CORDINATION
NERVOUS SYSTEM
What does the nervous system work with in combination?
works in combination with the following 4
EFFECTORS,which are the parts of the body that carry
out the response - in humans, these are the muscles (which produce movement) and the glands (which
produce hormones)
RECEPTORS, which detect stimuli and convert them into electrical signals; these electrical signals can be sent
around the body as messages
COMPOSITION:
central nervous system (CNS)
peripheral nervous system
FUNCTION
coordinates
our actions; it decides what we need to do and gives instructions to the rest of the body; it consists of the brain and the spinal cord
FUNCTION
carries messages around the body very quickly:
•sensory nerves carry messages from the receptors to the CNS
•motor nerves send instructions from the CNS to the effectors
What is our nervous system based on?
Our nervous system coordinates our response in a wide variety of situations, but particularly where we need to react very quickly.
PARTS of the nervous system
NERVES
CENTRAL NERVOUS SYSTEM
Nerves are made in groups of neurons.This happens very quickly. The electrical signals are called impulses.Neurons have special characteristics that allow them to do this:
NEURONS: are special cells that transmit electrical signals containing information.
The connection between neurons are called sinapses
The central nervous system consists of the brain and the spinal cord. Neurons within spinal cord or brain are called relay neurons
1.When an impulse arrives at the end of a neuron, chemicals are released. They move
across the synapse.
2. A new impulse is produced in the next
neuron.
Parts
REFLEXES
Our brain can decide very quickly how to respond to a stimulus. However, in some situations there is no time to wait for the brain to decide - for example, if quick action is needed to stop us being injured. Reflexes are automatic responses to stimuli - the body reacts without waiting for the brain to make a decision. A reflex arc is the route that the information in a reflex takes.
Example
NEURODEGENERATIVE DISEASES
When they are produced?
Are caused when neurons in the brain become damaged or die
what provoks?
This causes a gradual deterioration, so the diseases mainly affect people as they get older.In most cases there is no cure, but patients can be given treatments to slow down the development of the disease and/or make their lives easier.
EXAMPLES
1.Alzheimer's disease
2.Parkinson's disease
3.Multiple Sclerosis
Tlking problems
Movement pronblems
disrupts the transmission of impulses
MENTAL ILLNESSES
What are ?
are medical conditions that affect a person's thinking, feelings, moods and/or ability to relate to others. This can make everyday situations difficult.
SCHIZOPHRENIA
What is?
is a long-term condition that can affect people of all ages. People with schizophrenia may believe, see or hear things that are not real. This makes them confused and alters their behaviour
DEPRESSION
Simpoms
The symptoms of depression may include feeling sad or hopeless, and not enjoying things that you used to enjoy. However, it is not just feeling unhappy for a few days: it is a long-term condition that can be very serious
ATTENTION DEFICIT / HYPERACTIVITY
who is affected
Attention deficit and hyperactivity often affect children, but they can also affect teenagers and adults.
People suffering from these conditions find it difficult to sit still and concentrate, and are easily distracted. This often means that they have problems at school or work.
ENDOCRINE SYSTEM
What it consist?
The endocrine system consists of glands that produce hormones and release them into the blood. Hormones are chemicals that are transported around the body in the blood. Each hormone carries a message that is only understood by one specific type of cell.
What are hormones used for?
• controlling gradual changes, like growth and sexual development .
• regulating the level of substances in the body The diagram below shows the main glands in the human body, together with the hormones they produce and what these hormones do.
Anatomy
CORDINATION AND HOMEOSTASIES
HOMEOSTATISIS
homeostasis means maintaining a constant internal environment.
It iclues
• keeping the body temperature close to 37°C
• maintaining the correct levels of various substances in the blood, including water, sugar and sodium ion This is done through the body's coordination systems
They are two exaples for this
Mantaining a costant tenperature
Regulating blood sugar
PROBLEMS WITH THE ENDOCRINE SYSTEM
if too much or too little of a hormone in the body, it can cause various problems (see the examples below). There are various reasons why this can happen. For example:
-Not enought ormone is producet
-The body´s freedback system is not working proplely
-The ormone is not removed from the blood quikly enough
DIABETES
THYROID PROBLEMS
The body stops producing insulin, so the blood sugar level can rise dangerously.
A person with an overactive thyroid produces too much thyroxine
Comparison of the nervous and endocrine systems
COORDINATION - SUMMARY
In this chapter, you have learned about our two coordination systems: the nervous and endocrine systems. This included:
• the parts of the nervous system, including the brain, spinal cord and nerves
• neurodegenerative diseases and mental illnesses
• how the endocrine system controls gradual processes and performs homeostasis
• what happens if hormone levels are too high or too low
• how we respond to stimuli, including voluntary actions and reflexes
