Repro Anatomy 1 Flashcards
On the below diagram locate the following bony landmarks that make up the superior pelvic aperture (pelvic inlet/pelvic brim)
A
Sacral Promontory
On the below diagram locate the following bony landmarks that make up the superior pelvic aperture (pelvic inlet/pelvic brim)
B
Ala of Sacrum
On the below diagram locate the following bony landmarks that make up the superior pelvic aperture (pelvic inlet/pelvic brim)
C
Pubic Tubercle
On the below diagram locate the following bony landmarks that make up the superior pelvic aperture (pelvic inlet/pelvic brim)
D
Pubis Symphysis
On the below diagram locate the following bony landmarks that make up the superior pelvic aperture (pelvic inlet/pelvic brim)
E
Arcuate Line of Ilium
On the below diagram locate the following bony landmarks that make up the superior pelvic aperture (pelvic inlet/pelvic brim)
F
Pecten Pubis
On the below diagram locate the following bony landmarks that make up the superior pelvic aperture (pelvic inlet/pelvic brim)
G
Pubic Crest
The pelvic outlet is the inferior opening of the pelvis and is formed by bony features and ligaments
A
Inferior Margin of Pubic Symphysis
The pelvic outlet is the inferior opening of the pelvis and is formed by bony features and ligaments
B
Sacro-tuberous Ligaments
The pelvic outlet is the inferior opening of the pelvis and is formed by bony features and ligaments
C
Inferior Rami of Pubis
The pelvic outlet is the inferior opening of the pelvis and is formed by bony features and ligaments
D
Tip of Coccyx
what is the true pelvis?
(lesser pelvis)
below the pelvic brim between the pelvic inlet and the pelvic floor
located superiorly, it provides support of the lower abdominal viscera (such as the ileum and sigmoid colon). It has little obstetric relevance.
what is the false pelvis?
(greater pelvis)
above and in front the pelvis brim
located inferiorly. Within the lesser pelvis reside the pelvic cavity and pelvic viscera
what type of joint is the Sacroiliac joint?
Synovial
what type of joint is the Pubic Symphysis?
Secondary Cartilaginous
a secondary cartilaginous joint (a joint made of hyaline cartilage and fibrocartilage) located between the left and right pubic bones near the midline of the body
which is the male pelvis and which is the female pelvis?
left is male pelvis and right is female pelvis
Lesser pelvis (pelvis minor)
what is it like in males and females?
female - wide and shallow
male - narrow and deep
Pelvic inlet
what is it like in males and females?
female - oval shaped + rounded
male - heart shaped
Pelvic outlet
what is it like in males and females?
female - comparatively larger for child birth
male - Comparatively smaller
Subpubic angle
what is it like in males and females?
female - Obtuse: Greater than 90o
male - Acute: Less than 90o
Acetabulum:
what is it like in males and females?
female - small
male - large
Obturator foramen:
what is it like in males and females?
female - oval
male - round
With regards to the female pelvis and normal vaginal delivery:
What is the narrowest diameter of the pelvic inlet?
What is the narrowest diameter of the pelvic outlet?
13cm
11cm
The pelvic cavity has an antero-inferior wall, two lateral walls and a posterior wall.
The anterior-inferior wall is formed by the bodies and rami of the pubic bones and the pubic symphysis.
Which muscle is present in the posterior wall of the pelvis?
Piriformis and coccygeus
what is labelled?
sciatic nerve
what are the nerve roots of the sciatic nerve?
A combination of 5 nerve roots that exit from inside the lower lumbar and upper sacral spine - L4, L5, S1, S2, and S3
Which nerve network lies on the muscle forming the posterior wall of the pelvis?
sacral plexus
A
Levator ani – pubococcygeus
B
Levator ani – iliococcygeus
C
Puborectalis
D
Anococcygeal ligament
E
Perineal body (female)
what is the perineal body?
fibromuscular node lying in the midline of the perineum. It is pyramidal in shape and provides an anchor point for several of the muscles within the perineum
anococcygeal body?
the ligament runs in the midline between the inferior two segments of the coccyx and the posterior aspect of the rectum
2 muscles make up the majority of the pelvic floor – one of these has 3 separate paired muscles
what are the 2 muscles?
coccygeus muscle
levator ani muscles (3 paired seperate muscles)
Give two functions of the pelvic diaphragm/floor
1) Support of abdominopelvic viscera
2) Resistance to increases in intra-pelvic/abdominal pressure
3) urinary and faecal continence
What is the innervation of the pelvic diaphragm/floor?
anterior ramus of S4 and branches of pudendal nerve (roots S2, S3 and S4)
what is a cystocele?
prolapsed, herniated, dropped or fallen bladder – ligaments that hold up bladder and muscles between a women’s vagina and bladder stretches or weakens, allowing bladder to sag into the vagina
what is a rectocele?
herniation of the front wall of the rectum into the back wall of the vagina
Clinical – Pelvic Floor Injury
Injury to pelvic floor during childbirth is common and potentially damaging.
Why?
Can lead to incontinence (stress incontinence)
Why may an episiotomy minimise long-term damage?
Can help to prevent a severe tear of the perineum or speed up delivery
Why is a mediolateral episiotomy preferable to a midline episiotomy?
Lower risk of third and fourth degree laceration. Can lead to faecal incontinence
what is A and B?
bladder
what is C and D?
prostate
uterus, ovaries
what is E and F?
Rectum
Clinical – Digital Rectal Examination
As part of the clinical examination of the abdomen, a digital rectal examination (DRE) forms an important aspect of formulation of a diagnosis.
What structures can be palpated when performing a DRE (in males and in females)
Male: Prostate(, seminal vesicles, bladder)
Female: Cervix
Branches of the right and left internal iliac artery distribute blood to most of the pelvic organs, perineum and gluteal region except the testis, ovary and upper part of rectum.
Label the main branches of internal iliac artery on the image below
A
Common iliac artery
Branches of the right and left internal iliac artery distribute blood to most of the pelvic organs, perineum and gluteal region except the testis, ovary and upper part of rectum.
Label the main branches of internal iliac artery on the image below
B
Internal iliac a.
Branches of the right and left internal iliac artery distribute blood to most of the pelvic organs, perineum and gluteal region except the testis, ovary and upper part of rectum.
Label the main branches of internal iliac artery on the image below
C
Umbilical artery
Branches of the right and left internal iliac artery distribute blood to most of the pelvic organs, perineum and gluteal region except the testis, ovary and upper part of rectum.
Label the main branches of internal iliac artery on the image below
D
Superior vesical arteries
Branches of the right and left internal iliac artery distribute blood to most of the pelvic organs, perineum and gluteal region except the testis, ovary and upper part of rectum.
Label the main branches of internal iliac artery on the image below
E
Posterior division of the internal iliac artery
Branches of the right and left internal iliac artery distribute blood to most of the pelvic organs, perineum and gluteal region except the testis, ovary and upper part of rectum.
Label the main branches of internal iliac artery on the image below
F
Anterior division of internal iliac
Branches of the right and left internal iliac artery distribute blood to most of the pelvic organs, perineum and gluteal region except the testis, ovary and upper part of rectum.
Label the main branches of internal iliac artery on the image below
G
Inferior gluteal
Branches of the right and left internal iliac artery distribute blood to most of the pelvic organs, perineum and gluteal region except the testis, ovary and upper part of rectum.
Label the main branches of internal iliac artery on the image below
H
Internal pudendal
Bladder, seminal gland and prostate in males (and ureter)
anterior division of the internal iliac artery
the terminal branches of the internal iliac artery:
Arteries of pelvis - uterine artery
What is its distrubution/organ and what is its origin/branch of?
branches to the cervix and the vagina, small vessels to the uterine tube and the round ligament of the uterus
only in female, anterior division of internal iliac
the terminal branches of the internal iliac artery:
Arteries of pelvis - Gonadal (testicular or ovarian)
What is its distrubution/organ and what is its origin/branch of?
testicular = testes, within abdomen they supply the perirenal fat, ureter and iliac lymph nodes, within the spermatic cord, they supply the cremaster muscles
Ovarian = uterus, ovary, ureter, skin of labia and inguinal region, receives lymph form the lumbar lymph nodes
aorta
the terminal branches of the internal iliac artery:
Arteries of pelvis - Superior rectal artery
What is its distrubution/organ and what is its origin/branch of?
sigmoid colon, rectum and anal canal
terminal branch of the inferior mesenteric artery
the terminal branches of the internal iliac artery:
Arteries of pelvis - Middle and inferior rectal
What is its distrubution/organ and what is its origin/branch of?
middle = lower rectum, inferior = anal skin and musculature, skin of the buttock
internal iliac
the terminal branches of the internal iliac artery:
Arteries of pelvis - Vaginal
What is its distrubution/organ and what is its origin/branch of?
vagina, bulb of the vestibule, fundus of the bladder, contiguous part of the rectum
uterine artery
the terminal branches of the internal iliac artery:
Arteries of pelvis - Internal pudendal
What is its distrubution/organ and what is its origin/branch of?
Main artery to perineum
internal iliac
the terminal branches of the internal iliac artery:
Arteries of pelvis - Obturator
What is its distrubution/organ and what is its origin/branch of?
pelvic muscles and hip joint
internal iliac
The venous drainage of the pelvic structures is complex and involves interplay between the portal and systemic circulations. This has clinical significance especially in some pathologies e.g. liver cirrhosis, pelvic cancers
There are many venous plexuses formed in relation to pelvic organs (for example: rectal, prostatic) – some of these have clinical significance (e.g. prostatic venous plexus)
Which part(s) of the rectum drain(s) into the portal circulation?
Which part(s) of the rectum drain(s) into the systemic circulation?
superior
middle and inferior
What is the significance of understanding the venous drainage of the rectum?
may cause haemorrhoids in liver cirrhosis portal systemic anastomosis is there
Why might haemorrhoids be associated with cirrhosis of the liver?
due increased to increased portal pressure
The veins along the sides and base of the prostate join to form the prostatic venous plexus.
This makes the prostate a very vascular organ – important to consider the risks of bleeding associated with operations in the area.
With which venous plexus does the prostatic venous plexus communicate with on its posterior side?
Why is this important – think of how prostate cancer spreads…?
internal vertebral venous plexus
it can spread to bones easy, spreads to spinal cord
Nerve Supply to the Reproductive Organs
Somatic Nerves
The ___________ _____ originates from L1 and enters the inguinal canal at the _________ inguinal ring to supply skin at the root of the penis in the male and the labia in the female.
The __________ nerve originates at L1-2 and enters at the ____ inguinal ring.
ilioinguinal nerve
superficial
genitofemoral
deep
What structure(s) in the male are supplied by the genital branch of the genitofemoral nerve?
cremaster muscle and anterior scrotal skin
The pudendal nerve arises from the _____ plexus and follows the course of the pudendal artery to innervate the skin and the muscles of the perineum.
sacral
From which segmental level(s) does the pudendal nerve arise?
S2-4
note how the pudendal nerve travels from pelvis to perineum, via the gluteal region. This arrangement is essential to understand in bilateral pudendal nerve block for pain relief during childbirth, particularly for an instrumental (e.g. forceps) assisted vaginal birth
What bony landmarks are used when performing a pudendal nerve block during labour?
ischial spine
The autonomic nerve supply to the pelvis originates from the where?
pelvic plexus (or inferior hypogastric)
The sympathetic fibres originate from L1 and L2 via the hypogastric nerve and terminal aspect of the sympathetic trunk.
These fibres hitchhike on the arterial supply to reach their target organs.
They provide sympathetic supply to all internal pelvic organs.
In a male they supply the vas deferens, seminal vesicles, prostate and epididymis.
In a female they supply the ovaries, uterus, fallopian tubes and vagina.
Parasympathetic fibres in the pelvis originate from the pelvic splanchnic nerves (S2 to S4). In addition to providing parasympathetic supply to all the internal pelvic organs, they innervate erectile tissues in both male and female.
Confusing Splanchnics…
It is very easy to get confused when describing “splanchnic” nerves, as both parasympathetic and sympathetic nerves can be described as such
In the thorax the greater, lesser and least splanchnic nerves are ____________
In the pelvis the pelvic splanchnic nerves are ________________
sympathetic
parasympathetic
Applied clinical question:
After rectal surgery, why are some men unable to ejaculate?
Which part of the autonomic nervous system has been affected?
damage to sympathetic fibres
sympathetic, L1 and 2 sympathetic fibres
Lymphatics of the Pelvis
There are four primary nodes present in the pelvis receiving the lymphatic drainage of the pelvic organs. They are variable in number, size and location.
Remember that the lymphatic drainage of the pelvis tends to follow the arterial supply
Lymph node group in the pelvis - what pelvic area do the extenral iliac lymph nodes drain?
directly from pelvic structures, inguinal lymph nodes
Lymph node group in the pelvis - what pelvic area do the internal iliac lymph nodes drain?
Gluteal region, deep perineum and inferior pelvic viscera
Lymph node group in the pelvis - what pelvic area do the sacral lymph nodes drain?
posteroinferior pelvic viscera
Lymph node group in the pelvis - what pelvic area do the common iliac lymph nodes drain?
Drainage from the three main groups: external, internal and sacral lymph nodes
