Carpal Bones Anatomy Explanation - Wrist Bones

Carpal Bones Anatomy Explanation - Wrist Bones Learning

We are going to talk about the carpal bones or simply the carpus and the word Karpis is derived from the greek word car pause which means the wrist so basically and the couple bones our made up of eight bones a different bones which is divided into two groups the upper part or the proximal part and the distal part each part having four different bones.

Now the identification of the carpal bones is important to know the distinguishing character of each bone so first of all the scaphoid bone this one is the scaphoid bone this bone has a boat shaft and a tobacco on its lateral side so this is the lateral side as you can see here right over here this is the lateral side where there is the radius and this one is the medial side where there is the allah so this the scaphoid bone can be easily identified by the presence of the tubercle on the lateral side the presence of the tubercle on the lateral side and pc form which is the smallest bone among the eight bones this is the capitate bone the capitate bone is the biggest one so it is called capital capital means the temperature of the biggest one and this bone is the trapezoid bond it resembles it looks like in the shoe of a baby that's the reason why it is called trapezoid and this bone which is the Hemet which is wedged shape having a hoop near its base so it has a hook near its base and it is wedge-shaped so this is the reason it is called Hammett.

So these five bones are very important to remember how they can be identified so now some of the important points that should be remembered in studying these couple bones is that all these eight bones has six surfaces and when we talk about articulation of these bones we see that it's bone is articulated with the neighboring two or three one or more two bones but it's very important to keep in mind that the Palmer and the dorsal surfaces are none articular on the palmar surface this is the polymer surface you can see here this is the anatomical position the polymer polymer surface on the polymer surface and at the dorsal surface the bones and an articular except for the track which are and at the pisiform because the pisiform is attached anteriorly to the track which oh so that is why there is the articulation there is the relation between the track control and the pisiform and then no any other bones are articulated articulated on the palmar and a total surfaces so this is the very important point to be remembered and secondly the lateral surface of pisiform on this pisiform bone here and a lateral surface means this one the lateral surface of the pisiform bone is grooved by the ulnar nerve so this is the very important part this ulnar nerve there is a group for a learner so the lateral surface of pisiform is grooved by the ulnar nerve and the third point is the palmar surface of trapezium this one the palmar surface.

This is the palmar surface I've already told you that is the palmar surface the palmar surface of the trapezium has a vertical group this is the vertical group vertical group there is a vertical group for the insertion of the tendon of the flexor carpi radialis because you see this is the radial side so the flexor carpi you can remember that flexor carpi ulnaris flexor carpi radialis so here flexor carpi radialis dependent of this muscle is attached to this vertical group of the trapezium so this is also one of the most important point to be remembered now how we can remember these eight bones starting from the lateral side whenever you start naming these eight bones used to be start from the lateral side so this one so I am writing here this one is the scaphoid bone scaphoid and this one is the lunette bond unit means moon-shaped so you cannot forget this one Loonette means much lunar.

You can remember that and this one is the triquetra dike which'll bone and this one smallest bone the BC for one or pset1 pisiform bone so scroll scaphoid lunate three cuatro triquetral pisiform now on the distal part this is the trapezius the trapezium first this is the trapezium this is the trapezoid right is the trapezoid and this is the capitate and this ball is the helmet bone so the distinguishing character let me remind you once again Loonette is moon-shaped the scaphoid has a tubercle on the lateral side the triquetra is a triangular shape little bit it is track patrol means having three angles you see and pisiform bone it is the smallest bone and this is the only bone which is articulated with the track which'll with one of the with a couple another couple bone and this one is the trapezium under the trapezium has a group for the insertion of the tendons of the flexor carpi radialis and this is the trapezoid which is the shape of the shoe of a baby and this is the capitate which is the biggest among all these eight carpal bones and it is the Hammad which is the wet shell.

So we finished the identification now I am going to give you a way how to remember these bones right from the lateral side so there is a well known many monix which sees she looks I am writing here she looks she looks here she looks too pretty try to catch her it is really something that is not to be done but is for convenience of remembrance she looks too pretty which stirred s scaphoid this one Loonette this one triquetra and at this one p pisiform and this D stands for trapezium so you should not confuse trapezoid and trapezium trapezium which is the figure trapezium trapezium so this is first and the trapeze joint means looks like this trapezium something like that so this T trapezium this is T chop trapezoid this C for capitate and ice for Hammett.

So you can easily remember that and one important thing here the articulation we have not discussed now the ossification of these bones is very very important so now I am writing this is the proximal this is the proximal and this is the distal so you can not forget if I write here 5 4 3 1 2 and right here I am writing here 5 5 2 3 now what do I mean by writing 5 4 3 1 2 mins 5 is for s that is the scaphoid bone it is ossified at the age of 5 years so you can forget that and L the lunate bone is ossified at the age of 4 years and T for the triquetral bone is ossified at the age of 3 years but this pc from one small one it is ossified at the age of 12 years you can find out that so it's very easy to remember five four three one two now for the distal part T for trapezium it is ossified at the age of five and a trapezoid the trapezium has the same year of ossification same age of ossification five five years and four capitate two years and four Hammet at the age of three years these are the age of ossification it's very important so but the articulation as you can see here or let us take an example for example this capitate bone with how many bones this bond is articulated.

We can see if we have a diagram in front then it's very easy to find out how many bones are being articulated with this particular bone so there are one two three four five six maybe so something like that you can count and altogether it's not a very difficult task for you to identify how many bones are

 surrounding a particular bone now there are important part of these couple bones when we talk about the attachments of the muscles it is also an important part so as we talk about the attachment attachment of these muscles all the attachments are to the four pillars this is very very important one two three four or maybe the extreme corners you see the extreme corners so for bony pillars one two three four what is four bony pillars old attachments are done right over this for the last four corners so number one the first corner I'm writing tubercle of the skip way so you can easily

 understand this tobacco of the scaphoid number to the pc forum right over here this one the PC form and number three the trapezium and number four the Hammond.

There are only two muscles I'm not writing these muscles because it will take a lot of time so on the tubercle of the scaphoid the flexor retinaculum or transverse carpal ligament is attached flexor retinaculum you see tubercle of the scaphoid so right over here tubercle of the scaphoid here the flexor retinaculum or the transverse carpal ligament is attached the medial side you see here and a few fibers of the abductor pollicis brevis abductor pollicis brevis you sleep abductor pollicis brevis right over here so a few fibers of the abductor pollicis brevis are also at it right over here and on the pisiform bone the flexor carpi arise.

This is the pisiform bone so the flexor carpi ulnaris coming right over here and it is inserted here you see and flexor retinaculum and it's superficial sleep flexor retinaculum on the lateral side here andand medial side in the middle side here flexor retinaculum is inserted and abductor digiti minimi this one abductor digiti minimi abductor digiti minimi this also inserted right over here abduction abduction

 this one this one abduction so here it is inserted right over here and extensor retinaculum extensor retinaculum right over here extensor retinaculum it is also inserted here the pisiform bone coming around here and on the pc from bone.

Okay monetary surface it is inserted right over here and want to trapezium the crest gives origin to the abductor pollicis brevis the crest you have a crest here trapezium abductor pollicis brevis right over here flexor pollicis brevis also and opponens pollicis so these all these three muscles constitute a thinner eminence Turner eminence means this one you can see this Turner a million muscles these three muscles all these muscles are ordinated from this crest of the trapezium and second the edges of the group give attachment to the two layers of the flexor retinaculum two layers of flexor retinaculum here right over here and number three the lateral surface this lateral surface it gives attachment to the lateral ligament of the wrist joint wrist joint lateral ligament there is a ligament passing right over here right over here and it gives attachment to this lateral ligament and number four mm this groove this GRU Lord just means hides the tendon it inserts the tendon of the flexor carpi radialis flexor carpi radialis right over here flexor carpi radialis this one flexing carpi radialis here it's inserted and lastly we are talking about under Hemet and the tip of the hook the tip of the hook gives the treatment to the flexor retinaculum this one flexor retinaculum starting from here flexor retinaculum right over here you set it and this medial side made your side of the habit of the who gives attachment to the flexor digiti minimi flexor digiti minimi this one flexor digiti minimi this flexor digiti minimi here right over here so flexion you can see fraction and the opponens digiti minimi opponens digiti minimi so these two muscles flexor digiti minimi and opponens digiti minimi are attached on the medial side of the hook of the hammond.

Well those bones that you see here are the carpal bones right away we should actually point out that these carpal bones consist of the oops not here but of the proximal row and the distal row okay now the proximal row of these carpal bones is created by scaphoid lunate triquetrum and the pisiform bone the distal row however is created by the heme eight the capitate trapezoid and trapezium bone the first bone that I should explain is the scaphoid bone over here the scaphoid bone articulates as you can see with the radius of the forearm this here articular surface is for the radius now the scaphoid bone articulates also with many other bones such as the lunate bone and you can see that clearly on this surface here this concave surface is made for the capitate bone the capitate bone articulates here and of course on the front if we pay attention.

We can see that the scaphoid bone articulates with the trapezium over here and then separated by this Ridge over here is the surface for the trapezoid bone we're done with explaining the scaphoid bone it's often said that the scaphoid looks like a boat but to me it doesn't look much like a boat however here we have the bone cold lunate I will explain why it's called lunate in a minute but first let's say that it articulates here with the triquetrum here it articulates with the hamate or here with the cavitate and it also has the articular surface for the scaphoid bone all right then it also articulates with the radius and normally there is a disc an articular disc or here which helps it articulate with the head of the ulna.

Now why is this bone called a lunate well if you actually look at this bone from this perspective you will notice that it resembles a moon sickle moon and actually this bone is called lunate because Aluna in Latin means the moon or the sickle moon the next bone that we will talk about is the triquetrum the triquetrum bone can be seen right here it articulates with the lunate bone that we just explained and it also has this circular surface for the articulation with the articular disc that articulates with the head of the ulna now you can see this flat articular surface here it articulates with a small pisiform bone beautiful flat surface and then of course you can see this large articular surface for the articulation with the hamate bone here is that articular surface this way we have explained the triquetrum as well the last bone in the proximal row is the pizza form bone the the forum dome can be seen here it articulates only with the triquetrum.

Now let us explain the distal row of these bones we have so far explained the proximal row and the proximal row creates this concavity for the articulation of these distal bones it also articulates with the ulna and the radius the distal row however articulates with the meta carpal bones and also as I just said with a proximal row of the carpus the first bone that I should explain from the distal row is actually the trapezium bone the trapezium bone articulates here with the scaphoid here with the trapezoid with the second metacarpal bone and the first metacarpal bone the smaller bone over here is actually the trapezoid bone articulating with the scaphoid as well trapezium the second metacarpal bone and our next bone the capitate the capitate is large it articulates with trapezoid is already explained scaphoid is already explained 1 8 10 8 and then it articulates for sure and all the time with the third metacarpal bone with the second metacarpal bone and sometimes if you pay attention it can articulate here also with the fourth metacarpal bone so we come now to this boat over here and that is the hamate bone the hamate bone has this hook and we will talk about some details on the carpus later after we explained the articulations the hamate bone articulates with the lunate potat fourth metacarpal bone fifth metacarpal bone and the triquetrum and that is the last bone that we will explain from the distal row we notice that there are some prominences and Toorak holes on these bones.

So here we have the typical of the scaphoid and here is the tubercle of the trapezium bone and here we have the hook of the hamate bone the so-called

 amulets.

Carpal (Wrist) bones  - Human Anatomy | 

There are 206 bones in the human skeletal system of those there are 27 wrist and hand bones each bone is extinct based on its shape and placement there are eight carpal bones on each hand two rows of four on each starting with the first metacarpal on the distal row is a scaffold then lunate triquetrum and pisiform which is right over soup here to the scaphoid is a trapezium then going laterally is a trapezoid capitate hamate in order to remember each bone and its position there is a mnemonic to help Sally left the party to take Kathy home the beginning letter of each word represents a single bone in order from the proximal row to the distal row this mnemonic translates to scaphoid lunate triquetrum pisiform trapezium trapezoid capitate and hamate we are looking at the carpal bones of the left hand the scaphoid bone is the largest from the proximal row and it is bow shaped the lunate has an oval like shape with an articulation with the capitate the triquetrum has a flat bottom facing laterally which articulates with the loonie but has a round top it also has an indentation in the middle portion in which the pisiform is placed the pisiform is the smallest bone and sometimes it is not seen on an x-ray on the distal row medially.

The first bone is a trapezium this bone has a saddle shape that comes in contact with the first metacarpal it is wider on the proximal part right on top of the thumb the trapezoid is a smallest bone on the distal row and has a simple round shape the bone right in the middle of the hand is the capitate which is a large bone with the C shape the last bone on the distal row is a Hemi which has a hammer-like shape Hemi means hook and has a hook on the Palmer side these eight bones are classified as short bones which means they have no medullary cavity cavity these eight carpal bones articulate with the radius and ulna of the forearm approximately the scaphoid and lunate articulate with the radius the scaphoid articulates on the styloid process of the radius the Hamid's and pisiform articulate with the ulna the pisiform articulates directly on the styloid process of the ulna distally these a carpal bones articulate with one through five metacarpals the trapezium articulates with the first metacarpal the trapezoid articulates with the second metacarpal the capitate articulates with the third metacarpal and the hamate articulates with the fourth and fifth metacarpal the carpal bones form synovial joints of different kinds gliding con delight and saddle the gliding joint forms between the carpal bones and allows for non axial or transitional movement the articulation between the radius with the scaphoid and lunate form a condyloid joint.

This is when a joint of one bone in a fossa or elliptical cavity of another condyloid joints are able to have angular movement in two directions back and forth and side to side the trapezium and first metacarpal form a saddle joint this is this type of joint is similar to the condyloid joint accepted saddle joints have saddle shaped bones the flexors and extensors of the forearms allow movement of the wrist in different directions the radius and ulna articulation with the carpal bones along with the muscles allow supination palm up and pronation of the palm when the radius and ulna are parallel to each other the carpal bone supinate as shown here the palm facing up when the radius rotates over the ulna then the carpal bones pronate palm facing down the most commonly injured carpal bone is the scaphoid this type of injury usually occurs when the bone is compressed against the radius during direct contact with the palm of the hand this occurs from a fall placing the hand first and putting bodies way over it.

Motorcyclists are the most vulnerable to a scaffold injury when going at full speed and losing balance they place their hand first when falling to the ground due to poor vascular supply to the proximal portion of the bone the healing process is a slow and difficult one a British manufacturer by the name of Knox patented the scaphoid protection system better known as SPS this is designed for motorcyclists to provide protection when falling and placing the hand first it consists of two low friction pads positioned on the palm of each glove developed to eliminate the grab effect SPS allows the hand to slide forward simultaneously with the wear as shown in this picture the hand slides wit with the person instead of placing all of the body's weight onto the hand do you remember when Sally left the party to take Kathy home scaphoid lunate triquetrum pisiform trapezium trapezoid capitate and hamate.