16 Nervous Systems
Summary
TLDRThis script delves into the intricacies of the human nervous system, highlighting its three main divisions: the central nervous system (CNS), which includes the brain and spinal cord; the peripheral nervous system (PNS), encompassing nerves outside the CNS; and the autonomic nervous system (ANS), which controls involuntary actions. The ANS is further split into the sympathetic, responsible for 'fight or flight' responses, and the parasympathetic, which manages 'rest and digest' functions. The script promises a deeper exploration of these systems, particularly the CNS, in upcoming lectures.
Takeaways
- đ§ The human body has multiple nervous systems, not just one.
- đ The Central Nervous System (CNS) consists of the brain and spinal cord, controlling the mind and behavior.
- đż The Peripheral Nervous System (PNS) includes all nerves outside the CNS, extending throughout the body.
- đ The PNS is further divided into the Somatic Nervous System and the Autonomic Nervous System.
- đââïž The Somatic Nervous System is responsible for voluntary control of body movements through skeletal muscles.
- đ« The Autonomic Nervous System manages visceral functions that occur below the level of consciousness, such as heart rate and digestion.
- đ The Autonomic Nervous System is further split into the Sympathetic and Parasympathetic Nervous Systems.
- đš The Sympathetic Nervous System activates the 'fight or flight' response during crises or perceived threats.
- đ The Parasympathetic Nervous System takes over during rest and recovery, promoting digestion and relaxation.
- đ Only one of the two branches of the Autonomic Nervous System is active at a time, depending on the body's needs.
Q & A
What is the central nervous system (CNS) and what does it control?
-The central nervous system (CNS) includes the brain and spinal cord, and it controls the mind and behavior.
What is the peripheral nervous system (PNS) and how is it different from the CNS?
-The peripheral nervous system (PNS) consists of nerves that extend outside of the brain and spinal cord. It controls all other nerves in the body not directly connected to the CNS.
How is the peripheral nervous system divided?
-The peripheral nervous system is divided into the somatic nervous system, which controls voluntary movements, and the autonomic nervous system, which manages involuntary functions.
What does the somatic nervous system do?
-The somatic nervous system is responsible for voluntary control of body movements through skeletal muscles, such as writing, walking, or tapping your foot.
What are the key functions of the autonomic nervous system?
-The autonomic nervous system controls involuntary functions like heart rate, digestion, respiration, and perspiration, which occur below the level of conscious awareness.
What is the role of the sympathetic nervous system?
-The sympathetic nervous system activates the body's 'fight or flight' response during crisis situations, increasing heart rate, blood pressure, and preparing the body for action.
How does the parasympathetic nervous system function in contrast to the sympathetic nervous system?
-The parasympathetic nervous system is responsible for 'rest and digest' functions. It promotes recovery by slowing the heart rate and aiding in digestion when the body is not in a state of crisis.
Can the sympathetic and parasympathetic nervous systems be active at the same time?
-No, only one of the systems can be active at a time. If the sympathetic nervous system is engaged, the parasympathetic system is inactive, and vice versa.
What are examples of modern-day scenarios that can trigger the sympathetic nervous system?
-Modern scenarios like anxiety over sending an important email or facing a stressful work situation can trigger the sympathetic nervous system, causing symptoms like increased heart rate and blood pressure.
How does the sympathetic nervous system affect digestion and sleep?
-When the sympathetic nervous system is activated, it diverts energy away from non-essential functions like digestion and sleep, which is why stress can cause digestive issues and difficulty sleeping.
Outlines
đ§ Overview of the Nervous System
This paragraph introduces the concept of the nervous system, explaining that there is a common misconception that humans have just one nervous system, when in fact there are several. The central nervous system (CNS), which includes the brain and spinal cord, is responsible for controlling the mind and behavior. The peripheral nervous system (PNS) consists of nerves that extend beyond the CNS, and it is further divided into the somatic nervous system, which controls voluntary movements through skeletal muscles, and the autonomic nervous system, which oversees visceral functions such as heart rate, digestion, and respiration. The autonomic nervous system is further broken down into the sympathetic and parasympathetic systems, which are responsible for the 'fight or flight' response and restorative processes, respectively.
đ The Autonomic Nervous System: Sympathetic vs. Parasympathetic
The second paragraph delves deeper into the autonomic nervous system, highlighting the interplay between the sympathetic and parasympathetic systems. It explains that these two systems are mutually exclusive, meaning only one can be active at a time. The sympathetic nervous system activates during stressful or dangerous situations, preparing the body for 'fight or flight' by increasing heart rate and diverting energy away from non-essential functions like digestion. Conversely, the parasympathetic system takes over during rest and recovery, promoting digestion and relaxation. The paragraph also touches on how chronic activation of the sympathetic system due to stress can negatively impact digestion and sleep, illustrating the body's prioritization of immediate survival needs over restorative processes.
Mindmap
Keywords
đĄCentral Nervous System (CNS)
đĄPeripheral Nervous System (PNS)
đĄSomatic Nervous System
đĄAutonomic Nervous System
đĄSympathetic Nervous System
đĄParasympathetic Nervous System
đĄFight or Flight Response
đĄRest and Digest
đĄVisceral Functions
đĄNerves
Highlights
The body has several nervous systems, not just one.
The central nervous system (CNS) controls the mind and behavior, specifically the brain and spinal cord.
The peripheral nervous system (PNS) includes all nerves outside the brain and spinal cord.
The peripheral nervous system can be broken down into the somatic and autonomic nervous systems.
The somatic nervous system involves voluntary control of body movements through skeletal muscles.
The autonomic nervous system controls visceral functions below the level of consciousness, such as heart rate and digestion.
The autonomic nervous system is divided into the sympathetic and parasympathetic nervous systems.
The sympathetic nervous system activates during crisis situations, responsible for the fight-or-flight response.
The sympathetic nervous system can also be triggered by non-life-threatening situations, such as anxiety from sending an email.
The parasympathetic nervous system takes over when the sympathetic nervous system is not engaged, focusing on rest and digestion.
Only one of the sympathetic or parasympathetic systems is active at a time.
When the sympathetic nervous system is active, resources are diverted away from rest and digestion.
Anxiety or stress can lead to issues with digestion and sleep due to sympathetic nervous system activation.
The parasympathetic nervous system helps the body recover from stress, promoting rest and restoration.
A detailed exploration of the central nervous system will follow in subsequent lectures.
Transcripts
so when it comes to our body there's
kind of this belief that we just have
one nervous system but technically we
have several different nervous systems
so I want to briefly talk about them
here so first we have the central
nervous system or the
CNS the central nervous system controls
the mind and our
behavior and specifically we're talking
about the brain as well as the spinal
cord then we have the peripheral nervous
system or the
pns and the peripheral nervous system
involves nerves in the body that extend
outside of the central nervous system so
any nerves that we have in our body
other than you know where our spinal
cord is or where our brain
is the peripheral nervous system can
then be broken down into the sematic
nervous system as well as the autonomic
nerv nervous system so the sematic
nervous system involves voluntary
control of body movements through our
skeletal
muscles and then the autonomic nervous
system
involves visceral functions uh which
really occur below the level of
Consciousness so this includes things
like our heart
rate
digestion perspiration
our respiratory rate so how fast we're
breathing
Etc so essentially we have this whole
thing so we have our nervous system so
we have the central nervous system brain
and spinal cord we have the peripheral
nervous system now this slide breaks
them down a little bit more um into a
sensory nervous system for sensory
information and then the motor nervous
system uh which gets into then the
somatic and the autonomic nervous
systems
but essentially what we were just
talking
about
so and then we'll talk about the anomic
a little bit more than a minute so for
the sematic nervous system like I said
this controls um and coordinates
volunteer movement so anytime we are
moving something through our skeletal
muscles you know any Movement we choose
to do essentially writing tapping a foot
walking around Etc that involves our
sematic nervous system and really it has
to De with information between our
central nervous system you know our
brain and our spinal cord and our
body and then the autonomic nervous
system which like it says more
responsible for those visceral uh
reactions and all of that can then be
broken down into the sympathetic nervous
system and the parasympathetic nervous
system so so the sympathetic nervous
system is what controls us when we're
engaged in a
crisis so if we're in a situation that
requires essentially like fight ORF
flight or a body goes into like that
fight ORF flight response that's our
sympathetic nervous system taking
over and so that's going to rev us up to
deal with whatever the situation is now
in the past I was more along the lines
of you know we thought we were in danger
because we might be attacked by like a
bear nowadays that still might be the
case you know if we walking in the woods
you know maybe uh we are in the presence
of something that could attack us so our
sympathetic nervous system is going to
take over them um or if we're in the
situation where there could be a human
that might attack us you know our
sympathetic nervous system is going to
take over but since that sympathetic
nervous system will take over for more
kind of mundane things in a way compared
to like trying to outrun a beer um so
maybe you have an email you need to send
out but for whatever reason sending out
that email is giving you a lot of
anxiety you know you're really nervous
about how people are going to react to
whatever the message is and you start
feeling your heart rate increasing and
you start maybe not feeling your blood
pressure increase but you can kind of
feel that response it's still your
sympathetic nervous system kicking in so
your body is
still sensing that there's danger nearby
even though the danger here in this case
is an Emil versus a
beer we also have a parasympathetic
nervous system so the parasympathetic
nervous system is basically what takes
over when the sympathetic nervous system
is not engaged so this tends to deal
with things like rest
you know when we're trying to rest and
recoup from a sympathetic nervous system
take over um as well as things like
digestion uh so when it comes to the
autonomic nervous system specifically
the sympathetic and the
parasympathetic only one nervous system
takes over at a
time so if the sympathetic nervous
system is active the parasympathetic is
not and vice
versa um so only one is actually engaged
at a time it just depends on what the
situation
is and this is why you know like I say
the parasympathetic has to De with like
rest and digestion think about if you're
really stressed how you might not be
hungry or if you do eat it might not sit
with you well or you might not be able
to sleep it's because your sympathetic
nervous system is
activated and the sympathetic nervous
system doesn't have time to basically
devote resources to rest resources to
digestion and so that's why you can have
those issues if you're really anxious
about something or if you feel like you
are in absolute
danger so that's essentially what's
going on with the different nervous
systems like I said it's a very brief
explanation of everything um but we will
spend more time talking about especially
the central nervous system over the next
few lecture videos so I will end this
one
here
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