Control and coordination

Control and coordination

Topics to be covered are:- 

1.Introduction,

 2.Animals –Nervous system.

 3.What happens in reflex action 4.Human brain

 5.How are these tissues protected 6.How does the Nervous tissue cause action?

 7.Coordination in plants 8.Immediate response to stimulus 9.Movement due to growth 10.Hormones in animals. Introduction:-

 •Recall the previous:-

 •Feature of alive:-

 •Movement

 •Growth

 •Seed germination

Why do we associate such visible movements with life?

• Because all these are a response to a change

•For example :-bright ligh is focussef on our eyes, the size of pupil gets reduce. 

•We whisper in class

•Conclusion:- •All leaving organism respond to a change in the environment.

•The change in the environment to which organism respond is called stimuli such as light , heat , cold smell etc.

•Both plants and animals respond to stimuli but in different way.

•System for control and coordination in animals:- 

•It includes 2 main stats:-

 Nervous system 

Endocrine  system

•Animals – Nervous system -

In animals control and coordination are provided by nervous and muscular tissue 

•Nervous system is made up of neurons 

-All information of stimuli is detected and conducted by specialised neurons present at the tip of sense organs.

 -Such neurons are called receptors  -It conduct information via electrical impulses from one part of body to another

√On the basis of where the receptors present, it is of following types:

*Photoreceptor:-

 •Present in ear

 •Receive sound

•Help in hearing and maintaim balance of body.

 *Photoreceptor :-

•Present in eyes

•Receive Light 

•Help in seeing.

 *Thermoreceptors:-

 -Present in skin.

 -Feel temperature.

 -Help in feeling heat / cold and touch.

*Olfactory receptor:-

 -Present in nose.

 -sense of smell

 -help in detection of smell. *Gustatory receptors

 -present in tongue

 -Sense of taste.

 - help in detection of taste

Ques-What is neutron?

Ans:-Neuron is the structure And functional unit of nervous system. How neuron acquire and conduct information?

•What is the Functioning of neuron?

•Functioning of neuron:- Neuron acquire information at the end of dendritic tip.

 •As chemical reaction takes place that create an electric impulse

•The impulse travel from dendrite to cell body and then at the end of axon passing through it

•At the end of axon , electrical impulse set off the release of some chemicals.

•These chemicals cross the synapse and start a similar electrical impulse in the dendrite of next neuron

•A similar synapse finally allow delivery of such impulses from neuron to other cells(eg muscle cells or gland). 

*Parts of neuron:-

•Dendrite

- Acquire Information.

•Cell body:- Information acquired is now travelled as an electrical impulse.

•Axon:-Longest fibre on cell body is called axon.

                 -Transmits electrical impulse from cell body to dendrite of        next neuron.

•Synapse

Gap between nerve ending of one neuron and denrite of other neuron.

-Here electrical signals are converted into chemical signal for onward transmission.

•Types of neuron:-

Sensory Neurons:- Neurons which transmit messages from body parts to CNS.
Motor Neurons:- Neurons which transmit messages from CNS to body parts.
Relay Neurons:- Neurons which relay the signals within CNS.
                         - Also called mixed neuron
*Reflex action:- 
•It is sudden ,quick and automatic response to change in environment.
•Involves only spinal cord.
•Occur within fraction of seconds.:
•Example- knee jerk, withdrawal of hand on touching hot object.

Stimulus
Observable or detectabe change in external or internal environment to which an organism react.
Reflex arc :-
The path through which nerve impulses pass during reflex action is called reflex arc.
Heat(stimulus)-->Receptor(skin)--->Spinal cord--->Effector organ(muscle) -->Response(hand withdraw)
Response:- Final action after reflex action.
Voluntary and involuntary action
Voluntary action:- Action controlled by forebrain.
Example:- Walking , running, writing etc.
Involuntary action:- Actions controlled by mid brain and hind brain.
Example:- Beating of heart, digestion of food , breathing sweating ,working of kidney etc.
Need of reflex action:-
In some situations we need to act quickly otherwise our body would be harmed .
In these cases , response is generated from spinal cord instead of brain.
In this way ,time taken for action is reduced which save us from injury.
Some of these situations are touching a hot object , pinching etc.

Human brain
Main coordinating centre of body.
Consist of 3 parts:- 
-Fore brain 
-Mid brain 
-Hind brain 
Fore brain:-
Most complex and specialised part of brain
It consists of 
•Olfactory lobe
•Cerebrum
•Diencephalon
Function:-
Olfactory lobe:-Centre for sense of smell.
Cerebrum:-receive sensory impulse from various receptors
Main seat for will power, intelligency memory , experience and conscious sensation and voluntary action.
Diencephalon:- Center for temperature regulation, hunger and emotional reaction.
Mid brain:- consist of 1. Optic lobe ,2. Crura cerebri
Functions:- 
Optic lobe:- Centre of visual activities.
Control movement of eye ball and change in pupil size.
Crura cerebri:- Transmit impulse between fore brain and hindbrain.
Control reflex movement of head neck and trunk.
Hindbrain:- Consist of 1.Cerebellum 2. Pons varoli 3.medulla oblongata.
Functions:-
Cerebellum:- Maintain posture and equilibrium of body 
Regulate voluntary movement.
Example:- picking pen, walking in a straight line.
Pons varoli:-  control involuntary action.
Example respiration regulation
Medulla oblongata:- Control involuntary action .
Example:- Heart beat respiration ,blood pressure, coughing and sneezing etc.
Covering /Meanings of brain
Three menings- 1. Piameter2.Arachnoid membrane 3.Durameter.
Piameter :- innermost, extremely thin , delicate and vascular menings.
Arachnoid membrane:- Middle, thin vascular, give Webby appearance of spider.
Durameter:- Outermost, thick and fibrous layer.
Protection of brain :-
Brain is protected by hard bony structure called skull.
Along with this it is covered by 3 menings
Between piameter and arachnoid membrane, a clear alkaline fluid is present called cerebrospinal fluid
Functions of CSF:- Act as a shock absorber.
Forms a medium for exchange of nutrients and wastes among nerve tissue.
Protection of Spinal cord:-Spinal cord is protected by vertebral column called backbone.
How does Nervous tissue cause action? 
When a nerve impulse reaches the muscles, muscles fibre move.
Muscle cells moves by changing their shape so that they shortenHow muscle fibre change their shape?
Muscle cell have special protein named Actin and Myosin.
When these proteins receive impulse their shape and arrangement in the cell change.
When this happens, new arrangement of these protein give muscle cells a shorten form.Coordination in plants:-
Plants do not have nervous system.
Types of movement:-
Two types:-
1. Dependent on growth
2. Independent of growth
Independent of growth:-
It has immediate response to stimulus
Plants use electrical chemical means to convey information from cell to cell.
For movement to happen , cell change their shape by changing the amount of water in them, resulting in swelling or shrinking of cells.
Example:- Drooping of Touch me not plants on touching itDependent on growth:-
These movements are tropic movements(directional movement) in response to stimulus..
Tendrils:- pea plants climb up other support by tendrils.
Tendrils are sensitive to touch.
Part of tendril in contact with support grow slow as compare to part of tendril away from it.
This cause the tendril to circle around the object and cling to it.
Phototrophism :- growth of plant part towards sunlight.Shoot shows phototrophism.
Geotropism:- growth of plant parts toward earthRoots show geotropism.
Hydrotropism:-Growth of plant parts toward water.*Roots show hydrotropism.
Chemotropism :-growth of plant part towards chemicalsexample:- growth of pollen tube towards ovule.Plant hormones:-
Chemical compound which help to coordinate growth , development and responses to environment.
Main plant hormones are :-
Auxin
Gibberelin
Cytokinins
Abscisic acidFunctions of hormones:-
Auxin:- Hormones synthesis at shoot tip.
Help the cell to grow longer.
Involved in photosynthesis.
Gibberellin:-Help in growth of stem. 
Cytokinins:-Promote cell division.
Present in fruits and seeds in large concentration
Abscisic acid:-inhibit growth
Cause wilting of leaves.
Also known as stress hormones
Limitations of electric communication:-
Electric impulse reach to only those cells which are connected to nervous tissue.
Once an electric impulse is generated in a cell and transmitted, cell will take some time to reset it’s mechanism before it can generate and transmit a new impulse.Note:-
Along with electric communication, animals also use another means of communication between cells named chemical communication.
Plant donot use electrical communication and use chemical communication only.
Mechanism of transporting impulse in plants.
When an impulse is received by cell , it releases a chemical compound
This compound would diffuse all around original cell.
It other cells around have the means to detect this compound using special molecules on their surfaces then they would be able to recognise information and even transmit it. Hormones in animals:-
Chemical substances which coordination the activities of living organisms and also for their growth.
Hormones produced in one part of an organism move to another part to achieve desire effect.
Endocrine glands secretes their product (hormones  into the blood.
List of endocrine gland with their hormones name And their functions  are listed below:-
Importance of iodine:-
Iodised salt is necessary because iodine mineral is essential part of thyroxine hormones.
Thyroxine is released by thyroid gland.
Thyroxine regulates metabolism of carbohydrates, fats and proteins.
So we must consume iodised salt which is necessary for proper working of thyroid gland.
It’s deficiency causes a disease called goiter.
Diabetes
Due to deficiency of insulin hormones
Insulin is secreted by Pancreas.
Insulin is responsible to control blood sugar levels.
Treatment :-Injections of insulin hormones can be helpful.Feedback mechanism:-
The excess or deficiency of hormones has a harmful beffect on our body.
Feedback mechanism makes sure that hormones should be secreted in precise quantity and at right time.
Example:- Feedback mechanism to control the sugar level in blood as follows:-
Important ques assignment:--
write in detail about animals nervous system .
What are receptors  And it’s types?
What is neuron? Write about functioning of neuron.
Write about parts of neuron.
What are the types of neuron?
What is reflex action?
Define :- stimulus, reflex arc and response.
What is the need of reflex action?
What is voluntary and involuntary action?
Draw and give a detain about CNS.
How is brain protected?
How muscle fibre change their shape?
Give a detail account of coordination in plants.
Define :- Phototrophism, geotropism, hydrotropism and chemotropism
What are plant hormones? Explain in detail.
What are animal hormones? Explain in detail.
What is the importance of iodine?
What is diabetes?
What is feedback mechanism?