• How many are there in the human brain?• How many are they connected to?• What continually happens to these cells throughout a life

time?

• Neurons• 100 billion• 10,000• Connections between neurons are broken and remade

Nervous System• Receptors are located in the sense organs. These

receive information from the senses pass it to the CNS.

• The neurones in the CNS then passes the information to an effector which brings about a response

There are 3 types of neurones which allows the nervous

system carryout this function:

1. Sensory Neurone- a type of nerve cell that receives information from a sense organ and passes it to the CNS.

Our sense organs are: Eyes, ears, skin, tongue, nose

• Relay neurone- found in the CNS and connect sensory neurones to other neurones in the body.

• The information passed from the sensory neurone is passed on by the relay neurone.

• Motor neurone- carries information from the CNS to the part of the body that responds to the information.

• These responses take place in effectors and can be muscles or glands that produce hormones.

Nervous control

Learning Intention: To investigate the CNS, brain and nervous control.

Today’s Success Criteria: Identify the structure and function of the nervous system and neurones.

Starter

Starter

Sensory

Nervous control

Learning Intention: To investigate the CNS, brain and nervous control.

Today’s Success Criteria: Identify the function of reflexes.

Nervous system

• The way in which the neurones carry the information is known as a nerve impulse.

• It is similar to an electric current running through a wire!

• These nerve impulses travel very quickly. (up to 100 m/s !!!!)

• This allows someone to receive information and respond in a fraction of a second.

• WHY????

Nervous System• Nerve impulses are so fast, for survival!!• We can respond to a dangerous situation very

quickly or respond to a change in our surroundings or internal environment.

• What would happen if you put your hand on a very hot surface?

• Or if I put you in a freezer?• Remove your hand? Shiver?

• Removing your hand is an example of a reflex action.

• The rapid response usually occurs in a muscle.• Slower reactions can occur in glands.

Reflexes• Reflexes are design to respond to a situation

without us having to think about it.• We’ll use the hot surface as an example.

Touching a hot plate

Pain information passed on

Information carried as far as the spinal cord

Muscles of the arm move the hand away

Response sent to muscles

Relay neurone

Motor neurone

Signal

Passed alongSensory neurone

Reaction Practical's• Reactions are very similar to reflex’s in that they

occur very quickly and for a specific purpose.• One key difference though is that reactions are a

conscious, voluntary response.• A goalkeeper saving a penalty would be a good

example.To test your reactions:

1) Ruler drop- drop a 30cm ruler between thumb and index finger and try to catch it. Faster the reaction, smaller the number on the ruler! Does noise affect your time?

Reaction Practicals• 2) Reaction timers- react to the sequence of lights

and press the button. Faster your reactions the quicker the time you record!

• 3) Sheep Dash- using the white board, follow the link to the reaction timer. Is it easier to use the mouse or the board pen to get quick times??

• Sheep Dash

• 4) Catch and call- In three’s, one throw the ball, one catch and one hold up coloured cards. Call out the colour and make a successful catch at the same time. Difficult?

Reaction

Time

App

ResultsTest Time

(ms)

1

2

3

4

5

6

7

8

9

10Average

Investigating Reflex ReactionsYour task…

You must: Find the Reaction Time app on the iPad & have a trial run of the test.

You should: Record your results for 10 tests in a results table in your notebook.

You could: Calculate your mean average score and % change from test 1 to test 10.

Investigating Reflex Reactions

Conclusion1. Draw a suitable graph of your results.2. Describe the pattern of your results.3. Compare your average score with your partner –

what does this show about your reflex reactions?4. Explain what is happening in your nervous system

whilst you are taking the test.

Word BankSensory neurone, relay neurone, motor neurone,

reflex arc, rapid reflex action, receptor, stimuli and synapse.

Nervous control

Learning Intention: To investigate the CNS, brain and nervous control.

Today’s Success Criteria: Identify the function of reflexes.

Quick questions1. What do the letters CNS stand for?

2. Name the two principle types of neurone.

3. Which of these two links the brain with the muscles?

4. Describe two features of reflex actions.

5. Give two examples of reflex actions.

Answers

1. Central Nervous System

2. Sensory and Motor

3. Motor

4. They are quick, automatic and difficult to suppress

5. Coughing and Sneezing

Nervous control

Learning Intention: To investigate the CNS, brain and nervous control.

Today’s Success Criteria: Identify the function of reflexes and how nerve impulses travel.

Starter

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Synapse• Nerve impulses are transferred between the

different types of neurones. The junction between them is known as a synapse.

• The nerve impulse (positive charge) causes chemicals, neurotransmitters, to be released.

• These pass across the synaptic cleft to the next neurone.

• The impulse carries on along the next neurone.

Nerve Impulse

Positive charge moves inside the neurone as the impulse passes.

Neurotransmitter crosses the cleft and causes the impulse to continue along the next neurone

Positive charges cause neurotransmitters to be released

Nervous control

Learning Intention: To investigate the CNS, brain and nervous control.

Today’s Success Criteria: Identify the function of reflexes and how nerve impulses travel.

Hormonal control

Learning Intention: To investigate the role of hormones in the body

Today's Success Criteria: Identify types of hormone, where they are produced and their function.

Starter

Starter

Spinal cord

Endocrine system• The endocrine system is a network of glands that

release hormones into the bloodstream.

• An endocrine gland is a group tissues that produces these hormones

• What is a hormone? What do they do? Can you name any?

• Hormones are chemical messengers that regulate processes within the body.

• The hormones that are released are specific and target certain tissues that have specific receptors.

• Examples- insulin, adrenaline, testosterone, oestrogen glucagon, ADH, growth hormone, dopamine.

Endocrine system

Testosterone

Insulin & Glucagon

Adrenaline

Oestrogen

This diagram shows some of the glands that produce hormones in our body.

Some of the commonly known hormones are also shown.

HORMONES

ADH

Thyroxine

Hormonal control

Learning Intention: To investigate the role of hormones in the body

Today's Success Criteria: Identify types of hormone, where they are produced and their function.

Hwk Task- (Exercise 9)

• Research a gland found in the human body and write a report on it.

• You should at least include:- What it is, where it is in the body? What hormone does it produce? What affect does the hormone have on the body? Any other interesting information you can find out about it.

• Reference any books, journals or websites that you use.

• DO NOT, copy and paste from Wikipedia!!

Hormonal control

Learning Intention: To investigate the role of hormones in the body

Today's Success Criteria: Identify and explain an example of hormonal control

Hormonal control• Hormones work in a similar way to our nerve impulses.

• A stimulus is detected and this triggers a response.

• The response in this case is the release of a hormone.

• The hormone will then have an effect and correct or change what ever the stimulus is.

• Examples of this is the effect of insulin on our blood sugar levels and ADH on blood water concentration

1. Control of blood glucose levels

• Our blood glucose levels are controlled by the hormones Insulin and Glucagon.

• Insulin- released from the pancreas to stimulate the conversion of glucose into the storage carbohydrate Glycogen.

• Glucagon- released from the pancreas to stimulate the conversion of glycogen back into glucose.

• Both of these processes occur in the Liver and are controlled by enzymes.

• When would these hormones be released?

Change detected by receptor cells in the pancreas.

Pancreas releases more insulin into blood.

Liver cells store more glucose from the blood as glycogen.

Change detected by receptor cells in the pancreas.

Pancreas releases more glucagon into blood.

Liver cells convert glycogen into glucose and release it into the blood.

• The water concentration of the blood is another process in the human body that is controlled by hormones.

• ADH (Anti-diuretic Hormone) is produced in the pituitary gland in the brain and targets the kidneys.

• It causes the kidneys to produce a small volume of concentrated urine, to limit water loss.

• When would this be useful? When you are dehydrated and need to save

water.

2. Control of blood water concentration

water

water

Brain detects change

Less ADH produced by the pituitary gland

Kidneys produces a large volume of dilute urine

Normal blood water concentration

Normal blood water concentration

Brain detects change

More ADH produced by the pituitary gland

Kidneys produces a small volume of concentrated urine

Research- Diabetes( Exercise 10)

• If we cant control our blood sugar levels then we can develop a condition called Diabetes.

• Your task is to research diabetes and produce a leaflet/information poster for the class to view.

• You should include- what is it? types- number of sufferers effects on the body causes

treatments- types, costs to NHS affect of lifestyle

And any other significant/interesting information.

Hormonal control

Learning Intention: To investigate the role of hormones in the body

Today's Success Criteria: Identify and explain an example of hormonal control

Starter

• Name the two hormones involved in controlling blood sugar levels.

Starter

• Name the two hormones involved in controlling blood sugar levels.

• Insulin and Glucagon.

Diabetes• What did you find out?

• Type 1- Occurs when the body cannot produce

insulin which is needed to control blood glucose levels.

• Type 2- Develops when the body stops producing enough insulin or when the body is unable to effectively use the insulin that is being produced.

• April 2012- UK had 2.9 million sufferers (predominantly type 2) by 2025 estimated to over 5 million.

Causes and treatments

• Type 1- cells of the pancreas don’t produce insulin. Sufferers are often born with this or other medical conditions can lead to it developing.

• Treated by injecting insulin. Different varieties of insulin, some act quickly others over a longer period of time.

• Insulin pumps can be used rather than injecting.• New non-invasive ways are being developed, nasal

sprays, patches etc.

Cont’d• Type 2- often develops in later life. Linked to a

poor lifestyle but not the only cause.

• Type 2 linked to obesity, high fat and high sugar diets. As obesity is on the rise in the UK Type 2 also increasing.

• Treatments can include insulin but also medications to inhibit glucose uptake and healthy eating and exercise can also be used.

• Treatments cost the NHS an estimated £14 billion a year. £13 billion just on Type 2 treatments.

Effects on body• Classic symptoms- increased thirst, fatigue,

increased need to urinate, blurred vision, poor circulation.

• Diabetes can affect the heart, nerves, skin, eyes, kidneys, brain and digestive system.

• Diabetes can affect the blood vessels and limit blood flow to all areas of the body, causing damage. This can occur over many years.