064 Anatomical Planes and Spatial Relationships in the Human Body
Here’s another whole new episode to make anatomy easier for everyone. Learn about the different anatomical planes with Leslie as he goes through each one including the spatial relationships between parts in the human body. This will be a great help when you go deeper into anatomy and neuroanatomy making it easier for everyone to understand and learn new concepts.
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. In this episode, Episode 064, I’m going to be talking about the anatomical planes and spatial relationships in the human body. As we go into neuroanatomy, we’re going to need to know these planes and these spatial relationships. Let’s get right into it.
Here we have the human body. I want to talk about the three different types of planes that we have. First, we have the coronal or the frontal plane. That’s a vertical plane at a right angle to the cerebral axis. You can see that plane here.
If you got a right angle to that, of course, we have the sagittal plane, which is a vertical plane, but it is parallel to the cerebral axis. You can see that plane over here.
We have a mid-sagittal plane, which means it goes through the midline. You can see that plane over here in red, and then, we have a parasagittal plane, which is just off the midline. So, for example, a parasagittal plane would go through, instead of the midline, let’s say, it goes through right about here. And, that continues down just like the mid-sagittal plane. But, instead of going through the midline, it’s just off the midline. That’s parasagittal.
Then, we have the horizontal plane or the transverse plane, which is parallel to the floor.
Let’s look at some location terms in terms of spatial relationships between two parts of the body.
If we’re talking about something that’s ‘superior,’ that means it’s above another part. If it’s ‘inferior,’ which would be the exact opposite, that means it’s below another part. And then, we have terms like ‘rostral,’ which means towards the head. And, this is when we’re looking at general anatomy assuming that we’re talking about beneath the brain, beneath the head. ‘Rostral’ is towards the head, and ‘caudal’ would be toward the tail or the coccyx. In other words it’s the opposite of rostral.
And then, we have ‘anterior,’ that’s towards the front, or ventral, is also towards the front. And then, we have posterior or dorsal, and that’s towards the back. Anterior and posterior are opposite. Dorsal and ventral are opposite terms also.
We have a few more to go over. That would be ‘medial,’ which is towards the midline; ‘lateral,’ which is farther away from the midline as you can see here. We have ‘proximal,’ which is nearest to the point of origin so, it’s closer to something; and ‘distal’ means farther from the point of origin. So, it’s farther away from whatever that point of origin is. That’s not illustrated in the picture over here, but I’m sure you get the point.
Then, we have ‘ipsilateral,’ which is on the same side of the body. Opposite of that would be ‘contralateral,’ which is on the opposite side of the body. For example, if we are looking at the right leg, the ipsilateral arm would be the right arm. The contralateral arm, of course, would be the left arm. So, ipsilateral means it’s on the same side. Contralateral means it’s on the opposite side of the body.
The interesting thing about these directions is what happens when the spinal cord enters the cranium and we get the brain. Because beneath the brain or beneath the head, we said that rostral was towards the head, and caudal was away from the head; ventral or anterior is the front of the body; dorsal or posterior is towards the back of the body.
When we get into the brain, and we pass the midbrain region, which is this region over here, what happens is that there’s a hundred, approximately a hundred-degree bend. So, in other words, it comes and it bends in that direction. What we have then, is dorsal being the top of the brain, and ventral being towards the bottom of the brain; rostral being towards the front, rostral or anterior; caudal being towards the back, or posterior being towards the back of the brain. You can see we have this shift. Instead of dorsal and ventral being towards the back and towards the front. When we’re beneath the brain, as we pass the midbrain region, dorsal now shifts to the top of the brain, and ventral towards the bottom of the brain. So, the ventral surface of the brain would be this surface here. The dorsal surface of the brain would be towards this surface. Caudal surface or the posterior surface of the brain would be this end. And, the rostral or the anterior surface of the brain would be towards this part here.
Another way of looking at this is by looking at these little diagrams over here where we have rostral, caudal, ventral, and dorsal, but when we get above the brain, it’s a little different. It shifts. Rostral is no longer going towards the top, but now, that’s going towards the front. Caudal towards the back. Dorsal towards the top, and ventral towards the bottom of the brain.
However, when it comes to superior and inferior, that stays the same. Superior means towards the top of the brain. Inferior means towards the tail or coccyx, in other words, going towards the bottom. Anterior is always front, and posterior is behind.
This is going to be important when we go into specific details inside the brain and the spatial relationships between the different parts.
That’s pretty much all for now. As usual, I want to invite you to visit www.Interactive-Biology.com, that’s the website where you can find more of these Biology videos, other resources, and a bunch of stuff to help make Biology fun.
This is Leslie Samuel. That’s it for this video, and I’ll see you in the next one.