CONTROL AND CO-ORDINATION theory

CONTROL AND CO-ORDINATION

DIFFERENCE BETWEEN CONTROL AND CO-ORDINATION

	CONTROL	CO-ORDINATION

CO-ORDINATION IN ANIMALS

• Unicellular organisms like animals, respond to environmental stimulus by moving towards the stimulus (+ve taxis) or by moving away from the stimulus (-ve taxis)
• Except sponges (porifera), all multicellular animals have specialized sensory cells called as nerve cells (or neurons), which respond to stimuli and co-ordinate their activities.
• In simple multicellular , co-ordination takes place through nervous system , made up of nerve cell.
• Ex:-Nervous system of hydra consists of network of nerve cells jined to one another and spread through its body.
• In higher animals, (e.g. in vertebrates), control and co-ordiantion take place through nervous system as well as through endocrine system (hormonal system).

NERVOUS SYSTEM IN ANIMALS

Ns:- Nervous system is composed of nervous tissue (or neuron ) and is involved in control , co-ordination and integration of different parts fo body

Neurons (or nerve cells) are the structural and functional unit of nervous system

FUNDAMENTAL CHARACTER

PROPERTIES OF NERVOUS SYSTEM

1. Irritability: - Irritability (sensitivity+ responsiveness) help organisms to interact with day to day fluctuating environmental conditions..
2. Responsiveness:-The property by which an organisms respond toward a particular stimuli.

Functions of nervous system

1.      Nervous system is important to regulate, control and co-ordinate different body functions.

2.      Nervous system is used to regulate voulnatary , invounatary and reflex actions of body.

3.      Nervous system is important for sensation and complex thinking process in the body.

SOME BASIC TERMS

1.      Stimuli: - changes in external or internal environmental of body, which have energy to set up appropriate impulses in the sensory receptors, are called as stimuli.

Ex: - some common stimulus are: light , sound , heat or mechanical pressure etc.

2.      Receptors: - Receptors are a group of nerve cell that receives stimulus and changes these into electrical signals.

Different sense organs contain different receptors for detecting different stimuli.

Receptor	Sense	Stimulus
1.Photoreceptors	Eyes	Light
2.

SENSORY NERVE FIBERS;-

(AFFERENT);- Sensory nerve fibre receive stimuli by their dendrites and convey these sensoy impulses from receptors to CNS, (brain and spinal cord)

Those may be somatic sensory or visceral sensory.

CNS

MOTOR NERVE FIBRES

EFFECTORS

RESPONSE (FINAL ACTION)

COMPONENTS OF NERVOUS TISSUE

Nervous tissue consists of following 2 components:

1. Cells
2. Matrix

Cells: - Cells include neurons (nerve cells), neuroglia cells(packing and supporting connective tissue cells), ependymal cells and neurosecretory cells.

Neurons are the structural and functional unit of nervous system.

Matrix: - matrix are small amount of intercellular substance

NEURONS/ NERVE CELL

·         Neurons (nerve cells) are the structural and functional unit of nervous system.

·         Neurons are the highly specialized, most complicated and largest cells of vertebrate body.

Neurons consist of following 3 prominent parts;-

CELL BODY/ SOMA / CYTON/ PERIKARYON

·         Cell body of neuron is a typical animal cell which contains abundant cytoplasm, large central nucleus, numerous mitochondria, golgi body, ribosomes , lysosomes etc.

·         Cell body also contain Nissle’s granules or Nissle’s bodies. Nissl’s granules are irregular masses of ribosomes and RER. These remain associated with protein synthesis.

·         Neurons lack centriole hence cannot divide and remain in G₀ phase throughout life.

DENDRITES

·         Dendrites are several short, tapering, much, protoplasmic processes stretching our from the cell body of a neuron.

·         Dendrites receive nerve impulses from receptors. The information then travel as an electric impulse towards cell body.

·         Dendrites also conatin Nissl’s granules and neurofibrils.

AXON:-

·         Axon is a single, very long, cylindrical protoplasmic process (nerve fibre), arising from the cell body,

·         At its terminal end, axon is highly branched. Axon terminals are often knob like and these may end in nerve fibres (forming neuromuscular junction) or glands or form synapses, with dendrite of other neurons.

·         Axon is covered with one or two sheath. Sheathed axon is called as nerve fibre.

·         The axon has an insulating and protective sheath of myelin around it. But at intervals, myelinated nerve fibres possess unmyelinated areas called as nodes of Ranvier.

·         Myelinated nerve fibres conduct impulses more efficiently than non-myelinated nerve fibres.

CHARACTERISTIC PRPERTIES OF NEURONS

TYPES OF NEURONS

SENSORY NEURONS

MOTOR NEURONS

RELAY NEURONS

DIFFERENCE BETWEEN DENDRITES AND AXON

PHYSIOLOGY OF IMPULSE TRANSMISSION

1.      The information acquired at the end of dendritic tip, sets of a chemical reaction that creates an electrical impulses.

2.      This electrical impulse then travels from dendrites to cell body, and then along the axon to its end.

3.      At the end of axon, electrical impulses sets off release of some chemicals (called as neurotransmitters)

4.      These chemicals cross the gap between 2 neurons called as synapse and start a similar chemical impulse in dendrite of next neuron.

NEURO-MUSCULAR JUNCTIONS

HUMAN NERVOUS SYSTEM

BRAIN (ENCEPAHLON)

1.      Brain is a soft, whitish, and highest co-coordinating organ of the body.

2.      Brain is situated in the cranial cavity of skull. The bones of cranium (or brain box_ protect this delicate organ from mechanical injury.

3.      Inside cranium, brain is contained a fluid- filled balloon which provides further shock absorption.

4.      Brain is surrounded by 3 meninges. The space between these meninges is filled with CSF (cerebro-spinal fluid). It protects brain from mechanical shocks.

5.      Brain is differentiated into outer grey matter (formed of cell bodies) and inner white matter( formed of myelianted axon)

DIVISIONS OF BRAIN

FORE BRAIN: - FORE-brain is the main thinking part of brain. It has regions which receives sensory impulses from various receptors.

PARTS OF FORE-BRAIN

CEREBRUM:- cerebrum is the largest, most complex and specialized part of brain.

Cerebrum consists of 2 cerebral hemispheres separated partially by longitudinal fission, but connected internally by corpus callosum.

Broadman distinguished 44 areas within cerebral cortex. These are classified into 3 caterogies:

SENSORY AREAS: - receives and analyze sensory impulses.

ASSOCIATION ARES: - there are separate areas of association in forebrain. At association area, sensory information is interpreted by putting it together with information from other receptors as well as with information that is already stored in brain.

MOTOR AREAS:- motor area controls voluntary muscular movement. Based on interpreted result at association arena, a decision is made about how to respond and this information is passed on to the motor areas which controls movement of voluntary muscles (e.g. leg muscles)

Each cerebral hemisphere consists of following 4 lobes:-

(a)

(b) olfactory lobes:-

© diencephalons

(d0 haypothalmamus:- hypothalamus is located below thalamus. It contain centres for complex actions like hunger, thirst , thermoregulation (body temperature) and behaviioual paterna slike sleep, sex and stress.

MID –BRAIN

Mid –brain is a significantly small regions which consist of two fibre tracts called as corpora qudrigemian  and cerebral peduncles.

Mid-brain controls reflex mechanism of head, neck and trunk in response to visual stimuli.

Mid-brain also controls the reflex movements of eye –muscles, changes in pupil size and shape of eye lens.

HIND -BRAIN

CEREBELLUM:-

Cerebellum maintains the posture, equilibrium and muscle tone of the body. It enables us to make precise and accurate movements of body. Thus, walking in straight line, rising is bicycle and picking up a pencil involves cerebellum.

It is responsible for the precision of voluntary actions.

PONS VAROLLI

MEDULLAR OBLONGATA

Medulla oblongata controls many of involuntary action of body like:-

Rate of heart beat.

Breathing movements

Expansion and contraction of BV’s to regulate BP.

Medulla is also the controlling centre for reflexes such as swallowing, coughing, sneezing, secretion of saliva dn vomiting.

HOW DOES NERVOUS TISSUE CAUSE ACTION

Nervous tissue sets impulse, and impulse is then transmitted to the muscle tissue, which do the final action of movement by contraction and relaxation.

Muscles cells have 2 contractile myo-proteins called as actin and myosin. Actin and myosin change their shape and arrangement in the cell in response to nervous electrical impulses.

New arrangement of proteins give rise the muscle different shape by changing their shape, sucle cells move i.e. can contrl or relax.

The movement of muscle tissue cause final action.

In case of involuntary muscles (skeletol muscles), nerve impulse is generated automatically from medulla oblongata.

HUMAN ENDOCRINE SYSTEM

CO-ORDINATION IN PLANTS

MOVEMENTS IN PLANTS

What is the difference between co-ordination in animals and plants?

	Co-ordination in animals	Co-ordination implants
	Animals have a nervous system for controlling and and co-ordianting the activities aof body.	Plants nether have nervous system nor muscles

What is a tropic movement (growth movement). Give an example.

An:-tropic movements are Paratonic growth movements of curvature in which direction of movement is determined by direction of stimulus.

Ex: - when a seed germinates, root goes down and stem comes up into the air.

What is a nastic movement (non-growth movement). Give an example.

Nastic movements are non-directional movements of growth that involves turgor changes and are determined by structure of responding organ.

Ex.- When we touch the leaves of mimosa pudica (sensitive touch me not ) then they begin to fold up and droop.

What is the difference between tropic movement and nastic movement?

An:-   

	Tropic movement (Growth movment)	Nastic movement(non-growth movement)
	Tropic movement are paratonic growth movements i.e. movement depends upon growth	Nastic movement are turgor movement  i.e they are independent upon growth
	The direction of movement is related to the direction of sitmulus	The direction of movement is not-related with direction of stimulus.

                     

What is the difference between tropic movement and nastic movement?

How do auxins promote the growth of tendril of pea plant around a support?

Tendrils are sensitive to support

Less auxin occurs on the side of contact as compared to free side.

Due to more auxin present on free side, more growth occurs on free side.

As a result of growth on free side, tendrils coils around the support

Because this growth is directional, it appears as if plant shows movement in a particular direction.

Describe an experiment to demonstrate hydrotropism, phototropism and geotropism

Give examples of positive and negative geotropism, hydrotropism and phototropism

Give differences between growth in plants and growth in animals.

Give advantages and limitations of electrical impulses caused by nervous tissue in information transfer.

Give advantages and limitations of hormonal system over neuron tissue in information transfer.

If no nervous tissue and muscular tissue present in plant then how:-

Information is carried from point of touch to point of action.

Mimosa pudica causes fold and droop action.

PHYTOHORMONES

GROWTH PROMOTERS

HORMONES	FUNCTION/ PHYSIOLOGICAL ROLE	LOCATION
CYTOKININ	1.       Cytokinin promotes growth by cell division. 2.       Cytokinin delays ageing in leaves. 3.       Cytokinin helps to breaks the dormancy of seeds and buds.	It is present in higher concentration in areas of rapid cell division, such as in fruits and seeds.
AUXIN	1.       Auxin promotes growth by cell enlargement and cell differentiation. 2.       Auxin promotes stem and fruit growth. 3.       Auxin regulates important plant growth movements (i.e. tropisms).
GIBBERLLIN	1.       Gibberllin promotes growth by cell differentiation. 2.       Gibberllin promotes stem and fruit growth.

GROWTH INHIBITOR

HORMONE	FUNCTION/ PHYSIOLOGICAL ROLE
ABSCISIC ACID (ABA)	ABA inhibits growth by : ·         By wilting of leaves ·         By closing of stomata ·         By promotes dormancy in seeds and buds.