Anatomy, Lecture 2, Joints (Lecture Notes)

الرحيم الرحمن الله بسمIn the last lecture we start talking about joints and we said we have 3 types of

them based on the type of tissue that comes btw the bones

1-fibrous joints 2-cartigenous joints

3 -synovial joints

Synovial joints : they designed to allow 3 movements and we call it synovial bcz there is synovial membrane that separate the two bones and it is lining be synovial tissue which secret fluid for lubrication ;so the structure of the join it self allow it to do the 3 movements but the movements are affected by other

external factors (external to the joint not to the body) which are:

1-the shape of the bone

2 -adjacent anatomical structures like your thigh joint it's designed to allow 3 movements but the banding (amount of hyaline and how fit you are that limit the amount of joint flexibility

3-pressence of fibrous ligament

Now I'm going to talk about different types of synovial joints which have different degrees of freedoms regarding movements

1-plane joint: the bone are articulating with each other and have flat surface (sternoclavicular as an example) and we will cover that when we talk about the thoracic wall.

You see that the articulating bones are flat and as you see the bone are flat and there is no movement so we have what we call it (synovial membrane )

2 -Hinge joints: if you look at the door the joint btw the door and the wall is hinge one so it just allow 2 movements flexion and extension

By the joints we will talked about the one that found btw the 1st and 2ed cervical vertebra.

The vertebral column is made up of different vertebrae and usually name them by c1; c2; c3 etc as cervical bones and T1; T2; T3 for the thoracic one.But the first 2 have special names

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الرحيم الرحمن الله بسم1st =atlas 2end =axis Axis has process we call it( odontoid process) which articulate with a ring that’s made of bone structure which is part of the vertebra and ligament so together they make a ring which articulate with this process.

So which type of movement can this joint do? Only rotation.

The rest of the joints(condyloid ;ellipsoid saddle and ball-and-socket joints) each one of them has special categories that allow them to do special type of movement .

)DR said :I will leave this for you to study it from your text book(

Stability of joints: What do you think stability of joint mean?Articulating bones some times by accident or by aging they dislocate and fall.

The bones that were together they get separated so the resistant of the joint to this thing call (joints stability)and it depends on 3 factors:

1 -shape of the articulate surface : many joints the synovial one as an example we have convex and concave shape come together and here the deeper concave surface the more stable one.

For example the joint btw your thigh and your hip its very deep it looks like a ball and socket so its very stable joint if you compare it with the shoulder joint; for Example the socket is very shallow so we here a lot about shoulder dislocation more than hip dislocation.

2 -concave and convex depth ; that’s mean when they were deep they could be more stable than if they were shallow and good example of that is the hip and shoulder joints.

The ligament:

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الرحيم الرحمن الله بسم)b (is across section where a long joint and its limited the movement in extension

and lateral movement not by the structure of the joint but by the ligament that articulating bones together (go to slid nom 14 to see the picture ).

For example the medial collateral ligament prevent the adduction and abduction of the joint.

So in athletes some times they get dislocated of ligament so it will be separated from bones.

Another factor that determent the stability of the joint is the muscle tension; do you know what do we mean by muscle tension?

Muscles in our body no mutter how relaxation they will be stretched longer and could contract to be shorter. M.T is the minimal degree of contraction that presence in this muscle.

And it help ligaments to do there job bcz ligaments help stabilizing of joints for example look at the joint in metatarsals and dorsal.

Our feet isn’t flat they make an arch and this arch is made by this articulated bones and this arch is holed by ligament and excessive stress to this ligament can lead to lose there structure and arrangement in your feet .so what help this ligament is the M.T for example the previous ligament there must be kind of minimal contraction to help in keeping the arch in this way.

Nerve supply to the joint: Almost every part of our body receive innervations and innervations mean the presence of nerve that connect this structure to the CNS.

Hilton's law: Sensory nerve supply a joint also supplied the muscle moving the joint and the skin overlying the insertion of these muscles.

Do nerve receive motor innervations?No ; bcz it comes to the muscle that are around the muscle joint ;the CNS need to know what happened in the joint that is why we have sensory fibers collecting

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الرحيم الرحمن الله بسمinformation about the joint from the skin around the joint to know a bout the degree of movement.

Ligament:

robe like ;connective tissue they can be made of collagen or elastic fiber and the degree of elastic and collagen presence determent the stretch ability of the ligament and that mean the ligament can stretched and return back to its original size that mean it have a lot of elastic fiber.

And joint like ( I Didn't hear it carefully) in the knee it didn't need to be stretchable so it made of collagen.

We have other structure in our bodies called bursa which mean :a sac made manly of C.T and its lubricating device that’s found in area of fraction like( bone ;tendons; joints and skin) rub against each other

One good example is what we see in the knee joint

This is a sagittal view of the knee joint(go to slid nom 14) this is the patella ;femoral articulating with the tibia as you notice here where the muscle or the ligament of the quadriceps femur muscle rubs against bone we have a sac like structure and we call it the supra patella bursa ;where the patella rubs against skin for example we have pre patella bursa.

And btw the tendons and the bone we have bursa and btw tendons and skin we have bursa …….etc so bursa is a sac of connective tissue contain fluid to relives fraction On other terms called synovial sheath if the bursa takes tubercular shape why?To cover tubercular structure like when we have tendons.

In this picture(also go to slid nom 14) the bursa which is usually circular its invagente around the tendons and cover like a tube ; still it is boned of 2 layers (there is a close space btw the 2 layers filled with fluid we call it special type of bursa synovial sheath and of course it doesn't rubs completely around the ligament bcz it should allow arteries and innervations to take place so there area

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الرحيم الرحمن الله بسمor (neuron muscular ) bundle and the bundle of the tendons we call it messo tendons.

Cardio vascular system (CVS):

We will take about it in depth when we talk about the thoracic cavity and this thing you know it from high school.

Arteries and veins:

How could we defined arteries?

It is a vessel that carry blood away of heart some are oxygenated and some are deoxygenated.

Veins :carry blood to the heart some are oxygen and some carry the deoxygenated one.

And when the terminals of arteries (arterioles) and terminal of veins (venules ) met together we call it (capillary).

When the blood moved from arteries to veins throw capillary it came direct to the heart except in the portal hepatic system

Look at this picture(go to slid nom 16) ;the veins that collect blood from GIT in general it doesn’t takes blood to the heart immediately NO it goes to the liver where detoxification of nutrias that we need it for activities take place in the liver and again when it goes through the liver ; the liver has special structure of capillary called "sinusoids'' they are thin in wall but have larger and irregular diameter; they can be confused with open circulation when we don’t have vessels ; when the blood just go through the organ and we just found it in some lower animal ; so they are vessels but they look like open circulation.

When we talked about the venous system in the liver it is :Capillary system that comes btw 2 capillaries bud in the GIT

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الرحيم الرحمن الله بسمBud mean net work.

CVS:

We will cover the details about the valves arteries in the thoracic wall.

Most of the time terminal branches of the arteries (arterioles) they don’t travel alone they make anastomosis which means complex o branches (see picture) and if the anastomosis happened immediately btw arteries and veins we call it (arteriovenous anastomosis) and as we said before the met of arteries and veins except in some locations in our bodies like the tips of our fingers bcz the veins and arteries are so thin in order o met the circulation we don’t have capillary so immediately veins join to arteries .

What forces take the blood back to the heart?

Heart is pump it could pump the blood throw the arterial system but once it reach the capillaries the pressure is not that high so what forces take the blood back to the heart?

1-some smooth muscle and skeletal muscle contribute to that but most important feature of the venous system is the valves (it doesn’t found in the arterial system )

Valves make sure that blood flow is unidirectional so once the blood goes up it can't go down bcz the valves will be closed

** terminology ;anatomical and the function of arteries is not much important to know .

Lymphatic system :

All what you have to know about the lymphatic system is in the slid Lymphatic system consist of :

1- Lymphatic tissue :tonsils; spleen and thymus 'They made of C.T'

2- Lymphatic vessels

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الرحيم الرحمن الله بسم

3- The lymph

Look to the picture (radiograph slid nom 17) they called the lymph fluid and take it back to the venous system and they have plenty of valves bcz they are part of the venous system .**No pump to pump fluid inside them they use smooth muscle and skeletal muscle in contraction .

Lymph :

Type of fluid that accumulated inside the tissue space when it enter the lymphatic vessels we call it the lymph so the lymphatic system function is :

1- Help the CVS to carry fluid from tissue space to the venous system .

Where does the fluid come from?

Throw capillary bade there is exchange for everything ex:RBC;large protein ; the amount of fluid that exit the arterial side of the capillary is not equal to the amount of fluid that enter the venous system .

The difference is accumulated so we can loss some of our blood volume .

So the lymphatic system take the fluid and put it in the venous system and before doing that the fluid should pass at least throw one lymph node to filtrate that fluid and vessels that enter the nod we call it (afferent) and those vessels who leave the nod we call it (efferent)

Part(D): lymph vessels(go to slid nom 17) are very confused net work of vessels to collect fluid and they may go to one of the main trunks one is called 1- the thoracic duct 2- right thoracic duct .

So all the lymphatic vessels in our body they should go to one of the ducts in our bodies .

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الرحيم الرحمن الله بسمThe thoracic duct is responsible for the lift 75% of the body and the lower limbs and abdomen .

The right duct is responsible for the upper right quadrant .

Branches called lumber trunks that carried fluid from lumber area and lower limbs they come together in structure called 'cicterna chili ' which get origin to the thoracic duct .

And at what side of circulation do the right side of the thoracic duct and the terminal duct empty the fluid ?In the venous side at the root of the neck.

Skeletal system (S.S):

S.S is made of bone which is a C.T and when you hear C.T that mean we have cell ;fibers and extra cellular matrix (ECM) and depending of the properties of the ECM and presence of cell type .

C.T have different names (bone ;cartilage and others).

What special of bone is that the ECM is calcified (very rigid) if you take a cross section of any bone in our bodies you will notice that the outer layer is so rigid and hard bcz it made of compact bone .

If you look at this side the bone it made of like trubiculate which isn’t rigid as the outer layer .

(S.S ) function :

1- protection :skull to protect brain ;chest to protect lung And heart and the presence of muscle in our limbs to increase the force of our muscle .

2- Calcium storage : the dominant calcium store in our body is our bone and hematopoietic (RBC formation) and it happen in the bone marrow inside bones .

The skeletal system is divided to 2 parts :

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1-axial(skull vertebral column and the thoracic )

2- appendicular (upper and lower limbs +pectoral and pelvic girdles )

Gravel : some bones that connect the limb to the body .

And gravel for the upper limb is made of the scapula and clavicle and for the lower limb is made of the hip bone .

Surface marking :

If you take any bone it might be smooth for babies but when we reach puberty it will be more rigid and deviation take place depending on what attached to the bone bcz (tendons and ligament ) will not stick to the muscle surface so we need rough surface .

We don’t have to memorize the table in your text book but you should know the main categories Some bone aren’t smooth and have different thing in surface .

Bone are classified be region like maxillofacial bone and thoracic bone …etc ;and you have a table in your text book.

All bones can be classified according to their shape (long bone as the humerus bone in your arm ).Long bone is composed of long part called oliphesis (I didn’t hear carefully ) and just before the knee we call it epiphesis and during puberty growth this area called it epiphesial plate.

And when we talked about cartilage we said that they divided to primary and secondary and primary happen in long bone .

During growth long bones have high part of cartilage that made converting hyaline cell to bone cell so elongation of the bone will occur .

So we have long bone ; short bone (carpal bones in the wrist ; flat bone like sternum ; they composed of 2 parts o compact bone and there is a very thin wall of tubercle wall in-between.

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And any bone doesn’t fit any of this categories we call it irregular bone like (skull ;vertebral and hip bone ).

The special type of bone we call it the sasamoid bone ;they are not responsible of our skeletal ;the only example of that in our bodies ( patella) .

If you make an x-ray for your finger each one of us have different nodular along the axis that called sasamoid bone and as I said before we have a tendons that bcz of stress there .

Cartilage : C.T ;cells fibers and jelly like material and according the jell like matrix we have hyaline ;fibro cartilage and elastic .

Hyaline is very resistant so most of our articulators surfaces in our body ;joints are covered by layer of cartilage .

Fibro cartilage : disc btw joints(knee join) is one of them The bones don’t met together that mean there is a disc to give them a mechanical puberty .

Elastic : is found in specific areas and limited areas (auricle ;epigastric and oudotary tube).

Membranes : lining of our body if the lining is made of epithelial tissue and open to exterior (like the lining of our mouth ) we call mucus membrane .So usually it is a layer of epithelium that supported by layer of C.T called (basal lamina) and some time smooth muscle we call it muscularies .

If the membrane is closed it is sac like structure we call it either serous of synovial.

Serous:Lining by mesothelial (not by C.T)synovial made of C.T and we talked about that when we talked about the synovial fluid btw joints .

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الرحيم الرحمن الله بسمSerous like lungs (the pink tissue is supported by membrane of 2 layer and if you notice that the membrane is closed its not open at either sides .

The layer of the membrane that attached to the organ we call it the visceral layer and the outer layer we call it the partial side which is supported by somatic nerves and the visceral by autonomic nerves So the plural membrane is example of serous membrane.

The end...........................وأخيرا

ما متل يكون يارب بس هالوقت كل مني يوخد التفريغ أن ماتوقعت بصراحةو ساعدتني ما المادة بس سهلة بطريقة المحاضرة افرغ حاولت ألني بدكم

رب بعد من لوالهم الن بقطر أهلي بالكون أهل ألحلى التفريغ بهدي بالنهايةلهون بوصل ماكنت .العالمين

( ) في ورفيقتي اخوي حمودة القضاة محمد وأولهم تحيةاللدفعة أحلى وأكيدهديل األول !!!!الجهاد

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