Skeletal structure and function | Muscular-skeletal system physiology | NCLEX-RN | Khan Academy

Skeletal structure and function | Muscular-skeletal system physiology | NCLEX-RN | Khan Academy

So in this video we’re going to be
talking about skeletal structure and then the function
of those skeletons and specifically human skeletons is what we’re interested
in but before we talk about human skeletons
let’s talk about bug skeletons or the skeletons of arthropods are insects and so I’m going to draw a little
ladybug here and our little ladybug being an arthropod has what is called an
exoskeleton and the XO and XO skeleton actually first the fact that this
skeleton is outside of the ladybug so “exo” is actually Greek for outside or
external humans on the other hand we are vertebrates and as vertebrates we have
this amazing network of bones located on the interior of our bodies and so we
have what are called endo skeletons and endo is greek for within or inner
referring to the location of the skeleton is being inside of our bodies
as opposed to outside now as humans our endoskeleton performs a variety of
pretty vital functions the first of which is it supports our
body and provides a framework for movement so what does this mean are our body is
supported by the network of our bones which allows us to sit up and stand and
provide some sort of structure for our body and then the limbs of our body in
particular and various joints in our body provide a framework for movement
that allows you to run around to kick a soccer ball to type on a keyboard another important function of our
skeleton is that it protects our most vital organs so if you look at the skull for example
it houses our brain and the ribcage it protects our heart and lungs and other
organs and the third function of our skeleton is is that it performs a variety of
physiological roles in our body namely the storage of calcium and what is
called hematopoeisis, which is the production of all the cellular
components within our blood so our blood is made up of many
different components plasma proteins among other things and the cellular
components of our blood which are red blood cells white blood cells and
platelets are all formed within the bone marrow of my bones and so those are the
main functions of the bones that form our skeleton now one way of classifying bones is
differentiating between those that form the axial skeleton and then those that
form the appendicular skeleton now the axial skeleton is made up of our
skull and ribcage and our vertebral column that is the axial skeleton it
forms sort of the axis of our body right right in the center down the midline and
then the bones of the forelimbs and our pelvis form what is called the
appendicular skeleton and so go are four appendages form the
appendicular skeleton which is attached to our central or axial skeleton another
classification system for the bones in our skeleton is the difference between
flat bones and long bones now what are flat bones some examples of
flat bones are the bones that make up your skull the different bones that make up your
ribs and then also the bones in your pelvis and so flat bones really are
describing the shape of the bone these bones are made up of an inner
spongy or cancellous bone and then the outer shell is made up of compact bone there’s an inner spongy cancellous bone
in an outer shell of compact bone and flat bone serve primarily to protect our
organs and serve as a site for him at 0 police’s now long bones on the other
hand some examples of those would be the humerus in your upper arm or say the
femur and your lower leg and if I draw a long bone out here there are a few different terms to be
familiar with when you’re referring to different parts of the long bone the
long middle portion of a long bone is called the diathesis and then the end of
a long bone is called the APIs and there is the small area of bone in between the
two are in the middle of the diathesis and the purposes is called the
metaphysis and the metathesis contains the growth plate which is present in the long bones of children and these
long bones are made up of the same inner spongy cancellous bone with an outer
shell of compact bone just like flat bones and these long bones really are
the ones that provide a framework for movement like we talked about before and they also serve as a side of hematopoiesis. And speaking of hematopoiesi,
where exactly does this Hematopoiesis occur? I mentioned that it occurs in bone
marrow which is contained within bones and there are two different types of
bone marrow there is what is called red bone marrow
and then yellow bone marrow now red bone marrow serves as the
primary site for hematopoiesis, which makes sense because the red blood cells
from hematopoiesis actually make red bone marrow look red to the naked eye so you can remember that red bone
marrows for blood or hematopoiesis and you can typically find red bone
marrow within flat bones and then in the epiphyses of long bones. And then yellow
bone marrow on the other hand is primarily a site for fat storage made up
of fat cells called adipocytes and generally you can find yellow bone
marrow within the diocese of long bones

16 Replies to “Skeletal structure and function | Muscular-skeletal system physiology | NCLEX-RN | Khan Academy”

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