Key Points: Human Nervous System Types of neurons Structure of Human Brain Types of Reflexes Reflect Arc Plant Hormones Movements in Plants (Tactic, Tropic and Nastic) Endocrine Glands in Human

1. CHAPTER - 7
CONTROL & COORDINATION
Subhasish Khanda
Subha.subhasish.khanda@gmail.com

2. Control & Coordination In Animals
Plant Hormones/Phytohormones provides Control & Coordination in plant
Living organisms respond to stimuli in the form of body movements
A thing/event that evokes a specific functional reaction in an organ/tissue
Environmental change identified by organisms & helps them to respond
Stimulus
Eg :- Sunlight, temperature, pressure, gravity, water etc.
OR
Response
Reaction by an organism to a specific stimulus
Coordination
Working of various organs in an organism to produce proper response to
a stimulus is called coordination.
Nervous & Endocrine System provides Control & Coordination in animal

3. Human Nervous System
Parts of nervous system
Peripheral Nervous System (PNS)
• Cranial nerves
• Spinal nerves
Central Nervous System (CNS)
• Brain
• Spinal cord

4. NEURON: STRUCTURAL & FUNCTIONAL UNIT OF
NERVOUS SYSTEM
• Microscopic structure
• Major parts: Cell body, Dendrites & Axon
• Cell body contains a nucleus and cytoplasm
called neurocyton/ soma.
• Cytoplasmic component of cell body is
called as neuroplasm.
• Neuroplasm contains different cell
organelles.
• Neuroplasm contains certain protein
producing granular bodies called Nissl’s
granules.
• Funnel shaped portion of cell body with out
Nissl’s granules forms axon called axon
hillock.
• Short fibers project out of the cell body are
called dendrites
• Dendrites passes information as electrical impulse through axon

5. • Axon is a long tail like structure joins with
cell body at a junction called axon hillock.
• Axon is covered by a protective covering
called Myelin sheath.
• The gaps between two adjacent myelin
sheaths are called nodes of Ranvier.
• Distal end of axon is branched and each
branch terminates as a bulb-like structure
called synaptic knob.
• Each synaptic knob possess synaptic
vesicles containing chemicals called
neurotransmitters.
• Axons transmit nerve impulses away from the cell body to synapse.
• The junction between two neurons is called synapse.
• Messages pass through nerve cell in the
form of electrical signals called nerve
impulse.

6. Arrangement of Neurons
• End to end chain.
• But are not connected.
• Continuous transmission of impulses.
• Each neuron receives an impulse through its dendrite & transmits
it to the next neuron through its axon.
• Synapse or a small gap occurs between Axon of one neuron and
Dendron of next neuron.

7.  Cell body Concerned with the maintenance and growth of the cell.
 Dendrite Receives information and conducts it towards the cell body.
 Axon Conduct messages away from the cell body.

8. Sensory Neuron:
• Collect external stimuli & convert it into electrical impulses.
• Larger Dendron & smaller Axon.
Example: Olfactory, Optic, Auditory
Motor Neuron:
• Form a pathway through which impulses pass from the brain or spinal
cord to a muscle or gland.
• Larger Axon & smaller Dendron.
Example: Spinal accessory, hypoglossal nerve
Types of Neurons
Mixed Neuron:
Connect between sensory neurons & motor neurons
Example: Trigeminal, Facial, Glossopharyngeal

9. Human Brain
 Control & monitor every organ of the body as main coordinating center.
 Protected by a boney box like structure called Cranium
 Covered by three layer membranes called meninges
 Membranes of meninges: Duramater (outer layer), Arachnoid (middle
layer), Piameter (inner layer)
 Space between meninges filled by fluid called cerebro- spinal fluid (CSF)
Regions of Brain
 Forebrain (Prosencephalon)
 Midbrain (Mesencephalon)
 Hindbrain (Rhombencephalon)
 CSF acts as shock absorbent & protects
brain from injuries.
 Weight: About 1400 grams

11. Forebrain (Prosencephalon)
• Main thinking part of the brain.
• Consists of cerebrum, thalamus and hypothalamus.
• Forebrain has both sensory regions & motor regions.
• Sensory region receives sensory impulses from various receptors and
motor regions control movement of various muscles.
• Forebrain has separate areas specialized for hearing, smelling, seeing,
general sensation such as pain, touch, taste, etc.
Cerebrum
• Largest part of the brain (4/5th of weight)
• Divided by deep cleft into two parts called left & right cerebral hemisphere
• Left hemispheres connected with nerves coming from right side of the body
• Right hemispheres connected with nerves coming from left side of the body
• Information obtained through sense organs stored in cerebrum for future

13. • Control body temperature, urge for eating & drinking.
Part of the forebrain located below the cerebrum is diencephalon.
• Receives nerve impulses from
sense organs & transmits to
upper region.
• Coordinates sensor and motor
signaling.
• Involved in regulation of sexual behavior & expression of
emotional reactions (excitement, pleasure, fear)
Hypothalamus
Thalamus
Thalamus & Hypothalamus
• Secretes variety of Hormones

14. Midbrain (Mesencephalon)
 Region occupied is relatively smaller than forebrain & hindbrain.
 Connects cerebrum with the hind brain.
 Controls involuntary actions & reflex movements of head, neck, eyes
 Concerned with the sense of sight and hearing.
 Serves important functions in transmit motor impulses to perform
motor movement

15. Hindbrain (Rhombencephalon)
Components: Pons varoli, Cerebellum and Medulla oblongata
Cerebellum:
• Responsible for
maintaining body posture
& equilibrium of the body.
Pons varoli:
• Control facial expression, respiration etc.
• 04 pairs of cranial nerves among 12 pairs originate from pons varoli.
Medulla:
• Connected to spinal cord.
• Control involuntary
actions (Heart beat, Blood
pressure, Salivation)

16. Spinal Cord
• Spinal cord starts from the brain and runs
through the vertebral column.
• It carries messages to and from the brain
• It also controls reflex actions
• It has 31 pairs of spinal nerves
• Spinal column is separated into 5 specific functional
areas:
 Cervical / C 1-8
 Thoracic / T 1 – 12
 Lumbar / L 1 – 5
 Sacral / S 1 - 5
 Coccyx

17. Classification of Responses of Nervous System
Responses of Nervous System
Involuntary actions
Voluntary actions Reflex actions
Consciously controlled Cannot be controlled consciously Sudden involuntary action

18. Reflex Responses
Types of Reflexes
Conditional Reflex /Acquired Reflex
Unconditional Reflex
• Inborn, unconscious responses to
a given stimuli
Examples: Blinking of eyes when
an object is brought very close to
the eye
• Response acquired during the
life time
• controlled by CNS
Example: learning, playing,
driving
Reflex Action
Sudden, unconscious & involuntary response of effectors to a stimuli
Example: Suddenly withdrawing of hand if suddenly touch a hot object.
The pathway of a reflex action is called reflex arc
Reflex Arc
Pathway along which nerve impulse travels during reflex action
OR

19.  Receptor: Sense organs that receive stimulus
 Sensory neuron: Conduct nerve impulse from receptor to
brain/spinal cord
 Association neuron: Transmit nerve impulse from sensory neuron
to motor neuron.
 Motor neuron: Transmits nerve impulse to effector organs
 Effector: Muscles/glands where action takes place in response to
stimuli
Components of Reflex Arc

23. Coordination in Plants
Chemical substances called Plant Hormones or Phytohormones
Types of Phytohormones
 Natural (Auxins, Gibberillins, Cytokinins, Abscisic acid and Ethylene)
 Artificial (IAA, IBA, IPA, 2,4-D, Florigen)
Hormones Location Function
Auxin Stem, buds, and root tips Cell division, cell elongation
and growth
Gibberillin Seeds, young leaves, and
roots
Growth of stem and branches
Cytokinin Shoot apex, immature
organs
Formation of fruits and seeds
Abscisic acid Root and leaves Inhibits growth and affects
wilting of leaves
Ethylene Leaves, stems, roots,
flowers, fruits, seeds
Flowering and ripening of
fruits

24. Movements in Plants
Plant Movement
Tropic Nastic
Tactic
Phototactic
Chemotactic
Galvanotactic
Rheotactic
Phototropic
Hydrotropic
Geotropic
Photonastic
Chemonastic
Thermonastic
Sismonastic
(Positive & Negative) (Positive & Negative

25. Tactic Movement/ Taxis
Movement of plant body or organs due to the external stimuli like
light, temperature, chemicals, electric current.
Phototactic Movement:
Movement of whole plant body due to light as external stimuli.
Example: Volvox, Chlamydomonas.
Chemotactic Movement:
Movement of whole plant body due to chemical.
Example: Movement of sperm towards egg.
Galvanotactic Movement:
Movement of whole plant body towards desired direction when senses an
electric field .
Example: Movement of Paramoecium in side the water due to water
current
Rheotactic Movement:
Movement of organism due to the mechanical stimulus such as water flow

26. PHOTOTROPISM
GEOTROPISM
Tropic Movement / Tropism
Movement of plant body is directed by the source and directions of
external stimuli.
Positive Tropism: Movement or growth towards a stimulus
Negative Tropism: Movement or growth away from a stimulus
HYDROTROPISM

27. SISMONASTI
Nastic Movement/ Nasti
Movement of plant body is directed by the intensity of the stimuli
instead of source and directions of stimuli.
PHOTONASTI
Positive Nasti: Movement towards a stimulus
Negative Nasti: Movement away from a stimulus
THERMONASTI

28. What is a Gland?
A gland is a cell, tissue or an organ that secretes hormones/
enzymes/ sweat to do specific functions in the body..
 Endocrine Gland: Gland secretes its products directly into
the blood stream. (Hormones)
 Exocrine Gland: Gland secretes its products into ducts
that lead to the target tissue. (Enzymes, Sweat)
Types of Glands
A messenger system which is constitute of endocrine gland and
releases hormones directly into the blood and regulate target
organs.
Endocrine System
Hormones
Secretion of endocrine gland which acts as chemical messenger
& regulates different physiological processes in living organism
Coordination in Animals

29. ENDOCRINE GLANDS IN HUMAN
 Hypothalamus
 Pituitary
 Parathyroid
 Thyroid
 Adrenal
 Pancreas
 Ovaries (Female)
 Testes (Male)

30. Pituitary Gland
 Master gland: Regulate functions of many other endocrine glands.
 Divided into anterior lobe called adenohypophysis and posterior lobe
called neurohypophysis.
 Adenohypophysis: GH, TSH, ACTH, FSH, LH, PRL
 Neurohypophysis: Oxytocin and Vasopressin

31. Functions
 GH / STH: Stimulates growth of all tissues of the body, including bone.
 TSH: Regulates hormone secretion by thyroid gland.
 ACTH: Stimulates production & release of cortisol.
 FSH: Control menstrual cycle & stimulates growth of eggs in ovaries.
 LH: Control menstrual cycle & stimulates growth of eggs in ovaries.
 PRL: Milk production and development of mammary glands
 Oxytocin: Stimulates uterine muscles to contract, so labor begins
 Vasopressin/ ADH: Increase water reabsorption in kidney.
 GH / STH: Growth Hormone/ Somatotropic Hormone
 TSH: Thyroid Stimulating Hormone
 ACTH: Adrenocorticotropic Hormone
 FSH: Follicle Stimulating Hormone
 LH: Luteinizing Hormone
 PRL: Prolactin
 ADH: Antidiuretic Hormone

32. Acromegaly:
Cause: Over secretion of GH in adults
Symptoms: Excessive growth of nose,
jaws, hands and legs
Gigantism:
Cause: Over secretion of GH prior to puberty
Symptoms: Abnormal growth (excessive
growth and increase in height)
Dwarfism:
Cause: Less secretion of GH
Symptoms: Retarded growth, small
height, short and wide hands and
feet. short fingers and toes.
Pituitary Gland Related Diseases

33. Thyroid Gland
Location: Situated close to the trachea in the neck.
Hormones: Thyroxin (T4), Triiodothyronine (T3), Calcitonin.
Functions:
• Regulates carbohydrate, fat, and protein
metabolism.
• Increase BMR
• It indirectly affects the growth of the body
by promoting growth.
• Help in conversion of glycogen stored in
liver & muscle into glucose.
• Help in maturation of RBC

34. Simple Goiter:
Cause: Deficiency of iodine in diet
Symptoms: Swelling in neck due to enlargement of
thyroid gland.
Peoples of hilly region suffer due to deficiency of
iodine in water and soil.
Cretinism:
Cause: Under activity of the thyroid gland among children
Symptoms: Stunted growth, mental retardation, bow legs.
Myxoedema:
Cause: Under activity of the thyroid
gland among adults.
Symptoms: Low heart beat, low
metabolic rate, increased weight
Thyroid Gland Related Diseases

35. In case of danger, emergency, or stress, adrenaline secretes in large
quantities to prepare the body to face the situation. For this reason,
adrenalin is known as ‘emergency hormone’
Adrenal Glands (Suprarenal Gland)
Location: Attached to the top of each kidney
Parts:
• Outer Cortex
 Aldosterone (maintain salt and water levels)
 Cortisol (stimulates glucose production)
• Inner medulla
 Adrenaline (Epinephrine)
 Noradrenaline (Norepinephrine)
‘Emergency Hormone’.

36. Location: Behind stomach
Types: Mixed gland (endocrine & exocrine)
Secretory Part: Islets of Langerhans, secret
hormones insulin and glucagon.
Pancreas
Function:
• Opposite to insulin.(Secretes during low blood sugar)
• Helps in conversion of glucagon into glucose.
Function:
• Regulates blood sugar level in human body.(Secretes during high blood sugar
Deficiency:
Increases glucose level in blood & excretes excess glucose through urine.
Diabetes Mellitus (DM)
Glucagon
Insulin

37. Gonads
Components/ Organs:
Testes
Ovaries
Produces gametes and secrets hormones.
Testes
Hormone: Testosterone (male sex hormones)
(Production increase during puberty)
Nature: Steroid
Functions:
 Production sperm & regulating fertility.
 Red blood cell (RBC) production.
 Growth and development of male secondary sexual characters (increases
muscle mass & bones, body fat distribution, growth of body hair,
appearance of pubic hair & armpit hair)
Deficiency:
• Under developed sexual characteristics.
Location:
• Outside abdominal cavity, within a pouch called scrotum

38. Ovaries:
Location:
• One on each side of the lower abdomen.
Hormone: Estrogen & Progesterone (female sex hormones)
Nature: Steroid
Deficiency: Causes infertility
Functions:
• Development & regulation of
female reproductive system.
• Development of secondary
sexual characters (breast,
widening of hips, body fat
distribution, growth of body
hair, appearance of pubic hair
& armpit hair)
• Control menstrual cycles.
Estrogen
Deficiency:
Problem during pregnancy & child birth
Functions:
• Regulation of menstrual cycle
and maintaining pregnancy.
• Help in placentation formation
• Development of secondary sexual
characters
• Development of mammary gland.
• Helps in implantation of the
fertilized egg in the uterus.
Progesterone

39. EXERCISES
Which of the following is a plant hormone?
(a) Insulin (b) Thyroxin (c) Oestrogen (d) Cytokinin
The gap between two neurons is called a
(a) Dendrite (b) Synapse (c) Axon (d) Impulse
The brain is responsible for
(a) Thinking (b) Regulating the heart beat
(c) Balancing the body (d) All of the above
Cytokinin
Synapse
All of the above
Hormone produced by the anterior pituitary
(a) LH (b) TSH (c) ACTH (d) All of above
All of the above

40. Nissl’s granules present in the neurons are made up of
(a) Protein (b) ribosome (c) RNA (d) DNA
Name the basic structural and functional unit of the nervous system
a) Neuroglia b) Glial cells c) Neurons d) Perikaryon
Neurons
Which of the following is one of the parts of the hindbrain?
(a) Hypothalamus (b) cerebellum (c) corpus callosum (d) spinal cord
Cerebellum
Ribosome
Which part of a neuron is responsible for receiving information?
a. axon b. terminal fibre c. dendrite d. myelin sheath
Dendrite
Which of the following is a part of the rhombencephalon?
(a) Medulla (b) Substantia nigra (c) Thalamus (d) Temporal lobe
Medulla

41. The terminal buttons of a neuron are located at the end of its:
a. axon b. dendrite c. myelin sheath d. nodes of ranvier
Axon
The gap in between two adjacent myelin sheath is called
a)Soma b)Dendrite c)Node of Ranvier d)None of these
Node of Ranvier
Response of plant roots towards water is called:
(a) Chemotropism b) Phototropism (c) Hydrotropism (d) Geotropism
Hydrotropism
Movement of sunflower in accordance with the path of Sun is due to
(a) Chemotropism (b) Geotropism (c) Phototropism (d) Hydrotropism
Phototropism
Any change in the environment to which an organism responds is called
(a) stimulus (b) coordination (c) response (d) hormone
Stimulus

42. Which nerves transmit impulses from central nervous system
towards muscle cells?
(a) Sensory nerves (b) Motor nerves (c) Relay nerves (d) Cranial nerves
Motor nerves
Main function of cerebrum is
(a) thinking (b) hearing (c) memory (d) balancing
Thinking
Which part of nervous system controls the reflex activities of the
body?
(a) Brain (b) Spinal cord (c) Cerebrum (d) Cerebellum
Spinal cord
Which of the following acts as both endocrine and exocrine gland?
(a) Pancreas (b) Thyroid (c) Adrenal (d) Liver
Pancreas

43. Secretion of which hormone leads to physical changes in the body
when you are in puberty
(a) Oestrogen from testes and testosterone from ovar.
(b) Estrogen from adrenal gland and testosterone from pituitary gland.
(c) Testosterone from testes and estrogen from ovary.
(d) Testosterone from testes and progesterone from overy
Testosterone from testes and estrogen from ovary
Name the plant hormone which is responsible for the ripening of
fruits?
A. Ethylene B. Auxin C. Traumatic D. Cytokinins
Ethylene
Leaf movements of sensitive plant, Mimosa pudica is due to
(a) Seismonasty (b) Chemonasty (c) Thermonasty (d)
Hydrotropism
Seismonasty

44. Pneumatophores show
a. Positive geotropism b. Negative Phototropism c. Negative
geotropism d. None of above
Negative geotropism
System of the body which coordinates and controls its
activity is known as
a) Organ system b) Muscular system c) Nervous tissue d)
Excretory system
Nervous tissue
Movements where organism and its organs move from one
place to another in response to external stimuli are called
(a) Tropic (b) Bastic (c) Nutational (d) Tactic
Tactic

45. The pituitary hormone that helps in milk production from
mammary glands of female is:
A. GH B. LH C. Prolactin D. FSH
Prolactin
Secretions from which of these gland differs between males
and females?
A. Adrenal. B. Parathyroid C. Gonadal. D. Pancreas.
Gonadal
Calcitonin is a hormone of which of following:
A. Adrenal cortex B. Thyroid. C. Pituitary D. Thymus
Thyroid
Which of these is not an endocrine gland?
A. Pancreas B. Testes C. Salivary gland D. Parathyroid
Salivary gland

46. Posterior pituitary releases:
A. Growth hormone and prolactin B. Prolactin and oxytocin.
C. Oxytocin and antidiuretic hormone (ADH). D. ADH and growth hormone.
Oxytocin and antidiuretic hormone (ADH)
Which hormone helps in the blooming of flowers?
A. Traumatic B. Auxin C. Florigen D. None of the above
Florigen
Functions of Glucagon
(a) Accelerates protein synthesis within cells
(b) Accelerates conversion of glycogen into glucose
(c) Decreases conversion of glycogen into glucose
(d) Slows down glucose formation from lactic acid
Accelerates conversion of glycogen into glucose
Which of the following plant hormone is responsible for seed germination?
a) Auxin b) Gibberelline c) Ethylene d) Abscisic acid
Gibberelline

47. Thalamus and the hypothalamus are located in
a)Brain stemb)Cerebrum c)Cerebellum d)Diencephalon
Diencephalon
Growth of pollen tube towards embryo sac is
a. Geotropism b.Thermotropism c.Chemotropism d.All of these
Chemotropism
Growth regulators, which control plant growth & development
are called
a) Secondary metabolites b) Macro element
c) Nonessential elements d) Phytohormone
Phytohormone
Name the part of hind brain which takes part in regulation of
respiration. (CBSE Delhi 2004)
a) Medulla oblongata b)Cerebrum c)Cerebellum d) Spinal cord
Medulla oblongata

48. Name A gland-
i) Present in females but not in males
ii) Secretes hormones as well as digestive juice
iii) Associated with kidneys
Ovary; Mammary glands
Pancreas
Adrenal
Sourav suddenly withdraw his hand when a pin pricks. Name
the type of response involved in this action. (CBSE Delhi 2004)
Reflex action
Which hormone is responsible for the development of
moustache and beard in man ? (CBSE, 2004)
Testosterone

49. Name the hormone secreted by an endocrine gland during
emergency. Name the gland.
Hormone: Adrenaline Gland: Adrenal
Which system facilitates communication between central
nervous system and other parts of the body ?(CCE 2013, 2014)
Peripheral nervous system (PNS).
A young green plant receives sunlight from one direction
only. What will happen to its shoots ?
Shoots will bend towards the light and roots away from the light.

50. What is chemotropism? Give one example.
Chemotropism is the movement of a
part of the plant body in response to a
chemical stimulus.
Example: The growth of pollen tube
towards a chemical which is produced
by an ovule during the process of
fertilization in a flower.
Draw the structure of a neuron and explain its function.
Dendrite: Detects information's & transfer it to cell body
Cell Body: Maintains growth of cells
Axon: Conduct impulses away from cell body to next neuron.

51. What is the function of receptors in our body? Think of
situations where receptors do not work properly. What
problems are likely to arise?
How does phototropism occur in plants?
Receptors are present mainly in sense organs and they collect
information's and send it to the brain.
When receptors do not work properly, the environmental stimuli
are not able to create nerve impulses and body does not respond.
Tropic movement and growth of plant in response to light is called as
phototropism. Phototropism occurs due to increased auxin on the dark
side and decreased auxin on the illuminated side. Because of presence
of more auxin, stem in the darker side grows faster causing it to bend
towards the source of light.

52. What happens at the synapse between two neurons?
At the synapse between two neurons electric signals are transmitted
through chemical (neurotransmitter) and cross 200-300 A0 gap and
transfer messenger to next neuron.
How does chemical coordination occur in plants?
Growth, development and responses of plant to the environment is
controlled and coordinated by a chemical substances known as
phytohormone. Phytohormones are produced in one part of the plant
and are transported to all the needy parts of the plant. Both natural
and artificial phytohormone either acts as growth promoters (such as
auxins, gibberellins, cytokinins, and ethylene) or growth inhibitors
such as abscisic acid.

53. Why are some patients of diabetes treated by giving injections
of insulin?
Insulin regulates blood glucose by converting extra glucose to glycogen.
Diabetes is a condition when production of insulin is stopped or
decreased in human body. Thus, inadequate production of insulin leads to
adverse effect in human body. In order to maintain this situation diabetes
patients are treated with injections of insulin.
Which part of the brain maintains posture and equilibrium of
the body?
Cerebellum which is a part of Hind brain is responsible for
Controls the motor functioning and maintenance of posture,
equilibrium of the body.
Which body organ is surrounded by meninges. (CCE 2013)
Brain and spinal cord

54. Which signals will get disrupted in case of a spinal cord injury?
In case of a spinal cord injury Reflex action will be disrupted. Thus,
impulses from various body parts will not be conducted to brain and
message from brain will not be conducted to various organs of the
body.
Why is the use of iodized salt advisable?
Usage of Iodized salt is advisable to avoid the deficiency of Iodine. If
the intake of iodine is low, the release of thyroxine from the thyroid
gland will be decreased. This affects fat, carbohydrate and protein
metabolism. Thus a person may have goitre problem in case if the
intake of iodine is lowered.

55. How are involuntary actions and reflex actions different from each other?
Reflex actions Involuntary actions
• Rapid automatic responses to a
stimulus without the conscious
involvement of the brain
• Occurs without the
consciousness of an organism
• Controlled by spinal cord • Controlled by mid brain or
medulla oblongata
• Very quick and instantaneous • Relatively slower
• May involve any muscle or a
gland
• Involves only smooth muscles
• Can be conditioned • Cannot be influenced by
external conditioning
Examples: Blinking of eyes,
salivation
Examples: Beating of heart, blood
circulation

56. Nervous Control Hormonal Control
1 It is consist of nerve impulses
between PNS, CNS and
Brain.
1 It consists of endocrine
system which secretes
hormones directly into blood.
2 Here response time is very
short.
2 Here response time is very
long.
3 Nerve impulses are not
specific in their action.
3 Each hormone has specific
actions.
4 The flow of information is
rapid.
4 The flow of information is
very slow.
Compare and contrast nervous and hormonal mechanisms
for control and coordination in animals.

57. What is the difference between the manner in which movement
takes place in a sensitive plant and the movement in our legs?
Sl.
no
Sensitive Plants Movement Sl.
no
Our Legs Movement
1 The movement in a
sensitive plant is a response
to stimulus (touch) which is
an involuntary action.
1 Movement in our legs is a
voluntary action.
2 No special tissue is there
for the transfer of
information
2 A complete system CNS
and PNS is there for the
information exchange.
3 Plant cells do not have
specialized protein for
movements.
3 Animal cells have
specialized protein which
help muscles to contract.

58. Multicellular organism consists of a number of components and sub-
components to perform different specialized functions. So, it is necessary that
various organs of the body of an organism work together in a proper manner for
proper functioning to a stimulus.
In humans, control and coordination are carried out by nervous system and
endocrine system. Same role is plants are exhibited through various
phytohormones. Similarly, secretion of hormones from endocrine gland in
animal, regulate proper growth, development & functioning of different organs.
Whereas, nervous system helps to respond to our surroundings and to perform
daily activities. It does so by sensing stimuli (external and internal) followed by
a relay of sensory information to CNS (Central Nervous System) for processing
and generation of motor output in terms of involuntary or voluntary actions.
What is the need for a system of control and coordination in an
organism?

59. What is the role of the brain in reflex action?
Reflex actions are formed instantaneously in response to the stimulus
that has no time to think. Here the sensory nerves detect the external
stimuli are connected to the nerves that move the muscles of the hand
for action. Such a connection of detecting the signal from the nerves
(input) and responding to it quickly (output) is known as reflex arc.
Reflex action are generated in spinal cord and the information also
reaches to brain. This helps the brain to record this event and remember
it for future use. Brain helps the person to remember & aware regarding
similar stimuli. By identifying same types of stimuli, brain prevent
himself from similar situation.
How do we detect the smell of an agarbatti ?
Smell of an agarbatti is detected by Nose, which is consist of olfactory
receptors. These olfactory receptors send electrical signal to the fore
brain to interprets this signal. Thus the smell of agarbatti are detected.