Student ID : BC 220201140
Student Name :Maria Khan
• SEMESTER : 3RD B. ED 1.5 YEARS
• PRESENTATION : 2ND
• TOPIC : COORDINATION AND CONTROL IN HUMANS
• SOURCE : 10TH CLASS BIOLOGY PUNJAB TEXT BOOK BOARD
Objective
Understanding Nervous System
To understand Neurons and their types
To understand coordinated Action
To understand the Structure of brain and spinal cord
Introduction
Coordination can be defined as the working together of the different systems of an
organism in order to produce an appropriate reaction to stimuli.
There are two types of coordination in organisms:
i. Nervous coordination brought about by nervous system and
ii. Chemical coordination brought about by endocrine system.
Animals have both the nervous and chemical coordination systems in their bodies while
plants and other organisms have only chemical coordination.
Coordinated Action
1. Stimulus: Any change in environment (external and internal), which can provoke a response in
organism. Examples: heat, cold, pressure, sound waves, presence of chemicals, microbial infections
etc.
Receptors The organs, tissues or cells which are specifically built to detect particular type of stimuli are
called receptors.
Coordinators: organs that receive information from receptors and send messages to particular organs
for proper action. In nervous coordination, brain and spinal cord are coordinators.
Effectors : parts of body ( muscle or glands ) which receive messages from coordinators and produce
particular responses.
Response : On receiving the message from coordinators, the effector performs action. This action is
called response. For example, pulling our hand away from something very hot.
Nervous Coordination
Nervous vs endocrine coordination .
Human Nervous System
Two major components i.e. central nervous system and peripheral nervous system
Central nervous system comprises of coordinators i.e. brain and spinal cord while peripheral nervous
system consists of nerves that arise from central nervous system and spread in different parts of body
Peripheral vs Central nervous system.
Peripheral vs Central Nervous System
Nerve cell or Neuron
It Is the unit of the nervous system.
Neurons are specialized cells that are able to conduct nerve impulses from receptors to
coordinators and from coordinators to effectors .
The nucleus and most of the cytoplasm of a neuron is located in its cell body.
Dendrites conduct impulses toward cell body and axons conduct impulses away from
cell body .
Schwann cells are special neuroglial cells located at regular intervals along axons.
In some neurons, Schwann cells secrete a fatty layer called myelin sheath, over axons .
Between the areas of myelin on an axon, there are nonmyelinated points, called the nodes of Ranvier.
Myelin sheath is an insulator so the membrane coated with this sheath does not conduct nerve impulse. In
such impulses are called saltatory (‘jumping’) impulses. This increases the speed of nerve impulse.
Structure of Neuron .
Division of neurons on the basis of function
On the basis of their functions, neurons are of three types
1. Sensory neurons conduct sensory information (nerve impulse) from receptors towards the
CNS. Sensory neurons have one dendrite and one axon.
2. Interneurons form brain and spinal cord. They receive information, interpret them and
stimulate motor neurons.They have many dendrites and axons.
3. Motor neurons carry information from interneurons to muscle or glands (effectors). They
have many dendrites but only one axon.
Nerve
Nerve
A nerve means the union of several axons that are enveloped by a covering made of lipid.
Based on the property of axons, the nerves are classified into three types.
1. Sensory nerves contain the axons of sensory neurons only.
2. Motor nerves contain the axons of motor neurons only.
3. Mixed nerves contain the axons of both i.e sensory and motor neurons
Centeral Nervous System
It consists of brain and spinal cord.
A- Brain
Brain is situated inside a bony cranium (part of skull).Inside cranium, brain is covered by
three layers called meninges. Meninges protect brain and also provide nutrients and oxygen
to brain tissue through their capillaries. The brain contains fluid-filled ventricles that are
continuous with the central canal of spinal cord. Fluid within ventricles and central canal is
called cerebrospinal fluid (CSF).
Divisions of Brain
1. Forebrain
2. midbrain
3. hind brain
Lobes of Brain
Frontal lobe :
Control motor functions, permits conscious
control of skeletal muscles and coordinate
movements involves in speech
Parietal:
Contains sensory areas that receive impulses from skin.
Occipital:
Receives and analyzes visual information
Temporal:
Concerned with hearing and smell
B: Spinal Cord
The spinal cord is in fact a tubular bundle of nerves. It starts from brain stem and extends to
lower back. Like brain, spinal cord is also covered by meninges. The vertebral column
surrounds and protects spinal cord.
The outer region of spinal cord is made of white matter (containing myelinated axons).
The central region is butterfly shaped that surrounds the central canal. It is made of grey
matter (containing neuron cell bodies)
Spinal cord structure.
Home work
Draw the structure of Neuron.
Differentiate between Centeral and peripheral nervous system
Differentiate between Dendrite and axon
Label various lobes of brain .
