Legs

Question 1

what bones form the acetabulum?

Answer 1

If we look at the acetabulum, we see that it is formed by each of the three bones of the coccyx, the ilium, ischium, and pubis.

Question 2

inversion

Answer 2

big to in air

Question 3

“unhappy triad” injury

Answer 3

damage to medial collateral, medial meniscus, and ACL

The force is being applied to the leg from the lateral side. This leg is firmly planted

(player’s right leg) while the other leg is in the air so all the weight is on this leg

(player’s right leg).

•Somebody or something crashes into the lateral side of the joint and the damage

happens on the medial side.

•So the medial collateral ligament is going to be yanked out of place and tears. It will

pull the medial meniscus with it which is also going to be damaged, and the ACL will

tear as well.

•This is one of the nastiest sports injury, creating a lot of damage. The thing to know is

that even though the damage is on the medial side, the force is coming at you from the

lateral side.

Question 4

pes anserinus

Answer 4

semitendinosis

gracilis tendon

sartorius tendon

*tendon from eac compartment attaches

Question 5

ligaments of the hip joint

Answer 5

. Each of the coccyl bones gives rise to one of these ligaments: pubofemoral, illiofemoral, ischiofemoral ligaments. Of those three, the iliofemoral ligament is the strongest ligament we have in the body: it’s Y-shaped and it prevents hip hyperextension. If I stand and bend posteriorly [i.e. lean backwards] you hyperextnd the hip, so if you push into the inguinal crease, you can feel the iliofemoral ligament as it resists the head of the femur which is pushing out. All 3 ligaments form a synovial joint and they’re twisted: there’s tension in order to push the head deep into the acetabulum. If you cut the 3 ligaments and try to pull the head out, it would snap back into place because of fhe 4th ligament, the ligament of the head: it goes from the fovea into the posterior wall of the acetabulum. This one also stabilizes the joint. Over time, the labrum wears away and it doesn’t get replaced, you get bone on bone, osteoarthritis.

Question 6

what nerve can be damaged if the neck of the fibula fractures?

Answer 6

•Going back up north again, the proximal part of the fibula is the head of the fibula and

below that is a narrow neck. The neck of the fibula is important because it fractures.

And, if it fractures there’s a major nerve that passes right around it and that’s the

common fibular nerve and it’s often damaged in a fracture at the fibular neck.

Question 7

ischial tuberosity

Answer 7

in posterior compartment Where all the muscles except the short head have their origin.

Question 8

lumbar plexus

Answer 8

The lumbar plexus comes from ventral rami of L2-L4, and these somatic nerves come together to form this plexus. We’ll focus on two branches to understand the innervations of the thigh: the femoral nerve and the obdurator nerve. The million dollar question: is the femoral nerve medial or lateral to the psoas muscle? And the obdurator? The obdurator is medial, and if Vicky were to ask you “What functional fibers do you find in the obdurator nerve?” you’d say, “GSE for motor, GSAs because all skeletal muscle has proprioreceptors that are GSAs, and post-ganglionic sympathetic because every branch of nerve has it.”

Question 9

labrum

Answer 9

The head of the femur fits into the acetabulum, but it doesn’t go in all the way because surrounding the acetabulum is a fibrocartilaginous labrum. The function of the labrum is to increase the depth of the acetabular socket so that the head goes in more than half the hemisphere – if you try to disarticulate the head from the acetabulum, you would have to break the labrum. It’s a stable joint given the labrum but there are more ligaments

Question 10

what is the strongest ligament of the hip?

Answer 10

ileofemoral

On the left, the large iliofemoral ligament: the inverted Y that prevents hyperextension. The other ligaments, the ischiofemoral and pubofemoral ligaments.

Question 11

medial compartment of thigh innervation

Answer 11

obturator nerve

Question 12

eversion

Answer 12

small toe in air

Question 13

soleal line

Answer 13

The only feature on the posterior surface that we care about is this line. called the

soleal line. A muscle called soleus attaches there.

Question 14

sesamoid bones of the foot

Answer 14

These are sesamoid

bones. You’ve already seen one sesamoid bone and that was the…. Patella. And as

you know (I think), a sesamoid bone is a bone that’s entirely within a tendon. And the

purpose of these two sesamoid bones on the bottom of your foot, is that there is a

tendon that runs right between them to the big toe: the flexor hallucis longus. If you

remember the thumb was pollicus, the big toe is hallucis.

So the flexor hallucis longus muscle is located in the leg, we’ll see it, and its tendon

runs down under the foot to get to the big toe and these two bones (the little sesamoid

bones) elevate the sole of the foot enough so that you’re not stepping on that tendon

every time you take a step so the tendon passes through here (in between the

sesamoid bones) and these two bones kind of protect that tendon from being trampled.

•And all of the blue stuff indicates an articular surface, that’s where all the bones are

moving. And you can see that there’s articulation even here (pointing in between the

Question 15

ligament of the head

Answer 15

Frontal section showing the ligament of the head, the 4th ligament going from the fovea to the posterior surface of the acetabular fossa.

Question 16

where do the quadracep muscles attach?

Answer 16

•And on the anterior surface you will feel a bump on the bone and when you see the

bare bone it’s obvious to see this bump that is the tibial tuberosity and that’s where the

quadriceps muscle (inserts) attaches.

•This is an example for the many, many questions about what do we have to know

about origins and insertions. This would be something that you have to know because a

group of muscles attach here. What group? The quadriceps from the thigh: that’s the

three vastus muscles and the rectus femorus.

•And, because of their attachment here they they are able to straighten the knee joint or

extend the leg

Question 18

what bone has weight when stadning on toes?

Answer 18

heads of the metatarsals

Question 20

neurovasculature of the lateral compartment of the leg

Answer 20

Innervation

Brevis and longus are innervated by superficial branch of common fibular nerve

•The nerve is cutaneous to the lateral side of the leg and dorsal of the foot EXCEPT for the

web between the big toe and the second toe

o That web is innervated by the DEEP fibular nerve

Blood supply

•Fibular artery supplies blood

Question 21

dorsalis pedis

Answer 21

•Pic also shows anterior tibial artery coming down, which lies against bones → it changes

name to dorsalis pedis (on the anterior aspect of ankle joing)

o Dorsalis pedis is good place to take a pulse

o Not everyone has dorsalis pedis artery (or have it only on one side) – if you can’t

find the pulse, don’t assume they’re dead

Question 22

function of meniscus

Answer 22

•The other structure inside the knee joint, it’s not a ligament, these are pads of cartilage

called a meniscus. There’s a lateral meniscus and a medial meniscus. They are literally

cushions, they’re shaped sort of like a letter C, and they are there to act as shock

absorbers in the knee. The tibia is, every time you take a step, it’s getting the full weight

of your body all the way from your head down to your knee. So It’s very useful to have

these things to cushion the impact.

•Notice that on the medial side, the medial meniscus is attached to the medial collateral

ligament. On the lateral side that’s not the case. Traveling in that space is a tendon of

the muscle from the back of the knee that we will see shortly, it’s called the popliteus

muscle. And that tendon separates the lateral meniscus from the lateral collateral
ligament. This has functional consequences, if you have damage to the medial collateral

ligament it’s usually going to effect the medial meniscus as well so you’re going to get

two injuries for the price of one.

Question 24

intrinsic muscles in the dorsal foot

Answer 24

• Extensor hallucis brevis
• Extensor digitorum brevis
• They’re innervated by deep fibular nerve

Question 25

muscles in the anterior compartment of the leg

Answer 25

All 3 muscles in anterior compartment functions to dorsiflex the ankle •In front, most anteriorly placed muscle, next to tibia, is **tibialis anterior** o Tibialis posterior is the deepest muscle in the back o Tibialis anterior is an inverter (like tibialis posterior) • We have 2 inverters, one in front and one in back **•Extensor digitorum longu**s -- sits next to tibialis anterior at the same plane o Has tendon to each of the toes except for the big toe •Deeply placed in front and anterior compartment is **extensor hallucis longus muscle** o Note: flexor hallucis flexes big toe but CROSSES flexordigitorum tendons to get to big toe o Extensor digitorum does lie on SAME SIDE as big toe (e.g. lies medially)

Question 27

deep compartment of posterior compartment of the leg - muscles

Answer 27

•Deep compartment has 3 muscles and will also plantar flex ankle and toes o Flexor digitorum longus (just like hand 's FDL, will have tendon to everything but the big toe) o Flexor halucis longus -- goes to the big toe o Tibialis posterior -- pressed up against the back of tibia • In addition to plantar flex, tibialis posterior also inverts foot

Question 28

medial compartment of the thigh muscles

Answer 28

**Adductor longus**, and if there is a longus, there is also a Brevis, so **adductor Brevis**, The third one is so big that some of it cant fit into the medial compartment and is in the posterior compartment. Its called the **Adductor Magnus**. One muscle that will really save your butt on the practical, **The Gracilis muscle**. Why is it important… IN practical you cannot differentiate between the medial and the lateral muscles as all are very similar, and if the other part of the foot/toes are covered. You identify medial and lateral by the sartorius muscle (I think he meant Gracilis muscle??). The gracilis is a really powerful adductor of the thigh. Also called the “chastity muscle”. All muscles in this compartment are innervated by the obturator nerve.

Question 29

divisions of popliteal artery

Answer 29

Popliteal artery pass below the knee and split into anterior and posterior tibial artery * **Anterior tibial artery** disappears to go to front of leg (will only see a little bit in lab today) * **Posterior tibial artery** will go down to foot and travels with tibial nerve → artery superficial and deep posterior compartment of leg •A branch off posterior tibial artery is fibular artery o Fibular artery is more lateral and will supply lateral compartment through perforating branch of fibular artery

Question 30

what is the greatest sesamoid bone in the body?

Answer 30

patella ## Footnote body. It’s sesamoid because it develops from a tendon, in this case the quadriceps tendon.

Question 31

soleus function

Answer 31

inserts into achilles ## Footnote • Standing upright -- The muscle is always in state of tension and uses small contractions to help you stand upright for long period of time § If soleus is damaged, you tilt forward § This muscle helps you stand up straight

Question 32

split of the sciatic nerve

Answer 32

•There's monster giant nerve, the sciatic nerve → splits into tibial nerve and common fibular nerve o "Fibular" and "peroneal" (older term) are interchangeable (e.g. common fibular nerve = common peroneal nerve) o Sciatic often divide at the back of the knee, the popliteal fossa, but can be seen splitting up in gluteal region due to anatomical variation

Question 33

fascia lata

Answer 33

there’ll be a lot of fat in the superficial fascia. Immediately below it, you’ll find the deep fascia (found everywhere in the body). This fascia that wraps around the thigh is the fascia lata: if you look on the medial side of the thigh there’s a big gap and it’s for the drainage of a large superficial vein, the saphenous vein. It goes from the medial side of the foot all the way medially up the leg till it drains in the femoral vein. That hiatus is the called the saphenous hiatus. On the lateral side of the fascia lata, this material is reinforced by the tendon of the gluteus maximus plus the tendon of the tensor fascia latae. It creates a material so strong, it’s called the iliotibial tract.

Question 34

plantar flexion

Answer 34

Question 35

function of collageral ligaments

Answer 35

keep femur and tibia/fibula close togheter prevent rotation

Question 36

angle of inclination

Answer 36

formed between the head, the neck, and the shaft So the longest and strongest bone is the femur. We can see the head, the neck, the shaft of the body. The head and the neck form an angle with the shaft of about 125-126 degrees = angle of inclination. It is really important because if you snap the neck, which is the most likely place for a break, the surgeon has to restore this angle in order for the joint to properly transmit the weight down to the knee joint.

Question 37

what bone articulates at the ankle joint?

Answer 37

the talus, that articulates at the ankle joint. • The blue surface is the articular surface that contacts that inferior part of the tibia and fibula and this is how it rocks back and forth.

Question 38

crural fascia

Answer 38

fascia of the leg ## Footnote •However the crural fascia has an important positive function which is, it helps venous blood travel back up towards the heart. How does it do that? Well, as you can imagine by the time you get down to the leg and the foot, you’re pretty far away from the pumping of the heart and you are also fighting gravity to send the blood back up through your leg towards the heart. The contraction of the leg muscles, assists in pumping the blood back up and the fact that the crural fascia holds these muscles so tightly against the bones also helps propel the blood upwards back towards the heart. So the crural fascia assists in venous return. •This gets back to what we said earlier about the potential danger of a bleed into any of the leg compartments. If you knick that artery and it’s bleeding slowly, you don’t know that you’ve really been injured. The blood will eventually squeeze the other things that are in that particular compartment. It will compress the nerve, the other vessels, eventually the muscles and this is called compartment syndrome. This can cause a great deal of damage and if it’s not recognized and caught soon enough it can cause permanent muscle and nerve damage and you can lose the function, in fact lose the leg. I’ll show you a little more about how that can happen momentarily.

Question 39

contents of the femoral triangle

Answer 39

Content is the vein, artery and nerve.

Question 40

innervation of anterior compartment of the thigh

Answer 40

All of these muscles are supplied by the femoral nerve, ie nerve that innervates the anterior compartment. In addition to the 4 quads, there is 1 another muscle, it’s the sartorius muscle, origin from hip-anteriorsup illian spine Function: Quads: are the Extensors.

Question 41

sacral plexus

Answer 41

The sacral plexus: the formation of the sacral plexus comes from when the ventral rami of L4-L5 come together to form the lumbosacral trunk. The lumbosacral trunk is NOT the lumbosacral trunk, it’s only the ventral rami of L4-L5. To this trunk, we’ll add S1-S3, and that will form the sacral plexus. The one branch we’ll focus on is the **sciatic nerve,** which is the largest nerve of the body. It enters beneath the piriformis and is responsible for the muscles on the posterior region below the knee.

Question 42

gracilis muscle

Answer 42

u cant tell the medial from the lateral. Long head of biceps vs semitendinosis, you have to see the gracilis muscle. Points to Left of diagram..this is the gracilis so this is the medial side and the muscle is the semitendinosis,

Question 43

where does the ankle joint fit?

Answer 43

Down below, notice the space here is shaped sort of like an upside down U. That’s where the ankle joint fits. On both, the tibia and the fibula at the very distal end, there’s a bump or a ridge called the malleolus. The tibia being the medial bone has the medial malleolus and on the fibula there’s a lateral malleolus and you can feel these two pieces of bone at your ankle.

Question 44

innervation of the dorsal foot

Answer 44

intrinsic muscles (extensor digitorum prevus, extensor hallucis brevus) --\> deep fibular nerves cutaneous: superficial and deep fibular nerves

Question 45

posterior compartment of the thigh muscles

Answer 45

Posteriorly, 5 muscles are there. Biggest chunk: **Hamstring,** : Laterally: **Long and short head of the biceps**. Medially: **Semitendinosis and semimembrinosis**. And the 5th muscle is the rest of the **adductor magnus** that couldn’t fit in the medial comp, i.e the post part of Adductor magnus. Last pointer before delving into the muscles: All the muscles of the post compartment except the Adductor Magnus, cross the knee joint.

Question 46

adducter canal

Answer 46

Key here is that the femoral vessels are the only ones here to supply blood to the lower limb. So these need to get to the leg and the foot and the posterior compartment of the thigh. To reach the leg and foot, the vein and artery run this adductor canal, till they reach the medial side where there is an opening in the adductor magnus, allowing to get them to the back of your knee. Once the femoral vessels get to the back of the knee they are then called the popletial vessels. The femoral nerve does not traverse the canal, it leaves the canal before you reach the back of the knee. Its only function is to innervate the anterior compartment and the cutaneous part of the ant thigh.

Question 47

lateral ligaments of the ankle

Answer 47

prevent over inversion of the ankle aversion fracture - break tendon and pull of a piece of the bone

Question 48

dorsiflexion

Answer 48

•The movement at the ankle joint, we talked about dorsi flexion and plantar flexion, up and down. The talus rocks up and down underneath the tibia and the fibula.

Question 49

compartment syndrome

Answer 49

•Because the crural fascia is so tight, it won't allow expansion as blood fills the compartment and cause compression of surrounding structures o This can happen when someone is given a leg cast, if there's too much compression or if there's a leaky vessel (in which case the cast makes things worse) •If someone in a cast has severe pain, don't assume it's due to the fracture -- you always have to check for compartment syndrome!! o Toe is typically left out b/c * Ankle is immobilized but flexing toes up and down helps with venous return * Toes can be used to test for compartment syndrome by plantarflexing them (bending toes downward) § By pulling toes down, you stretch anterior compartment → patient will be in even more pain → now can be very suspicious that there may have compartment syndrom •Treatment is deciding which compartment is affected → then make incision in crural fascia o Once crural fascia is cut, will allow blood to flow out o If this is early enough, will save person from damage o Good thing about compartment syndrome is that pain is very severe and will cause person to come back to ER room so it's early enough to save the person • You get into trouble when people decide they can be heroes and live with the pain and come back the next day

Question 50

what muscles are in the lateral compartment of the leg?

Answer 50

•Fibularis longus -- more superficial than brevis o Its tendon is on fibula and runs from lateral side of leg to go under the foot o Tendon starts laterally and goes medially to big toe o When fibers contract, will pull foot outward (evert) •Fibularis brevis -- o Does not go under the foot but attaches to base of fifth metatarsal (lateral side) o When it contracts, it will pull lateral side outward o Both brevis and longus acting together (pulling from lateral and medial side, respectively) → foot everts

Question 52

boundaries of femoral triangle

Answer 52

The boundaries that make the femoral triangle are the sartorius muscle laterally, inguinal ligament on the top and the Adductor longus medially

Question 53

blood supply to the sole of the foot

Answer 53

posterior tibial artery passes medially under the foot and divides into medial and lateral plantar arteries

Question 54

osteoarthritis

Answer 54

* Arthritis caused just by wear is called osteoarthritis * If you live long enough, probably not accurate to say almost everyone but probably 85% of the population has osteoarthritis in some joint or another. And of course the knees, the hips are the most common because they get the most weight-bearing. • When a little bit of cartilage wears away you may remember from histo or you may not, cartilage has no blood supplies and no nerves. Cartilage is not innervated. So when you have a bone above with cartilage on it, resting on bone below with cartilage on it, there’s no pain, no pressure: you don’t feel it. As cartilage wears away, bone is innervated and that’s when it starts to hurt • If we look up here (referring to where arrow is pointing to small focal lesion), there’s a little bit of, the cartilage is normally white and shiny like this. This is a small area where the cartilage has eroded, this is the beginning of arthritis. That pinkish thing or beige, that’s bone. So when this piece of bone rests on the piece of cartilage below, that hurts. What hurts more is when it gets down to what they call bone on bone. That’s really painful. • These are actually pictures of sheep (pointing at bottom picture). This sheep is in a desperate situation. You can’t really see it at this magnification, but around the edges here, it’s very raggedy looking, it’s not a smooth, even circle or oval. Those little jagged edges are going to crack and eventually they’ll form visible cracks, you can see lines in the cartilage here. And here (hole on the left of the bottom picture) the entire cartilage has worn away and here (hole on the right of the bottom picture) what we’re looking at is bone and here is even worse you can see the blood vessels in the bone. This sheep is in desperate need of a joint replacement.

Question 55

boundaries of the popliteal fossa

Answer 55

Boundaries of popliteal fossa * Lateral: bicep femoris * Medially: semitendinosus and semimembranosis (Sally she's she would include both these muscles even though only 1 is labeled) • Inferior boundary: lateral and medial head of gastrocemius muscles

Question 56

posterior compartment of thigh innervation

Answer 56

. All muscles in the post comp except the short head of biceps originate from Ischial tuberosity. All the muscle which originate from the ischial tuberosity, are innervated by the tibial nerve. That leaves The short head of the biceps to be supplied by the other nerve, called the common peroneal nerve. The *Tibial nerve* and the c*ommon peroneal nerve* together lie in a sheath, forming the S**ciatic Nerv**e. So, sciatic N is not one big N, but 2 really big nerves wrapped up in a sheath, forming the sciatic nerve

Question 57

foot drop

Answer 57

o If you cut off common fibular nerve, will cause numbness, then pain and won't be able to elevate the toes (dorsiflex) o When you can't pick up foot at ankle or elevate your toes, you have foot drop • Foot drop -- person has to raise leg at the knee to raise the foot because can't pick up foot otherwise § Foot drop is caused by compression of deep fibular nerve

Question 58

what bone makes up the heel?

Answer 58

The bone that actually forms your heel is the calcaneus and you can feel this bone right through the back of your foot. On the bottom of the calcaneus there’s a fat pad. and as you get older and spend more and more time on your feet as you likely will in this profession, that fat pad wears away and your feet start to hurt.

Question 59

iliotibial tract

Answer 59

On the lateral side of the fascia lata, *this material is reinforced by the tendon of the gluteus maximus plus the tendon of the tensor fascia latae. It creates a material so strong, it’s called the iliotibial tract. This reinforcement on the lateral side of the thigh is called the illeo-tibial tract. Its importance is to hold the muscle on the lateral side of the thigh tightly, but it also goes down to form this connective tissue band around the knee to protect it.* As discussed earlier, the knee cannot resist displacement forces very well in either of the directions, ant, post, medial, lateral, and this retinaculum is tough Connective tissue ,comes down and helps reinforce the tissue by forming the capsule.

Question 60

innervation to the sole of the foot

Answer 60

• Tibial nerve goes to bottom of foot and divides into medial and lateral plantar nerve

Question 62

planatarus muscle function

Answer 62

•Plantarius has long tendon that also fuses with calcaneal tendon o Functions: similar to soleus and gastrocnemius -- plantar flex • If you lose platarius muscle, won't have any deficit in function o Like palmaris longus that has a long tendon in the forearm, b/c plantarius is not important for function -- you can harvest the plantarius tendon (it's not too deep down)--to repair tendons/ligaments torn elsewhere in body

Question 63

transverse acetabular ligament

Answer 63

Here, the acetabular notch has the transverse acetabular ligament and through the acetabular foramen runs the blood supply to the hip, which is very important – if you injure this blood supply, one will get necrosis of the hip.

Question 64

linea aspera

Answer 64

), you’ll also note a roughened area that extends the length of the shaft called the linea aspera. It’s important because not a single muscle but an entire group of muscles insert here, the adductors of the thigh. The adductors bring the leg back to the midline. […his microphone fell off here: Inferiorly, the femur / condyles / the knee isn’t an incredibly stable joint…)].

Question 65

obturator nerve

Answer 65

innervates medial compartment ## Footnote The dissection of this compartment is really nice because the obturator nerve is really your friend here. It divides into and ant and post division. In the anterior compartment uo always find the anterior division between longus and brevis. And the posterior division between brevis and magnus. So u can easily find the plane of dissection because of the divisions of the obturator nerve.

Question 66

what maintains the shape of the arch of the foot?

Answer 66

* There are curves built into the bones * Action of muscles around the arch * Ligaments and plantar fascia

Question 67

trimalleolar fracture

Answer 67

•This is a weird one. There are two malleoli, there’s a lateral malleolus on the fibula and a medial malleolus on the tibia. What is a trimalleolar fracture if there’s only two of them. •A trimalleolar fracture refers to you also, you break both the lateral and medial malleoli and you also break off a little piece of the posterior tibia. This is a complicated one to fix because you have to come at it from three different directions, this is how it’s done

Question 68

what nerve innervates posterior compartment of the leg

Answer 68

•Both superficial and deep muscles of posterior compartment are innervated by tibial nerve (branch of sciatic) o Tibial nerve runs down posterior of leg and to bottom of foot

Question 69

function of ACL and PCL

Answer 69

•These two ligaments like the others also hold the bones together, close to each other. But, their additional function is they prevent the tibia from sliding forward or backward. The ACL prevents the tibia from sliding forward under the femur and the PCL prevents it from sliding backwards.

Question 70

what travels behind medial malleous to bottom of foot

Answer 70

•Arteries, nerve, vein, and tendons will travel behind medial malleolus to the bottom of the foot o "Tom, Dick, and a very nervous Harry" mnemonic may be useful * "Tom" is tibialis posterior tendon -- most medial * "Dick" is flexor digitorum longus tendon * "And" is artery * "Very" is vein * "Nervous" is tibial nerve * "Harry" is hallucis longus longus tendon

Question 71

deltoid ligament

Answer 71

only ligament in the ankle we care about ## Footnote * Deltoid is actually a bunch of ligaments hanging together. * The deltoid ligament protects you against over-eversion. It won’t let your ankle slide all the way out theoretically, unless of course it tears. •So the deltoid ligament on the medial side of the ankle prevents over-eversion, you don’t have to know nay of the labels on the slide here

Question 72

tibia vs fibula

Answer 72

•The big, heavy weight-bearing bone is the tibia and that is medially placed, it’s on the medial side and you can all feel the tibia right under your skin. It’s subcutaneous, easy to get to. And I’m sure at some point, all of you have bumped into a table leg or the edge of your bed or what and you can easily feel the sensation in the tibia. It’s not just the skin that has sensory innervation, the bone is innervated also. •Next to it on the lateral side of your leg is the fibula and if you compare the two of them you can see that this is a very thin, not particularly sturdy looking bone. And in fact the fibula is not weight-bearing at all. It does not participate in the knee joint only the tibia and femur are part of the knee. The fibula is there mostly to provide muscle attachment space

Question 73

nail bed of foot - innervation

Answer 73

Nailbeds are similar to hands where neve wraps around from below to innervate * Medial 3.5 toes are innervated by medial plantar nerve * Lateral 1.4 are innervated by lateral plantar nerve

Question 74

why is it important to do imaging if dislocated knee, even if it popped back?

Answer 74

1) always take anterior and lateral imagery 2) •So, this is the politeal artery and you may recall that once upon a time in the front of the thigh there was the femoral artery. The femoral artery and vein disappear into the adductor hiatus and come around to the back of the leg. and of course, they change their names to popliteal artery and vein •So once we see them back here, this is already the popliteal artery. And what this X-ray and the arrow are showing you is that when the joint dislocated, the artery is the closest structure to the bone and it has a little tiny nick here •There’s something weird about dislocated knees, they very often resolve by themselves. At least, approximately half the time this joint will reposition itself. •So you’re on your way to the emergency room, by the time you get to the ER, you’re feeling much better, but it’s very important for you to tell the ER doc that your knee was dislocated because it’s possible that some damage happened to the blood vessel. Here you can see that little nick in the artery better. This is going to cause a slow leak, maybe not so slow and we’ll see soon that leaking blood vessels in the leg can cause extreme damage and in fact may even result in the loss of the limb below the knee.

Question 75

anterior compartment of the thigh

Answer 75

Anterior compartment, for people who did track/running, this muscle is pulled quite often, its called **the quadriceps**. It is **Made of Rectus femoris muscle and the three Vastus muscles, Vastus lateralis-Lateral, Medialis-Medial and intermedius-Neither lateral/Medial and sartorius muscle**These 4 form the quadriceps, and all together form the quadriceps tendon. The quadriceps tendon continues over the knee and encompasses the patella (making it a sesamoid bone), in theory its given another name-then it is called the patellar tendon, that is where you take your rubber hammer and test the knee jerk reflex.

Question 76

patella function

Answer 76

Patella is a Sesamoid bone –Not critical for our existance if we are not too active, but maybe in an athlete. Its Importance: If no patella, the quadriceps tendon would insert into the tibial tuberosity at a very shallow angle, and because of that the extension is not that powerful. **Due to the patella, the angle of insertion is more sharp and the result is that the last 10-15 degrees of the extension is very powerful.** Especially important in kickers, basketball, football players etc. If the patella is badly fractured, it is surgically removed. If it is not that badly fractured, it is left in place to heal. It takes a long time to heal though when left to heal.

Question 77

what muscles insert into achilles tendon?

Answer 77

Muscles that insert into Achilles tendon--gastrocnemius, soleus, plantarius •Gastrocnemius is the most posterior muscle on calf and ends in enormous tendon called calcaneal tendon or more commonly the Achilles tendon o In the lab, you should appreciate the thickness and strength of the tendon o Functions: * Plantar flex ankle * Assists in flexing the knee a little -- gastrocnemius crosses the knees a little § Note that the main flexors of knee are in hamstrings § Soleus does NOT cross the knee and has no function in flexing the knee

Question 78

neurovascular of anterior compartment of the leg

Answer 78

* All 3 muscles innervated by deep fibular nerve * Blood supply is from anterior tibular artery