Cerebral Cortex: Functional Organization (Nursing)

00:01 So speaking of the functional organization, let's talk a little bit about all of the different parts of the cerebral cortex and how they are important for different functions of our body.

00:14 We have sensory areas which are responsible for receiving sensory signals, motor areas which are responsible for delivering motor output, and association areas which are more responsible for the integrative signals and processing.

00:37 So the first of the functional areas that we'll discuss in this lecture is going to be the primary sensory cortex.

00:46 This is a sensory area of the cerebral cortex that receives impulses for touch, pressure, vibration, itch, tickle, temperature, pain, and proprioception.

01:01 This part of the cerebral cortex contains what is known as a sensory homunculus.

01:08 Homunculus actually translates to little human.

01:13 And so what this part of the brain has or the cerebral cortex has is basically a map of your entire body found in this area so that when you feel a sensation in a part of the body, it has a map that knows where that sensation is coming from.

01:33 Another sensory area is the primary visual area.

01:39 This is responsible for visual perception.

01:42 A third sensory area is the primary auditory area.

01:48 The primary auditory area is responsible for auditory reception.

01:54 So if we move on to the motor areas of the cerebral cortex, we start with our primary motor area.

02:02 This motor area is responsible for contraction of specific skeletal muscles on the opposite side of the body.

02:11 So the primary motor area on the left is going to be responsible for contraction of skeletal muscles on the right side of the body.

02:19 Like the primary sensory area, the primary motor area also contains a homunculus called the motor homunculus.

02:29 There are crude differences between the sensory area and the motor area, however.

02:35 For example, in this part of the motor area, more cortex is going to be devoted for muscles that have complex movements.

02:47 So for examples, we use our fingers for very precise complex movements and delicate movements and so we're gonna have more cortex devoted to that than we do for the toes which don't really do much.

03:02 Another motor area is the Broca's area.

03:07 This area is referred to as the area for production of speech.

03:12 This involves coordinated contractions of your speech and your breathing muscles that enable you to speak and this area works closely with the primary motor area as well as a premotor area to make speech happen.

03:29 Damage to this area can cause a person to not be able to form words in order to articulate a thought.

03:40 So next we move on to some of our association areas.

03:47 The somatosensory association area is an association area that allows you to determine things like the shapes and textures of an object as well as an orientation of an object relative to another object by way of touch.

04:06 It is also responsible for your memory of past somatosensory experiences so that you remember when you touch a pencil, you don't have to remember that a pencil is a pencil every single time.

04:19 It stores that into your memory.

04:22 Another association area is the visual association area.

04:28 This is responsible for recognizing and integrating visual stimuli.

04:34 For example, being able to recognize objects that you see often.

04:40 So for example, when you see a pencil, again, you know that a pencil is a pencil because you've seen it before.

04:48 Another association area is going to be our auditory association area.

04:55 Like the visual association area is associated with recognizing objects or recognizing visual stimuli, the auditory association area is responsible for recognizing sounds.

05:08 So this allows you to tell the difference between when a person is talking versus when a person is singing or versus when you're listening to music or if you're hearing a loud noise. Another association area is the Wernicke's area.

05:27 This is the area that is responsible for understanding speech and allows you to recognize words and translate those words into thoughts.

05:38 Damage to this area allows you to be able to speak but instead, your words don't make any logical sense and kinda creates a word salad.

05:50 So this is in opposition to the Brocca's speech area which you can think -- you can have logical thoughts but you're not able to actually speak them.

06:01 Another association area is the somatic motor association area, also known as the premotor area.

06:10 This area allows for muscles to contract in specific sequences and it also creates a memory bank for these movements.

06:20 So for example, in order to write your name, you have to memorize all of the different movements that your hand needs to make with the pencil from holding the pencil to all of the different ways that you move your hand in order to write your name.

06:38 And then another association area is our prefrontal cortex.

06:44 This one is responsible for your personality, your decision-making processes, your intuition, and your ability to develop abstract thought.

06:56 So in summary, our cerebrum is going to contain sensory areas that are involved in perception of sensory information, motor areas that are involved in control of execution of voluntary movements, and association areas that are going to deal with the more complex integrative functions like memory, personality, traits, and intelligence.

07:23 As well in our cerebrum, we have our basal nuclei which help us initiate as well as in terminate movements and also suppress unwanted movements and regulate muscle tone.

07:36 Finally, we have our limbic system which is found in parts of the cerebrum.

07:41 This system is going to promote our ranges of emotions including pleasure, pain, docility, affection, fear, and anger.