ADVANCE LEVEL

BIOLOGY
COODINATION 1
PREPARED BY
TEACHER. LAILA AB.MNSOUR
BSED: BIO AND GOGRAPHY
 TOPIC COVERAGE
1. CONCEPT OF CORDINATION AND IRRITABILITY /SENSITIVITY
2. SYSTEM OF CORDINATION
3. PHYSIOLOGY OF CORDINATION
4. APLICATION OF SYNTHETIC PHYTOHOMONE
CONCEPT OF COORDINATION AND
IRRITABILITY
Meaning of the term Coordination;
• Is the linking together of various body activities in living organism so
that they work at appropriate time and rate required by organisms.
• The body parts of organisms work together for various roles resulting
into a coordinated body.
Meaning of Irritability or sensitivity;
• Refers to their ability of organisms to detect and respond to a
stimulus.
• This is a characteristic feature of all living organisms.
Con………..
• Stimulus is received by a receptor found in the body of organisms.
• It is then transmitted by means of nerves or hormones.
• An effector bring about a response
 FORMS/SYSTEM OF CORDINATION
• There are two form of coordination which are
HORMONAL OR ENDOCRINE
NERVOUS COORDINATION
 CONT……
Animals have two systems of coordination which are;
Nervous coordination;
• This composed by the nervous system which are nerve fibres, brain
and spinal cord.
• Nervous system is very quickly to bring a responses.
Endocrine coordination (hormonal coordination);
• This composed by endocrine system which is the endocrine glands.
• Endocrine glands secretes a chemical messenger called a
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hormones.
• Hormones are chemical is nature that bring a slowly responses.
In plants have only hormonal coordination;
• Plants responses are in form of slow modified growth or movements
called turgor movement.
• All simple and complex organisms need to coordinate their body
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activities in order to be able to detect changes in their environment
and respond to them.
• Coordination of various body parts of an organisms requires a
system which should be able to detect changes in the environment.
• Also be able to transmits information from the environment to the
appropriate parts in the body.
ANIMAL CORDINATION
Component Of Coordination In Mammals
 Stimulus
• Stimulus is the changes in the external and internal environment
to which the organisms respond and react.
• Living organisms show response to stimuli.
Example of stimuli are;
• Light, heat, cold, smell, sound, pains, wind, temperature, pressure,
touch, force of gravity etc.
• There are two types of stimuli which are;
1. An external stimuli.
2. An internal stimuli.
 An External Stimuli
• These are stimuli associated with the surrounding environment.
These includes the following;
• Light, heat, cold, smell, sound, pains, wind, temperature, pressure,
touch, force of gravity etc.
An Internal Stimuli
• They occurs within the body of organisms.
Example of internal stimuli are as follow;
• Sense of body position, Glucose level and Blood pressure.
 Receptors
• These are specialized cells that detect changes in the environment.
• Examples of receptor are sense organs
• There are five sense organs which are;
1. The eye.
2. Ear.
3. Nose.
4. Skin.
5. Tongue.
 Coordinator
• This is an organ that receive and interprets change from receptors.
• Coordinators include the brain and spinal cord.
• Brain and spinal cord forms the central nervous system (CNS).
• Coordinators uses massages to link activities in the body.
• The massage received are called nerve impulse.
 Effectors
• These are the cells, organs or organelles which receive motor
impulses from the brain or spinal cord and bring about appropriate
response.
• The effectors include muscles, cilia, flagella and glands.
• Between receptors and effectors are conducting cells of nervous
system called neurons.
• Neurons are basic structural and functional of nervous system.
• It spread through the organism forming a complex communication
network.
 Response
• This is any change shown by organisms responding to stimulus.
• Response may involves movement of the whole or part of the
organism’s body.
• This movement can be either toward or away from the stimulus.
Example of response are;
1. Quick removal of the leg if pricked by a sharp object
2. Pulling of the hand away if it accidentally touches a hot object.
FEEDBACK
• The animals decides what to do after the response.
 Degree of Sensitivity
• Degree of sensitivity differ from one group of organism to
another.
Multicellular organisms example animals such as mammals are
more sensitive than unicellular such as amoeba.
• This is because presence of cephalic or head contain brain.
Also sensitivity differ from plant and animal, since animal are
more sensitive than plant. This is because;
• Animal coordination brought about by two system which are
nervous system and hormonal system.
• Plant coordination is only brought about by hormonal system.
 Nervous Coordination in Mammals
• Mammals as in other animals nervous coordination is brought
about by the nervous system.
• The mammalian nervous system consists of the following;
Central nervous system (CNS);
• It is made up of the brain and spinal cord.
Peripheral nervous system (PNS);
• Made up of the nerve fibres other than brain and spinal cord.
• This include cranial nerves and spinal nerves.
• Nerve fibres branch from CNS and extend to all parts of the body.
• Coordination is accomplished through a set of signals channeled
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into a series of nerve cells.
• Nerves that transmit signals from the body to the CNS called
afferent nerves. These nerves are sensory and relay neurons.
• Those nerves which transmit signals from the CNS to the effectors
called motor or efferent nerves. These nerves are motor neurons.
• Nervous coordination enables a mammal to respond rapidly to
external and internal stimuli.
• This enables the organisms to react to those changes in a way
which ensures its survival.
• Without coordination, body activities would be disorderly and the
body would fail to function properly.
 Nervous Tissue
• This is a specialized tissue made up of nerve cells called neurons.
• Neuron is the basic unit or structure of the nervous tissue which
consists of cell body, dendrites and axon.
• Nervous tissues made up by the following:-
Central Nervous System (CNS);
• It consists of the brain and spinal cord.
Peripheral Nervous System (PNS);
• It is comprises of the cranial nerves and spinal nerves.
• These are packed together with their motor and sensory endings.
• Nervous tissue is the main tissue component of the nervous system.
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• It consists of closely packed nerve cells or neurons with very small
intercellular spaces.
• Nervous tissue contains two types of cells which are;
Neuroglia;
• Neuroglia are non-neuronal cells which assist in propagation of the
nerve impulses and provision of nutrients to the neurons.
Neurones;
• Neurones are specialized nerve cells which generate and conduct
nerve impulses.
 Neuroglia
• Neuroglia are non-neuronal cells which assist in propagation of the
nerve impulses and provision of nutrients to the neurons.
• Neuroglia also serve as supporting cells that provide electrical
insulation and remove debris.
• Cells of the neuroglia produce myelin sheath that increases the
speed of propagation impulses along the axon of the neuronal
fibres.
• Cells of the neuroglia also offers protection for the axon.
• Collection of glia cells residing within the walls of intestinal tract
which beginning in the oesophagus and extending down to the
anus called enteric glia.
 Types of Neuroglia
• There are six types of neuroglia found in both CNS and PNS.
• Four neuroglia are found in the CNS which are;
1. Astrocytes.
2. Microglial cells.
3. Ependymal cells.
4. Oligodendrocytes.
• Two neuroglia are found in the PNS which are;
1. Satellite cells.
2. Schwann cells.
 Microglial Cell
• Microglial cells are the smallest
neuroglial cells.
• They are macrophage cells which
make up the primary immune
system for the CNS.
• These phagocytic cells help to
remove bacteria and waste, mean
that cleaning neuronal debris.
 Astrocytes
• These are star-shaped macroglial cells
with many processes.
• They are the most abundant glial cells
in the CNS.
• Their roles are provide metabolic and
structural support to the neurons.
 Oligodendrocytes
• These are cells with very few processes.
• They are found in the central nervous
system (CNS).
• They form myelin sheath on the axons of
a neurons.
• Myelin sheath have lipid-based insulation
for increasing the speed of action potential
which down the axons.
 Ependymal Cells
• These are ciliated cells which line
up the central cavities of the brain
and spinal cord.
• They form fairly permeable barrier
between cerebrospinal fluid that
fills these cavities.
 Schwann Cells
• These are equivalent to oligodendrocytes.
• They surround nerve fibres in the PNS.
• They help to maintain axons and form
myelin sheaths in the PNS.
 Satellite Cells
• They line the surface of neuronal cell
bodies in ganglia within the PNS.
• They are analogous to astrocytes.
General Function of Neuroglia Cells
Neuroglia cells has the following general functions;
1. They support neurons mechanically by filling up interneuron
space.
2. They convey nutrients from the blood stream to the neurones.
3. They prevent the inversion of foreign particles when brain is
damaged.
4. They synthesize myelin sheath for myelinated nerve fibres.