9 Articulations - Lecture notes Chapter 9 Joints PDF

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Summary

A detailed description of various types of joints, movement, and types of Articulations.
Teacher Dr. Neiswenter ...

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Chapter 9 Joints you have different types of joints characterized under two categories 1. structure 2. function

structure------------1. referring to the composition of the joint 2. whether it had a space in between such as a synovial cavity

function--------------the degree of movement of the joint

structure------------composition bony--------synestosis 1. fibrous joints-----------composed of dense irregular connective tissue, no synovial joint, rich in collagen fibers 3 fibrous joiints (sutures, syndesmosomes (gomphosis), interosseous membrane) 2. cartilaginous joint------------------composed of cartilage, also has no synovial joint 2 types, synchondroses and symphyses 3. synovial joints------------has a space in between the joint, makes up a synovial joint, and united by dense irregular connective tissue

function 1. synarthrosis------------an immovable joint 2. amphiarthrosis---------slightly moveable 3. diarthrosis-----------freely moveable joint, also has a synovial joint

Fibrous joints question-------------what kind of joint would form between the sutures in the head? Answer------------------they are synarthrosis, in other words they dont move, however, that doesnt always apply. for instance, baby sutures can still slightly move amphiarthrosis.

question----------what is another name for synarthrosis? Answer------------synosis synostosis--------------a hardened ossified suture, as seen in adults, in other words, a bony suture is synarthrosis

syndesmoses syndesmoses------band or ligament in which there is a greater distance between the articulating surface and more dense irregular connective tissue than in a suture in other words, there is a larger distance between the articulation points, as a result, you have a ligament that attaches to form an articulation that creates slight movement

Ex----------the anterior distal tibiofibular ligament

here you have an example of a syndesmoses, note that at the most distal end you have a long ligament creating an articulation point, because of this ligament, the articulation can slightly move, if there is slight movement, it is amphiarthrosis, remember the space aspect of syndesmoses, so space is very important

here the ligament (anterior tibiofibular ligament) connects the tibia and fibula

here is an example of another joint which uses dense fibrous connective tissue, its a fibrous joint gomphosis---------is a joint between the bony inversion of the maxila and a tooth. this is seen in the roots and teeth, it should be synarhrosis note------------there is a tiny membrane that lines the socket of alveolar process, this is called the periodontal ligament

note-----------this joint is synarthrosis, meaning that it doesnt move

so here you have a band of interosseous membranes

is a type of membrane that is found in between neighboring long bones copmposed of dense irregular connective tissue, it beings neighboring long bones and allows for some slight movement, in other words it is amphiarthrosis

notice---------your tibia and your fibula being held by two types of joints, one is the syndesmosomes, and interosseous membrane joint, both allow for some form of amphiarthrosis

Question-------------what is the commonality between the fibrous joints, and cartilogenous joints? Answer-----------they are the same in the sense that they have one thing in common and one thing with commonality. the first being is that they contain dense irregular connective tissue, the second is that there is no space in between each joint, they are highly packed together.

cartilaginous joint two types here 1. synchondrosis------------------------is a type of joint in which the joint is held together by hyaline cartilage, an example of this is in the epiphyseal growth plate note-------------joints with a synchondronsis are synarthrosis, for instance, when you have reached maturity and have ceased to grow anymore, the epiphyseeal plate will stop eventually become bony, in other words, synostosis which is a form of synarthrosis 2. symphyses-------------------------is a type of joint in which the ends of the articulating bones are connected by a flat disc of fibrocartilage.

note-----------these types of joints are primarily found in the middle of articulations case in point, the pubic symphisis, which hold the bone from the anterior, a symphisis is slightly moveable so it is amphiarthrosis

synovial joints question----------------Although this pertains to a joint that is fibrous, what is the difference between the fibrous joints and cartilage joints? Answer----------the difference between the other 2 compared to joints from the synovial joints is that it has a space called a synovial cavity also called joint cavity between the articulating bones question----------what is the type of functional classification of a synovial joint? Answer-----diarthroses, note that all synovial joints are free moving, that is why it is diarthrosis

note---------in between a synovial joint, you have different components, the first component is that synovial joints are covered by a layer of hyaline cartilage called articular cartilage. the articular cartilage covers the articulating component of the joint, this allows the area to be smooth and slipery, and reduce overall frication. note that the articular cartilage does not bind the joint together

articular capsule articular capsule---------also called a joint capsule, is a capsule that holds the joint together, and encapulates the actual synovial joint. question-------------what is the composition of the articular capsule/joint capsule?

Answer--------------it is composed of two parts, an outer component made of dense irregular connective tissue, mostly collagen, and an inner and an inner synovial membrane. ligament------------is connective tissue that holds two bones together, typically by a type of connective tissue such as dense regular connective tissue and dense irregular connective tissue, ligament is the fibrous connective tissue that connects bones to other bones and is also known as articular ligament, articular larua,[1] fibrous ligament, or true ligament. capsule-------dense regular ligament----------dense irregular question------------what is the ligament a continuation of? Answer-----------it is usually a continuation of the periostium synovial membrane---------composed of areolar connective tissue with elastic fibers articular fat pads-------------is the presence of adipose tissue which can be found in the synovial joint question--------------what does it mean to be double jointed? Answer--------------double jointed simply means that there is instability between the joint, the result is that the person is more flexible, but is also more susceptible to dislocating bones

synovial fluid synovial fluid---------------------is a viscous fluid that lubricates the joint

note----------synovial membrane, and the joint capsule

in addition, you have an outer capsule, this capsule will make the ligament

synovial fluid-----------produced by synovial cells in the synovial membrane and interstitial fluid that is fitered from the blood plasma, note that it also supplies oxygen and removes waste from the chondrocytes. note that chondrocytes are avascular, synovial fluid also contains phagocytic cells to remove debri from the area

question-------------why do our knuckles crack? answer-----------when your synovial joints are more open, the space in between the joint increases, this increase in space creates a suction effect, which draws CO2 and O2, when the synovial joint gets small, the pressure increases, and bursts the bubbles that form during the initial suction.

Accessory ligaments, artiuclar discs and labra some or many synovial joints have accessory ligaments outside of the synovial space

accessory ligaments----------ligaments found

accessory ligaments can be found in two forms 1. extracapsular ligaments 2. intracapsular ligaments

extracapsular ligaments-----------------lie outside the articular capsule, ex include fibular and tibial collateral ligaments of the knee joint

here you can see the tibial (medial) collateral ligament

on the left you can see the fibial (lateral) collateral ligament

intracapsular ligament---------occur within the articular capsule, but excluded from the actual synovial joint

ex-----------posterior and anterior cruciate ligaments of the knee

on the posterior side, you can see the posterior cruciate ligament, again part of the inside

towards the anteriro part, you can see the anterior cruciate ligament

articular discs/ menisci-----------lie between articular surfaces of the bones, made of fibrocartilage, and lie between the articular surfaces of the bones

note-----------look at the anterior and posterior cruciate ligament, notice that if one is standing up, the anterior ligament is more taut, when sitting down, the posterior ligament is taut

note that the meniscus binds tightly to the inside of the fibrous membrane and usually subdivide the synovial cavity into two spaces note here------------the synovial joint is separate from the meniscus section question------------what is the purpose of the meniscus?

Answer-------------shock absorption, better fit between articulating body surfaces 3) produce adaptable surfaces for combined movements 4) weight distribution over a greater surface area 5) distribution of synovial lubricant across the articular surfaces of the joint labrum-----------found in ball and socket joints, it is a fibrous lip composed of fibrocartilage that extends from the edge of the joint, this allows to deepen the pocket of the joint and increase the area of contact between the socket and the ball like surface

here in this picture, the outer area is known as the labral, notice that it forms a lip for better attachment

glenoid labrum

Nerve and blood supply note-----------in the synovial joints, you do have an inervation of nerves distributed to the articular capsule and associated ligaments question------------what might be the purpose of these nerves? Answer-----------pain perception and to detect degree of movement when you stretch, this can be an example of when you have an automatic reflex Question------------does the articular joint have any blood vessels?

Answer----------no, they are avascular, however, they do get their nutrients from the peripherey, arteries in the vicinity send out numerous branches that penetrate the ligaments and articular capsule to deliver oxygen and nutreints

just another picture showing all the parts of the joint, including the actual synovial capsule and ligament, and the accessory ligaments associated

some arteries and capillaries shown around that area

Question----------how do nutrients and wastes circulate around the synovial joint?

Answer-----------most of if has to do with indirect contact, for instance, chondrocytes get nutrients from synovial fluid derived from blood , waste is produced by chondrocytes, which then pass from the chrondrocytes, into veins note-------------this occurs at the synovial joints only, in other joints carbon dioxide into veins directly, without the use of synovial fluid as a medium to the blood

bursae and tendon sheaths bursae------------found in the shoulder and knee joints and placed strategically in places in order to reduce friction, they arent part of the synovial joint note----------they do have a composition, they consist of an outer fibrous membrane of thin dense connective tissue lined by a synovial membrane, they are also filled with a viscous fluid similar to synovial fluid

tendon sheath-----------similar to the bursa, they comonly found in areas where there is alot of friction, there is alot of friction because these tendons pass through tunnels of connective tissue, therefore these sheaths create two structures, a visceral layer, which attaches to the tendon and a parietal layer, which attaches to a bone, between the synovial layer is filled with fluid note---------tendon sheaths are essentially bursa in a tube like structure where the tendon passes through to not make alot of contact with the connective tissue in its surroundings

types of movements at synovial joints

movements of synovial joints are grouped into 4 categories 1. gliding 2. angular movement 3. rotation 4 special movement

gliding-----------can occur in the intercarpals and intertarsals question----------------what is the range of motion of these joints answer-------------the motion is limited to side to side, back to front and rotation ass seen in these pictures,

note that the motion is limited because of the articular capsules and associated ligaments

Angular movements

the point of these movements is to increase or decrease the angle of each movement flexion---------characterized by a decrease in angle extension-----------characterized by an increase in angle, designed to support the movement back to the anatomical position, movement across the same plane, i.e sagittal plane lateral flexion---------is a different type of flexion in the sense that it doesnt occur in the sagital line, this occurs at the frontal/coronal plane, this involves a movement of left and right from the side hyperextension-----------------extension beyond the anatomical position , some of the hyper extension movements cannot happen do ligaments and the anatomical alignment of the bones abduction (radial deviation)--------movement of the bone away from the midline adduction (ulnar deviation) -------movement toward the midline note-------------abduction and aduction occur in the same plane, that is, the frontal plane

circumduction Question-------------what movement moves the body toward the anatomical position at the frontal plane? Answer--------------aduction, since it moves toward the center of the line

question------------what is used to determine if something is abducted or aducted in a thumb? Answer--------imaginary line drawn through the longitudinal axis of the middle longest finger and the fingers move away from the middle circumduction---------is the movement of the most distal end in a circle manner, it is a continuous sequence of flexion, abduction, extension, adduction and rotation of the joint note--------------this is found in the shoulder, leg, and fingers note-------------circumduction is not as profound in the hip joints

rotation

rotation--------is a type of movement that occurs at its longitudinal plane, only two components can perform this type of movement, the first being movement of the head, and of the spine while staying in the anatomical position

an example of a type of rotation medial internal rotation------------movement of limbs relative to the midline lateral rotation-------movement of limb relative to the lateral part of the body note---------always take into consideration the anatoimcl postion

summary of these types of movement flexion and extension---------------occur at the sagital line abduction and adduction-----------towards the frontal plane

special movements special movements-------------occur only at certain joints elevation-----------superior movement involving closing of the mouth at the temporomandibular joint or shruging your shoulder depression-------------inferior movement involving, ex includes opening the mouth protraction------------ex includes moving the mandible forward, so that the mandible is slightly more anterior than the maxilla question--------------in what plane does the protraction occur?

Answer-------transverse, moving to the anterior side retraction-----------ex, moving your mandinble back, retracting it, moving posteriorly at a tranverse plane inversion----------------is the movement of the sole medially at the intertarsal joints eversion-----------------is the opposing movement of inversion dorsiflexion------------------being of the foot at the ankle or talocrurual joint in the dicretion of the dursom superior surface, movement where you stand on your heels

plantar flexion-----------involves bending of the foot at the ankle joint in the direction of the plantar or inferior surface, ex standing on your toes

Types of Synovial Joints note---------synovial joints can be divided into 6 categories based on type of movement 1. plane 2. hinge 3. pivot 4. condyloid 5. saddle 6. ball and socket Question--------------are all synovial joints triaxial? Answer---------------no, theres many types of synovial joints

plane joint

permits back and forth, and side to side movements between flat surfaces, you can also have some rotation, question------what type of movements can you have? Answer------------gliding, sliding, typically found in the wrist and ankles Biaxial joints allow movements in two planes. These joints may be of several different

types. The wrist is a good example of a biaxial joint. It allows movement of the hand from side to side (adduction and abduction), and forward and backward (flexion and extension). It is easy to confuse a biaxial joint with a multiaxial joint because if you combine the two movements in sequence the joint appears to be rotating in all planes. Another biaxial joint is found at the base of the thumb. Manipulate your thumb and try to determine in which two planes it can actually move. Again, it is easy to confuse this joint with a multiaxial joint

Multiaxial joints allow movement in any plane. Unlike biaxial joints, rotation may take place at these joints. The shoulder is a good example of a multiaxial joint which allows true rotation. Which joint in your leg do you think is a multiaxial joint?

Hinge Points (gynglymus)

question---------what kind of movement does a hinge form?

answer--------------the movement that is produced is an angular movement, such as flexion and extension

note the convex surface

question--------what is another name for a hinge joint? Answer----------gynglymus joints

pivot points (trochoid) type of uniaxial movement in pivot joints the axis of a convex articular surface is parallel with the longitudinal axis of the bone

ex----------atlas articulating with the axis, atlas rotates around the axis and permits head movement ex------radioulnar joint, allows the palms to turn anteriorly and posteriorly as the head of the raidous pivots around its long axis in the radial notch of the ulna

note--------the anular ligament surrounds the head of the radious, and pivots on the radial notch of the ulna

note----------the in this picture, this is an example of the radious, which attaches to a convex articular joint (radial notch) and pivots in a uniaxial movement to turn the ulnar radial joint and make the palms move anteriorly and posteriorly

question--------what is another name for a pivot joint? Answer--------throchoid joint

Condyloid joints (ellipsoidal) example of a condyloid, it is considered biaxial, in these types, you can have movement such as flexion, extension, abduction, and adduction and to a certain degree, circumduction found in radiocarpal wrists, metacarpophaangeal joints

note that the Condyloid (ellipsoidal) joints have a oval convex surface in an oval concave depression and are biaxial this is why you cant have a full circumduction movement question---------what is another name for a codyloid joint? Answer------------ellipsoidal

saddle joints (sellar)

note-----------saddle joints are similar to condyloid joints in the sense that they are biaxial, when you have a biaxial joint, you can have two ty...