Control and Coordination for Class X Biology

3. Control & coordination
• A system of control and coordination is
essential in living organisms so that
the different body parts can function as
a single unit to maintain homeostasis
as well as respond to various stimuli.

4. Movements
• Some movements are connected with
growth ex- seed germination
• Some movements are not connected
with growth
• Ex- -A cat running
• Buffaloes chewing cud
• Children playing on swings

5. Seed germination

6. A cat running behind the rat

7. Cattle chewing cud

8. Children playing on swings

9. What is movement
• It is a response to a change in the
environment of the organism
Or
• It is an attempt by living organism to
use changes in their environment to
their advantage

12. • All the movements in response to the
environment are carefully controlled Each kind
of change in the environment evokes an
appropriate movement in response
• The movement to be made depends on the
event that is triggering it
• Therefore such controlled movements must be
connected to the recognition of the various
events in the environment, followed by correct
movement in response
• In multicellular organisms specialized tissues
are used to provide these control & coordination

13. Nervous system in animals
• In animals control & coordination are
provided by the nervous & muscular
tissues

14. Receptors
• To detect the
changes in the
environment
organism has
receptors.
• They are
present in the
sensory organs

15. Cutaneous receptors

17. RECEPTORS IN THE TONGUE

18. Receptors in the ear

19. STRUCTURE OF THE NEURON
Cell bodyCell body – main part– main part
DendriteDendrite – receives action– receives action
potential (stimulation)potential (stimulation)
from other neuronsfrom other neurons
AxonAxon – branches from– branches from
cell body, where thecell body, where the
action potential occursaction potential occurs
Axon terminalAxon terminal – end of an– end of an
axonaxon
Myelin sheathMyelin sheath – lipid layer– lipid layer
for protection overfor protection over
neuronsneurons
Nodes of RanvierNodes of Ranvier – gaps– gaps
in myelin sheathin myelin sheath

20. Types of nerves
• : A nerve is formed by the union of several
nerve fibres. Nerve fibres are axons and they
are enveloped by a covering made of lipid.
Based on the property of nerve fibres, the
nerves are classified into several types.
• Sensory Nerve
• it is formed by the union of sensory nerve
fibres. It carries sensory impulses from the
receptors to brain or spinal cord.
• Motor Nerve:
• It is f ormed by the union of motor nerve fibres.
• It carries motor impulses from brain or spinal
cord to different parts of the body.

21. Nerve impulse
• Nerve impulses travel in the following
manner from one neuron to the next :
Dendrites - Cell body - Axon Nerve
endings at the tip of axon - Synapse
-Dendrite of next neuron.

22. It is the junction between the two neurons

23. Conduction of the nerve impulse

24. Conduction of the nerve impulse
• The information is acquired at the end of
dendritic tip of the neuron that are
present in the sense organs / receptors.
• This sets of a chemical reaction in the at
the dendrites generating an electrical
impulse.The electrical impulse
thentravels from the dendritic tip to
cyton and then to the axon of that
neuron. When it reaches the nerve
endings certainchemicals are released
in response to the electrical impulse.
• These chemicals cross the gap or
synapse and start asimilar electrical
impulse in a dendrite of the next neuron.
A similar synapse finally allows the
delivery of such impulse from neurons
to other cells such as muscles or
glands.

25. Conduction of the nerve impulse at synapse

26. Reflex acion
• It is defined as fast, unconscious, immediate,
automatic and involuntary response of the body
(through effectors) to a stimulus. It is monitored
through spinal cord.
Examples of reflex actions:
• Closing eyes when bright light falls on the eyes.
• Knee-jerk
• Withdraw Hands when pricked by a pin.
• Choking stimulates cough reflex
• Withdraw hand or leg when it touches an hot object.
• Women knitting a sweater while watching TV
(conditioned reflex).

27. Examples of reflex action
Knee jerk

28. Reflex actions
• Touching a flame is an urgent &
dangerous situation
• If we think about it our hand will be
burnt
• The solution to solve this problem is
having reflex arc connections

29. How does our body design
solve this problem
• Rather than thinking
about the situation of
the heat , if the nerves
that detect the heat are
connected to the
nerves that move the
muscles in simpler way
, the process of
detecting the signal
( input) & responding
to it ( out put) may be
completed quickly.
Such a connection is
commnly called reflex
arc

31. ADVANTAGS OF REFLX ACTION
• 1) Enables the body to give quick
responses to harmful stimuli, thus
protecting the body.
• 2) Minimises overloading of brain.
• 3) Efficient way of functioning in the
absence of true thought processes.

32. Sudden action in
response to some
thing in the
environment is
called Reflex action
Thinking is not
involved in this

33. Where should reflex arc
connections made between
input nerve & an output nerve
• Nerves from all over the body meet in
abundle in the spinal cord on their way
to the brain
• reflex are formed in the spinal cord

34. No, brain also involves in some reflex actions
Spinal cord is made up of nerves which supply
information to think about
We are thinking animals
Thinking involves more complex mechanisms
& neural connections
These are concentrated in the brain, which is
the main coordinating center of the brain
Is the reflex action is the only
function of the spinal cord

35. Role of the brain in reflex action
•
Brain has no role to play in creation of
reflex action response. Instead spinal
cord is the control centre of a reflex
action. In fact brain becomes aware
after the reflex arc has been formed

38. The ways by which nervous
system sends message to the
muscles
• 1. Through the spinal cord- spinal
reflex
• 2. Through the brain
• The communication between the
central nervous system& the other
parts of the body is facilitated by the
peripheral nervous system

39. It has two parts
1. Brain
2. Spinal cord

40. Functions of the central nervous
system
• They receive the information from all parts
of the body & integrate it

43. Protection of brain tissues
• Brain is covered
by a brain box
or cranium
• inside the box
brain is
contained in a
fluid filled ballon
which provides
further shock
absorption
Cranium

44. The brain allows us to think & take action sbased on the
thinking

46. Structure of the brain
• Brain has three regions
• 1. Fore brain
• 2. Mid brain
• 3. Hind brain

48. FORE BRAIN
• It has
• 1. cerebrum
• 2.Hypothalamus
• It is the main thinking part of the brain
• It has regions which receive sensory impulses from
various receptors
• Separate areas of the fore brain are specialized for
hearing, smell, sight, learning
• There are separate areas of association where the
sensory information is interpreted by putting it
together with information from other receptors as
with the information that is already stored in the
brain. Based on all this a decision is made about
how to respond & the information is passed on to
the motor area which control the movement of
voluntary muscles

50. Mid brain & hind brain
• Many of the involuntary actions are
controlled by mid brain & hind
brain

51. Hind brain
• 1. Cerebellum
• 2. Medulla
oblongata

54. Components o the peripheral
nervous system
• 1. cranial nerves- which arise from
brain
• 2. Spinal nerves – Which arise fronm
spinal cord

55. Junction between motor neuron
&muscle

56. limitations of nervous system in
human body
Nervous system in human body works or communicates using nerve
impulses which are form of electrical impulses. Electrical impulses are
an excellent means of communication in human body but they have
following limitations:
•
They reach only those cells that are connected by nervous tissue, not
each and every cell
• Cells cannot continually create and transmit electrical impulses.
once an electrical impulse is generated in a cell and transmitted, the
cell will take some time to reset its mechanisms before it can generate
and transmit a new impulse.
• Due to above said limitations most multicellular organisms use
another means of communication between cells, namely, chemical
communication i.e. hormone or endocrine system. It is slower than
nerve cells but potentially reach all cells of the body.

57. How do animal muscles move
• The movements of muscle tissues
are brought about by the
contraction and relaxation of the
contractile proteins inresponse to
nerve impulses.
• When a nerve impulse reaches the
muscle, at the cellular level, the
electrical impulsecauses the release
of some chemicals at the neuro-
muscular junction. In response to
this chemical signal the musclecells
move by changing their shape so
that they shorten.
• Muscle cells have special
contractile proteins that change
boththeir shape and arrangement
• in the cell in response to nervous
electrical impulses. When this
happens, a newarrangement of the
proteins gives the muscle a shorter
form causing movement of muscles.

58. Plant movements
• Coordination in Plants:
• Plants lack nervous and muscular
system.
• Plants respond to stimuli by showing
two types of movements
1. Growth independent and
2.Growth dependent.

59. Nastic movements
• Growth independent movements are
usually quicker than growth dependent
ones, and involve the use
of electrochemical signals by the plant. To
achieve this movement, the plant cells
change shape by altering their
watercontent.
• Eg. drooping of leaves of a touch-me-not
plant when it is touched.

60. Growth independent movement

61. Tropic movements
• Growth dependent movements or tropic movements
are slow, occurring either towards or away from the
stimulus. The movement of plants in the direction of
stimulus is known as 'tropism'
• Tropic movements are shown in response to
environmental factors such as light, gravity, water
and chemicals.
• Plant roots are positively geotropic and
negativelyphototropic whereas plant shoots are
usually negatively geotropic and positively
phototropic.
• Pollen tubes show chemotropism by growing
towards the ovule

62. Tropic movements
• Phototropism
• Directional movement of a plant/plant part in response to light, for example:
shoots show positive
• Geotropism
• Directional movement of a plant/plant part in response to gravity, for example:
roots show positive
•
• Chemotropism
• Directional movement of a plant/plant part in response to chemicals, for
example- growth of the pollen tube towards the ovule
• Hydrotropism
• Movement of a part of a plant in response to water, for example: roots
• Thigmotropism
• Growth of tendrils
When a tendril comes in contact with a support, then the part of the tendril
away from the support grows more rapidly than the part of the tendril that is in
contact with the object, thus the tendril circlesaround the object and appears
to cling to it.

64. Phototropism
• Directional
movement of a
plant/plant part in
response to light,
for example: shoots
show positive

65. Geotropism
Directional movement
of a plant/plant part in
response to gravity,
for example: roots
show positive

66. Thigmotropism
Growth of tendrils
When a tendril comes in
contact with a support, then
the part of the tendril away
from the support grows
more rapidly than the part
of the tendril that is in
contact with the object,
thus the tendril circles
around the object and
appears to cling to it.

68. Growth hormone
• Source- Pitutory
gland
• Function-
Stimulates the
growth of the
bones & muscles

69. DiSORDERS OF GROWTH
HORMONE IMBALANCE
• 1. Dwarfism
• Cause- Less
secretion of growth
hormone during Child
hood stage
• Symptoms
• Persons are
abnormally short
( Dwarf)

70. 2. Gigantism
• Cause – Excessive
secretion of growth
hormone during Child
hood stage
• Symptoms – Persons
are abnormally tall

71. Growth hormone imbalance

72. How does our body respond to
emergency situations like fight?
• In case of flight or fight reaction to an
emergency situation, Adrenal glands release
adrenaline into blood
• 1. The heart begins to beat faster resulting in
supply of more oxygen to the muscles.
• ii. The blood to the digestive system and skin is
reduced due to the contraction of muscles
around small arteries in these organs.This
diverts the blood to our skeletal muscles.
• iii. The breathing rate increases because of the
contraction of the diaphragm and the rib
muscles.iv. All these responses together enable
the body to be ready to deal with the situation.

74. Source- Pancreas
Function- Controls sugar level in the blood

75. Disorders of insulin imbalance
Diabetes
• Cause- less
secretion of insulin
• Symptoms – High
glucose level in
the blood

76. Cause- Deficiency of Iodine which leads to the less secretion of
Thyroxine
Symptoms- Enlargement of thyroid gland

78. Feed back mechanism
• A good example of negative feedback is the hormone insulin.
Insulin is a hormone that is made by the pancreas. Insulin is
released by the pancreas when you eat glucose (a kind of
sugar).
• The glucose goes from your stomach to the blood. The amount
of glucose in the blood goes up. The pancreas sees this high
glucose level. It makes insulin and releases it into the blood.
Then the insulin goes through the whole body and tells cells to
take glucose out of the blood. When cells take up glucose from
the blood this makes the glucose level go down.
• The pancreas sees this and stops making insulin. When the
pancreas stops sending this message (insulin), the cells in the
body stop taking extra glucose out of the blood. So the
negative feedback works to keep the blood glucose level
normal.If glucose is high, the pancreas makes insulin. The
insulin causes the glucose to fall. Then this lower level of
glucose tells the pancreas to stop making insulin.

79. Plant hormones
• Plant hormones affect growth of various parts in the plant.
• Auxin: When growing plants detect light, a hormone called auxin,
synthesised at the shoot tip, helps the cells to grow longer. When light
is coming from one side of the plant, auxin diffuses towards the shady
side of the shoot. This concentration of auxin stimulates the cells to
grow longer on the side of the shoot which is away from light. Thus,
the plant appears to bend towards light.
• Gibberellins: Gibberellins help in the growth of the stem.
• Cytokinins: Cytokinins promote cell division, and it is natural then that
they are present in greater concentration in areas of rapid cell
division, such as in fruits and seeds. These are examples of plant
hormones that help in promoting growth.
• Abscisic Acid: But plants also need signals to stop growing. Abscisic
acid is one example of a hormone which inhibits growth. Its effects
include wilting of leaves. It also inhibits growth of buds. This is
necessary when environmental conditions are not favourable to
plants. For example during summer wilting of leaves helps prevent
excess water loss due to transpiration. During winters fruit buds may
be killed because of freezing temperature, so their growth is inhibited.