Muscles of Sublumbar and Pelvic Regions PDF

Muscles of sublumbar and pelvic regions  Muscles of the pelvis and thigh 2 groups cannot be sharply differentiated The muscles of the pelvis and thigh are closely connected and often work together, making it hard to separate them into two dist...

Muscles of sublumbar and pelvic regions  Muscles of the pelvis and thigh 2 groups cannot be sharply differentiated The muscles of the pelvis and thigh are closely connected and often work together, making it hard to separate them into two distinct groups. Here’s why: Shared Connections: Some muscles start in the pelvis and end in the thigh, so they belong to both areas. Working Together: These muscles often help with the same movements, like bending or straightening the hip and knee, so they need to be considered together. Overlap: Because of their overlapping roles and locations, it's not easy to say where the pelvis muscles end and the thigh muscles begin. c pas marqué dans cours mais c pr toi)  Thigh muscles: Act primarily on the stifle joint in hindlimb: femur and tibia Designated as: cranial, caudal, and medial Caudal group: Large, fleshy mass on the caudal side of the femur mm. biceps femoris, semitendinosus, and semimembranosus (hamstring muscles Cranial group: m. quadriceps femoris, m. capsularis and m. sartorius cranialis Medial group: m. gracilis, pectineus, adductores, and sartorius caudalis.  Pelvic muscles: Hip muscles belong to the pelvic group and act mostly on the hip joint, but a few act also on the sacroiliac joint pelvis-femur Divided into 3 groups: pelvis-hip bone Lumbar hypaxial muscles: Origin: Ventral surface of the lumbar vertebrae and ilium M. psoas minor, psoas major, iliopsoas, iliacus, and quadratus lumborum. Lateral pelvic muscles: M. gluteus superficialis, medius, and profundus, piriformis, and tensor fasciae latae. Medial pelvic muscles: Deep and partly inside the pelvis M. obturator internus, gemelli, external obturator and quadratus femoris.  Pelvic muscles: Lumbar hypaxial muscles: Origin: Ventral surface of the lumbar vertebrae and ilium Insertion: pelvic bone and femur, organized in several layers Innervate: ventral branches of last few thoracic and lubar nerve M. psoas minor, psoas major, iliopsoas, iliacus, and quadratus lumborum.  Pelvic muscles: Lumbar hypaxial muscles: M. psoas minor Origin: Most ventral muscle arising from the ventral surfaces of the last thoracic and first 4- 5 lumbar vertebrae Insertion: On the ilium adjacent to the iliopubic eminence Function: Mainly to stabilize the vertebral column. It may also rotate the pelvis at the sacroiliac joint.  Pelvic muscles: Lumbar hypaxial muscles: M. Iliopsoas Refers to the combination of the psoas major and the iliacus at their inferior ends. These muscles are distinct in the abdomen, but usually indistinguishable in the thigh. Psoas minor does not contribute to the iliopsoas muscle Function: flexor of the hip and an outward rotator of the thigh Innervation: Femoral nerve which is formed by the nerve roots L4, L5 and L6  Pelvic muscles: Lumbar hypaxial muscles: M. psoas major Origin: It arises laterally from psoas minor muscle and ventral to the quadratus lumborum muscle from the last two thoracic vertebrae and ribs and most of the lumbar vertebrae. Insertion: Common with the iliacus muscle as the iliopsoas, on the lesser trochanter of the femur. Action: Flexes and rotates laterally thigh; The psoas head probably also contributes to the stability of the vertebral column.  Pelvic muscles: Lumbar hypaxial muscles: M. iliacus Origin: Arises from the ilium and fuses with the psoas major muscle Insertion: Lesser trochanter of the femur  Pelvic muscles: Lumbar hypaxial muscles: M. quadratus lumborum Origin: It arises from ventral surfaces last ribs (and from the transverse processes of the lumbar vertebrae) Insertion: On the wing of the sacrum (sometimes also on the ilium). It stabilizes the lumbar portion of the vertebral column. Action: Stabilizes the lumbar portion of the vertebral column  Sacrotuberous ligament Function Stabilization: The sacrotuberous ligament helps stabilize the sacroiliac joint, which is the joint between the sacrum and the ilium (part of the pelvic bone). Limiting Movements: It prevents excessive forward tilting of the sacrum by anchoring it to the ischial tuberosity. Dog: Cord extending between the caudolateral angle of the sacrum and the lateral part of the ischial tuber Cat: Absent Ungulates: Sacrosciatic ligament because it is expanded to a broad sheet that fills the space between the lateral border of the sacrum and the dorsal border of the ilium and ischium, originating 2 foramina adjacent to the greater and lesser sciatic notch  Pelvic muscles: Lateral pelvic muscles: M. gluteus superficialis, medius, and profundus, piriformis, and tensor fasciae latae. Lateral pelvic muscles: tensor fasciae latae. Pelvic muscles: phtot voir screen Origin: Proximally to the tuber coxae and from the aponeurosis of the gluteus medius. Lies between the sartorius cranially, the middle gluteal caudodorsally and the quadriceps femoris distomedially Divided: Cranial portion: more superficial and is inserted on the lateral femoral fascia, which radiates over the quadriceps and blends with the fascial insertion of the biceps femoris. Caudal portion (deeper): inserted on a layer of lateral femoral fascia that runs deep to the biceps femoris toward the stifle on the lateral surface of the vastus lateralis. Action: Tension of the fascia lata and thus tension of the hip joint; extension of the stifle joint. Nerve: Gluteus cranialis. Lateral pelvic muscles: Pelvic muscles: M. gluteus superficialis, Most superficial of the gluteal muscles Origin: Gluteal fascia, tuber sacrale, caudal fascia, lateral border of the sacrum, first caudal vertebra, and half of the proximal part of the sacrotuberous ligament Covers portions of the m. gluteus medius and piriformis, and also the sacrotuberous ligament. Insertion: Trochanter tertius of the femur. Action: Extension of the hip joint. Innervation: N. gluteus caudalis. Lateral pelvic muscles: Pelvic muscles: M. gluteus medius. Largest of the group Origin: Iliac crest and most of the tuber sacrale Some fibers also come from the dorsal portion of the sacroiliac ligament and from the deep surface of the gluteal fascia Lies on the gluteal surface of the ilium Insertion: Greater trochanter Action: Extension of the hip joint Medial rotation of the hip and prevention of lateral rotation during weight bearing Innervation: Cranial gluteal nerve Lateral pelvic muscles: M. gluteus profundus, Pelvic muscles: Origin: Lateral surface of the body of the ilium near the ischiatic spine. Covered by the m. gluteus medius and piriformis Converge over the hip joint distolaterally and form a tendon Insertion: Cranially on the trochanter major distal to the insertion of the m. gluteus medius. Synovial bursa deep to the tendon Action: Extension of the hip and abduction Medial rotation of the hip and prevention of lateral rotation on weight bearing Innervation: Gluteus cranialis Lateral pelvic muscles: M. piriformis. Pelvic muscles: Origin: Lateral surface of the third sacral and first caudal vertebrae. Caudal and medial to the m. gluteus medius and is completely covered by the m. gluteus superficialis Insertion: Joins the m. gluteus medius on the greater trochanter of the femur. Action: Extension of the hip joint. Nerve: Gluteus caudalis.  Pelvic muscles: Medial pelvic muscles: Deep and partly inside the pelvis M. obturator internus, gemelli, external obturator and quadratus femoris. Medial pelvic muscles: Pelvic muscles: M. obturator internus. Origin: Covers the obturator foramen internally Arises medial to the foramen on the pelvic surfaces of the rami of the pubis and ischium, the ischiatic table and from the ischiatic arch It converge laterally and pass over the smooth surface of the lesser ischiatic notch directly caudal to the ischiatic spine and ventral to the sacrotuberous ligament Insertion: Trochanteric fossa Embedded deeply between the edges of the mm. gemelli that lie deep to it. Caudally the tendon of the m. obturator externus accompanies it. Action: Lateral rotation of the hip joint. Nerve: Ischiadicus Medial pelvic muscles: M.gemelli Pelvic muscles: Origin: Lateral surface of the body of the ischium in the arch ventral to the lesser ischiatic notch. Fusion of 2 parts and that lies between the m. obturator internus and externus, and caudal to the m. gluteus profundus and the hip joint. Covered superficially by the internal obturator tendon Insertion: Trochanteric fossa with the obturator internus. Action: Lateral rotation of the hip joint and prevention of medial rotation on weight bearing Nerve: Ischiadicus. Medial pelvic muscles: M.external obturator. Pelvic muscles: Origin: Ventral surface of the pubis and ischium adjacent to the pelvic symphysis. Covers the obturator foramen externally Caudal border is covered by the quadratus femoris and cranial border is hidden by the adductor muscle. Insertion: Fibers converging toward the trochanteric fossa form a thick tendon that passes between the terminations of the gemelli and internal obturator dorsally and the quadratus femoris ventrally. Insert in the trochanteric fossa. Action: Lateral rotation of the hip joint and prevention of medial rotation on weight bearing. Innervation: N. obturatorius. Medial pelvic muscles: M. quadratus femoris. Pelvic muscles: Origin: Arises on the ventral surface of thei schium medial to the lateral angle of the ischial tuberosity. It is surrounded by the origins of the mm. adductor magnus et brevis, semimembranosus, semitendinosus, biceps femoris, and obturator externus. Insertion: Trochanteric fossa. Action: Extension and lateral rotation of the hip joint and prevention of medial rotation on weight bearing. Innervation: Sciatic n.  Pelvic diaphragm Vertical closure of the pelvic cavity through which the rectum passes. M. coccygeus and the m. levator ani The space between the two coccygeus muscles dorsal to the anus is closed by the external anal sphincter and the smooth internal anal sphincter and rectococcygeus muscles  Pelvic diaphragm M. coccygeus Origin: Ischiatic spine, cranial to the internal obturator muscle It crosses the medial aspect of the sacrotuberous ligament Spreading like a fan, extends to the lateral surface of the tail. Insertion: Transverse processes of the second to fifth caudal vertebrae; Ventral to the m. intertransversarii dorsales caudae It is partially covered by the caudal portion of the m. gluteus superficialis. Action: Bilateral: to press the tail against the anus and genital parts and, in conjunction with the depressors, to draw the tail between the pelvic limbs. Unilateral: lateral flexion. Innervation: Ventral branches of the third sacral nerve.  Pelvic diaphragm m. levator ani Origin: Triangular muscle originating on the medial edge of the shab of the ilium, on the dorsal surface of the ramus of the pubis, and on the en]re pelvic symphysis. Lies cranial and medial to the coccygeus. Based on origin, divided into: m. iliocaudalis and m. pubocaudalis Insertion: Bilaterally, the muscles spread out and radiate dorsocaudally toward the root of the tail. They surround the genitalia and rectum. End son the hemal process of the seventh caudal Action: Bilateral: to press the tail against the anus and genital parts; cause the sharp angulation between the sixth and seventh caudal vertebrae, which is characteristic for defecation; compression of the rectum. Unilateral: to bring the tail cranially and laterally. Innervation: Ventral branches of the third (last) sacral and the first caudal nerve  Pelvic diaphragm rectococcygeus muscles Origin: Composed of fibers from the external longitudinal musculature of the rectum. Pass through the fascial arch formed by the attachment of the external anal sphincter to the fascia of the tail Right and left portions of the muscle fuse beneath the third caudal vertebra Insertion: The median muscle formed lies between the ventral sacrocaudal muscles and passes caudally to insert on the fifth and sixth caudal vertebrae. Function: The attachment on the tail serves to anchor the rectum and provide for caudal traction in defecation. Extension of the tail during defecation aids in evacuating the rectum M.rectococcygeus, by shortening the rectum, aids in evacuation of the fecal column. Innervation: Autonomic fibers from pelvic plexus.  Pelvic diaphragm smooth internal anal sphincter m Thickened portion of the circular coat of the anal canal. Composed of smooth muscle fibers and is smaller than the striated external anal sphincter. Between the two sphincter muscles on either side lies the paranal sinuses (anal sacs). The duct from the paranal sinus crosses the caudal border of the internal sphincter muscle.  Pelvic diaphragm the external anal sphincter muscles Composed of striated muscle fibers, surrounds the anus, covers the internal sphincter except caudally, and is largely subcutaneous. Cranial border united by fascia to the caudal border of the levator ani. Dorsally attaches to the caudal fascia at the level of 3rd caudal vertebra. Remaining superficial ventral fibers end on the urethral muscle and the bulbocavernosus muscle (male) or constrictor vulvae (female) Innervation: External anal sphincter: caudal rectal nerve Internal anal sphincter: hypogastric nerves and pelvic plexus  Pelvic diaphragm M rectractor penis: Origin: Arises ventrally on each side of the sacrum or first two caudal vertebrae Divided: pars analis and a pars rectalis. Superficially these retractor muscles are covered by the levator ani, with which there may be some fiber interchange Insertion: Some fibers insert in the external sphincter Male: It continues distally as the retractor penis muscle. Female: It continues as retractor clitoridis  Urogenital diaphragm The hiatus between the pelvic diaphragm and the caudal margin of the pelvic floor is closed by the urogenital diaphragm that is penetrated by the urogenital canal accompanied by the bulbospongiosus or by the constrictor vestibuli and constrictor vulvae muscles Fascia of the urogenital diaphragm attaches to the ischial arch and curves cranially, dorsally, and medially to blend with the ventral edge of the pelvic diaphragm and embrace the vestibule. It helps anchor the reproductive tract against a forward drag when the pregnant uterus sinks within the abdomen and against a backward displacement during parturition.  middle gluteal m superficial gluteal m internal obturator m ? semimembranosus m gracilis m semitendinosus m biceps femoris m gastrocnemius m lateral digital extensor m  thoracolumbar fascia rectus abdominis m middle gluteal m superfiscial gluteal m external obturator m coccygeus muscle internal obturator m gracili m external sartorius m abdominal oblique m gemullus m guadratus lumbrorum m deep gluteal m psoas major m piriformis m iliacus m psoas minor m internal obturator m gracilli m levator ani m en enlevant m d’avant: