CONTROL AND COORDINATION
One Shot
1 2 3
Nervous Coordination Chemical Chemical
in Humans Coordination in Coordination in
Animals Plants
1
Nervous Coordination
in Humans
Important Terms
Stimulus
Stimulus is an event or any change in the external environment
that generates a specific reaction in an organ or tissue.
Receptor
Receptors are specialised structures located on the different parts of
the body that are capable of recognizing and receiving messages.
Response
Response is how an organism reacts to a stimulus and results in a
change in behaviour.
Nervous system
Neuron
Facilitates the communication between central
nervous system and other parts of the body.
SIGNAL TRANSDUCTION
Dendrite
Synapse Axon
Axon
Nerve ending Nerve ending
Dendrite
SIGNAL TRANSDUCTION
SIGNAL TRANSDUCTION
Neuron 1
Synapse
Neurotransmitter
Neuron 2
SUMMARY
Types of Neurons
Sensory Neuron Motor neuron Relay Neuron
The neurons that transmit
The neuron that transmit Also called interneurons allow
impulses from brain and
impulses from sense organs sensory and motor neurons to
spinal cord to different parts
to brain. communicate.
of the body
Eg: Neurons present in the
Eg: Sensory neurons present Eg: Neuron present in spinal
nerve connecting the brain
in optic nerve cord
and muscles of arm
Nerve
Nerves are bundles of axons covered by myelin sheath.
Reflex Action
Reflex, or reflex action, is an involuntary and nearly
instantaneous movement in response to a stimulus.
Hot object
Reflex Arc
Receptors Relay neuron
Sensory neuron
Hot object
Spinal cord
Motor neuron
Effector in muscle
The reflex arc is a special type of neural circuit that begins
with a sensory neuron at a receptor (e.g., a pain receptor in
the fingertip) and ends with a motor neuron at an effector
(e.g., a skeletal muscle).
Reflex Arc
Receptors Relay neuron
Sensory neuron
Hot object
Spinal cord
Motor neuron
Effector in muscle
Nervous system
Central Nervous System Peripheral Nervous System
Protection of CNS
Cranium Vertebral column
Bony covering of the brain Bony covering of the spinal
(Brain box) cord.
Protection of CNS
Three layered protective covering around the
brain and spinal cord.
Skull/ Vertebral Column
Dura Mater
Arachnoid Mater Meninges
Pia Mater
Brain/ Spinal Cord
Cerebrospinal fluid
Present in between the meninges.
• Absorbs shocks and jerks.
• Keep the CNS moist.
• Supplies food and oxygen to different
parts of the CNS.
Parts of a Brain
CEREBRUM
CORPUS
CALLOSUM FOREBRAIN
THALAMUS
HYPOTHALAMUS
MIDBRAIN
PONS
CEREBELLUM
HINDBRAIN
MEDULLA
OBLONGATA
Parts of a Brain
FOREBRAIN
• Main site for receiving and
processing sensory information like
thinking, hearing and smell
• Receives sensory impulses
• Controls body temperature,
emotions, hunger, sleep etc.
Parts of a Brain
MIDBRAIN
• Site for auditory and visual processing
like facial expressions
Parts of a Brain
Functions of midbrain
Controls the activities like blinking of eyes, changing pupil size, etc.
In bright light
pupil
Iris
In dim light
In normal light
Parts of a Brain
HINDBRAIN
• Includes the cerebellum, pons and
medulla oblongata
Functions of Hindbrain
Pons regulates the respiratory system.
Functions of Hindbrain
Cerebellum is responsible for the precision of voluntary actions.
Cycling Writing Maintaining posture
Functions of Hindbrain
Medulla oblongata controls the involuntary actions.
Blood pressure Salivation Vomiting
Nervous system
Central Nervous System Peripheral Nervous System
Brain Spinal cord Somatic nervous Autonomous
system nervous system
• Control centre Sympathetic Parasympathetic
• Connects brain
and peripheral
nervous sytem
Nerve
Types of Nerve
Cranial nerve
• The cranial nerves are a
set of 12 paired nerves
in the back of your brain.
• Carry signals to your
brain to help you touch,
taste, smell and see.
Nerve
Types of Nerve
Spinal nerve
• Nerves that interact
directly with the spinal
cord to modulate motor
Spinal nerve
and sensory information
from the body's
periphery.
SUMMARY
2
Chemical
Coordination in
Humans
Types of Coordination
Chemical Coordination
WHAT ARE HORMONES?
Hormones are chemical substances synthesized by specialized glands
which are transported by the blood to the target organs where they
control growth, metabolism, reproduction and other functions.
ENDOCRINE GLANDS
Ductless glands which secrete hormones that diffuse into
blood are called endocrine glands.
PITUITARY GLAND
THYROID GLAND
ADRENAL GLAND
PANCREAS
TESTIS
OVARY
PITUITARY GLAND
Hypothalamus
Pituitary gland
• Called the master
gland as it secretes
hormones which
help in secretion of
other hormones from
various endocrine
glands.
THYROID GLAND
Disorders:
Exophthalmic Goitre, Hormones: Thyroxine and Calcitonin
simple Goitre, Cretinism and
Myxoedema Location: Each side of the trachea, at the base of the larynx
Functions:
Regulates the body's metabolic rate, brain development and bone
maintenance
ADRENAL GLAND
Adrenal gland
Hormones: Adrenaline
Location: Above each of the kidneys.
Functions: Acts as the flight and fight
hormone in emergency situations.
PANCREAS
Hormones: Insulin, Glucagon
Location: Surrounded by the duodenum and the spleen.
Functions: Insulin decreases sugar level in the blood and Glucagon
helps to breakdown glycogen and raise the sugar level in blood.
PANCREAS
MAINTAINS GLUCOSE LEVEL
PANCREAS
DEFICIENCY: TYPE I DIABETES
PANCREAS
DEFICIENCY: TYPE II DIABETES
TESTIS
Hormones: Testosterone
Location: In the scrotal sac in males
Functions: Helps in production of sperm
and development sexual characters.
OVARY
Hormones: Oestrogen, Progesterone
Location: In the pelvis in females
Functions: Oestrogen helps to develop secondary sexual
characters in female and progesterone helps in retention of
fertilised egg and its development.
SUMMARY
3
Chemical
Coordination in
Plants
After few days
DO
PLANTS
MOVE?
Do
plants
also respond to
Stimuli?
Movements in Plants
Nastic Movement Tropic Movement
TROPISM
The growth movement of a plant in
the direction of an external stimulus.
Light
Chemicals
STIMULI Touch
Water
Gravity
PHOTOTROPISM (Light)
GEOTROPISM (Gravity)
TROPISM HYDROTROPISM (Water)
THIGMOTROPISM (Touch)
CHEMOTROPISM (Chemicals)
PHOTOTROPISM (Light)
PHOTOTROPISM (Light)
Towards light
Positive
Negative
Against light
GEOTROPISM (Response
to gravity)
Against gravity
Negative
Positive
Towards gravity
HYDROTROPISM
(Response to water)
Against water
Negative
Positive
Towards water
HYDROTROPISM
(Response to water)
Against water
Negative
Positive
Towards water
THIGMOTROPISM
(Response to touch)
CHEMOTROPISM
(Response to chemicals)
Movements in Plants
Nastic Movement Tropic Movement
• Growth dependent
• Directional response
• Response is due to change
in the growth of the
specific plant part in
response to stimuli
• Slow response.
NASTIC MOVEMENTS
The non-directed movements by plants to the stimuli.
Nastic Movement
Non-directional movement
in response to light.
TROPIC MOVEMENTS NASTIC MOVEMENTS
Directional response Non-directional response
Growth dependent Growth independent
Slow movement Immediate movement
Plant hormones or Phytohormones
Control and coordination in plants is done by chemicals
messengers called plant hormones or phytohormones.
Their site of production and action are different.
Auxin
Gibberellins
Cytokinin
Abscisic
acid
Ethylene
Plant Hormones
Plant Hormone Site of Synthesis Function
In shoot apical meristems • Promotes cell elongation
Auxins
and young leaves • Promotes apical dominance
After few days
Plant Hormones
Plant Hormone Site of Synthesis Function
In shoot apical meristems • Promotes cell elongation
Auxins
and young leaves • Promotes apical dominance
In meristems of apical buds • Helps in stem elongation
Gibberellins
and roots • Breaks seed dormancy
• Promotes growth by cell division.
In roots and transported to
Cytokinins • Promotes chlorophyll synthesis.
other parts by xylem cells
• Inhibit apical dominance
Plant Hormones
Plant Hormone Site of Synthesis Function
• Induces fruit ripening
Mostly in meristematic
• Promotes senescence
tissue, In senescent leaves
Ethylene • Reduction in cell elongation
and flowers, germinating
• Promotes growth of roots and
seeds and ripening fruits
root hairs
• Induces dormancy in bud and
In green fruits and seeds at seeds
Abscisic acid the beginning of wintering • Stimulates closing of stomata
period • Plant growth inhibitor
• Accelerates senescence
SUMMARY
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