Main content
MCAT
Course: MCAT > Unit 11
Lesson 1: Biological basis of behavior: Nervous system- Biological basis of behavior: endocrine system questions
- Structure of the nervous system
- Functions of the nervous system
- Motor unit
- Peripheral somatosensation
- Muscle stretch reflex
- Autonomic nervous system
- Gray and white matter
- Upper motor neurons
- Somatosensory tracts
- Overview of the functions of the cerebral cortex
- Hemispheric differences and hemispheric dominance
- The old brain
- Cerebellum
- Brainstem
- Subcortical cerebrum
- Cerebral cortex
- Neurotransmitter anatomy
- Early methods of studying the brain
- Lesion studies and experimental ablation
- Modern ways of studying the brain
- Endocrine system and influence on behavior - Part 1
- Endocrine system and influence on behavior - Part 2
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Functions of the nervous system
In this video we explore the different functions of the nervous system. Created by Matthew Barry Jensen.
Want to join the conversation?
- Are we even certain that consciousness exists? I mean, we're aware of ourselves, but then a combination of cognition and emotion would explain that pretty well.
Unless consciousness is the difference between being awake and dreaming?(18 votes)- Being responsive to stimuli is one definition of consciousness and I don't think that is what the speaker is referring to in this video. He is referring to a phenomenon that we believe to be uniquely human whereas being responsive to stimuli could be applied to most any animal (and actually in plants as well). Philosophers have been trying for centuries to define consciousness and determine whether or not it exists. In response to the original question, I suppose we do not really know anything for certain, but I think that consciousness is related to being aware of our cognition and emotions. For example, our ability to think about thinking.(32 votes)
- why aren't there any nerves on the face/cheek??(6 votes)
- The trigeminal nerve (cranial nerve V) does innervate the face and cheek.(19 votes)
- Why is it difficult to define conciousness?(5 votes)
- Consciousness is difficult to define because it exists in more than just the purely physical sense of which science is used to defining. We can't really touch it, we can't see it, we can't feel it, and we certainly can't define it. This is because consciousness, at its core, is more than the mental awareness of the person, the ability to respond to stimuli, to have coherent thoughts, to understand their location, to know who they are and what they are doing, to respond to stimuli, et cetera. It's extraordinarily difficult to define but easy to understand. May I also add that your conscious mind is reading and understanding this? That's one of the great can't-pin-it-down's of neuroscience.(7 votes)
- Will it described as "autonomic" rather than automatic in the 3rd category of the basic functions of the nervous system?(5 votes)
- if you're asking if they're the same thing then yes they are.(10 votes)
- What category is dreaming in?(7 votes)
- Where can I find the "parts of the brains"?Do you have a video of that?(4 votes)
- They have an overview on the brain and videos dedicated to some major parts of the brain like the Cerebral Cortex, the Brainstem, and the Cerebrum. They don't go over each and every part of the brain in detail though.(1 vote)
- Who controls basic functions?(3 votes)
- The brain or the neurons or can be called as syndromes.(0 votes)
- In my science class we talked about the main organs in the nervous system, the spinal chord, peripheral nerves, and the brain. How do these play into the functions of the nervous system?(2 votes)
- In my humble opinion, consciousness is a mass network of cognition muscles. Until babies form certain amount of cognition muscles or thinking abilities, they do not remember the past events well.
If the state of mind infants have is also consciousness, then gold fish also has to have consciousness since it has 3-second memory, thus consciousness does not deserve the title of "higher brain function". After infants build up some cognition muscles, I think they start to have "consciousness". The key clue to this research I think is to analyze the components that are involved with the formation of our earliest memories. Also, I think consciousness and memories are all interconnected. What makes part of me and the state of mind I have is the memories I have from the past.(3 votes) - Aroundwhat does the narrator mean by "tone?" 2:21(2 votes)
- "Tone" is the resting tension of muscles. It can be seen with how much mass a muscle has, or how stiff it is.(2 votes)
Video transcript
Voiceover: In this video,
I'm going to talk about some of the functions
of the nervous system and how I think about these functions and have organized them in my mind. The nervous system performs many functions that allow a person to
experience their life and which create their behavior, as well as many necessary
functions of the body, for which a person is usually unaware, and these functions can be
categorized in different ways. The way I like to think
about the functions of the nervous system
is first to divide them into two big categories that I think of as the basic functions of the nervous system and the higher functions
of the nervous system, and you could use whatever
words you wanted here. You could say the lower functions
and the higher functions or the basic functions
and the complex functions, but the reasons I like to use these words is that the basic functions
aren't really that simple. They're actually fairly
complex when you start to get into them, and
they're not really lower in any particular way either. Really, you need the basic functions and the higher functions. Now, dysfunction of different
parts of the nervous system may cause different
patterns of abnormalities of the functions of the nervous system, either the basic functions,
the higher functions, or both, and patterns of abnormal
functions we call syndromes. Let me just write that
word down, syndromes, which means patterns of abnormalities, and certain syndromes
involving abnormal functions of the nervous system are
more common than others, because they're caused by neurological or psychiatric disorders
that occur more frequently. The basic functions of the
nervous system are performed by many parts of both the
central nervous system, which is mainly the brain
and the spinal cord, and the peripheral nervous system, which is mainly the nerves. When it comes to the nerves, the cranial nerves primarily
perform the basic functions of the head and the neck, whereas the spinal
nerves primarily perform the basic functions for
the limbs and the trunk, because that's where
those nerves generally go. Now, I like to divide
up the basic functions of the nervous system
into three big categories. The first category I would call motor, and the word motor, in this context, refers to control of skeletal muscle. So, skeletal muscle,
the main muscle we have that's all over our body and
attached to our skeleton, and by controlling skeletal muscle, the motor functions of the nervous system cause movement, tone, and posture, which are the end results of
contraction of skeletal muscle. The next big category of basic functions of the nervous system I like
to call sensory functions, and this involves all of the senses, basically anything that the
nervous system can detect. And we're used to hearing
about five senses, but it actually turns
out that if you kind of split them up into finer categories, there's way more than five senses. There's vision, there's
hearing, smell, taste. There's a sense from the inner ear, called vestibular sense, and there's multiple senses of the body, called somatosensation, and somatosensation includes
the senses of touch, the position of body
parts, vibration, pain, temperature, and several others. And for each of these categories, we'll get into a lot more
detail on these in later videos, because there's really a lot going on within these categories. And the third big category I think of, when I think of the basic
functions of the nervous system, I like to call automatic
functions, automatic, and these are things that don't require conscious involvement, and that includes a lot of different things, like reflexes, like when your doctor taps
on your knee at the clinic, and your leg kicks out
without you telling it to, and there's all sorts
of different reflexes of the nervous system, and
we'll go over a few of them in later videos, but there's
also all sorts of other kind of automatic functions
the nervous system does without requiring the
involvement of consciousness, including control of a number
of the body systems involved and really important
things like circulation, respiration, and digestion. So, more on that later too. But now, the higher functions
of the nervous system are not performed by huge areas of both the central and the
peripheral nervous system. The higher functions are
performed by parts of the brain, and like the basic functions
of the nervous system, I like to divide up the higher functions of the nervous system
into three big categories. The first big category
of the higher functions of the nervous system I
like to call cognition, cognition, and people
use this word in a number of different ways, so it can get confusing when you're reading about cognition, but I like to think of this as kind of the thinking functions of the brain, like thinking, but there's
also a whole bunch of other things that we can often put
under this term of cognition, including things like learning
and memory and language and a group of things we
call the executive functions, which involve creating goals and organizing behavior
to achieve those goals. So, more on that later, because there's plenty going on there. The next big category of higher functions of the nervous system I call emotions, and emotions, of course, are our feelings, but it turns out there's
a lot more to emotions than just kind of what we feel, because emotions play a
major role in our experience of life and a lot of
other functions of both the nervous system and
the rest of the body. And the last category I
like to think of under the higher functions of the nervous system is consciousness, and consciousness is a really tough word to define. I don't know that I
have a great definition, because people have been
trying to come up with a definition everyone can
agree with for quite some time, although we all sort of
know what consciousness is. The best I can probably
come up with is that consciousness is related to the awareness of being a person, of
experiencing one's life, and controlling one's actions, and while there's a
lot we don't understand about how the nervous
system does pretty much all of these functions or
categories of functions that I've written out here, consciousness is the one
we know the least about, where many many people
are doing lots and lots of research to try to understand how this phenomenon of consciousness is created by the nervous system. So, this is how I like to think about the functions of the nervous system and how I like to break them up into some big categories, and like I said, we'll go into the details
of lots of these categories in later videos, and if you
look in different textbooks and things, you'll see
people have organized the functions of the nervous system in lots of different ways, and in some ways, it doesn't
really matter how you organize all the different functions of the nervous system, as
long as you find some system that makes sense to you,
to keep track of it all.