Class 1 Flashcards
What is the sacral promonotory and ala of the sacrum?
What is the arcuate line (OF THE ILIUM)?
(Not same as the arcuate line of the rectus sheath)
What is the pecten pubis also called?
Where is it located?
AKA Pectineal line
Ridge on the superior ramus of the pubic bone
Describe the location of the pubic crest.
What attaches here?
Medial to the pubic tubercle is the pubic crest, which extends from this process to the medial end of the pubic bone.
Gives attachment to the conjoint tendon, the rectus abdominis, the abdominal external oblique muscle, and the pyramidalis muscle.
List the structures/ bony margins forming the boundary of the inferior pelvic aperture (pelvic outlet)
- Inferior margin of pubic symphysis anteriorly
- Inferior rami of the pubis (and ischial tuberosities) anterolaterally
- Sacrotuberous ligaments posterolaterally
- Tip of the coccyx posteriorly
Which parts of the pelvis are termed the true and false pelvis?
True below inlet
False above inlet
How do the greater and lesser pelvis (pelvis major and minor) differ in male and female?
Greater pelvis:
- Female: Shallow
- Male: Deep
Lesser Pelvis:
- Female: Wide and Shallow
- Male: Narrow and Deep
What is the shape of the pelvic inlet and outlet like in men and women?
Pelvic inlet:
- Female: Oval and rounded
- Male: heart shaped
Pelvic outlet:
- Female: Comparatively large
- Male: comparatively small
How does the subpubic angle differ between males and females?
Female: Obtuse -> greater than 90 degrees
Male: Acute -> less than 90 degrees
How do the obturator foramens differ between men and women?
Females -> oval
Male -> round
How does the acetabulum differ in men and women?
Females -> small
Men -> large
What type of joints are the sacroiliac and pubic symphysis joints?
Sacroiliac joint -> synovial plane
Pubic symphysis -> secondary cartilaginous
What are the walls of the pelvic cavity?
- Antero-inferior wall
- (formed by the bodies and rami of the pubic bones and the pubic symphysis)
- Two lateral walls
- Posterior wall
Which muscle occupies the lateral pelvic wall?
Obturator internus
Which muscle is present on the posterior wall of the pelvis?
Piriformis
Which nerve network lies on the muscle forming the posterior wall of the pelvis?
Sciatic
What forms the pelvis floor?
Levator ani + ischiococcygeus
Levator ani = puborectalis, pubococcygeus, iliococcygeus
What is a raphe?
a groove, ridge, or seam in an organ or tissue, typically marking the line where two halves fused in the embryo
What are the perineal and anococcygeal bodies?
Irregular fibromuscular mass located in the median plane
What is the function of the pelvic diaphragm/ floor
- Support of abdominopelvic viscera (bladder, intestines, uterus etc.) through their tonic contraction.
- Resistance to increases in intra-pelvic/abdominal pressure during activities such as coughing or lifting heavy objects.
- Urinary and fecal continence. The muscle fibers have a sphincter action on the rectum and urethra. They relax to allow urination and defecation.
What is the innervation of the pelvic diaphragm/ floor?
PUDENDAL NERVE
Damage to the pelvic floor during childbirth is common and potentially damaging.
Why?
- Weakening of levator ani and pelvic fascia
- This alters position of the neck of the bladder and urethra causing urinary stress incontinence
What is an episiotomy and why does it minimise damage during childbirth?
Enlarges vaginal opening by cutting into muscular area between vagina and anus (perineum)
This reduced damage to pelvic floor
name 3 parts of the alimentary system that are present in the pelvis
- rectum
- Anal canal
- transverse colon
Branches of the right and left internal iliac artery distribute blood to most of the pelvic organs, perineum and gluteal region except what?
- Testes
- ovary
- upper part of rectum
The venous drainage of the pelvis structures consists of which 5 different veins?
- Internal iliac veins
- Superior rectal veins
- Median sacral vein
- Gonadal veins
- Internal vertebral venous plexus
Which part(s) of the rectum drain into the portal and systemic circulation?
Superior = portal
Middle and inferior = systemic
The veins along the sides and base of the prostate join to form the prostatic venous plexus.
With which venous plexus does the prostatic venous plexus communicate on its posterior side?
Batson Venous Plexus
This drains into the internal vertebral venous plexus.
Cancer commonly spreads through this route from prostate to vertebral bodies
Which nerve supplies skin at the root of the penis in the male and the labia in the female?
Ilioinguinal nerve
What nerve root does the ilioinguinal nerve originate from?
L1