Anatomy and Physiology - ANAT 1010 Week 10 Notes PDF

ANATOMY AND PHYSIOLOGY – ANAT 1010 NICOLA ROBERTSON WEEK 10 Week Monday Friday comp SCHEDULE 10 Muscled Muscles and Lower limb 11/11 and joints: LE muscles joints: LE...

ANATOMY AND PHYSIOLOGY – ANAT 1010 NICOLA ROBERTSON WEEK 10 Week Monday Friday comp SCHEDULE 10 Muscled Muscles and Lower limb 11/11 and joints: LE muscles joints: LE All comps MUST be 11 Muscles Muscles and Spinal 18/11 and joints; Spine muscles completed by 29th joints; November Spine- Online 12 Muscles Mini Mini 25/11 in action presentation presentatio n 13 Exam Exam prep N/A 2/12 prep class 14 MCQ In person N/A exam exam QUESTION TIME / KAHOOT HIP JOINT SUMMARY Ball and socket Synovial joint Connects lower limb to the pelvic girdle Articulations; acetabulum and head of femur Designed for stability and weightbearing HIP JOINT MOVEMENTS JOINT ARTICULATIONS The hip joint is enclosed by a strong fibrous capsule and lined internally by synovial membrane The capsule attaches proximally to the acetabulum , distally to the intertrochanteric line anteriorly and the femoral neck posteriorly. Its cavity is deepened by the presence of a fibrocartilaginous collar – the acetabular labrum. The head of femur is hemispherical, and fits completely into the acetabulum Both the acetabulum and head of femur are covered in articular cartilage, which is thicker at the places of weight bearing. LIGAMENTS OF THE HIP There are three capsular ligaments iliofemoral -arises from the anterior inferior iliac spine and then bifurcates before inserting into the intertrochanteric line of the femur. It has a ‘Y’ shaped appearance and prevents hyperextension of the hip joint. It is the strongest of the three ligaments. Pubofemoral -spans between the superior pubic rami and the intertrochanteric line of the femur, reinforcing the capsule anteriorly and inferiorly. It has a triangular shape, and prevents excessive abduction and extension. Ischiofemoral ligament spans between the body of the ischium and the greater trochanter of the femur, reinforcing the capsule posteriorly. It has a spiral orientation, and prevents hyperextension and holds the femoral head in the acetabulum. The intracapsular ligaments of the hip joint are found inside the capsule and include the transverse ligament of the acetabulum and the ligament of the head of the femur.  Flexion – iliacus, psoas, rectus femoris, sartorius, pectineus Extension – HIP gluteus maximus; semimembranosus, semitendinosus and biceps femoris (the hamstrings) MUSCLES Abduction – AND gluteus medius, gluteus minimus, piriformis and tensor fascia latae Adduction MOVEMENT adductors longus, brevis and magnus, pectineus and gracilis S Lateral rotation biceps femoris, gluteus maximus, piriformis, assisted by the obturators, gemilli and quadratus femoris. Medial rotation anterior fibres of gluteus medius and minimus, tensor fascia latae The degree to which flexion at the hip can occur depends on whether the knee is flexed – this relaxes the hamstring muscles, and increases the range of flexion. Extension at the hip joint is limited by the joint capsule and the iliofemoral ligament. These structures become taut during extension to limit further movement. STABILITY The primary function of the hip joint is to weight-bear There are a number of factors that act to increase stability of the OF THE HIP joint. The first structure is the acetabulum. It is deep, and encompasses nearly all of the head of the femur. This decreases the probability of the head slipping out of the acetabulum (dislocation). the acetabular labrum which increase in depth provides a larger articular surface, further improving the stability of the joint. The iliofemoral, pubofemoral and ischiofemoral ligaments are very strong, and along with the thickened joint capsule, provide a large degree of stability. In addition, the muscles and ligaments work in a reciprocal fashion at the hip joint: Anteriorly, where the ligaments are strongest, the medial flexors (located anteriorly) are fewer and weaker. Posteriorly, where the ligaments are weakest, the medial rotators are greater in number and stronger – they effectively ‘pull’ the head of the femur into the acetabulum. SUMMARY Type Articular Synovial ball and socket; multiaxial Head of femur, lunate surface of acetabulum SLIDE FOR surfaces Ligaments Capsular: iliofemoral, pubofemoral, ischiofemoral THE HIP Innervation Intracapsular: transverse ligament of the acetabulum, ligament of the head of the femur Femoral nerve, obturator nerve, superior gluteal nerve, nerve to quadratus femoris Blood supply Medial and lateral circumflex femoral arteries, obturator artery, superior and inferior gluteal arteries Movements Flexion, extension, abduction, adduction, external rotation, internal rotation and circumduction MUSCLES 1. Iliacus 10. Adductor longus 2. Psoas 11. Adductor brevis 3. Rectus femoris 12. Adductor Magnus 4. Pectineus 13. Gracilis 5. Gluteus maximus 14. Obturators 6. Semimembranosus 15. Gemelli 7. Semitendinosus 16. Quadratus femoris 8. Bicep femoris 17. Gluteus med 9. Gluteus minimus 18. TFL KNEE JOINT SUMMARY Modified hinge type synovial joint Articulations; between the patella, femur and tibia. KNEE JOINT MOVEMENTS flexion and extension of the knee in the sagittal plane. allows limited medial rotation in a flexed position and in the last stage of extension, well as lateral rotation when “unlocking” and flexing the knee. the knee joint is not a true hinge since it has a rotational component, an accessory motion that accompanies flexion and extension, hence it is termed as a modified hinge joint. Knee abduction then a stretch would be happening on the inside of the joint and a compression would be happening on the outside of the joint. Adduction is different at the knee joint, because a straight leg offers a knee adduction JOINT ARTICULATIONS The knee joint consists of two articulations – tibiofemoral and patellofemoral. The joint surfaces are lined with hyaline cartilage and are enclosed within a single joint cavity. Tibiofemoral – medial and lateral condyles of the femur articulate with the tibial condyles. It is the weight- bearing component of the knee joint. Patellofemoral – anterior aspect of the distal femur articulates with the patella. It allows the tendon of the quadriceps femoris (knee extensor) to be inserted directly over the knee – increasing the efficiency of the muscle.  The medial and lateral menisci MENISCUS are fibrocartilage structures in the knee that serve two functions: To deepen the articular surface of the tibia, thus increasing stability of the joint. To act as shock absorbers by increasing surface area to further dissipate forces. They are C shaped and attached at both ends to the intercondylar area of the tibia. In addition to the intercondylar attachment, the medial meniscus is fixed to the tibial collateral ligament and the joint capsule. Damage to the tibial collateral ligament usually results in a medial meniscal tear. The lateral meniscus is smaller and does not have any extra attachments, rendering it fairly mobile. BURSA bursa is synovial fluid filled sac, found between moving structures in a joint – with the aim of reducing wear and tear on those structures. There are four bursae found in the knee joint: Suprapatellar bursa – an extension of the synovial cavity of the knee, located between the quadriceps femoris and the femur. Prepatellar bursa – found between the apex of the patella and the skin. Infrapatellar bursa – split into deep and superficial. The deep bursa lies between the tibia and the patella ligament. The superficial lies between the patella ligament and the skin. Semimembranosus bursa – located posteriorly in the knee joint, between the semimembranosus muscle and the medial head of the gastrocnemius. LIGAMENTS The major ligaments in the knee joint are: Patellar ligament – a continuation of the quadriceps femoris tendon distal to the patella. It attaches to the tibial tuberosity. Collateral ligaments – two strap-like ligaments. They act to stabilise the hinge motion of the knee, preventing excessive medial or lateral movement Tibial (medial) collateral ligament – wide and flat ligament, found on the medial side of the joint. Proximally, it attaches to the medial epicondyle of the femur, distally it attaches to the medial condyle of the tibia. Fibular (lateral) collateral ligament – thinner and rounder than the tibial collateral, this attaches proximally to the lateral epicondyle of the femur, distally it attaches to a depression on the lateral surface of the fibular head. Cruciate Ligaments – these two ligaments connect the femur and the tibia. In doing so, they cross each other, hence the term ‘cruciate’ (Latin for like a cross) Anterior cruciate ligament – attaches at the anterior intercondylar region of the tibia where it blends with the medial meniscus. It ascends posteriorly to attach to the femur in the intercondylar fossa. It prevents anterior dislocation of the tibia onto the femur. Posterior cruciate ligament – attaches at the posterior intercondylar region of the tibia and ascends anteriorly to attach to the anteromedial femoral condyle. It prevents posterior dislocation of the tibia onto the femur. TRIGGER WARNING – INJURY VIDEO MUSCLES AND MOVEMENTS Flexion: hamstrings, gracilis, sartorius and popliteus. Extension Produced by the biceps femoris and other quads Lateral rotation Produced by five muscles; semimembranosus, semitendinosus, gracilis, sartorius and popliteus. Medial rotation NB: Lateral and medial rotation can only occur when the knee is flexed (if the knee is not flexed, the medial/lateral rotation occurs at the hip joint). ADDITIONAL FACTS As the patella is both formed and resides within the quadriceps femoris tendon, it provides a fulcrum to increase power of the knee extensor and serves as a stabilising structure that reduces frictional forces placed on femoral condyles. Neurovascular Supply The blood supply to the knee joint is through the genicular anastomoses around the knee, which are supplied by the genicular branches of the femoral and popliteal arteries. The nerve supply, according to Hilton’s law, is by the nerves which supply the muscles which cross the joint. These are the femoral, tibial and common fibular nerves. KNEE SUMMARY SLIDE Type Tibiofemoral joint: Synovial hinge joint; uniaxial Patellofemoral joint: Plane joint Articular surfaces Tibiofemoral joint: lateral and medial condyles of femur, tibial plateaus Patellofemoral joint: patellar surface of femur, posterior surface of patella Ligaments and Menisci Extracapsular ligaments: patellar ligament, medial and lateral patellar retinacula, tibial (medial) collateral ligament, fibular (lateral) collateral ligament, oblique popliteal ligament, arcuate popliteal ligament, anterolateral ligament (ALL) Intracapsular ligaments: anterior cruciate ligament (ACL), posterior cruciate ligament (PCL), medial meniscus, lateral meniscus Innervation Femoral nerve (nerve to vastus medialis, saphenous nerve) tibial and common fibular (peroneal) nerves, posterior division of the obturator nerve Blood supply Genicular branches of lateral circumflex femoral artery, femoral artery, posterior tibial artery, anterior tibial artery and popliteal artery Movements Extension, flexion, medial rotation, lateral rotation COMPARTMENTS OF THE THIGH There are three compartments of the leg we will be exploring: the anterior, posterior, and medial compartments.​Each of these are separated by a layer of dense connective tissue called fascia. Anterio r Medial Femu r Posteri or  ANTERIOR COMPARTMENT In the anterior compartment we have muscles primarily responsible for thigh flexion and extension of the knee. Anterio Right r the hip -Flex Leg Psoas -Extend the knee Iliacus -Femoral Nerve Sartorius Quads Medial Femu r Posteri or Psoas Major and Iliacus Origin: Psoas Major: Anterior surfaces of transverse processes of T12-L5 Iliacus: Iliac fossa and crest Insertion: Lesser trochanter of femur Action: Flexion and external rotation at hip joint Innervation: (L1-L3) L2-L4 femoral nerve Illiacus and Psoas Major come together into a single tendon. We call the two muscles together “Iliopsoas”.  POSTERIOR COMPARTMENT In the posterior compartment we have muscles primarily responsible for both knee flexion (as it crosses the joint) and thigh extension. These are all two joint muscles. Anterio Right r the hip -Flex Leg -Extend the knee Hamstrings -Femoral Nerve Medial Femu r Posteri or -Extend the hip -Flex the knee -Sciatic Nerve  MEDIAL COMPARTMENT In the medial compartment of the thigh we have muscles that are primarily responsible for adduction of the thigh. Anterio Right r the thigh -Flex Leg (hip) -Extend the knee Adductor Longus -Femoral Nerve Adductor Brevis Medial Adductor Magnus -Adduction of the Femu thigh (hip) r Gracillis -Obturator Nerve Posteri or -Extend the thigh (hip) -Flex the knee -Sciatic Nerve TIB/FIB JOINT The proximal and distal tibiofibular joints refer to two articulations between the tibia and fibula of the leg. These joints have minimal function in terms of movement but play a greater role in stability and weight-bearing. PROXIMAL TIB/FIB JOINT Articulating Surfaces The proximal tibiofibular joint is formed by an articulation between the head of the fibula and the lateral condyle of the tibia. It is a plane type synovial joint; where the bones to glide over one another to create movement. Supporting Structures The articular surfaces of the proximal tibiofibular joint are lined with hyaline cartilage and contained within a joint capsule. The joint capsule receives additional support from: Anterior and posterior superior tibiofibular ligaments – span between the fibular head and lateral tibial condyle Lateral collateral ligament of the knee joint Biceps femoris – provides reinforcement as it inserts onto the fibular head. Neurovascular Supply The arterial supply to the proximal tibiofibular joint is via the inferior genicular arteries and the anterior tibial recurrent arteries. The joint is innervated by branches of the common fibular nerve and the nerve to the popliteus (a branch of the tibial nerve).  Articulating Surfaces The distal (inferior) tibiofibular joint consists of an articulation between the fibular notch of the distal tibia and the fibula. DISTAL It is an example of a fibrous joint, where the joint surfaces are by bound by tough, fibrous tissue. TIB/FIB Supporting Structures JOINT The distal tibiofibular joint is supported by: Interosseous membrane – a fibrous structure spanning the length of the tibia and fibula. Anterior and posterior inferior tibiofibular ligaments Inferior transverse tibiofibular ligament – a continuation of the posterior inferior tibiofibular ligament. As it is a fibrous joint, the distal tibiofibular joint does not have a joint capsule (only synovial joints have a joint capsule). Neurovascular Supply Arterial supply to the distal tibiofibular joint is via branches of the fibular artery and the anterior and posterior tibial arteries. The nerve supply is derived from the deep peroneal and tibial nerves. ANKLE JOINT The ankle joint is also called the talocrural joint a synovial joint located in the lower limb. It is formed by the bones of the leg (tibia and fibula) and the foot (talus). Functionally, it is a hinge type joint, Neurovascular Supply The arterial supply to the ankle joint is derived from the malleolar branches of the anterior tibial, posterior tibial and fibular arteries. Innervation is provided by tibial, superficial fibular and deep fibular nerves.  Plantarflexion – produced by the muscles in the posterior compartment of the ANKLE JOINT leg (gastrocnemius, soleus, plantaris and MOVEMENTS AND posterior tibialis). MUSCLES Dorsiflexion – produced by the muscles in the anterior compartment of the leg (tibialis anterior, extensor hallucis longus and extensor digitorum longus). ARTICULATING SURFACES The ankle joint is formed by three bones; the tibia and fibula of the leg, and the talus of the foot: The tibia and fibula are bound together by strong tibiofibular ligaments. Together, they form a bracket shaped socket, covered in hyaline cartilage. This socket is known as a mortise. The body of the talus fits snugly into the mortise formed by the bones of the leg. The articulating part of the talus is wedge shaped – it is broad anteriorly, and narrow posteriorly: Dorsiflexion – the anterior part of the talus is held in the mortise, and the joint is more stable. Plantarflexion – the posterior part of the talus is held in the mortise, and the joint is less stable. LIGAMENTS Medial Ligament or Deltoid ligament is attached to the medial malleolus (a bony prominence projecting from the medial aspect of the distal tibia). It consists of four ligaments, which fan out from the malleolus, attaching to the talus, calcaneus and navicular bones. The primary action of the medial ligament is to resist over- eversion of the foot. LIGAMENTS The lateral ligament originates from the lateral malleolus (a bony prominence projecting from the lateral aspect of the distal fibula). It resists over-inversion of the foot, and is comprised of three distinct and separate ligaments: Anterior talofibular – spans between the lateral malleolus and lateral aspect of the talus. Posterior talofibular – spans between the lateral malleolus and the posterior aspect of the talus. Calcaneofibular – spans between the lateral malleolus and the calcaneus. SUBTALAR JOINT is an articulation between two of the tarsal bones in the foot – the talus and calcaneus. structurally as a synovial joint functionally as a plane synovial joint. Neurovascular Supply The subtalar joint receives supply from two arteries and two nerves. Arterial supply comes from the posterior tibial and fibular arteries. Innervation to the plantar aspect of the joint is supplied by the medial or lateral plantar nerve, whereas the dorsal aspect of the joint is supplied by the deep fibular nerve. ARTICULATING SURFACES The subtalar joint is formed between two of the tarsal bones: Inferior surface of the body of the talus – the posterior talar articular surface. Superior surface of the calcaneus – the posterior calcaneal articular facet. As is typical for a synovial joint, these surfaces are covered by articular cartilage. Note: Some texts will refer to the talocalcaneal part of the talocalcaneonavicular joint as being part of the subtalar joint. Although this forms part of the functional joint, the true anatomical subtalar joint consists only of the surfaces mentioned above. STABILITY The subtalar joint is enclosed by a joint capsule, which is lined internally by synovial membrane and strengthened externally by a fibrous layer. The capsule is also supported by three ligaments: Posterior talocalcaneal ligament Medial talocalcaneal ligament Lateral talocalcaneal ligament An additional ligament – the interosseous talocalcaneal ligament – acts to bind the talus and calcaneus together. It lies within the sinus tarsi (a small cavity between the talus and calcaneus), and is particularly strong; providing the majority of the ligamentous stability to the joint. MOVEMENT The subtalar joint is the chief site within the foot for generation of eversion and inversion This movement is produced by the muscles of the lateral compartment of the leg.and tibialis anterior muscle respectively. The nature of the articulating surface means that the subtalar joint has no role in plantar or dorsiflexion of the foot. Range of movement is in the range of 25° to 30° in inversion and 5° to 10° in eversion, respectively MUSCLES OF THE LOWER LIMB The anterior compartment is, as the name implies, on the anterior portion of the leg. These muscles are responsible mainly for dorsiflexion of the ankle and toes. The posterior compartment is on the posterior part of the lower leg The muscles in this compartment are responsible mainly for plantar flexion of the ankle and toes (if you stand on your tippy-toes you will feel your gastrocnemius contracting). MUSCLES 19. Popliteus 28. Gastrocnemius 20. Obturator 29. Tibialis posterior 21. Gemelli 30. Fibularis Longus 22. Rectus femoris 31. Extensor digitorum longus 23. Vastus medialis 32. Extensor Hallucis longus 24. Vastus lateralis 33. Plantaris 25. Vastus intermedius 34. Flexor digitorum longus 26. Tibialis anterior 35. Flexor hallucis longus 27. Soleus 36. Flexor digitorum brevis GROUP LEARNING 1. Be able to identify 4 muscles of the lower limb their origin, insertion, and action for comp – complete today 2. See worksheet for additional practice /resources 3. Bone games 4. Complete quiz