Pelvis Anatomy and Structures Quiz

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Questions and Answers

What structure forms the superior part of the acetabulum in the hip bones?

Pubis

Ilium (correct)

Sacrum

Ischium

Which ligament contributes to the boundary of the pelvic outlet?

Sacrospinous ligament

Pubofemoral ligament

Sacrotuberous ligament (correct)

Iliolumbar ligament

Which pubic structure lies along the superior margin of the pubic symphysis?

Pubic crest (correct)

Pecten pubis

Superior pubic ramus

Ischial tuberosity

What is the anatomical position of the lesser pelvis in relation to the greater pelvis?

Inferior to the greater pelvis Signup and view all the answers

Which notch is located inferior to the ischial spine?

Lesser sciatic notch Signup and view all the answers

Which ligament unites the sacrum with the ischial spine?

Sacrospinous ligament Signup and view all the answers

What is the function of the sacrotuberous and sacrospinous ligaments?

They facilitate limited upward movement of the sacrum during increased weight bearing. Signup and view all the answers

Which joint is formed between the auricular surfaces of the sacrum and ilia?

Sacroiliac joint Signup and view all the answers

What structure does the ureter pass medial to in females?

Origin of the uterine artery Signup and view all the answers

Which of the following best describes the lateral boundary of the pelvic compartment?

Obturator foramen Signup and view all the answers

What is the primary function of the detrusor muscle in the urinary bladder?

Pumping urine from the bladder Signup and view all the answers

Which structure is located posterior and slightly superior to the pubic bones?

Urinary bladder Signup and view all the answers

What is the role of the puboprostatic ligaments in males?

Holding the neck of the bladder in place Signup and view all the answers

Which part of the female urethra ends at the external urethral orifice?

Intramural part Signup and view all the answers

What separates the bladder from the pubic bones?

Retropubic space Signup and view all the answers

Where do the seminal vesicles lie in relation to the bladder?

Between the fundus of the bladder and the rectum Signup and view all the answers

What part of the male urethra is surrounded by the internal urethral sphincter?

Intramural part Signup and view all the answers

Which organ is located anteriorly to the rectum and serves as a passage for urine and sperm?

Prostate Signup and view all the answers

What structure connects the ovaries to the lateral pelvic walls?

Suspensory ligament Signup and view all the answers

What anatomical feature is formed by the fusion of the ductus deferens and duct of seminal vesicle?

Ejaculatory duct Signup and view all the answers

Which part of the uterus communicates with the vagina?

Cervix Signup and view all the answers

What is the primary function of the para-urethral glands in females?

Lubricating the urethra Signup and view all the answers

What is the function of the puborectalis muscle related to the rectum?

Forcing a posteroinferior curve Signup and view all the answers

Which part of the anal sphincter is innervated by the pudendal nerve?

External anal sphincter Signup and view all the answers

In females, the broad ligament serves which of the following functions?

Suspending the uterus and ovaries Signup and view all the answers

What is the function of the internal anal sphincter?

Involuntary contraction to maintain continence Signup and view all the answers

Which nerve carries both sensory and motor fibers to the external genitalia?

Pudendal nerve Signup and view all the answers

What anatomical feature is located at the anorectal junction?

Pectinate line Signup and view all the answers

Which structure provides the blood supply to the erectile tissue?

Internal pudendal artery Signup and view all the answers

What action must the puborectalis and external anal sphincter take to prevent defecation?

Voluntary contraction Signup and view all the answers

What is the function of the pelvic splanchnic nerves?

Facilitate visceral reflexes Signup and view all the answers

At which level does the rectum become continuous with the sigmoid colon?

S3 Signup and view all the answers

What structure does the cardinal ligament specifically support in females?

Cervix and vagina Signup and view all the answers

Which ligaments are formed by the gubernaculum in females?

Suspensory ligament of the ovary and round ligament of the uterus Signup and view all the answers

What is the primary function of the levator ani muscle?

Support the pelvic floor Signup and view all the answers

Which muscle passes through the greater sciatic foramen?

Piriformis Signup and view all the answers

What anatomical feature extends laterally and posteriorly from the rectum in females?

Rectouterine pouch Signup and view all the answers

In females, what does the perineal membrane primarily do?

Seals the urogenital triangle Signup and view all the answers

What does the pubococcygeus muscle primarily contribute to?

Maintaining fecal continence Signup and view all the answers

Which ligament is associated with the management of blood flow around the bladder in males?

Puboprostatic ligament Signup and view all the answers

What is the location of the deep perineal pouch?

Inferior to the levator ani Signup and view all the answers

Which structure does the obturator muscle primarily relate to?

Lesser sciatic foramen Signup and view all the answers

In which region does the urogenital diaphragm extend?

From ischial tuberosities to pubic symphysis Signup and view all the answers

Which muscles are part of the pelvic diaphragm?

Coccygeus and levator ani Signup and view all the answers

What is the main role of the superficial perineal pouch?

Contains external genitalia in both sexes Signup and view all the answers

What is the origin of the internal pudendal artery?

Anterior division of internal iliac artery Signup and view all the answers

Which artery supplies the ductus deferens?

Artery to ductus deferens Signup and view all the answers

Where does fertilization typically take place in the female reproductive system?

Uterine tube Signup and view all the answers

What is the primary function of the greater vestibular glands?

Secrete mucus during sexual arousal Signup and view all the answers

What anatomical structure is primarily supplied by the lateral sacral arteries?

Piriformis muscle and vertebral canal Signup and view all the answers

Which artery supplies blood to the lower part of the bladder and prostate?

Inferior vesical artery Signup and view all the answers

What type of drainage does the vesical plexus primarily provide?

Drainage for the inferior vesical veins Signup and view all the answers

What sets the pathway of an unfertilized ovum in the female reproductive tract?

Ovary → peritoneum → uterine tube → body of uterus → cervix → vagina Signup and view all the answers

Which artery runs medially on the levator ani in the female reproductive system?

Uterine artery Signup and view all the answers

Which of the following arteries is responsible for supplying the iliopsoas muscle?

Iliolumbar artery Signup and view all the answers

What is a unique characteristic of venous drainage in the pelvic region?

Accompanied by arteries Signup and view all the answers

Which area drains into the lumbar lymph nodes except for a specific portion of the rectum?

Deep perineal pouch Signup and view all the answers

Where does the ejaculatory duct enter the male reproductive system?

Prostatic urethra Signup and view all the answers

Which structure allows sperm to pass from the epididymis to the ejaculatory duct?

Ductus deferens Signup and view all the answers

What represents the innermost layer of the scrotum?

Tunica vaginalis Signup and view all the answers

Which muscle primarily controls the internal urethral orifice in males?

Internal urethral sphincter Signup and view all the answers

The pampiniform venous plexus is responsible for draining blood from which structure?

Testes Signup and view all the answers

Which component of the spermatic cord arises from the inferior vesical artery?

Artery of ductus deferens Signup and view all the answers

The external urethral sphincter in females originates from which anatomical structure?

Inferior pubic ramus Signup and view all the answers

What stimulates the detrusor muscle to contract during bladder fullness?

Parasympathetic reflex Signup and view all the answers

What is the primary role of the cremaster muscle?

Regulate temperature of the testes Signup and view all the answers

Which part of the urethra is referred to as the membranous urethra in males?

External urethral sphincter Signup and view all the answers

Which cranial nerve fibers are involved in the parasympathetic innervation of the bladder?

Pelvic splanchnic nerves Signup and view all the answers

What structure does the compressor urethrae muscle encircle in females?

Vagina Signup and view all the answers

Which anatomical feature is described as the location where ureters pass obliquely through the bladder wall?

Trigone Signup and view all the answers

What occurs during detumescence?

Decreased firmness of tissue Signup and view all the answers

The sympathetic nerve fibers responsible for the bladder primarily originate from which spinal segments?

T11-L2 Signup and view all the answers

Study Notes

Bony Walls of Pelvic Girdle

The pelvis is located inferoposterior to the abdomen, serving as a transition zone between the trunk and lower limbs.
Comprised of hip bones formed by the fusion of ilium, ischium, and pubis.
Each hip bone features key components:
- Ilium has an ala (fan-shaped) and body (forms the acetabulum).
- Anterior superior and inferior iliac spines are landmarks on the ilium.
- Ischium includes the body, ischial ramus, and notable spines (greater and lesser sciatic notches).
- Pubis consists of the pubic tubercle and superior/inferior pubic rami.
Sacrum is formed by five fused sacral bones, and coccyx consists of four fused coccygeal vertebrae.
The pelvic inlet is bounded by the linea terminalis and includes the pubic symphysis and sacral promontory.
The greater pelvis lies superior to the pelvic inlet while the lesser pelvis is situated between the inlet and outlet.

Joints and Ligaments of Pelvis

Joints:
- Sacro-iliac joints link the auricular surfaces of the sacrum and ilia, providing strong weight-bearing support.
- Interpubic disc found in the pubic symphysis allows slight movement.
- Lumbosacral joint occurs between L5 and S1 vertebrae.
- Sacrococcygeal joint connects the sacrum to the coccyx.
- Zygapophysial joints between L5 and S1.
Ligaments:
- Iliolumbar ligaments connect ilia to the L5 transverse processes.
- Sacro-iliac ligaments (anterior and posterior) stabilize the sacro-iliac joints.
- Interosseous sacro-iliac ligament further supports this joint.
- Sacrotuberous and sacrospinous ligaments maintain the position of the sacrum relative to the ischium.
- Superior and inferior pubic ligaments are located around the interpubic disc.

Bony/Ligamentous Boundaries of the Perineum

Pelvic Compartment:
- Bounded anteriorly by pubic bones, laterally by the obturator foramen, posteriorly by the sacrum, and inferiorly by the pelvic diaphragm.
Perineal Compartment:
- Anteriorly defined by the pubic symphysis, anterolaterally by inferior ischiopubic rami, laterally by ischial tuberosities, and posteriorly by sacrotuberous ligaments extending to the coccyx.

Pelvic Viscera

Ureters:
- Muscular retroperitoneal tubes that run posteroinferiorly towards the bladder and have specific anatomical relations to male and female structures.
Urinary Bladder:
- Located posterior and slightly superior to the pubic bones; expands upward when full.
- Contains trigone area defined by ureteric orifices and internal urinary sphincter.
- Maintained in position by puboprostatic ligaments in males and pubovesical ligaments in females.
Urethra:
- Shorter in females and longer in males, passing through various anatomical structures.
Rectum:
- Begins at the rectosigmoid junction and terminates anteroinferiorly to the coccyx, containing the anal canal and anal flexure.
Male Internal Genital Organs:
- Testes and epididymis involved in sperm production and maturation.
- Ductus deferens transports sperm, seminal vesicles provide fluid, and prostate adds prostatic fluid to semen.
Female Genital Organs:
- Vaginal canal extends from cervix of uterus to vestibule, with the uterus positioned above the bladder.
- Uterine tubes facilitate ovum transport and fertilization, while ovaries produce oocytes and hormones.

Peritoneal Cavity and Ligaments

Forms pouches such as the vesicouterine pouch in females and rectovesical pouch in males, which play roles in fluid accumulation.
Ligaments from gubernaculum include the ligament of the ovary and round ligament of the uterus, while visceral pelvic fascia condenses to form supporting ligaments in the pelvis.

Muscles of the Pelvis

Pelvic Diaphragm:
- Comprised of levator ani and coccygeus muscles that create the pelvic floor and separate the pelvis from the perineum.
Components:
- Pubococcygeus, iliococcygeus, and puborectalis play crucial roles in continence.
- Urogenital diaphragm includes components that support urinary and reproductive structures.

Blood Supply and Lymphatic Drainage

Blood supply primarily from the internal iliac artery, with specific branches supplying pelvic viscera and structures.
Venous drainage mirrors arterial pathways and involves various plexuses around the organs.
Lymphatic drainage from pelvic structures generally follows venous paths, with specific nodes receiving lymph from diverse regions.

Reproductive Tracts

Ovum Pathway:
- Travels from ovary, through peritoneum, into uterine tube for fertilization, followed by implantation in the uterus.
Sperm Pathway:
- Sperm travels through the male reproductive system, including the epididymis, ductus deferens, and out through the urethra.
Functions and positions of reproductive organs are crucial for understanding fertility and sexual health in both genders.### Spermatozoan Pathway
Sperm is produced in seminiferous tubules of the testes.
Travels through straight tubules to the rete testis.
Moves to the epididymis for storage until ejaculation.
The tail of the epididymis continues as the ductus deferens.
Ductus deferens ascends in the spermatic cord through inguinal canal, crossing over external iliac vessels.
Joins duct of the seminal gland to form ejaculatory duct at the lateral wall of the pelvis.
Ejaculatory ducts enter prostatic urethra near the bladder neck via the utricle.
Sperm exits the prostatic urethra into the intermediate urethra, mixing with secretions from bulbospongiosus glands.
Sperm travels through spongy urethra in corpus spongiosum to exit via the external urethral orifice.

Scrotum Layers

Layers from superficial to deep include skin, dartos muscle and fascia, external spermatic fascia, cremaster muscle and fascia, internal spermatic fascia, and tunica vaginalis.
Tunica vaginalis is a remnant of the parietal and visceral peritoneum, surrounding the anterior part of the testis.

Spermatic Cord Contents

Contains ductus deferens, testicular artery, artery of ductus deferens, cremasteric artery, pampiniform venous plexus, sympathetic nerve fibers, genital branch of the genitofemoral nerve, lymphatic vessels, and vestige of the processus vaginalis.
Testicular artery arises from the aorta at L2, supplying the testis and epididymis.
Vasoconstriction leads to increased tone in arteries; detumescence refers to the softening post-ejaculation.

Bladder Innervation

The vesical nerve plexus connects to the inferior hypogastric plexus, consisting of both parasympathetic (pelvic splanchnic nerves) and sympathetic fibers (from T11-L2).
Parasympathetic fibers contract the detrusor muscle and relax the internal urethral sphincter.
Sympathetic fibers relax the detrusor and contract the internal urethral sphincter.
Somatic innervation via the deep perineal branch of the pudendal nerve controls the external urethral sphincter.

Ureters and Urethra

Ureteric orifices and internal urethral orifice located at trigone angles; ureters pass obliquely through bladder wall.
Internal urethral sphincter is involuntary, regulating the internal urethral orifice; muscle fibers in females are continuous with the urethra wall.
External urethral sphincter originates from the inferior pubic ramus and ischial tuberosity, innervated by the deep branch of the perineal nerve.

Rectum and Anal Sphincters

The rectum is part of the alimentary tract, beginning at the rectosigmoid junction at S3.
Contains anal columns, anal sinuses, and anal valves, with a pectinate line separating zones.
Internal anal sphincter is involuntary; relaxation occurs through visceral afferents detecting distension in the rectal ampulla.
External anal sphincter is a voluntary sphincter innervated by S4 via the inferior anal nerve.

Pudendal Nerve

The pudendal nerve carries sensory and motor fibers, innervating external genitalia and sphincters of the bladder and rectum.
Originates in Onuf’s nucleus, sacral plexus (S2-4), passing between piriformis and coccygeus muscles.
Exits pelvis through greater sciatic foramen, reenters via lesser sciatic foramen, giving off inferior rectal nerves, deep perineal nerve (to dorsal nerve of penis/clitoris), and superficial perineal nerve (to post-scrotal/labial region).

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Description

Test your knowledge on the anatomy of the pelvis, including the bony walls, joints, ligaments, and pelvic viscera. Learn about the bony and ligamentous boundaries of the perineum and their anatomical relationships. This quiz covers essential aspects of pelvic anatomy for students of anatomy and health sciences.