1.1.1 Pelvis & Pelvic Diaphragm Flashcards
The puborectalis runs posterior to the anorectal junction forming what angle?
Anorectal angle
Describe the pelvic diaphragm
A muscular funnel that surrounds the anal canal
Infections around the anus and rectum
Perianal abscesses
What is the most important subdivision of the levator ani muscle when is comes to birthing?
pubococcygeous b/c it encircles; most often injured muscle during parturition
Name this space and its clinical significance.
Sacral Hiatus; Epidural injections
What this be?
Bleeding due to straddle injury
Describe the anatomical boundaries of the perineum
When does the pelvis completely fuse?
~20 years of age
What shape of pelvis?
Android - typical male shaped pelvis
What are the covered parts
Describe the dimensions of the pelvic inlet (explain the diagonal and obstetrical (true) conjugate.
The pelvic diaphragm is made of what two muscles?
Levator ani muscle
coccygeus muscle
What are the three parts of the external anal sphincter? What is its innervation?
Inferior rectal nerve (S2-4)
Which hormones are thought to partially degrade the cartillage of the immobile joints of the pelvis to allow for some movement?
Progesterone and Relaxin
Type of injuries that damage external genitalia which may lead to bleeding into the superficial perineal space
Straddle injuries
Describe the lymphatic drainage above an below the pectinate line.
Above - internal iliac lymph node
Below - Superficial inguinal lymph node
What type of exercises are thought to help prevent injury during parturition?
Kegel exercises
What shape of pelvis?
Gynecoid - typical female shaped pelvis
Formed by the ishial tuberosities and the tip of the coccyx
Anal triangle
The inferioposterior portion of the abdomen that serves as a transition from the trunk to lower limb
Pelvis
The surface of the pubic surface gets smoother until what age? When does it start to pit?
~30-40 years; >50 years
Shape of pelvis?
Anthropoid - a pelvis that has an enlongated anterior to posterior dimension, similar to man
What are the three subdivisions of the levator ani muscle?
pubococcygeous, puborectalis, iliococcygeous
What is the innervation of the internal anal sphincter?
Pelvic splanchnic nerve
What this be?
Anal fissure
What are the bones present in the bony pelvis?
Compare these structures of male and female pelves: general structure, subpubic angle, greater pelvis, true pelvis, pelvic brim, and pelvic outlet.
Compare the angles of the subpubic angle in males and females?
Females: ~90 degrees
Males: 70 degrees
Area b/t the upper thighs
Perineum
What are the two spaces created by the perineal membrane?
What runs through the pelvic diaphragm in men? females?
Males: Anus and urethra
Females: anus, urethra, and vagina
What does the peritoneum include in women?
Anus and vulva (external genitalia)
Shape of pelvis?
Platypelloid
What three bones fuse together to form the innominate bone?
ilium, ischium, and pubis
Identify these three muscles
What three types of fascia can be present in the superficial membranous fascia
What does the peritoneum include in men?
anus, penis, and scrotum
What are the two areas of the pelvis?
What is true about pelvic fractures?
Most commonly have multiple fractures when fractures occur; most commonly due to car accidents
What type of joint is the sacroiliac joint?
fibrous and synovial
Identify
A fibrocartillagenous joint with an interpubic disc b/t the pubic bones in the midline
Pubic symphysis
What are the characteristics of a pilonidal cyst?
What are the covered parts?
