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065 The Anatomy and Functions of the Frontal Lobe

Learn more about the brain gyri and sulci or fissures. Get familiar with the anatomy and functions of the frontal lobe in this easy to understand video. Leslie has also included an interesting video about an individual with Broca’s aphasia, a defect in the Broca’s Motor Speech area resulting in speech problems.

Have fun learning!

Transcript of Today’s Episode

Hello and welcome to another episode of Interactive-Biology TV where we’re making Biology fun! My name is Leslie Samuel and in this episode, Episode 065, I’m going to be talking about the anatomy and functions of the frontal lobe. But, before I talk about that, let’s talk about the folds in the cerebrum.

Now, when we’re talking about ‘gyri,’ we’re talking about the folds. You can see here in this brain, we have all these little folds that go all throughout the brain. Those are called ‘gyri.’ If you’re dealing with one of them, you’re not going to say gyri, but you’re going to say ‘gyrus.’

Then, we have the ‘sulci’ or the ‘fissures.’ Sometimes, we use these interchangeably, but these are the depressions in the brain that define the lobar boundaries. Here, we have the different lobes, and you can see we have all of these depressions, in other words, we have all of these grooves that are going throughout the different lobes of the brain. Those are called, ‘sulci,’ and in some cases, we call them, fissures.

So, with that understanding, let’s look at the frontal lobe in the brain. Now, the frontal lobe, we have two major boundaries that define the frontal lobe. Over here, we have the central sulcus. You can see that’s going through here. That is the posterior aspect (okay, so that’s towards the back). The posterior aspect of the frontal lobe, the boundary is the central sulcus.

Then, if we go inferiorly here, we have the lateral sulcus, or we can call it the Sylvian sulcus. That’s this boundary here on the inferior end of the frontal lobe. The central sulcus, posteriorly, and the Sylvian or lateral sulcus, inferiorly. And, this here would be the frontal lobe.

The first thing I want to talk about is this section here that’s called the precentral gyrus. Here, you can see in this case, it’s called the anterior central gyrus, but this is the precentral gyrus. The function of that region is it serves as the primary motor cortex. So, it’s basically getting motor signals from different parts of the brain, and it’s integrating it in this region. The precentral gyrus. This is where a lot of that motor function is integrated.

Just anterior to that, it’s not shown in this image, but I’m just going to kind of draw a section in here coming from the, from this part all the way. Maybe it’s not that right. It’s kind of, it’s not exact, but this is the pre-motor cortex, which makes sense. If this is the primary motor cortex, and this is, right before that, it’s the pre-motor cortex. Here, we have kind of an area that we call the ‘supplemental motor area.’ So, it’s the supplemental motor area. That plays a big role in initiating movements. You want to move, there’s an initiation that has to happen, and this has something to do with that process of initiating movements.

Now, as I said before, the boundaries aren’t necessarily definitely defined. I can’t see that it goes from right here to right there. But, in this area here, let’s show this area. I’ll just color it in a little bit. We have what’s called the ‘frontal eye fields.’ (Let me write that out—frontal eye fields). And, that is involved in the movement of the eyes, but a specific movement. When I look to the left and I look to the right, my eyes are moving horizontally. The frontal eye fields are involved in the horizontal movement of the eye.

Let’s move on. Then, we have, if we go anterior from that area, we have the superior frontal gyrus, the middle frontal gyrus, and the inferior frontal gyrus. So, superior, middle, and inferior frontal gyrus.

And, in the left hemisphere of the brain in the frontal lobe, we have an area that we call the Broca’s motor speech area. That has a big part to do with the motor components of speech. So, you’re speaking, I am speaking into this microphone right now, my mouth is moving in certain ways, and there are muscles that are controlling that, and this Broca’s motor speech area is very much involved in that process. Once again, it’s in the left hemisphere, not the right, and that deals with motor control of speech.

Now, if there’s damage to this area. If something happens, and that causes this area to be damaged, the result of that can be what we call, ‘Broca’s aphasia.’ When you have that condition, it causes a form of language impairment where you cannot speak well. It’s not that you can’t comprehend, but the motor control of that speech doesn’t function as well because the Broca’s motor speech area is damaged.

I have a little video here to show an example of that. So, let’s go ahead and take a look at that right now. (Video starts to play).

So, this is an example of Broca’s aphasia. You can see he had some problems speaking. Not necessarily in comprehension, but in just the motor control in forming the words and putting together long strings of the words to make complete sentences. That is an example of Broca’s aphasia.

If we look all the way into the anterior section, you’ll see that we have the prefrontal cortex and that plays a very important role in the process of intellectual functioning, and emotional responses, and so on. So, intellectual and emotional events that has a lot to do with what happens in the prefrontal cortex.

There’s another area that we cannot see in this picture, and in order to see it, we need to remove a section from here because it’s deeper in, it’s more medial. We’re going to do that now, and take a look at that. Here, you can see we have removed the part of the temporal lobe and part of the frontal lobe and then, here, there’s an area that we call the ‘insula.’ You can see it over here, and you can also see right here. This is the insular cortex. This picture over here is a coronal section of the brain. We just take a section of the brain right in this area, and you can see the insula right here.

Depending on what book you read, you might get different explanations as to the function of the insula, anything from taste, sensation, to emotions, to thoughts, pain sensations, visual sensations in terms of, you know, feeling hungry and thirsty. That’s attributed to that region. We’re not 100% clear on how this works, but we do have some suggestions as to its function.

The last thing I want to talk about is what we see right here. This structure is called the corpus callosum. That is responsible for connecting the two hemispheres, and you can see as the cortex goes medially, it borders in the inferior aspect with that corpus callosum. We can see it even clearer here. We can see the corpus callosum. You can see it starts here in the frontal cortex, and it goes back here. So, this is the corpus callosum. If we’re dealing with the frontal cortex, that does border with the corpus callosum inferiorly. That is shown very well right there.

That’s pretty much all I want to cover for this episode. As usual, you can visit the website at Interactive-Biology.com for more Biology videos. You could find transcripts of all the videos and a number of other resources to help make Biology fun.

This is Leslie Samuel. That’s it for now, and I’ll see you in the next one.

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Leslie Samuel is the creator of Interactive Biology. His mission is to use this site to Make Biology fun for people all over the world.

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Leave An AWESOME Comment

42 Responses to “065 The Anatomy and Functions of the Frontal Lobe”

  1. RochelleHansonMusic August 19, 2011 at 2:22 pm #

    lol the pulral of Gyri is Gyrus lol. And the plural of Jairus could be Jairai lol ;) Inside Joke about a boy named Tait lol. Love your vids! I really do.

  2. RochelleHansonMusic August 19, 2011 at 6:22 pm #

    lol the pulral of Gyri is Gyrus lol. And the plural of Jairus could be Jairai lol ;) Inside Joke about a boy named Tait lol. Love your vids! I really do.

  3. InteractiveBiology August 20, 2011 at 8:56 pm #

    @RochelleHansonMusic Wow Rochelle, LOL. Thanks for the laugh and the inside joke ;)

  4. InteractiveBiology August 20, 2011 at 8:56 pm #

    Wow Rochelle, LOL. Thanks for the laugh and the inside joke ;)

  5. InteractiveBiology August 21, 2011 at 12:56 am #

    Wow Rochelle, LOL. Thanks for the laugh and the inside joke ;)

  6. saronah8008 August 24, 2011 at 11:52 pm #

    I like how u explain the brocas area nice job

  7. saronah8008 August 25, 2011 at 3:52 am #

    I like how u explain the brocas area nice job

  8. InteractiveBiology August 25, 2011 at 6:24 am #

    @saronah8008 Thanks. I like how you left that comment :D

  9. InteractiveBiology August 25, 2011 at 6:24 am #

    Thanks. I like how you left that comment :D

  10. InteractiveBiology August 25, 2011 at 10:24 am #

    Thanks. I like how you left that comment :D

  11. Djalitana September 7, 2011 at 7:16 am #

    I get that Broca’s something when I have to do an exam. why does the web give me mediation clips when I ask for pineal gland?

  12. Djalitana September 7, 2011 at 7:16 am #

    I get that Broca’s something when I have to do an exam. why does the web give me mediation clips when I ask for pineal gland?

  13. Djalitana September 7, 2011 at 11:16 am #

    I get that Broca’s something when I have to do an exam. why does the web give me mediation clips when I ask for pineal gland?

  14. TheKingspoon08 October 28, 2011 at 7:46 am #

    WOW AWESOME SITE GOING TO SHARE WITH EVERYONE…

  15. TheKingspoon08 October 28, 2011 at 11:46 am #

    WOW AWESOME SITE GOING TO SHARE WITH EVERYONE…

  16. forgetmenoot November 30, 2011 at 4:55 pm #

    Thank you so much for this, you’re saving lives :)

  17. forgetmenoot November 30, 2011 at 9:55 pm #

    Thank you so much for this, you’re saving lives :)

  18. InteractiveBiology December 1, 2011 at 5:30 am #

    @forgetmenoot You’re welcome! :) Stay tuned for more life-saving Biology videos ;) Have fun!

  19. InteractiveBiology December 1, 2011 at 5:30 am #

    You’re welcome! :) Stay tuned for more life-saving Biology videos ;) Have fun!

  20. InteractiveBiology December 1, 2011 at 10:30 am #

    You’re welcome! :) Stay tuned for more life-saving Biology videos ;) Have fun!

  21. RorySmith1990 December 11, 2011 at 2:58 pm #

    Thank you so much for your videos. I find these videos very helpful. Especially how you break down complicated things such as brain anatomy and action potential etc into such easy chunks. :) Just wondering if you are goin to do a video on the limbic system anytime? Its the part that im struggling to understand most at the moment.

  22. InteractiveBiology December 11, 2011 at 7:41 pm #

    @RorySmith1990 Hi! Thank you for watching our videos. Glad you liked them :) Leslie might or might not add more videos on the limbic system anytime soon. But, he is adding more videos to the site from time to time. So, please stay tuned!

  23. InteractiveBiology December 11, 2011 at 7:41 pm #

    Hi! Thank you for watching our videos. Glad you liked them :) Leslie might or might not add more videos on the limbic system anytime soon. But, he is adding more videos to the site from time to time. So, please stay tuned!

  24. RorySmith1990 December 11, 2011 at 7:58 pm #

    Thank you so much for your videos. I find these videos very helpful. Especially how you break down complicated things such as brain anatomy and action potential etc into such easy chunks. :) Just wondering if you are goin to do a video on the limbic system anytime? Its the part that im struggling to understand most at the moment.

  25. InteractiveBiology December 12, 2011 at 12:41 am #

    Hi! Thank you for watching our videos. Glad you liked them :) Leslie might or might not add more videos on the limbic system anytime soon. But, he is adding more videos to the site from time to time. So, please stay tuned!

  26. ashishviswas March 2, 2012 at 1:36 pm #

    Sir , Thats Perfect…awesome videos…

  27. ashishviswas March 2, 2012 at 1:36 pm #

    Sir , Thats Perfect…awesome videos…

  28. ashishviswas March 2, 2012 at 6:36 pm #

    Sir , Thats Perfect…awesome videos…

  29. Travis April 8, 2012 at 11:32 pm #

    I realize that this has been said time and again, but Leslie, I commend you and truly thank you for these videos. I have tried EVERYTHING in an attempt to better understand and memorize brain physiology, and your videos break them down into such clear and VERY well made videos. Seriously, the production quality, forethought, and overall organization of your videos make them an INDISPENSABLE resource!

    Thank you, thank you, thanks you!

    • Leslie Samuel April 9, 2012 at 10:17 am #

      You are very much welcome Travis. Glad to hear that you are finding so much value in the videos, and all the best on your journey of Education :)

  30. Nottsmed1 April 12, 2012 at 12:29 pm #

    excellent video, other than possibly adding the brodmann areas and possibly mentioning higher cognitive functions and planning/decision making (Brodmann 9/10) and mentioning the in depth cortical cellular connections (stellate and pyramidal cells) I think you covered the frontal lobe in its entirety. definitely a fan! look forward to seeing more!

  31. Nottsmed1 April 12, 2012 at 4:29 pm #

    excellent video, other than possibly adding the brodmann areas and possibly mentioning higher cognitive functions and planning/decision making (Brodmann 9/10) and mentioning the in depth cortical cellular connections (stellate and pyramidal cells) I think you covered the frontal lobe in its entirety. definitely a fan! look forward to seeing more!

  32. Michael June 18, 2012 at 6:43 am #

    This site is amazing! Leslie is doing a great job here assisting people understand biology and he is pretty entertaining too… definately recommend this to everyone.

  33. Ahmed Reda Muhammed Abdelkader August 27, 2012 at 2:06 am #

    Excellent. But You should pay more attention to the medial surface of frontal lobe, I mean paracentral lobe, SSMA and cingulate cortex

  34. RedOak5ix November 13, 2012 at 9:39 pm #

    Thank you very much. The part on the Brocas was interesting indeed. But the vid didn’t answer the question why the man did suffer from speach-depression? Is there a possibility to temporally block the signals to the broca’s with central stimulants or alcohol, is this the reason why our ability to speak goes weak after too much vine?

  35. xraybea January 18, 2013 at 4:10 pm #

    I love how say “Making biology FUN!”

  36. Luis Polena January 20, 2013 at 2:15 pm #

    Thank you! I love your videos!

  37. baykomious January 27, 2013 at 10:45 am #

    Khan Academy is great too you should check them out sir you would be a great teacher

  38. Lisa Flurie February 1, 2013 at 2:52 pm #

    My brother at 21 had a motorcycle accident and sustained Frontal Lobe Damage to the Brain resulting characteristics of Schizophrenia. He has now 59 years old and is trapped in Florida’s Mental Health System. Is this common to treat him with Medication only for Schizophrenia and no treatment for a Brain injury?

  39. fitch90210 March 28, 2013 at 8:43 pm #

    Is the frontal eye field on both hemispheres? or just one?

  40. Realville420 June 29, 2013 at 11:25 am #

    Very informative… great job… keep up the vids..

  41. nuks nunu July 6, 2013 at 8:13 am #

    Very informative video!! Thank you.. It helps me a lot to understand what happened with my husband’s broca aphasia after stroke and my son’s autism verbal problem.