 arms and legs are our appendages. So the arm and the leg, these are appendages. So the bones that make up these appendages is called appendicular skeleton. So all of these bones, the arms, the legs and the bones that connect them with the rest of the skeleton is called the appendicular skeleton. So in this video that's what we are going to look at. You and I together we will explore how the different bones make up the appendicular skeleton and what they are called. So these are the arm bones and these are the leg bones and there are quite a few parallels between these two. So that's why I've kept them side by side and we will make comparisons as we go along. So these are the arm bones and this thing over here it connects the arm bones with the axial skeleton. You might remember from our previous video that the axial skeleton consists of all the bones that is close to the long axis of our body. So these bones include the rib cage, the vertebrae, the skull etc. So this part here it's called the pectoral girdle. So this is the pectoral girdle. The pectoral girdle consists of two bones. This one, the long one right here it's the collar bone and the scientific name for it is the clavicle. And the triangular bone over here this is present on the back on the dorsal side and is called the scapula. The English term for it, the common English term for it is the shoulder blade. The parallel of the pectoral girdle for the leg is the pelvic girdle. So this right here is the pelvic girdle. The word pelvic refers to a basin. It originally means a basin. So the pelvic girdle on both sides the right and the left they form a basin like hollow space inside our body and hence the name pelvic. Whereas pectoral means chest and this is very close to the chest hence the name. So just as the pectoral girdle connects the arm with the axial skeleton similarly the pelvic girdle connects the leg with the axial skeleton. And what is the bone that the pelvic girdle is made of? It's called the hip bone or the coxial bone. The hip bone is made up of three bones which are fused from the hip bone. We will see shortly the more details of that. Now let's come to the arm. So this is the bone of the upper arm and is called the humerus and similar to that our leg has the femur. So that's the thigh bone. Then in the forearm we have these two bones radius and ulna. So this is radius and this is ulna. Now you can ask me how can you tell between radius and ulna? So remember the radius bone always is on the side where the thumb is whereas ulna is on the opposite side. Similar to radius and ulna the portion below the knee has two bones so this is tibia and this is the fibula. Again the same question how do you know which is the tibia and which is the fibula? So I remember when I was in 11th grade my teacher told me that the bone that looks more feeble so this is thin and feeble compared to this bone. That feeble bone is fibula. Now there is an extra bone over here in the leg which is not there in the arm which is this rounded bone over here and it's the kneecap called the patella. There is no such bone in the arm. Now let's come to the hand and the foot. Again the bones that are there are very similar so the bones that are there in the wrist are called carpals and there are eight of them and the bones that are there in the heel they are called tarsals. Sound very similar carpals and tarsals. Tarsals are seven though one less than the carpals. Then the palm. The palm is made up of these bones which are the metacarpals. So the bones right next to the carpals are the metacarpals and there are five of them five four for each finger and then one for the thumb so five metacarpals and then corresponding to metacarpals we have metatarsals in the foot so metatarsals again there are five of them so in the hand after the palm we have the fingers right. So the fingers are made up of these little bones called phalanges so each of these bones are phalanges. How many of them are there? So each finger has three phalanges and the thumb has two phalanges so four fingers times three twelve plus two fourteen so there are fourteen phalanges and the corresponding bones in the foot are called the same phalanges again and once again there are fourteen of them. So these were all the bones in the arms and the legs. Now let's look more closely at the pectoral girdle and the pelvic girdle. So first the pectoral girdle so this is the collar bone or the capicle so this is the collar bone and the collar bone is connected to the scapula the triangular bone and this part of the scapula is the one that connects through a joint to the collar bone as you can see and this is called the acromion. Then you see this curved edge of the scapula this is called the glenoid cavity. This is where the end of the humerus the upper arm bone fits. Now let's move on to the pelvic girdle the details of it. So as I told you earlier the pelvic girdle has only one bone on each side so this whole bone this is called the hip bone or the coxal bone. The hip bone originally had three bones which got fused it has three parts to it which are actually fused to each other so this part here this is called the ilium then this part here the second part is the ischium and the smallest one right here at the end is the pubis. The two hip bones on either side they join over here through a cartilage and this cartilage is called pubic symphysis. Just like the glenoid cavity in the pectoral girdle there is a depression in the pelvic girdle into which the head of the femur fits. So this depression is called the acetabulum. To summarize the appendicular skeleton consists of the arm bones the leg bones the pectoral girdle and the pelvic girdle. The pectoral girdle has the collar bone or the clavicle the scapula then the scapula has this part called the acromion which connects to the collar bone. There is this glenoid cavity at the end of the scapula which connects to the top of the humerus this is the humerus the upper arm bone then there is the radius on the forearm on the side of the thumb the ulna the other bone on the forearm then the wrist bones are the carpals the palm bones are the metacarpals the finger bones are the phalanges then in the pelvic girdle we have the hip bone and two hip bones are joined by the pubic symphysis then in the leg we have the femur the thigh bone the kneecap the patella the tibia the stronger bone in the lower leg and fibula the weaker bone then the ankle has tarsals the sole has metatarsals and the fingers of the feet have phalanges