Anatomy L54 - 57.pdf

Anatomy Study Tables Lectures 54-57 Christopher Ephron - TBR Campus: (850) 607-3920 Dylan Sehgal - FTL Campus: 440-339-2696 10/1/2024 Study Tables Disclaimer: The Department of Medical Education offers non-mandatory study tables for courses throughout the semester based on the availabi...

Anatomy Study Tables Lectures 54-57 Christopher Ephron - TBR Campus: (850) 607-3920 Dylan Sehgal - FTL Campus: 440-339-2696 10/1/2024 Study Tables Disclaimer: The Department of Medical Education offers non-mandatory study tables for courses throughout the semester based on the availability of student tutors. In the event a qualified student tutor cannot be obtained for a specific course, a study table session may not be provided. The purpose of the study tables is to review the information presented in class by the instructor. All material from the instructor remains the official information students will be tested on. Discrepancies in the material presented by the student tutors will not be eligible for consideration on the exams. The following study tables are resource material meant for individual student use not for distribution. Lectures 54 & 55 Christopher Ephron  Pelvis The pelvis is composed of the sacrum, coccyx, and bilateral hip bones. Each hip bone (innominate bone) has 3 components ○ Illium ○ Ischium ○ Pubis Image taken from: Lecture 54 and 55 These 3 hip bones fuse at the joint socket slide 15 known as the acetabulum Functions of the pelvic girdle ○ Protect pelvic viscera ○ Provide support for viscera ○ Attachment for erectile bodies of genitalia ○ Provide attachment for muscles and Image taken from: Lecture 54 and 55 membranes slide 6  True Pelvis vs False pelvis The False Pelvis aka the greater or major pelvis The True Pelvis aka lesser pelvis ○ Part of the pelvis superior to the pelvic ○ Between pelvic inlet and pelvic outlet inlet ○ Bounded by the hip bones, sacrum, and ○ Bounded by the iliac alae posterolaterally coccyx and S1 posteriorly ○ Contains the pelvic splanchnic nerves ○ Contains abdominal viscera, Image taken from: Lecture 54 and 55 slide 22  Pelvic Inlet The pelvic inlet is delineated by the pelvic brim aka linea terminalis, which is composed of: ○ Sacral promontory ○ Ala of sacrum ○ Arcuate line ○ Pectineal line ○ Pubic crest This line provides a boundary between the true and false pelvis The Pelvic brim is sloped forward and downward at an angle of 55 degrees Image taken from: https://www.sciencedirect.com/topics/veterinary-science-and-veterinary-medicine/pel ○ This is called pelvic tilt vic-brim  Pelvic Outlet The pelvic outlet is the inferior boundary of the true pelvis Boundaries ○ Anterior = pubic symphysis ○ Posterior = coccyx ○ Anterolateral = ischiopubic ramus ○ Posterolateral = sacrotuberous ligament Image taken from: https://clinicalgate.com/pelvis-and-perineum/ Pelvic Inlet vs Outlet Image taken from: Lecture 54 and 55 slide 20  Shapes of the Pelvis Gynecoid = stereotypical female pelvis ○ Round ○ Ideal for child delivery Android = stereotypical male pelvis ○ Heart shaped Anthropoid ○ Anterior segment narrower than posterior ○ Adequate for child delivery Platypelloid ○ Wide transverse and short AP ○ Not conducive to vaginal delivery Image taken from: Lecture 54 and 55 slide 30  Male vs Female Pelvis Image taken from: Lecture 54 and 55 slides 32 and 33 Pelvic ligaments ***The interosseous sacroiliac ligaments are the primary structures transferring the weight of the axial skeleton to the ilia *** relaxin is released during delivery which relaxes the muscles and ligaments of the pelvis Image taken from: Lecture 54 and 55 slides 43 and 44 Pelvic ligaments ***The interosseous sacroiliac ligaments are the primary structures transferring the weight of the axial skeleton to the ilia *** relaxin is released during delivery which relaxes the muscles and ligaments of the pelvis Image taken from: Lecture 54 and 55 slides 43 and 44  Sciatic Foramen Greater Sciatic Foramen Borders Superior = anterior sacroiliac ligament Posteromedial = sacrotuberous ligament Anterolateral = greater sciatic notch of ilium Inferior = sacrospinous ligament and ischial spine Lesser Sciatic Foramen Borders Superior = sacrospinous ligament and ischial spine Anterior = ischial spine, lesser sciatic notch, ischial tuberosity Posterior = sacrotuberous ligament Image taken from: Lecture 54 and 55 slide 40  Joints of the Pelvis Sacroiliac joint ○ Common cause of back pain ○ Unites the axial and appendicular skeleton Pubic Symphysis ○ Fibrocartilaginous disc that unites the pubic bones ○ Superior and inferior pubic ligaments are above and below the symphysis Sacrococcygeal Joint ○ Joins the apex of the sacrum to the base of the Image taken from: Lecture 54 and 55 slide 47 coccyx ○ Reinforced by anterior and posterior sacrococcygeal ligaments Lumbosacral joint ○ Joins L5 and the base of the sacrum  Pelvic Tilt Pelvic tilt is a common cause of immobility and movement dysfunction Posterior pelvic tilt ○ ASIS moves superior, PSIS moves inferior ○ Due to tight hamstrings, abdominal, or gluteal muscles Anterior pelvic tilt ○ ASIS moves inferior, PSIS moves superior ○ Imbalance between pelvic and low back muscles in lower crossed syndrome ○ Can be due to tight hip flexors Lateral pelvic tilt ○ Lateral shift causes one hip to be higher than the other Image taken from: Lecture 54 and 55 slide 56  Birth Canal The birth canal consists of ○ Pelvic inlet ○ Deep pelvis ○ Pelvic outlet ○ Pelvic cavity lies between inlet and outlet Longer posteriorly than anteriorly Image taken from: https://www.sciencealert.com/human-birth-is-seriously-twisted-researchers-think -they-ve-figured-out-why Pelvic Muscles Review Images taken from: Lecture 54 and 55 slides 62 and 63  Superficial Muscles of the Gluteal Region All innervated by superior gluteal nerve (L4 - S1) EXCEPT the Gluteus Maximus, which is innervated by the inferior gluteal nerve (L5 - S2) All perform abduction EXCEPT the tensor fascia lata All perform medial rotation EXCEPT the gluteus maximus performs lateral rotation Gluteus maximus = **lateral rotation, abduction, main thigh extender Gluteus Medius = medial rotation, abduction, tilt pelvis when walking Gluteus Minimus = medial rotation, abduction Tensor Fascia Lata = **thigh flexion, medial rotation, tenses fascia lata ○ Insertion = Iliotibial tract (IT band)  Deep Muscles of the Gluteal Region All perform lateral rotation with NO EXCEPTIONS!! Piriformis + Obturator Internus help with ABduction Obturator Externus helps with ADDuction Mnemonic: PGOGOQ Innervations ○ Piriformis = S1, S2 ○ Superior Gemellus = L5 - S2 ○ Obturator Internus = L5 - S2 ○ Obturator Externus = posterior branch of obturator nerve (L2 - 4) ○ Inferior Gemellus = Nerve to Quadratus femoris ○ Quadratus femoris = Nerve to quadratus femoris  Piriformis The piriformis originates from the anterior aspect of the sacrum and travels through the greater sciatic foramen before attaching to the greater trochanter of the femur Area above the piriformis = suprapiriform recess ○ Contains the superior gluteal neurovascular bundle Area below the piriformis = infrapiriform recess ○ Contains the inferior gluteal neurovascular bundle The sciatic nerve also travels below the piriformis ○ Spasm of the piriformis may lead to sciatica Images taken from: Lecture 54 and 55 slide 65  Pelvic floor The pelvic floor is composed of the Levator ani muscle and coccygeus muscle Levator ani is composed of 3 muscles (all innervated by S4 and pudendal nerve) ○ Puborectalis U shaped sling that surrounds the rectum Controls fecal continence ○ Pubococcygeus ○ Iliococcygeus Elevates the pelvic floor Coccygeus (AKA ischiococcygeus) ○ Most posterior muscle of pelvic floor Images taken from: Lecture 54 and 55 slide 80  Pelvic Walls Lateral wall = obturator internus Posterosuperior wall = piriformis Images taken from: Lecture 54 and 55 slide 81 Pelvic and Peritoneal Fascia Images taken from: Lecture 54 and 55 slides 83 and 90 Questions Which of the following describes the false pelvis? a. It is also known as the lesser pelvis b. It is the area between the iliac alae and the pelvic inlet c. It is the area between the pelvic inlet and pelvic outlet d. It contains the pelvic splanchnic nerves Which of the following describes the false pelvis? a. It is also known as the lesser pelvis b. It is the area between the iliac alae and the pelvic inlet c. It is the area between the pelvic inlet and pelvic outlet d. It contains the pelvic splanchnic nerves What is the anterior border of the pelvic inlet? a. Ala of the sacrum b. Arcuate line c. Sacrotuberous ligament d. Pubic symphysis What is the anterior border of the pelvic inlet? a. Ala of the sacrum b. Arcuate line c. Sacrotuberous ligament d. Pubic symphysis Which of the following is a heart-shaped pelvis? a. Android b. Gynecoid c. Platypelloid d. Anthropoid Which of the following is a heart-shaped pelvis? a. Android b. Gynecoid c. Platypelloid d. Anthropoid *** bonus: is this more common in males or females? Which of the following is a heart-shaped pelvis? a. Android b. Gynecoid c. Platypelloid d. Anthropoid *** bonus: is this more common in males or females? males T/F: The male pelvis has a wider pubic arch than the female pelvis a. True b. False T/F: The male pelvis has a wider pubic arch than the female pelvis a. True b. False What is the inferior border of the greater sciatic foramen? a. Sacrotuberous ligament b. Sacroiliac ligament c. Sacrospinous ligament d. Pubic symphysis What is the inferior border of the greater sciatic foramen? a. Sacrotuberous ligament b. Sacroiliac ligament c. Sacrospinous ligament d. Pubic symphysis Tight hip flexors would likely lead to what kind of pelvic tilt? A. Anterior B. Posterior C. Lateral D. Medial Tight hip flexors would likely lead to what kind of pelvic tilt? A. Anterior B. Posterior C. Lateral D. Medial A patient is feeling weakness in their posterior leg and thigh with numbness and tingling down into their foot. Spasm of what muscle may be causing these symptoms? a. Gluteus maximus b. Piriformis c. Biceps femoris d. Gluteus medius A patient is feeling weakness in their posterior leg and thigh with numbness and tingling down into their foot. Spasm of what muscle may be causing these symptoms? a. Gluteus maximus b. Piriformis c. Biceps femoris d. Gluteus medius *** bonus: what nerve is being affected? A patient is feeling weakness in their posterior leg and thigh with numbness and tingling down into their foot. Spasm of what muscle may be causing these symptoms? a. Gluteus maximus b. Piriformis c. Biceps femoris d. Gluteus medius *** bonus: what nerve is being affected? Sciatic nerve Which muscle of the pelvic floor forms the rectal sling? a. Puborectalis b. Ischiococcygeus c. Pubococcygeus d. iliococcygeus Which muscle of the pelvic floor forms the rectal sling? a. Puborectalis b. Ischiococcygeus c. Pubococcygeus d. iliococcygeus Lectures 56-57 Dylan Sehgal  Blood Supply https://anatomy.lexmedicus.com.a Abdominal aorta -> common iliac u/collection/pelvis-hip arteries -> external/internal iliac arteries Internal iliac artery supplies blood to pelvic organs, gluteal muscles, peritoneum Clinical Correlation: Ligation of of Internal Iliac artery ○ Does not stop blood flow but reduces BP ○ Due to 3 Anastomoses Lumbar (aorta) to iliolumbar Median sacral (aorta) to lateral sacral Superior rectal (IMA) to middle rectal  Branches of Internal Iliac Artery Posterior trunk: ○ Iliolumbar ○ Lateral sacral ○ Gluteal (superior) Anterior trunk: ○ Internal Pudendal (inferior rectal, scrotal/labial, perineal, deep and dorsal arteries of the penis and clitoris ○ Inferior vesical ○ Inferior gluteal ○ Middle rectal ○ Obturator ○ Umbilical (superior and middle vesical) ○ Uterine (vas deferens in men) ○ Deferential Artery https://ditki.com/course/gross-anatomy/gloss ary/gross-anatomic-microscopic-structure/ar teries-internal-iliac-branches  http://xradiologist.com/dual%20blood%20sup ply%20to%20ovary/index.html Ovary Supply Ovarian arteries direct branches off the abdominal aorta Ovarian veins ○ Left drains into the left renal vein ○ Right drains into the inferior vena cava https://anatomyqa.com/ ovary-anatomy/  Venous Return Small veins -> internal iliac vein -> https://teachmeanatomy.info/pelvis/vasculature/venous-drainage/ common iliac vein -> IVC Vertebral Venous plexus of Batson ○ Collateral drainage within the neural canal ○ Drains into the superior sagittal sinus internal and external iliac vein merge to for the common iliac vein which then dumps into the inferior vena cava  Dr. Jones Slides Lymphatics External/internal inguinal lymph Nodes ○ Region of trunk and perineum Internal Pelvic lymph nodes ○ Perineum and gluteal region External iliac lymph nodes ○ External: Femoral vein Internal iliac lymph nodes ○ Perineum and gluteal region Sacral lymph nodes ○ Between pelvic organs and internal iliac nodes Common iliac lymph nodes ○ Receive from other pelvic nodes Pararectal Nodes ○ Proximity of internal iliac lymphatic vessels Lumbar ○ Along aorta and IVC Superficial inguinal and deep inguinal ○ Region of the trunk and perineum  https://www.jaypeedigital.com/book/9788184484618/chapter/ch10 Superficial Inguinal LN Superficial fascia below the inguinal ligament 2 groups: horizontal and vertical ○ horizontal - below and parallel to inguinal ligament Medial: Anterior abdominal wall Perineum Urethra External genitalia Lower half of anal canal Lateral Below iliac crest - gluteal region ○ Vertical - along great saphenous vein Lymph from LE  https://www.jaypeedigital.com/book/9788184484618/chapter/ch10 Deep Inguinal Lymph Node Located in deep fascia of the thigh - medial side of femoral vein ○ Drainage from glans of penisor clitorisas well as superficial lymph nodes ○ Drains directly into the external iliac lymph nodes  Common - Internal/External LN Located around the common, external, and internal iliac arteries Drain into the para-aortic LN ○ Arranged around the right and left sides of aorta ○ Receive lymph from(kidney-suprarenal glands)—(testes or ovaries-uterine tubes-fundus of uterus)— (abdominal wall- common iliac lymph nodes) Cutaneous Innervation/ Dermatomes Dr. Jones Slides Dr. Jones Slides Lumbosacral Plexus https://www.osmosis.org/answers/lumbosacral-plexus  Nerve Travel Sciatic Nerve : Runs UNDER piriformis muscle and through greater sciatic foramen Superior Gluteal Nerve: Travels SUPERIOR piriformis and through greater sciatic foramen. Also laterally, between gluteus medius + minimus Inferior Gluteal Nerve: Travels INFERIOR piriformis, DEEP to gluteus maximus, SUPERFICIAL to sciatic nerve, through the greater sciatic foramen Nerve to Quadratus Femoris: Travels INFERIOR piriformis through greater sciatic foramen Nerve to Obturator Internus: Travel INFERIOR piriformis, through greater sciatic foramen, LOOPS BACK AROUND, and re-enters through the lesser sciatic foramen. Posterior Femoral Cutaneous Nerve: Travels INFERIOR piriformis, travels through greater sciatic foramen, lies alongside the sciatic nerve. Pudendal Nerve: Travels INFERIOR piriformis, through greater sciatic foramen, LOOPS BACK AROUND to enter the PERINEUM, through the lesser sciatic foramen entering the PUDENDAL CANAL  Inferior Piriformis: Greater Sciatic Foramen ○ Sciatic ○ Sciatic ○ Inferior gluteal ○ Inferior gluteal ○ Nerve to quadratus femoris ○ Superior gluteal ○ Nerve to obturator internus ○ Nerve to quadratus femoris ○ Posterior femoral cutaneous nerve ○ Nerve to obturator internus ○ Pudendal nerve ○ Posterior femoral cutaneous nerve ○ Pudendal nerve Superior Piriformis: Lesser Sciatic Foramen ○ Superior gluteal nerve ○ Nerve to obturator internus ○ Pudendal nerve  Clinical: Anesthesia Childbirth ○ Spinal = L3 - L4 subarachnoid space. Waist down is numb (even legs) ○ Pudendal = S2 - S4 dermatomes - feel for ischial spine Lower ¼ vagina and most perineum are anesthetized https://www.advancedpaintherapynj.com/pudendal-nerve-blocks.html Cervix, uterus, and upper vagina are not affected - thus FEEL CONTRACTIONS ○ Epidural Give in advance and is most preferred It affects S2-S4 nerve roots, pain fibers from the uterus and upper vagina, and the afferent fibers from the pudendal. Therefore, the birth canal, most of the perineum, and the pelvic floor are anesthetized. LEGS ARE SPARED Caudal Anesthesia ○ Feel for sacral hiatus ○ Used in pediatrics for subumbilical procedures such as inguinal hernias and urological interventions ○ Helps with back pain 57  Pelvic/Urogenital Diaphragm https://aneskey.com/pelvis-and-perineum/ Skeletal muscle areas that support the pelvic and perineal structures ○ Innervated by pudendal nerve Pelvic Diaphragm ○ Separates pelvis from perineum ○ Two muscles: Levator ani and coccygeus Puborectalis is the sling that marks the boundary between rectum and anal canal Urogenital Diaphragm ○ Inferior to pelvic diaphragm ○ 2 muscles: Sphincter urethrae and deep perineal muscles (Horizontal) ○ Penetrated by urethra in males, urethra/vagina in female ○ Sphincter urethrae also serves as external urethral sphincter (voluntary muscles of micturition) Surround membranous urethra and maintains urinary continence.  Pelvic Outlet Surface: Diamond Area when legs are spread ○ Anatomical Borders: Coccyx (P), Ischial tuberosities (L), inferior pubic ramus (L), pubic symphysis (A), Roof: Pelvic floor, Base: Skin/fascia Closed by pelvic diaphragm, covered by perineum, and reinforced by urogenital diaphragm ○ Surface Borders Base of Penis (A/Males) or Mons pubis (A/Females), Medial surface of thighs (L), Superior end of the intergluteal cleft (P) Two Triangles ○ Urogenital Triangle and Anal triangle A line connecting the ischial tuberosities divides the two and overlies the perineal body (central tendon) Fibromuscular mass located in median plane between anal canal and the vaginal orifice (female) and bulb of the urethra (male) Both share levator ani muscles and blood supply  Ischio-Anal Fossa Space filled with fat just lateral to the anal https://teachmeanatomy.info/pelvis/areas/perineum/ canal and below the pelvic diaphragm Laterally by the ischium and overlapping inferior part of the obturator internus, covered with obturator fascia. Medially by the external anal sphincter, with a sloping superior medial wall or roof formed by the levator ani as it descends to blend with the sphincter; both structures surround the anal canal. Posteriorly by the sacrotuberous ligament and gluteus maximus. Anteriorly by the bodies of the pubic bones, inferior to the origin of the puborectalis  Urogenital Triangle Borders: ○ Anterior: Pubic Symphysis ○ Posterior: line between ischial tuberosities Contents: ○ External Genitalia (F: labia majora, minora, mons pubis; M: penis, scrotum, testes, epididymis, spermatic cord) ○ Perineal Muscles - superficial and https://teachmeanatomy.info/pelvis/areas/perineum/ deep transverse perineal muscles ○ Erectile Tissue (F: clitoris; M: corpus cavernosum, corpus spongiosum)  Anal Triangle https://www.jaypeedigital.com/book/9788184484564/chapter/ch16 Borders ○ Anterior: line between ischial tuberosities ○ Posterior: Coccyx, Sacrotuberous ligament, Gluteus maximus ○ Superior: Levator ani muscles forms floor Contents: ○ Fat, Inferior rectal vessels and nerve ○ Posterior femoral cutaneous nerve ○ Anal canal and anus Guarded by external anal sphincter ○ Pudendal canal (Alcock’s canal) Internal Pudendal artery, vein, and pudendal nerve Canal is made from obturator internus fascia  Perineal Body Supports the pelvic diaphragm If damaged it can compromise the integrity https://teachmeanatomy.info/pelvis/areas/perineum/ of pelvic diaphragm Clinical: episiotomy - incision made to increase vaginal canal during childbirth - care is taken to make incision lateral to the perineal body Attachments: ○ Superficial and deep transversus perineal muscles ○ Bulbospongiosus muscle (originates from the perineal body) ○ Levator ani muscle ○ Sphincter ani muscle ○ Superficial and deep perineal fascia Ischiocavernosus does not attach to the perineal body  Dr. Jones Slides Female External Genitalia Mons Pubis: Round fatty eminence anterior to pubic symphysis ○ Bigger during puberty and smaller during menopause ○ Covered with hair Labia Majora ○ Two folds of skin that provide protection for urethral, vaginal openings and great vestibular glands ○ United anteriorly by anterior labial commissure and posterior via posterior labial commissure ○ Fourchette: Membrane in young children over posterior commissure Labia Minora ○ Thin delicate folds of fat free hairless skin between labia majora Clitoris ○ Erectile organ measuring 2-3 cm ○ No transferred by urethra (No corpus spongiosum) ○ Posterior to anterior labial commissure and anterior to urethra/vaginal orifices Blood Supply: ○ Internal/External pudendal arteries Nerves ○ Ilioinguinal nerve (L1) and genital branch of the genitofemoral nerves (L1-L2) Male Genitalia Dr. Jones Slides Outlet for urine and semen Consists of root, body, and glans penis Body has two muscles ○ Ischiocavernosus muscle When enters body of penis, turns into corpus cavernosum ○ Bulbospongiosus muscle When enters body of penis, turns into corpus spongiosum Surrounds penile urethra Enlarges distally to form glans penis Remember P and S: Point (parasympathetics) and Shoot (sympathetics) Dr. Jones Slides Epididymis, Testicle, Scrotum Dr. Jones Slides Epididymis ○ Small compacted tubules that store/mature sperm ○ Posterior of testes ○ Contains head, body, and tail that is continuous with ductus deferens Testes ○ Left is typically lower than right ○ Covered via tunica albuginea (Tough) ○ Produces sperm and hormones (Testosterone) ○ Tunica vaginalis covers a thin layer around testes Scrotum ○ Fibromuscular sac that contain testes and other structures ○ There is a midline scrotal raphe what is continuous with ventral surface of penis and posterior with the raphe of the perineum ○ Blood supply: Internal/external pudendal, testicular, and cremasteric arteries ○ Nerve: Ilioinguinal, genital branch of the genitofemoral, posterior femoral cutaneous (Perineal branches)  Prostate Location Inferior - external urethral sphincter Anterior - retropubic space, prostatic venous plexuses, puboprostatic ligament Posterior - rectovesical fascia (denonvilliers fascia), ampulla of rectum Lateral - pelvic floor, levator ani https://learnsurgeryonline.com/prosta te/  Homologous Perineal Structures Male/Female Dr. Jones Slides Any Questions