Hey guys, it's Medicosus Perfectionatus where medicine makes perfect sense. Let's continue our anatomy playlist. In the previous video, we talked about the terms of position.
What's anterior, what's posterior, what's superior, what's inferior, etc. Today, we'll talk about terms of movement in anatomy because anatomy is not just a science, it's a language. You have to understand the terms flexion versus extension, abduction versus adduction, or abduction versus adduction. supination versus pronation.
We shall also talk about internal rotation versus external rotation. And since you're watching medicosis, there will be some clinical implications. Now let's get started. Have you ever wondered what the word anatomy even means?
Ana means up. Tomi means to cut. There is a machine used by the pathologist known as the microtome.
Micro means small or microscopic. Tomi means to cut. A microtome is a thin slicer. It cuts into tissue. Tomi is to cut.
Anem means up. Anatomy literally means to cut you up, to dissect you. I have other anatomy videos on my channel.
The first terms of movement. Flexion versus extension. What is flexion? Bending.
What is extension? Straightening. Whenever you're talking about a movement, you have to refer to the joint that's being moved which flexion are you talking about oh i'm talking about elbow flexion or i'm talking about shoulder flexion or i am talking about hip flexion you have to specify the joint in this case we are flexing the elbow or extending the elbow okay mycosis i get it but can you give me the technical definition of flexion sure flexion is the movement that includes the following one approximation of two morphologically ventral surfaces.
Ventral of course means anterior. You're getting this part closer to this part by flexing the elbow. Two, you're decreasing the angle between these two parts of the body.
And three, flexion is what helps you assume the fetal attitude or the fetal position. Example, this is flexion right here. But when you arch your back, that's called extension of your vertebral column. Okay, medicals, tell me about the definition of extension. It's the reverse of flexion, and it's the movement that includes the following.
Moving two ventral surfaces away from each other, increasing the angle between the two parts of the body, and assuming a position that's opposite to that of the fetus. Do we have some special situations? Sure. Be very careful when you talk about the flexion of the thumb.
Flexion of the thumb is the thumb moving inwards. And when you're standing in the anatomical position, the thumb is moving medially, i.e. towards the midline of your body and closer to your fifth digit. Next, it's time to talk about abduction versus adduction.
Abduction is the movement which carries your extremity away from the median plane or away from the core of your body. How about... adduction or adduction. It's the exact opposite.
It's the movement which carries your extremity closer to the median plane towards the core of your body. Do we have exceptions or special circumstances here? Sure. When it comes to your digits, fingers and toes, adduction and abduction are slightly different. In this situation, abduction means that your digits are moving away from each other.
They are fanning out. It's the movement of your digits away from the long axis that starts here and goes backwards. This axis is the exact same as the long axis of the second toe or of your middle finger, which is slightly inappropriate for a scientific discussion.
How about adduction then? It's the exact opposite. It's the movement of your fingers or your toes closer to the long axis that we have just mentioned.
What's next? rotation. We have internal rotation and external rotation.
Internal rotation has another name, medial rotation. External is also known as lateral rotation. Look at this arm. Oh, this is external rotation. Laterally, it's rotating away from the median plane, away from the core of my body.
How about medial rotation or internal rotation? It's the exact opposite. It's the rotation of the extremity or the limb towards the midline. But wait, there is more!
Supination versus pronation. Oh, by the way, this movement is unique to the forearm. You do not find this just anywhere in the body.
No, this is peculiar to the forearm. They are rotational. movements. Supination is like this, but when you flip it, it's pronation.
When your palm is looking to the sky, this is supination. When it's facing the ground, it is pronation. But what's the technical definition of melichosis?
To understand the technical definition, just remember that you have two bones here, radius and ulna. Radius is the lateral bone, but the ulna is the medial bone. Now here's the definition of supination. It's when the radius lies parallel with the ulna and the palm is facing forward.
Conversely, pronation is when the radius crosses in front of the ulna, over the ulna, interior to the ulna. and when the dorsum or the back of your hand faces forwards. Now, let's take it to the clinic.
Let's get some real-life applications. First of all, you have to understand something. Friedrich E. Hayek once said, we shall not grow wiser until we realize that much of what we have done before was foolish.
Similarly, you shall not grow wiser in anatomy until you realize that your upper extremity is the mirror image or the exact opposite of your lower extremity. You don't believe me? Consider this. When you flex the elbow, your forearm is moving forwards and upwards. But when you flex the knee joint, your lower leg is moving backwards and upwards.
They are the exact opposite. Why is this metacosis? It's because embryologically speaking, when you were a baby in your mama's womb, Your upper extremity and lower extremity rotated in opposite directions.
And that's why the cubital fossa is in front of your elbow, but your popliteal fossa is behind your knee. But if you follow the definition which says that flexion is the decrease of the angle between the two parts of the body, it actually makes sense. What does not make sense is the part of the definition of flexion that says flexion is the approximation of two morphologically ventral surfaces.
Well, that's a ventral surface and that's a ventral surface. So it makes sense here. But that's not a ventral surface.
That's a dorsal surface. Oh, now I get it. So my lower extremity is the opposite of my upper extremity. Yep. Is this clinically relevant?
Very relevant. Consider this. There is a disease known as eczema or atopic dermatitis.
There is a skin rash or an aximitus rash that affects these persons. And it usually affects the flexor surfaces. And that's why you will see it in front of my elbow, but behind my knee. Very important! Because your upper extremities and your lower extremities are opposites.
They rotated differently during embryological development. Do not expect to hear this from your woke anatomy professor anytime soon. Next, palpation of the radial pulse. Pulse, by the way, is not the same as heart rate.
Pulse is an umbrella term that includes gazillion things. One of them is the rate. Others include the rhythm, the volume, equality between the right and the left side, etc. Here is the radius. That's a bone.
Near it, there is an artery known as radial artery. Oh, so you're trying to say that there is an ulnar artery there too? That's right.
Radial artery, ulnar artery. Radial artery is more lateral, ulnar artery is more medial. They came from a singular origin known as brachial artery. So brachial artery was here, then it divided into radial artery and ulnar artery. Very important.
How do I palpate the radial pulse? With three fingers. That's the best way.
Index finger, middle finger, and ring finger. And you put it on the radial artery, and you gently push the artery against bony prominence. Oh, that's how you feel the pulse.
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