1.
Control and
Coordination
Class X- Science-Chapter 7 Biology
by Eswari Kumaravel M.Sc., M.Phil., B.Ed.

2.
Co-ordination
• Coordination:
o Various organs working together in a systematic,
controlled and efficient way to produce proper
response to various stimuli is known as coordination.
• Why is it necessary?
o Each organ in an organism is specialized to perform a
particular function.
o It is necessary that various organs work together to
produce proper response to stimulus.

3.
Control and Coordination in Humans
• Systems responsible for Coordination:
o Nervous System: through electrical impulse.
o Endocrine Glands: through hormones
• Hormones
o Hormones are chemical messengers made of proteins.
o Secreted by endocrine glands into blood stream.
o Act on specific tissues or organs known as target
organs.
o Production of Hormones and functioning of hormones
is controlled by Nervous system.

4.
Hormonal Coordination
Nervous
System
Stimuli
‘Secrete”
Pushes Hormone
into Blood
Acts on the target
Organ

5.
Nervous System vs. Endocrine System
Endocrine System Nervous System
No direct connection with organs or
tissues.
Direct connection and control over
tissues and organs
Information of coordination
transmitted slowly
Information is transmitted very fast
Effect is long lasting Effect is short-lived
Nervous coordination Hormonal coordination
Network of nerves connect different body
parts to Central Nervous System
Hormones from Endocrine Gland,
reach different parts through blood.
Messages through Nerves Messages through hormones
Nerves and Central Nervous System
control and coordinate different functions.
Every function is controlled and
coordinated by special Hormone
As it is an impulse, there is no such thing
as quantity affecting organs.
Increase and decrease of Hormone
quantity affect target organs

6.
Nervous System
• Animals have specialized
structures called sense
organs (receptors) to
receive external stimuli.
• Stimulus
o One which brings
response in an organism.
• Impulse
o Nerves pass information
through electro-chemical
signals known as
impulse.

7.
Types of Receptors
• Photo Receptor
o For light. e.g. eye
• Audio Receptor
o For Sound e.g. Ear.
• Olfactory Receptor
o For Smell e.g. Nose
• Gustatory Receptor:
o For Taste e.g. Tongue

8.
Vertebrate Nervous System
• It is composed of two main
components:
• Central Nervous System
(CNS)
o Includes brain and spinal
cord.
• Peripheral Nervous
System
o Includes cranial, spinal
and visceral nerves.
o For communication
between CNS and other
parts of the body.

9.
Protective Feature of CNS
• Brain is protected by the bony
cranium.
• It is covered by three
membranes called Meninges
• Space between Meninges is
filled with Cerebro Spinal
Fluid. It protects brain from
Mechanical Shocks.
• Meninges and Cerebro spinal
fluid covers Spinal Cord too.
• Spinal Cord is protected by
Vertebral Column.

10.
Peripheral Nervous System
• Peripheral Nervous
System is
composed of
Cranial Nerves and
Spinal Nerves.
• 12 Pair of Cranial
nerves come out of
brain and cover the
organs in head.
• 31 pair of spinal
nerves come out of
spinal cord and
cover all the organs
below head region.

11.
Structure of Neuron
• Structural and functional unit of Nervous system is
neuron. Neuron is a cell.
o Dendrites: Receives information from axon of another cell
and conducts the messages towards cell body.
o Cell Body: Contains nucleus, Mitochondria and other
organelle.
o Axon: Conducts messages away from cell body
o Synapse: Small gap between two adjacent neurons. Here
nerve impulse passes from one neuron to other.

12.
Transmission of Impulse
• Electrical impulse is acquired by Dendrite in the neuron.
Electrical impulse travels through
Dendrite
Cell
body
Axon
Nerve
Ending

13.
Types of Neurons
Sensory Neuron
• Conveys
Stimulus from
Receptors to
Brain
Associative
Neuron
• Interprets
Stimulus
• Gives
appropriate
command to
Motor Neuron
Motor Neuron
• Conveys motor
commands to
effectors
(muscles /
glands)

14.
Autonomous Nervous System
• Autonomous Nervous System
o Chain of nerve ganglion that runs along the spinal cord.
o It controls all involuntary actions.
o Two types 1. Sympathetic and 2. Parasympathetic nervous
system.
Sympathetic Nervous System Parasympathetic Nervous
System
Heightens the activity of an
organ as per need
Slows down the activity of an
organ. Has a calming effect
For e.g. It increases breathing
rate and heart rate during
running.
This is to meet increase in
oxygen demand
For e.g. breathing rate and heart
rate slows down during sleep

15.
Autonomous Nervous System

16.
Voluntary & Involuntary Actions
Factors Voluntary Action Involuntary Action
Type of Response Not automatic
(With awareness)
Automatic
(without awareness)
Part of the Brain that
controls actions
Cerebrum Medulla Oblangata
Speed Slow Fast
Nervous pathway Receptor → Spinal
Cord → Cerebrum →
Spinal Cord →
Effector
Receptor → Spinal
Cord → Medulla
Oblangata → Spinal
Cord → Effector
Examples Speaking, Walking,
Writing etc
Heart beat,
Respiration,
Peristalsis etc.

17.
Reflex Action
• Reflex Action is an automatic and rapid response to
a stimulus.
Response
Receptor
(Sense Organ)
Effectors
(Muscles /
glands)
Sensory
Neurons
Motor
Neurons
Spinal Cord
Stimulus

18.
Reflex Actions - Example

19.
Reflex Arc
• Reflex Arc is the pathway along which nerve impulse
travels during the reflex action.
Stimulus Receptors Sensory Neurons
(sense organs)
Spinal Cord
Response Effectors Relay Neurons
(Muscles / glands)

20.
Reflex Arc

21.
Differences
Voluntary Action Involuntary Action Reflex Action
Not automatic
(with awareness)
Actions which do not
need thinking and
performed
unknowingly
Rapid automatic
response to a stimulus
Controlled by Brain
(Cerebrum)
Controlled by Brain
(Medulla Oblangata)
Controlled by Spinal
Cord
Slow Fast Sudden and Fast
Example: Walking Example: Heart Beat Example: Touching a hot
pan

22.
How Nervous Tissues cause Muscular movements?
Nerve Impulse
reaches muscle
Muscle fibres
move
Proteins change
shape and
arrangement
Muscle Cells
Shrinks
This makes
muscle cells
contract
This movement is
caused by Special
proteins

23.
How Nervous Tissues cause Muscular movements?

24.
Structure of Brain
• Brain is the highest
coordinating Centre
• It is protected by
cranium.
• It is covered by three
membranes. Space
between membranes
is called Meninges.
• Meninges is filled
with Cerebro spinal
fluid

25.
Structure of Brain
• Cerebrum
• Olfactory Lobe
Fore
Brain
•Connects fore brain
& Hind brain
•Controls reflex
involving eyes &
Ears
Mid
Brain
•Cerebellum
•Pons
•Medulla Oblangata
Hind
Brain

26.
Structure of Brain
• Visual
Reception
Occipital
Lobe
•Auditory
Reception
Temporal
Lobe
•Touch, Smell,
Temperature
•Conscious association
Parietal
Lobe
•Muscular
Activities
Frontal
Lobe
OlfactoryLobe

27.
Functions of Brain
Part Function
Cerebrum • Main thinking part of brain
• Responsible for reasoning, speech, intelligence, sigh,
hearing and usage of information.
Thalamus • Send sensory information to Cerebrum
Hypothalamus • Controls body temperature
• Maintain Water Balance
• Controls urge of eating, drinking
• Controls pituitary Gland
Cerebellum • Controls and coordinates different muscular actions
• Maintains posture and equilibrium of the body
during various activities such as walking, drinking
riding etc.
Pons • Controls breathing rate
• Controls facial expression, mastication of food etc.
Medulla Oblangata • Controls involuntary actions such as Breathing, Blood
Pressure, Movement of alimentary canal etc.
• Regulates reflex responses like salivation and
vomiting.

28.
Endocrine Glands
• Endocrine glands
are ductless glands
that secrete
hormones directly
into blood.

29.
Functions of Endocrine Glands
Gland Secretion Hormone Function
Pituitary
Gland
Growth Hormone Regulates the growth
Hypothalamus Releasing
Hormone
Regulates the secretion of
hormones from Pituitary Gland
Thyroid Thyroxine Controls metabolic rate of
carbohydrates, fats and proteins
Parathyroid a. Calcitonin
b. Parathormone
Lowers blood calcium level
Increases Calcium and decreases
Phosphate level
Adrenal Adrenaline Increases Heart rate, respiration,
blood pressure during
emergency situations.

30.
Functions of Endocrine Glands
Gland Secretion Hormone Function
Pancreas a. Insulin
b. Glucagon
Decreases blood glucose
Increases blood glucose
Testis Testosterone Regulates male secondary sexual
characteristics
Helps in the formation of sperms
Ovary Progesterone
and Estrogen
Progesterone:
• Helps to prepare the wall of uterus for
attachment of fertilized egg.
• Maintains Pregnancy
Estrogen:
• Controls development of female sex
organs, ovulation etc.
• controls Menstrual cycle
Thymus Thymosin Produces immunity
Pineal Melatonin Stimulates muscle contraction

31.
Feedback mechanism
The timing and amount of hormone released is
regulated by feedback mechanism.
• If glucose level increases
in blood, pancreas secretes
required amount of insulin.
• Insulin reduces the glucose
level.

32.
Why is Iodine Salt advisable?
• Iodine is required by Thyroid to make Thyroxin
hormone.
• Thyroxin regulates metabolism of carbohydrate,
protein and fats.
• Iodine deficiency in our diet causes Goitre, where
Thyroid gland enlarges causing swelling in neck.
• Iodised common salt contains proper content of
Iodine. To avoid deficiency of Iodine, iodised salt is
recommended.

33.
Coordination in
Plants

34.
Coordination in Plants
• Only Chemical coordination.
• No brain like structure in plants to adapt themselves
according to change in surroundings.
• Growth is controlled by growth hormones.
Plant
movements
Tropic
Movement
Nastic
Movement

35.
Tropic and Nastic Movements - Differences
Feature Nastic Movement Tropic Movement
Growth Growth independent
movement
Growth dependent
movements
Time of action Immediate Slow
Response to
stimulus
Non-directional Directional
Reason for
Action
Change in turgor Cell division
Examples Folding of leaves of
touch me not (mimosa),
opening and closing of
stomata.
Phototropism,
Geotropism,
Hydrotropism,
Chemotropism

36.
Tropic Movements
• Response of an organism in the direction of stimuli or away
from it is called tropic movement or tropism.
o It may be negative (away from stimulus) or positive (towards
stimulus).
Phototropism Geotropism
• Stem tip grows in the
direction of light.
• Positively Phototropic.
• Response of organism to
gravity.
• Root grows towards pull
of gravity. Positively
Geotropic

37.
Tropic Movements
Chemotropism Hydrotropism
• Response to chemicals.
• Pollen tubes grow
towards a chemical
produced by ovule.
• Response of organism to
Water
• Root grows towards
presence of water.

38.
Tropic Movements
Thigmotropism
• Response to touch or solid surface.
• Tendrils and other climbers are
positively Thigmotropic

39.
Plant Hormones
• Phyto hormones help in control and coordination in
plants.
• Present in very small quantities in plant tissues.
• Produced in any part of the plant and transmitted to other
parts by diffusion.

40.
Plant Hormones
• Produced at shoot tip
• Helps in growth of stem
Auxin
• Helps in vegetative growthGibberellins
•Promotes cell division
• Present mainly in fruits and
seeds
Cytokinins
• Inhibits growth and induces
wilting of leaves
Abscissic Acid
• Helps in ripening of FruitEthylene

41.
Activities

42.
Activity – 7.1
• Put some sugar in your mouth and observe how it tastes.
• Block the nose and eat sugar again. Observe the
difference in taste.
• While eating lunch, block your nose in the same way and
note your observation.
• Observation:
o We don’t get the same taste of food and sugar as we had
earlier.

43.
Activity – 7.2
Place wire mesh on
a conical flask with
water
Place 2 or 3
germinated bean
seeds on wire mesh
Keep the conical
flask in a card
board box.
Keep the open side
of the box facing
light coming from
window
Leave it for 3 day

44.
Activity – 7.2
• Observation: Shoot bends and moves towards the
light.

45.
Activity – 7.2
• Continued..
o Rearrange the flask so that the shoots are away from light
and the roots towards light.
o Leave it undisturbed for few days.
• Observation:
o Old Parts of the root and shoot will change their direction.
o There will be differences in the growth of shoot.
• Conclusion:
o Light influences the direction of growth of shoot.