Bio 2230 Chapter 9.1 PDF

Leg Day! Muscles that Move the Hip and Lower Limb - Anterior and Medial Quadrants Additional muscle pictures for this lecture can be found in Canvas as part Biology 2230 FA24 of your Lab Manual....

Leg Day! Muscles that Move the Hip and Lower Limb - Anterior and Medial Quadrants Additional muscle pictures for this lecture can be found in Canvas as part Biology 2230 FA24 of your Lab Manual. Lecture 9.1 Print the quadrant charts for this lecture m. iyengar and bring them to class to fill out. Organization of Lower Limb Muscles For each muscle, you will need to know: Name and location At least two points of attachment (origin & insertion), Functions/actions Innervation (nerve supply) The leg alone has over 50 muscles, so that would be over 300 things to know. We will use nerve supply (innervation) to create four chunks of information to learn, AKA the “quadrant system.” Nerve Supply - The Lumbosacral Plexus The limb is made of body six (6) segments. superior l Six spinal nerves, L2-S2, innervate the limb rs a from three (3) superior and inferior Do segments. Each spinal nerve splits into dorsal l ra nt and ventral divisions in the embryo. Ve inferior Count 1-2-3 four (4) times to create the four (4) terminal nerves needed to innervate the skin and muscles of the lower limb. al rs Do l ra ANTERIOR (L2-4) – Femoral N. Fibul nt MEDIAL (L2-4) – Obturator N. ar Ve LATERAL (L5-S2) – Fibular + Gluteal N. POSTERIOR (L5-S2) – Tibial N. Attachments for the Hip-Thigh Muscles Four (4) nerves and quadrants exist, but the coxae is a fusion of three (3) bones. What are they? Where do they fuse? If the ilium is divided into a front and back portion, then four (4) bone areas are created. Attachments for the Hip-Thigh Muscles Anterior quadrant muscles Attach to the front of the ilium ilium Innervated by the Femoral nerve (L2-L4) pubis ischiu Medial quadrant muscles m Attach to the pubis Innervated by the Obturator nerve (L2-L4) Lateral quadrant muscles Attach to the back of the ilium Innervated by the Fibular + gluteal nerve (L5-S2) ilium Posterior quadrant muscles ischiu pubis Attach to the ischium m Innervated by the Tibial nerve (L5-S2) Anterior Hip - Thigh Quadrant System Muscles: Quadriceps (Rectus Femoris, Vastus Muscles: Lateral Intermedius, Vastus Medialis, Vastus lateralis), Psoas major, iliacus, Sartorius, Common Attachments: Back of the Ilium Common Attachments: Ilium front, Anterior Superior/Inferior iliac spine, Patella and patellar ligament, lesser trochanter, Medial tibial Action: Tuberosity, Intertrochanteric line, Nerve: Gluteal and fibular Action: Flexion, extension Nerve: Femoral Nerve (l2-l4) Muscles: Muscles: Common Attachments: Pubis Common Attachments: Ishium Action: Action: Nerve: Obturator Nerve: Tibial Nerve Posterior Medial Anterior Leg (knee to ankle) Quadrant System Lateral Muscles: Muscles: Common Common Attachmen Attachmen ts: ts: Action: Action: Nerve: Nerve: Muscles: Muscles: Common Common Attachmen Attachmen ts: ts: Action: Action: Nerve: Nerve: Posterior Medial Hip-Thigh Anterior Quadrant – Femoral Nerve L2- L4 Femoral Nerve L2-L4 Commonly referred to as the quadriceps group. Notice how they spiral across the leg! Why? They work to flex the hip (Coxal joint) and extend the knee (Tibiofemoral and Patellofemoral joints). Where should they attach? What Do Lower Limb Muscles Spiral? Development of the Limbs (1) Limbs start as little paddles; (2) There’s a knee and ankle, then (3) The foot turns forward, causing muscles to spiral across the front of the limb. Knee Paddle Joints twisting Ankle Hip-Thigh Anterior Quadrant – Femoral Nerve L2- L4 Psoas major Origin: T12-L5 lateral vertebral bodies and transverse processes. Insertion: Lesser trochanter Innervation: Ventral rami of spinal nerves Functions: Flex and laterally rotate the hip (Coxal joint). *The psoas major and iliacus are referred to as the iliopsoas muscle. Hip-Thigh Anterior Quadrant – Femoral Nerve L2- 4 Iliacus Origin: Internal iliac fossa Insertion: Lesser trochanter Innervation: Femoral nerve Functions: Flex and laterally rotate the hip (Coxal joint). *The psoas major and iliacus are referred to as the iliopsoas muscle. Hip-Thigh Anterior Quadrant – Femoral Nerve L2- 4 Sartorius Origin: Anterior superior iliac spine Insertion: Medial tibial tuberosity Innervation: Femoral nerve Functions: Flexes and laterally rotates hip (Coxal joint) — weak knee extensor (Tibiofemoral and Patellofemoral joints). Important boundary between the anterior and medial quadrants With gracilis and semitendinosus forms, the Pes Anserinus stabilizes the medial aspect of the Hip-Thigh Anterior Quadrant – Femoral Nerve L2-4 Rectus femoris Origin: Anterior inferior iliac spine Insertion: Tibial tuberosity via patellar ligament Innervation: Femoral nerve Functions: Flex hip (Coxal joint). Extends knee (Tibiofemoral and Patellofemoral joints). Hip-Thigh Anterior Quadrant – Femoral Nerve L2-4 Vastus intermedius * Deep to rectus femoris Origin: Intertrochanteric line Insertion: Tibial tuberosity via patellar ligament Innervation: Femoral nerve Rectus femoris cut way Function: Extends knee (Tibiofemoral and Patellofemoral joints) Patellar ligament Tibial tuberosity Hip-Thigh Anterior Quadrant – Femoral Nerve L2-L4 Vastus medialis Origin: Linea aspera and intertrochanteric line Insertion: Tibial tuberosity via patellar ligament Innervation: Femoral nerve Function: Extends knee (Tibiofemoral and Patellofemoral joints). Hip-Thigh Anterior Quadrant – Femoral Nerve L2-L4 Vastus lateralis Origin: Linea aspera and greater trochanter Insertion: Tibial tuberosity via patellar ligament Innervation: Femoral nerve Function: Extends knee (Tibiofemoral and Patellofemoral joints) Hip-Thigh Anterior & Lateral Quadrants – Superior Gluteal Nerve L4-L5 TFL Tensor Fascia Latae is musc le Origin: Anterior superior iliac spine Insertion: Iliotibial band Innervation: Superior gluteal nerve L4-L5 *L4 segment is from the Femoral nerve IT band is not Functions: Flexes, abducts, and medially muscle & rotates hip (Coxal joint). covers vastus lateralis Leg Anterior & Lateral Quadrants – Fibular Nerve L4-L5 Tibialis Anterior Origin: Tibia lateral condyle and anterior interosseous membrane Insertion: Medial cuneiform and 1st metatarsal Innervation: Fibular nerve L4-L5 Function: Dorsiflex and invert foot (Talocrural joint). Tibialis anterior is the only muscle distal to the knee innervated by the Femoral nerve (in part) because L4 reaches past the knee by hopping onto the Fibular nerve. The Femoral Triangle Separates the anterior from the medial quadrants. Unusual, superficial placement of nerves and arteries is an area of clinical danger. Superiorly, the inguinal ligament runs from the anterior superior iliac spine to pubic tubercle. Laterally, the edge of the Sartorius muscle. Medially, the edge of the Adductor longus muscle. Hip-Thigh Medial Quadrant – Obturator Nerve L2- L4 Obturator Nerve L2-L4. Commonly referred to as the adductor group or “groin” muscles. They work to adduct the hip (Coxal joint). Where should they attach? Hip-Thigh Medial Quadrant – Obturator Nerve L2-L4 Pectineus Origin: Super pubic ramus Insertion: Pectineal line and linea aspera Innervations: Obturator nerve Function: Adduction, flexes, and medially rotates hip (Coxal joint). Hip-Thigh Medial Quadrant – Obturator Nerve L2-L4 Gracilis Origin: Inferior pubic ramus and pubis symphysis Insertion: Medial condyle of tibia Innervation: Obturator nerve Functions: Adduction, flexes, and medially rotates hip (coxal joint). * With sartorius and semitendinosus forms, the Pes Anserinus stabilizes the medial aspect of the knee. Hip-Thigh Medial Quadrant – Obturator Nerve L2-L4 Innervation: Obturator nerve Functions: Adduction, flexes, and medially rotates hip (Coxal joint). Adductor brevis Origin: Inferior pubic ramus Insertion: Linea aspera Adductor longus * Important boundary of the femoral triangle Origin: Inferior pubic ramus Insertion: Linea aspera Hip-Thigh Medial Quadrant – ObturatorPectineus Nerve L2-L4 (covered by Femoral NAVL) Adductor magnus Origin: Inferior pubic ramus Gracilis Insertion: Linea aspera Adductor longus Innervation: Obturator nerve (superficial) Adductor brevis (deep) Functions: Adduction, flexes, and medially rotates hip (Coxal joint). Adductor magnus (deep) is best Cut muscles seen on the posteromedial include: (inner) aspect of the thigh Pectineus Adductor brevis Adductor longus Vastus Leg Medial & Posterior Quadrant – Tibial Nerve L4-L5 Tibialis Posterior Origin: Posterior interosseous membrane Insertion: Navicular, cuneiforms, metatarsals 2-4 Innervation: Tibial nerve L4-L5. Functions: Plantar flexion and invert foot (Talocrural joint). Tibialis posterior is the only muscle distal to knee to be innervated by the Obturator nerve (in part) because L4 reaches past the knee by hopping onto the Tibial nerve. Check your understanding What are the innervation, segments, attachments, and action(s) for the muscles located in the: Anterior quadrant of the hip Anterior quadrant of the leg Medial quadrant of the hip Medial quadrant of the leg Which muscles of the lower limb cross two quadrants? What two quadrants do they span? What is the innervation associated with the muscle? Why do they span those two quadrants? Check your understanding What structure does the femoral nerve pass through? What structure does the obturator nerve pass through? What are the three borders/boundaries for the femoral triangle? What important structure are found within these boundaries? What quadrants are divided by the femoral triangle?