What 3 bones fuse to form the pelvis?
At what structure does the union of these bones occur?
Where do the paired pelvic bones (os coxa) articulate anteriorly? Posteriorly?
• The pelvis (os coxa) is formed by the fusion of three bones: ilium, ischium, and pubis.
• The union of these three bones occurs at the acetabulum.
• The paired os coxae articulate posteriorly with the sacrum at the sacroiliac (SI) joints and anteriorly with the pubic symphysis.
Identify the labeled bony structures.
The pelvic outlet is diamond-shaped and formed by ____ AND ____.
The pelvic outlet is diamond-shaped and formed by bone AND ligaments.
What are the boundaries of the pelvic outlet?
The anterior part of the pelvic outlet is formed by the pubic symphysis. The lateral edge is formed by the ischiopubic ramus. The sacrotuberous ligament extends from the ischial tuberosity to the coccyx and sacrum completing the pelvic outlet.
Pelvic outlet bounded by:
1. Inferior margin of pubic symphysis
2. Inferior rami of pubis and ischial tuberosities
3. Sacrotuberous ligament
4. Sacrum and coccyx
What type of joint is the sacroiliac joint? Describe the mobility of this joint.
What ligaments reinforce the sacroiliac joint?
What type of joint is the pubic symphysis? What ligaments reinforce it?
Lumbosacral - between L5 and S1 vertebrae
1. Sacroiliac - strong synovial joints/ very little motion here; reinforced by the anterior and posterior sacroiliac ligaments and the interosseous sacroiliac ligament.
2. Pubic symphysis - fibrocartilaginous joint; reinforced by the superior and inferior pubic ligaments.
The pelvic foramina allow for communcation between what parts of the body?
Key concept: The pelvic foramina allow for Communication between the:
• Abdomen and Pelvis
• Pelvis and Lower Extremity
• Pelvis and Perineum.
What structures pas through the following foramina? If applicable, state what forms the foramina:
greater sciatic foramen
lesser sciatic foramen
• covered by obturator membrane, obturator internus and externus muscles.
• transmits obturator nerve and artery through obturator canal.
Greater Sciatic Foramen
• major route of communication between the pelvic cavity and the lower limb.
• transmits the superior and inferior gluteal nerves and vessels, piriformis muscle, sciatic nerve, pudendal nerve, internal pudendal vessels, posterior femoral cutaneous nerves, and the nerves to the obturator internus and quadratus femoris muscles.
Lesser sciatic foramen
• formed by the lesser sciatic notch, ischial spine, sacrospinous and sacrotuberous ligaments.
• transmits the obturator internus muscle to the femur.
• transmits the pudendal nerve and internal pudendal vessels to the perineum.
Explain the pathway that the pudendal nerve takes through the pelvis.
The pudendal nerve exits greater sciatic foramen, loops under the sacrospinous ligament, goes through lesser sciatic foramen, and then goes under ishchiopubic ramus.
What are the 3 openings of the urinary bladder?
2 openings fro entrance of urine from ureters, 1 outflow opening to urethra
Identify the labeled structures of the urinary bladder.
What part of the bladder frequently gets infected in UTIs?
Where is the neck of the bladder?
What does the male reproductive system consist of?
The male reproductive system consists of the paired testes, epididymis, ductus deferens, seminal vesicles, ejaculatory ducts, prostate gland and penis.
Identify the labeled structures.
The _____ covers the superior aspect of most pelvic organs.
The peritoneum covers the superior aspect of most pelvic organs.
What pelvic structures does the peritoneum cover in males? What pouch is formed in the process?
The pelvic cavity is lined by peritoneum continuous with the peritoneum of the abdominal cavity that drapes over superior part of the pelvic cavity. The bladder is anterior and the rectum is posterior. (In females, the uterus lies between the bladder and rectum.)
• from the anterior abdominal wall to the level of the pubic bone,
• superior surface of the urinary bladder
• posterior surface of the bladder
• caps the seminal vesicles
• lines the rectovesical fossa (pouch)
• envelops the sides of the rectum (upper 1/3)
What vessels is the ureter near? What are its anatomical relationships to these vessels?
What is the relationship of the ureter to the vas deferens?
• anterior to the common iliac artery - medial to the obturator vessels
• posterior and inferior to the vas deferens
Where does the vas (ductus) deferens enter the pelivs?
What is its relationship to the inferior epigastric vessels? To the ureter?
What is the terminal portion of the ductus deferens called?
What is the relationship of the semainl vesicules the vas deferens?
Vas (ductus) Deferens
• enters the pelvis at the deep inguinal ring
• lateral to the inferior epigastric vessels - anterior (and superior) to the ureter
• terminal portion of the vas expands to form the ampulla
• lateral to the ampulla of the vas deferens
What structures come together to form the ejaculatory ducts? What structure do the ejaculatory ducts open into?
• union of vas deferens and ducts of seminal vesicles
• open into the prostatic urethra of the seminal colliculus (future lecture)
What forms the base of the urinary bladder and receives the ejaculatory duct?
• base of the urinary bladder
• receives the ejaculatory duct
What are the 3 parts of the male urethra?
Male Urethra (3 parts)
1. Prostatic urethra
2. Membranous urethra (in deep perineal space)
3. Penile spongy urethra
What are the 2 important openings of the prostatic urethra? From what structures does it accept contents?
What 2 urethral spincters are present in male? What types of muscle are they made of? What are their functions?
There are 2 important openings in the prostatic urethra. The urethral sinuses have openings for the prostate and the seminal colliculus has openings for the ejaculatory ducts.
Key concept: There are 2 urethral sphincters.
• The Internal Urethral Sphincter is made of smooth muscle and constricts during ejaculation to prevent the flow of semen into the urinary bladder.
• The External Urethral Sphincter is made of skeletal muscle and is under voluntary control.
Key relationships on the male posterior urinary bladder
Identify the labeled structures of the male bladder.
What structures are covered by peritoneum in the female pelivs? What pouces are formed from this?
The pelvic cavity is lined by peritoneum continuous with the peritoneum of the abdominal cavity that drapes over superior part of the pelvic cavity. The bladder is anterior and the rectum is pos-terior. In women, the uterus lies between the bladder and rectum.
1. from the anterior abdominal wall
2. to the level of the pelvic bone
3. superior surface of the urinary bladder
4. forms the vesicouterine pouch
5. covers fundus, body of the uterus; extends over posterior fornix and wall of the vagina
6. forms the rectouterine pouch (Pouch of Douglas)
7. passes on to the front and sides of the rectum
Generally, how does the urethra in females compare to the urethra in males?
What are the fornices of the vagina?
Urethra – very simple and short
-Anterior, posterior, and two lateral fornices
-Upper portion of the posterior wall covered by peritoneum
fornix means arch
What are the parts of the uterus?
• Body - upper two thirds
• Fundus - rounded part of the body that lies superior to the orifices of the uterine tubes
• Isthmus - constricted region just above the cervix
• Cervix - narrow, inferior portion that protrudes into the uppermost vagina
What are the parts of the uterine tube?
Uterine Tube (Fallopian Tube)
• Infundibulum - funnel shaped distal end, opens into the peritoneal cavity
• Ampulla - widest and longest part, oocytes usually fertilized here
• Isthmus - thick walled part, enters the uterus horn
• Uterine part - short segment that passes through the uterine wall and opens through the uterine cavity
What connects the ovaries to the pelvic wall? What structures are conveyed within this structure?
Ovaries - connected to the lateral pelvic wall by the suspensory ligament of the ovary (which conveys the ovarian vessels, lymphatics, and nerves to the ovary)
How many layers of pertioneum make up the broad ligament of the uterus?
What are the 3 parts of the broad ligament of the uterus?
What is contained within the broad ligament of the uterus?
Broad ligament of the uterus
• two layers of peritoneum
• 3 parts: mesosalpinx, mesovarium and mesometrium
• uterine tube is contained within its free margin
• contains the round ligament of the uterus and the proper ligament of the ovary
• the lateral extension and fold of the broad ligament is the suspensory ligament of the ovary, it contains the ovarian vessels and lymphatics, and autonomic nerves .
What is the anatomical relationship of the ureter (in females) to the following structures?:
common iliac aa
The relationship of the uterine artery to the ureter is critically important. The ureter runs under the uterine artery. Remember that “water runs under the bloody bridge.”
• Crosses the pelvic brim anterior to the common iliac artery.
• Runs medial to the obturator vessels.
• Posterior to the ovary
Identify the labeled structures.
Identify the labeled structures.
What is the difference btwn the pelvic floor and pelvic diaphragm?
There are differences between the pelvic floor and the pelvic diaphragm.
1. The pelvic diaphragm is formed by the levator ani and coccygeus muscles from both sides.
2. The pelvic floor is formed by the pelvic diaphragm, the deep and superficial perineal spaces.
3. The pelvic floor separates the pelvic cavity, above, from the perineum, below.