The pelvis Flashcards
What area of the pelvis is the false pelvis?
Ilium
What is does the false pelvis contain?
Pelvic inlet
Does not have any pelvic organs
What is the pelvic outlet?
Where everything comes out- feces, urine, babies
It’s part of the lesser/true pelvis
What is the true pelvis?
Houses the pelvic organs- bladder, reproductive organs etc.
What do the pelvic ligaments do?
Prevent the pelvis from rotating superiorly and helps protect the organs
Sacrospinous ligaments attachments
Goes from sacrum down to ischial spine
sacrotuberous ligaments attachments
goes from sacrum to ischial tuberosity
Intraosseous Sacroiliac ligaments attachments
Goes from sacrum to ilium
What is the purpose of the intraosseous sacroiliac ligament?
Transmit all the force from the upper body to the lower body
What are the male pelvis features?
- Pelvic inlet is heart shaped
- Pelvic outlet is oval
- Sub-pubic angle can be estimated with peace fingers
- Lesser Q-angle
What are the female pelvis features?
- Pelvic inlet is oval shaped
- Pelvic outlet is circular
- Sub-pubic angle can’t be approximated with peace fingers
- Pelvis is wider in general
- Greater Q-angle
Origin and Insertion of Piriformis muscle
O: 2nd-4th sacral segments, greater sciatic notch, and sacrotuberous ligament
I: Greater trochanter of femur
Innervation of Piriformis muscle
Nerve to the piriformis (S2, S3)
Piriformis muscle action
Rotates the thigh laterally, A-Bducts the thigh, and holds the femur in the acetabulum
Obturator internus origin and insertion
O: Pelvic surface of ilium and ischium, obturator membrane
I: Greater trochanter of femur
Action of the obturator internus muscle
rotates the thigh laterally, holds the femur in the acetabulum
Innervation of obturator internus muscle
Nerve to the obturator internus
L5,S1,S2
Characteristics of obturator internus muscle
- Passes through lesser sciatic foramen
2. Lined by the obturator internus membrane which forms the tendinous arch
Characteristics of piriformis muscle
- Passes through greater sciatic foramen
- Posterior muscle
- Provides a bed for the sacral plexus
Pelvic floor contents
- coccygeus muscles
2. Levator ani muscles
What are the Levator ani muscles?
- Puporectalis
- Pubococcygeus
- Iliococcygeus
Origin and insertion of levator ani muscle
O: Body of pubis, tendinous arch of levator ani, ischial spine
I: perioneal body, coccyx, anococcygeal ligament, walls of prostate, vagina, rectum, anal canal
Action of levator ani muscle
Supports pelvic viscera, resists increases in intra-abdominal pressure
Levator ani innervation
- Nerve to levator ani (S4)
- Inferior Rectal nerve
- Coccygeal plexus
Origin and insertion of coccygeus muscle
O: ischial spine
I: Inferior end of sacrum
Action of coccygeus muscle
Supports pelvic viscera, flexes coccyx
Coccygeus muscle innervation
branches of S4 and S5 nerves
Branches of lumbar plexus
- Lumbosacral trunk
- Obtruator nerve
- Accessory Obturator nerve (if present)
Sciatic nerve
- Divides into anterior and posterior divisions
- Exits via greater sciatic foramen
- Supplies everything in the leg minus the anterior compartment
What is Sciatica?
pain causes from piriformis muscle impinging the sciatic nerve
What are the branches from the sciatic nerve?
- Common femoral/ peroneal
- Tibial
- Pudendal
- Superior and Inferior Gluteal
Characteristics of pudendal nerve
- nerve of shame- goes to genitalia and reproductive parts
- part of anterior division
- exits pelvis from greater sciatic foramen
- enter perineum via lesser sciatic foramen
What are the branches of the pudendal nerve?
- dorsal nerve of the clitoris or penis
- Perineal nerves
- Inferior rectal nerve
Characteristics of superior gluteal nerve
- innervates gluteus minimus and medius, and the tensor fascia latae muscles
- part of the posterior division
- Exits the pelvis via the greater sciatic forament
Characteristics of the inferior gluteal nerve
- Innervates the gluteus maximus
- Part of the posterior division
- Exits the pelvis via the greater sciatic foramen
Where does the sympathetic chain end?
ganglion impar
What levels are the sympathetics located?
T11-L2 spinal segments
synapse in inferior mesenteric ganglion
What levels are parasympathetics located?
S2-S4
called pelvic splanchnic nerves
Where do parasympathetics synapse?
- In ganglia
2. On target organ or gut plexus
What are the branches of the common iliac artery?
- Internal iliac
2. External iliac
What are the divisions of the internal iliac artery?
- Anterior division
2. Posterior division
What arteries are in the anterior division?
- Umbilical
- Obturator
- Inferior vesicular
- Middle rectal
- Internal pudendal
- Inferior gluteal
- Uterine
What artery branches from interior vesicular?
prostatic
What artery branches from the uterine artery?
vaginal
What does the umbilical artery supply?
Gives off the superior vesicular artery that supplies the bladder and ductus deferens in males
What does the obturator artery supply?
Pelvic muscles, ilium, and head of the femur
What does the inferior vesicular artery supply?
Bladder and ureters
What does the prostatic artery supply?
seminal gland and prostate
What does the rectal artery supply?
Seminal gland, prostate, and rectum
What does the internal pudendal artery supply?
Main artery to perineal skin and urogenital triangle, erectile tissues
What does the inferior gluteal artery supply?
Piriformis, coccygeus, levator ani, and gluteus maximus
What does the uterine artery supply?
Ureter, uterus, uterine tube, and vagina
What does the vaginal artery supply?
Vagina and bladder
What arteries are in the posterior division?
- Iliolumbar
- Lateral sacral
- Superior gluteal
What does the iliolumbar artery supply?
iliacus, psoas major, quadratus lumborum muscles, cauda equina
What does the lateral sacral artery supply?
Piriformis muscle and vertebral column
What does the superior gluteal artery supply?
This vessel can come off the anterior!
gluteal medius, gluteal minimus, and the tensor fascia latae
Describe the male urethra
- internal urethral sphincter- bladder muscle continuous with prostate fibromuscular tissue
- Much longer with 2 curves
- Passes through the prostate
- composed of 4 parts
What are the 4 parts of the male urethra?
- Pre-prostatic
- Prostatic
- Membranous vs. spongy part
- external urethral meatus
Where are the ejaculatory ducts located?
Part of the prostatic urethra
What joins to make the ejaculatory ducts?
seminal vesicles and ductus deferens join and mix with the prostatic ducts to make semen
What are the parts of the uterine tubes?
- Isthmus
- Ampulla-
- Infundibulum- opening
- Fimbriae- finger-like projections
Where is the isthmus of the uterus?
Narrow passageway from the body to the cervix
What 2 structures are a remnant of the gubernaculum that support the uterus?
- ovarian ligament
2. Round ligament
What are the mesenteries of the broad ligament?
- Mesovarium- attaches ovareis to mesosalpinx
- Mesosalpinx- connects uterine horns to uterus
- Mesometrium- attaches uterus to body wall
Innervation of the vagina?
- lower 1/4 deep perineal branch of pudendal
2. Upper 3/4 autonomics
What is the normal placement of the uterus?
anteverted + anteflexed
What do the bulbourethral glands do?
secrete before ejaculation to clean the urethra
What nerve allows erection of the penis?
Parasympathetic fibers of the prostatic nerve plexus
During a prostate removal these fibers are often resected causing impotency
