Assignment 1 – Unit 9 Lewis Keyte
Regulation of the Cardiovascular and Respiratory
Systems
The Nervous System
Introduction – A brief summary
The nervous system is composed of an advanced set of neurones which communicate with the brain in
order to respond to certain stimuli. The nervous system plays a vital role in everyday life as it allows the
organs to communicate with other parts of the body, even while unconscious. It is important for organs
to receive information from other parts of the body (most notably from the brain) because they can
stimulate instructions on how to react to any environmental changes e.g. the brain sends signals to the
adrenal glands to pump adrenaline around the body during a fight or flight response, providing large
doses of reserved energy. A fight or flight response is a result from the sympathetic nervous system;
one of the two components of the involuntary, autonomic nervous system. This means the brain
stimulates this phenomenon automatically and does not require conscious control.
---------------------------------------------------------------------------------------------------------
The CNS and PNS
The nervous system is categorised into two segments:
The Central Nervous System (CNS)
The Peripheral Nervous System (PNS)
The peripheral nervous system is responsible for forming communication links between the brain and
spinal cord with the rest of the body. The peripheral nerves are located all throughout the human body
and can be located from the top of the neck to the tips of the toes, with some nerves being over a metre
long as nerves fibres in the feet need to connect to the central nervous system at the spinal cord.
These nerves tend to become thinner with the increasing distance from the CNS, meaning the
peripheral nerves in the toes are much slimmer than that of the ones in the ribs (they can vary from
1cm to 1mm in diameter).
The central nervous system only consists of the brain and spinal cord. The CNS receives electrical
impulses from sensory neurones (from the PNS) which are connected to the sense organs (eyes, nose,
ears, tongue and most commonly skin). The peripheral nervous system always connects to the CNS to
relay the information through the spinal cord, to the brain, to find a response before ordering another
impulse to be travelled down a motor neurone to the effector which is closest to the stimuli. An effector
is most commonly a muscle or gland which will contract the body away from harm.
The peripheral nervous system is also divided into two sections; the autonomic nervous system and
the somatic nervous system. These systems help the body to function under both conscious and
unconscious control, which is essential for life as 95% of the brains activity is beyond conscious
awareness.
Receptor – a nerve which responds
to environmental changes such as
heat.
Effector – Most commonly a muscle
which contracts the body from harm
such as sharp objects.
,The Somatic nervous system is also known as the voluntary nervous system because most of its
actions require conscious control. The somatic system provides movement through the control of
muscles from sensory and motor neurones which transmits impulses to and from the CNS. Once the
brain has received the impulse, it re-directs another impulse to travel along a set of motor neurones to
reach the effector (muscles or glands) which allow for movement of muscles. However, not all
movements in the somatic nervous system is under conscious control as muscles can be forced to
contract away from harmful stimuli at a seconds notice. This is known as a reflex arc and does not
require the brain to force the contraction of muscles. A reflex arc is an involuntary movement as it is
automatic and does not require conscious control.
Contrasting to this, the autonomic nervous system is known as the involuntary nervous system as
most of its actions are handled automatically and unconsciously. However some autonomic tasks can
be trained or altered due to a process called conditioning. A famous example of this was made by Ivan
Pavlov where he managed to examine how dogs react to sounds to indicate the presence of food,
causing them to salivate automatically because of their frequent experience with this phenomenon. The
dogs would begin to salivate at the thought of food just by hearing Pavlov’s assistant’s footsteps as
they have learned a conditioned response (they have automatically adjusted to the sounds to signal a
reoccurring event). This can also be seen in humans as the body can trigger a conditioned response to
automatically to pull of certain tasks such as constricting bladder.
The autonomic system maintains heartbeat, breathing, body temperature, digestion and blood
pressure, meaning its involvement in day-to-day activities is very frequent and is especially noticed
during exercise. It also helps to maintain homeostasis which is achieved through positive and
negative feedback loops. This nervous system also alerts the brain to prompt an emergency
response when a sudden stimulus is detected without any warning. This is known as the sympathetic
system and is also under involuntary control. Unlike the sympathetic system, the autonomic system
has the potential to calm the body down and allows for a resting or recovery process. This allows the
body to return to a normal equilibrium after receiving an increase in blood flow and using high amounts
of reserved energy. This is known as the parasympathetic nervous system.
---------------------------------------------------------------------------------
The sympathetic nervous system (SNS) can respond to stress and anxiety by increasing heartbeat
and blood flow from the cardiovascular system, and releasing adrenal hormones (adrenaline) to
prepare the body for what is known as a ‘fight or flight response’. This response is caused by motor
neurones in the central nervous system which transmit information to other muscles or glands in the
body, providing energy to either run or defend itself. Neurones in the SNS are mainly centred at the
spinal cord (also known as thoracolumbar as the nerve fibres are placed between the thoracic and
lumbar vertebrae in the upper/lower centre of the spine) in what is known as a sympathetic chain.
These neurones are placed close to the spine because they can co-ordinate the functions of many
organs at once, allowing for a quick, sudden response.
With this in mind, the body also requires a recovery process to undo the sympathetic system. The body
has to undergo this recovery procedure to conserve energy for later use. This means that we need a
parasympathetic nervous system which will decrease respiration (rapid breathing) and heartrate and
will increase digestion. If the body did not consist of the parasympathetic system, then there will be little
energy to use for even the most basic movements such as walking, which would quickly become tiring.
, Assignment 1 – Unit 9 Lewis Keyte
Regulations of the Cardiovascular and Respiratory
Systems
Neurones in the Nervous System
All nerves in the body are made from smaller neurones which chain together to connect to the central
and peripheral nervous system. These neurones are located in all multicellular animals and are
essential for sustaining life as they make up all the nervous systems in the body, including autonomic,
somatic, sympathetic and parasympathetic systems. Neurones are so small they have to be measured
in microbes (µm) where some measure to 1µm in diameter, which is equivalent to 0.001mm.
Neurones also allow for the communication between other organs, to trigger specific responses such
as the sympathetic system, where the brain will instruct the heart to increase heartrate to fuel the
body with an increased supply of oxygen and energy during the fight or flight response. This
communication link simply wouldn’t be possible without neurones as there would be no impulses
nor a pathway, this means bodily functions would not operate and the body would not support
movement, digestion, breathing, seeing, tasting or hearing, making it impossible to efficiently sustain
life.
Different neurones consist of a different structure to fulfil a specific purpose. Neurones can be
located in the peripheral and central nervous system.
There are three main types of neurones:
Relay neurone
Sensory neurone
Motor neurone
----------------------------------------------------------------------------------------------
Structure Function
Controls all functions in the cell.
Responsible for protein synthesis
Nucleus (the formation of proteins).
Maintains the cells structure.
Consists of the nucleus, mitochondria
Cell Body and ribosomes.
Tail-like pathway which allows for
impulses to travel along.
Axon
Signal receptors which contain
proteins which process and transfer
Dendrites information to the cell body.
Glial cells made from myelin which is
an insulated material which forces
Schwann Cells electrical impulses to leap over.
Located at the end of a neuron
Regulation of the Cardiovascular and Respiratory
Systems
The Nervous System
Introduction – A brief summary
The nervous system is composed of an advanced set of neurones which communicate with the brain in
order to respond to certain stimuli. The nervous system plays a vital role in everyday life as it allows the
organs to communicate with other parts of the body, even while unconscious. It is important for organs
to receive information from other parts of the body (most notably from the brain) because they can
stimulate instructions on how to react to any environmental changes e.g. the brain sends signals to the
adrenal glands to pump adrenaline around the body during a fight or flight response, providing large
doses of reserved energy. A fight or flight response is a result from the sympathetic nervous system;
one of the two components of the involuntary, autonomic nervous system. This means the brain
stimulates this phenomenon automatically and does not require conscious control.
---------------------------------------------------------------------------------------------------------
The CNS and PNS
The nervous system is categorised into two segments:
The Central Nervous System (CNS)
The Peripheral Nervous System (PNS)
The peripheral nervous system is responsible for forming communication links between the brain and
spinal cord with the rest of the body. The peripheral nerves are located all throughout the human body
and can be located from the top of the neck to the tips of the toes, with some nerves being over a metre
long as nerves fibres in the feet need to connect to the central nervous system at the spinal cord.
These nerves tend to become thinner with the increasing distance from the CNS, meaning the
peripheral nerves in the toes are much slimmer than that of the ones in the ribs (they can vary from
1cm to 1mm in diameter).
The central nervous system only consists of the brain and spinal cord. The CNS receives electrical
impulses from sensory neurones (from the PNS) which are connected to the sense organs (eyes, nose,
ears, tongue and most commonly skin). The peripheral nervous system always connects to the CNS to
relay the information through the spinal cord, to the brain, to find a response before ordering another
impulse to be travelled down a motor neurone to the effector which is closest to the stimuli. An effector
is most commonly a muscle or gland which will contract the body away from harm.
The peripheral nervous system is also divided into two sections; the autonomic nervous system and
the somatic nervous system. These systems help the body to function under both conscious and
unconscious control, which is essential for life as 95% of the brains activity is beyond conscious
awareness.
Receptor – a nerve which responds
to environmental changes such as
heat.
Effector – Most commonly a muscle
which contracts the body from harm
such as sharp objects.
,The Somatic nervous system is also known as the voluntary nervous system because most of its
actions require conscious control. The somatic system provides movement through the control of
muscles from sensory and motor neurones which transmits impulses to and from the CNS. Once the
brain has received the impulse, it re-directs another impulse to travel along a set of motor neurones to
reach the effector (muscles or glands) which allow for movement of muscles. However, not all
movements in the somatic nervous system is under conscious control as muscles can be forced to
contract away from harmful stimuli at a seconds notice. This is known as a reflex arc and does not
require the brain to force the contraction of muscles. A reflex arc is an involuntary movement as it is
automatic and does not require conscious control.
Contrasting to this, the autonomic nervous system is known as the involuntary nervous system as
most of its actions are handled automatically and unconsciously. However some autonomic tasks can
be trained or altered due to a process called conditioning. A famous example of this was made by Ivan
Pavlov where he managed to examine how dogs react to sounds to indicate the presence of food,
causing them to salivate automatically because of their frequent experience with this phenomenon. The
dogs would begin to salivate at the thought of food just by hearing Pavlov’s assistant’s footsteps as
they have learned a conditioned response (they have automatically adjusted to the sounds to signal a
reoccurring event). This can also be seen in humans as the body can trigger a conditioned response to
automatically to pull of certain tasks such as constricting bladder.
The autonomic system maintains heartbeat, breathing, body temperature, digestion and blood
pressure, meaning its involvement in day-to-day activities is very frequent and is especially noticed
during exercise. It also helps to maintain homeostasis which is achieved through positive and
negative feedback loops. This nervous system also alerts the brain to prompt an emergency
response when a sudden stimulus is detected without any warning. This is known as the sympathetic
system and is also under involuntary control. Unlike the sympathetic system, the autonomic system
has the potential to calm the body down and allows for a resting or recovery process. This allows the
body to return to a normal equilibrium after receiving an increase in blood flow and using high amounts
of reserved energy. This is known as the parasympathetic nervous system.
---------------------------------------------------------------------------------
The sympathetic nervous system (SNS) can respond to stress and anxiety by increasing heartbeat
and blood flow from the cardiovascular system, and releasing adrenal hormones (adrenaline) to
prepare the body for what is known as a ‘fight or flight response’. This response is caused by motor
neurones in the central nervous system which transmit information to other muscles or glands in the
body, providing energy to either run or defend itself. Neurones in the SNS are mainly centred at the
spinal cord (also known as thoracolumbar as the nerve fibres are placed between the thoracic and
lumbar vertebrae in the upper/lower centre of the spine) in what is known as a sympathetic chain.
These neurones are placed close to the spine because they can co-ordinate the functions of many
organs at once, allowing for a quick, sudden response.
With this in mind, the body also requires a recovery process to undo the sympathetic system. The body
has to undergo this recovery procedure to conserve energy for later use. This means that we need a
parasympathetic nervous system which will decrease respiration (rapid breathing) and heartrate and
will increase digestion. If the body did not consist of the parasympathetic system, then there will be little
energy to use for even the most basic movements such as walking, which would quickly become tiring.
, Assignment 1 – Unit 9 Lewis Keyte
Regulations of the Cardiovascular and Respiratory
Systems
Neurones in the Nervous System
All nerves in the body are made from smaller neurones which chain together to connect to the central
and peripheral nervous system. These neurones are located in all multicellular animals and are
essential for sustaining life as they make up all the nervous systems in the body, including autonomic,
somatic, sympathetic and parasympathetic systems. Neurones are so small they have to be measured
in microbes (µm) where some measure to 1µm in diameter, which is equivalent to 0.001mm.
Neurones also allow for the communication between other organs, to trigger specific responses such
as the sympathetic system, where the brain will instruct the heart to increase heartrate to fuel the
body with an increased supply of oxygen and energy during the fight or flight response. This
communication link simply wouldn’t be possible without neurones as there would be no impulses
nor a pathway, this means bodily functions would not operate and the body would not support
movement, digestion, breathing, seeing, tasting or hearing, making it impossible to efficiently sustain
life.
Different neurones consist of a different structure to fulfil a specific purpose. Neurones can be
located in the peripheral and central nervous system.
There are three main types of neurones:
Relay neurone
Sensory neurone
Motor neurone
----------------------------------------------------------------------------------------------
Structure Function
Controls all functions in the cell.
Responsible for protein synthesis
Nucleus (the formation of proteins).
Maintains the cells structure.
Consists of the nucleus, mitochondria
Cell Body and ribosomes.
Tail-like pathway which allows for
impulses to travel along.
Axon
Signal receptors which contain
proteins which process and transfer
Dendrites information to the cell body.
Glial cells made from myelin which is
an insulated material which forces
Schwann Cells electrical impulses to leap over.
Located at the end of a neuron
