Anatomy of the uterus and cervix Flashcards
1
Q
Describe the shape and size of the uterus
A
1) It is a hollow pear-shaped organ that sits on the urinary bladder
2) It is flattened anteroposteriorly (it appears triangularin a coronal section, and like a slit in a saggital section)
3) It measures 1 inch in thickness, 2 inch in width, and 3 inch in length
2
Q
Describe the relationship between the body and the cervix in females before and after puberty
A
Before puberty, the body and cervix are equal in length, however, after puberty, the body becomes twice the length of the cervix
3
Q
What are the different levels of the fundus of the uterus during pregnancy?
A
1) In 12 weeks, it is in the pelvis
2) By the 24th week, it is close to the umbilicus
3) By the 36th week, it is close to the costal margin
4
Q
Where is the uterus situated?
A
1) It lies in the middle of the lesser pelvis with the uterine tubes and ovaries on either sides
2) It is between the sigmoid colon, rectum, and the urinary bladder
5
Q
What are the different parts of the uterus?
A
1) Fundus (above the entrance of the fallopian tube “cornu”)
2) Body (between the fallopian tube and the cervix)
3) Cervix (the narrowest part, projects to the vagina, it is surrounded by a fornix between it and the upper part of the vaginal wall “vault”)
6
Q
What are the various ligaments attached to the uterus?
A
1) Ovarian ligament
2) Round ligament
3) Uterosacral ligament
7
Q
What is the cornu?
A
It is an intramuscular part that forms the entrance of the uterine tubes, AKA intramural part”
8
Q
What is the fornix?
A
- Pouches/gaps around the opening of the cervix in the vagina
- There are 4 fornixes in total (1 anterior, 1 posterior, and 2 laterals)
9
Q
What is the Isthimus?
A
- It is part of the cervix that is adjacent to the body
- It is mainly used by clinicians, and it is not an anatomical structure
- If a woman is pregnant, it increases in length and becomes soft (Hegar’s sign)
10
Q
Describe the cavity of the cervix
A
It communicates with the cavity of the body at the internal OS (opening), and with the cavity of the vagina at the external OS (opening)
- The area around the internal OS is the isthimus
11
Q
What are the structural changes that occur in the external OS (opening)?
A
It is circular in nullipara; however, after the first childbirth, it tears during the process, and it will have an anterior lip and a posterior lip
12
Q
Describe the anatomical position of the uterus
A
1) In the erect posture with the bladder empty, the uterus lies in a horizontal plane
2) The body of the uterus is freely mobile, and as the bladder fills with urine, the uterus rises
3) The cervix of the uterus is not mobile as it is held in position by several ligaments
13
Q
Which part of the uterus is mobile?
A
The body of the uterus
14
Q
Which part of the uterus is not mobile?
A
The cervix as it is held on by multiple ligaments
- The Cervix is fixed anteriorly to the pubic symphysis via the pubocervical ligament
- The Cervix is fixed posteriorly to the sacrum via the sacrocervical (AKA uterosacral) ligament
15
Q
What are the various possible rotations of the uterus?
A
- Most women
1) Anteverted
2) Anteflexed
- Some women
3) Retroversion
4) Retroflexion
- FYI: “Version” is both the body and cervix (the angle is between the uterus and the vagina), while “Flexion” means the body only (the angle is between the body and the cervix)
16
Q
What is meant by anteflexed?
A
When the long axis of the body of the uterus is bent forward at the level of the internal OS (opening) with the long axis of the cervix at 170 degrees (between the body and cervix)
- In the anteverted and anteflexed position, the uterus is pressed against the bladder when the intra-abdominal pressure is increased
17
Q
What is meant by anteverted?
A
The long axis of the uterus is bent forward on the long axis of the vagins (-90 degrees “between the uterus and the vagina”)
- In the anteverted and anteflexed position, the uterus is pressed against the bladder when the intra-abdominal pressure is increased
18
Q
What is meant by retroversion?
A
The cervix and the body of the users are bent backwards on the vagina
- Retroversion and retroflexion can be very dangerous because they can get a prolapse of the uterus, Uterus usually rests on bladder; in this case, it’s completely resting on the pelvic floor, which can eventually collapse
19
Q
What is meant by retroflexion?
A
When the body of the uterus is bent backwards
- Increased intra-abdominal pressure tends to push the introverted uterus into the vagina which might result in prolapse
- Retroversion and retroflexion can be very dangerous because they can cause a prolapse of the uterus. The uterus usually rests on the bladder; in this case, it’s completely resting on the pelvic floor, which can eventually collapse
20
Q
What are the relations of the body of the uterus?
A
1) Anterior surface: Covered by peritoneum, which reflects forward onto the superior surface of the bladder to form the uterovesical pouch
2) Posterior surface: Covered by peritoneum which extends over the posterior fornix of the vagina into the anterior surface of the rectum forming the rectouterine pouch (Pouch of douglas)
21
Q
What are the relations of the anterior surface of the body of the uterus?
A
It is covered by peritoneum, which reflects forward on the superior surface of the bladder, forming the uterovesical pouch
22
Q
What are the relations of the posterior surface of the body of the uterus?
A
It is covered by peritoneum, which reflects onto the anterior surface of the rectum, forming the rectouterine pouch (pouch of Douglas)
- The Douglas pouch is prone to accumulating pus and infection when the patient is lying supine (approached through the posterior fornix to remove the pus)
23
Q
What are the relations of the cervix of the uterus?
A
1) Anteriorly (supra-vaginal part: Non-peritoneal, and it is related to the base of the bladder
2) Posteriorly: It is covered with peritoneum and it is related to the sigmoid colon and the small intestine
24
Q
What are the different types of uteral support?
A
1) Primary
2) Secondary
25
What are the primary support?
1) Muscular
2) Visceral
3)Fibro-muscular
26
What are the muscular support of the uterus?
1) Pelvic diaphragm
- Musculo-fascial partition between the pelvic cavity and perineum
- Pubovaginalis is part of the pubococcygeus-main support
2) Perineal body
- Fibromuscular node
3) Urogenital diaphragm
- Musculo-fascial partition
27
What is the visceral support of the uterus?
1) Urinary bladder
2) Vagina
3) Uterine axis
28
What is the fibromuscular support of the uterus?
- All of them are attached to the cervix (and thus it is immobile)
1) Pubo-cervical ligament (anterior pelvic wall)
2) Sacro-servical ligament (posterior pelvic wall)
3) Trans-cervical/Cardinal/Mackenrodt's ligament (lateral pelvic wall)
- The ureter and the uterine vessels lies in the upper part of the cardinal ligament
4) Round ligament
29
What are the secondary support of the uterus?
1) Peritoneal folds
2) Pelvic connective tissue
30
What are the peritoneal folds that form the secondary support of the uterus?
1) Broad ligament
2) Utero-vesical fold
3) Recto-uterine fold
31
What is the broad ligament?
It is a wide, flat sheet of connective tissue that stretches from the sides of the uterus to the lateral walls and the floor of the pelvis, acting like a mesentry for the uterus and fallopian tubes
- It holds the uterus in position, supports the ovaries and uterine (fallopian tube), and contains important structures
- It can be involved in endometriosis, ectopic pregnancy, or tumors like broad ligament fibroids.
32
What are the divisions of the broad ligament?
1) Suspensory ligament of the ovary & infundibulopelvic ligament (some say the infundibulopelvic isn't part of it)
2) Mesometrium (the largest portion, and it surrounds the uterus)
3) Mesosalpinx (the upper part, and it supports the fallopian tube)
4) Mesovarium (the posterior fold, it attaches to the ovary and contains ovarian vessels)
33
What are the features of the suspensory ligament of the ovary/infundibulopelvic ligament?
- It is the lateral quarter of the upper edge of the board ligament
- It contains the ovarian vessels and lymphatics
34
What is the mesovarium?
It suspends the ovary from the posterior surface of the broad ligament
35
What is the mesosalpinx?
It lies between the uterine tube and the mesovarium
36
What is the mesometrium?
connects the ovary to the uterus
- from superior to inferior:
1: Mesosalpinx
2: Mesovarium
3: Mesometrium
37
What is the content of the round ligament?
1) Areolar tissue
2) The ligament of the ovary and the round ligament of the uterus
3) Uterine and ovarian vessels and lymphatics
4) Embryonic remnants (which might accumulate fluid and form cysts like Gartner duct cysts)
38
What is the ligament of the ovary?
- It connects the uterine pole of the ovary to the Cornu of the uterus
- It provides a structural support
- It is visible as a ridge on the posterior layer of the broad ligament
39
What are the parts of the uterine tube?
1) Infundibulum: Trumpet-like expansion of the lateral end
2) Ampulla: Medial continuation of the infundibulum (the site where fertilization usually occurs)
3) Isthmus: (near to the opening into the body "before it enters the muscle")
4) Intramural part: the narrowest part of the uterine tube (it passes through the uterine wall)
40
How can infection of the vagina, uterus or the tubes result into peritonitis?
The uterine tube allows communication between the peritoneal cavity and the exterior of the body through the uterus and vagina and thus infection in those structures can result into peritonitis
41
What is the relationship between the appendix and the ovary and uterus?
The appendix lies close to the ovary and uterine tube. This close relationship can explain why a ruptured tubal pregnancy or peritonitis might be misdiagnosed as acute appendicitis, where in both cases, the parietal peritoneum is inflamed, and the pain is referred to the right lower quadrant of the abdomen
42
What is salpingitis?
- Inflammation of the fallopian tube, mainly due to STI (Chlamydia trachomatis, Neisseria gonorrhea)
- It will lead to the blockage of the uterine tube, which is a major cause of infertility
43
What is meant by hysterosalpingography?
It is the injection of a radiopaque material into the uterus and the tubes to study the patency of the tube and the abnormalities of the uterus
44
Where is the ovary situated?
1) New born: Above the pelvic brim
2) In nulliparous: It lies in the ovarian fossa
- External iliac vessels anteriorly
- Internal iliac vessels and ureter posteriorly
- The obturator nerve crosses the floor of the fossa
3) After pregnancy: The position of the ovary is variable
- Before puberty, the ovary is smooth; however, after puberty it becomes progressively scarred due to degeneration of the corpora lutea
45
What are the boundaries of the ovary in nulliparous women?
1) Anteriorly: External iliac vessels
2) Posteriorly: Internal iliac vessels and ureter
3) Floor: Obturator nerve
46
What is meant by irritation of obturator?
- A diseased ovary may cause pain along the medial side of the thigh, due to the irritation of the obturator nerve in the ovarian fossa
- The obturator nerve sends a cutaneous branch to the medial thigh
47
Describe ovarian pain?
- Originally the ovary abdominal organ (embryoligically), and thus the sensory innervation is sympathetic
- Mittelschmerz (middle pain)
1) Para-umbilical pain experienced by some women at ovulation
2) Streching of the ovarian wall
3) Afferent impulses reach the central nervous system at the T10 segment, and the pain is referred to T10 dermatome
48
Describe the structure of the vagina?
- It extends upwards and backwards from the vulva
- It is 8cm long
- Has opposed anterior and posterior walls
- The urethra is embedded in the anterior wall
- The posterior wall is more extended than the anterior wall; hence, the posterior fornix is deeper
49
What are the relations of the vagina?
1) Anterior: Base of the bladder above and urethra
2) Posterior relation:
- Upper third: Peritneum of the rectouterine pouch of Douglas
- Middle third: Rectal ampulla
- Lower third: Perineal body separating the vagina from the anal canal
3) Lateral relations:
- Upper part (above the pelvic diaphragm): Ureter, uterine artery and the lateral cervical ligament
- Middle part: Levator ani
- Lower part: Urogental diaphragm, build of the vestibule and the greater vestibular gland
50
51
52
53
What are the structures felt in a vaginal examination?
1) Anteriorly: Bladder, Urethra, Pubic (when the bladder is empty)
2) Posteriorly: Rectum, douglas pouch
3) Laterally: Pulsation of the uterine artery, rarely a stone in the ureter (through the ateral fornix)
4) Apex: Cervix (you can feel the degree of dilatation during labour, and the consistency of the cervix which becomes soft during pregnancy and has the consistency of a lip)
54
55
56
57
58
What supports the vagina?
1) Upper part: Levator ani, transverse cervical, pubocervical and the sacrocervical ligament
2) Middle part: Urogenital diaphragm
3) Lower part: Perineal body
59
What supports the upper part of the vagina?
1) Levator ani
2) Transverse cervical
3) Pubocervical and the sacrocervical ligament
60
What supports the middle part of the vagina?
Urogenital diaphragm
61
62
What is a vaginal fistula?
- An open communication between the vagina and the adjacent bladder, urethra, rectum, or the perineum
63
What are the types of the vaginal fistula?
1) Vesicovaginal and urethrovaginal fistulas: the urine will enter the vagina
- If the flow of urine is continuous, it is attributed to a vesicovaginal fistula
- If the urine flow occurs during micturation only, then it results from a urethrovaginal fistula
2) Rectovaginal fistula: the fecal matter would discharge from the vagina
3) Vagioperineal fistula: opening into the perineal region/ischiorectal fossa
64
What is the cause of a vaginal fistula?
Obstetrical trauma during long and difficult labor
65
What is the blood supply of the uterus?
They are the anastomoses between the uterine artery and the ovarian artery, where the uterine artery originates from the internal iliac artery
- The ovarian artery comes from the suspensory ligament of the ovary, and thus it supplies the lateral-most aspect of the uterine tubes. it then enters the broad ligament to supply the ovary and then anastomose with the uterine artery
- The internal iliac branches are also:
1) Uterine artery
2) Vaginal artery
3) Middle rectal artery
4) Internal pudendal artery
66
What is the blood supply of the uterus?
1) Uterine artery
2) Ovarian artery
3) Uterine plexus of vein
67
What is the blood supply of the uterine tube?
1) Ovarian artery
2) Uterine artery
3) Ovarian plexus
4) Uterine plexus
68
What is a hysterectomy?
The surgical removal of the uterus
69
What is the blood supply of the vagina?
Branches of the internal iliac artery:
1) Vaginal artery
2) Middle rectal artery (posterior part)
3) Internal pudendal artery (entrance)
70
Where is the pain transmitted to the pelvic organs?
- Pelvic viscera that are in contact with the peritoneum are superior to the pelvic pain line
1) Sympathetic fibers transmit pain impulses from viscera superior to the pelvic pain line (abdominopelvic splanchnic nerves (T11-L2)
2) Pain impulses that originate from visceras inferior to the pain line are transmitted by parasympathetic fibers then through the pelvic splanchnic nerves (S2-S4)
- If covered by peritoneum (uterus), pain goes up by the sympathetic
- If not covered by peritoneum (vagina), pain goes down by the parasympathetic and somatic
71
What is the nerve innervation of the uterus?
1) Sympathetic fibers (mainly the inferior hypogastric plexus) T11-L1
2) Maybe motor to the uterine muscles (as these muscles respond to hormonal changes mainly)
3) Sensory is the pelvic pain line
72
What is the nerve innervation of the cervix?
Sensory parasympathetic fibers (pelvic splanchnic) S2-S4, and it senses pain when the cervix dilates and the pain might get referred to the posterior thigh resembling sciatica
73
What is the nerve innervation of the vagina?
1) Upper part: Visceral sensation (parasympathetic S2-S4), which is sensitive to distension
2) Lower part: Somatic sensation (pudendal nerve S2-S4), which is sensitive to touch and temperature
- The reason the lower vagina has a different innervation has to do with the embryological development of the area
74
In which space is the anesthesia of the childbirth administered?
The epidural space
74
Describe the (caudal epidural block) anesthesia done during childbirth
- It is administered to the EPIDURAL SPACE
- It affects the S2-S4 spinal nerve roots, which includes the pain fibers from the uterine cervix and the superior vagina (autonomic), and the afferent fibers from the pudendal nerve (somatic)
74
What are the types of anesthesia done for childbirth?
1) Caudal epidural block
- The local anesthetic drug is injected into the space surrounded by the dura mater and NOT into the CSF (subarachnoid space)
2) Spinal block
- The injection is below L2 to avoid damage to the spinal cord
- Typically in the L3-4 interspace
- Needle inserted into subarachnoid space between the arachnoid and pia mater
75
What are the nerves that are affected by the anesthesia during childbirth?
S2-S4 spinal nerve roots, including the pain fibers from the uterine cervic and the superior vagina (autonomic) and the afferent fibers from the pudendal nerve (somatic
76
What are the structures that are affected by the anesthesia?
1) Cervix
2) Vagina
3) Pelvic floor
4) Majority of the prineum
77
What are the structures that are not affected by the anesthesia?
1) Lower limbs
2) Pain fiber from the uterine body (and thus the mother is aware of the uterine contractions
78
What is the spinal block anesthesia for childbirth?
- Administered into the spinal subarachnoid space at the L3-L4 vertebrae (Injection is below L2 to avoid damage to the spinal cord, the needle is inserted into the subarachnoid space between the arachnoid and pia mater)
- Complete anesthesia inferior to the waist level (including the birth canal, perineum, and the lower limbs), More general than the caudal epidural block, includes all the lower limbs and the uterus
- In this anesthesia, the mother is conscious, but she must depend on the electronic monitoring of uterine contractions
79
What is the lymphatic drainage of the Uterine tube, fundus, and the upper portion of the body of the uterus?
The Para-aortic (lumbar) lymph nodes
80
What is the lymphatic drainage of the lower body of the uterus?
The external iliac lymph nodes
81
What is the lymphatic drainage of the cervix of the uterus?
1) External iliac lymph node
2) Internal iliac lymph node
3) Sacral lymph node
82
What is the lymphatic drainage of the cornu of the uterus?
Along the round ligament, it drains into the superficial inguinal lymph nodes
83
What are the different congenital abnormalities of the uterus and vagina?
- Incomplete fusion of the embryonic paramesonephric ducts from which the uterus is formed will result in a variety of congenital anomalies:
1) Double uterus with double vagina
2) Uterus arcuatus
3) Bicornuate uterus (two uterus, 1 vagina)
84
Describe the clinical importance of the posterior vaginal fornix
- The rectouterine pouch can be drained through the posterior vaginal fornix
- It is a site that allows the insertion of instruments to examine the ovaries and the uterine tubes (culdoscope)
- FYI: Introducing a sharp instrument or an intra-uterine contraceptive (IUD) could lead to peritonitis
85
Upon rectal examination, what anatomical structure is likely being palpated by the gynecologist when they detect a solid mass positioned centrally in front of the rectum, palpable through the anterior rectal wall?
Cervix of the uterus
86
After vaginal delivery, a 32-year-old woman complains of urinary incontinence exacerbated by coughing and sneezing. Tearing of which muscle is most likely to be implicated in her condition?
Pubococcygeus
87
Following a fall from the stairs, a 34-year-old female construction worker presents at the A&E with a deep penetrating injury to the anterior aspect of the lower abdominal wall. Examination reveals a deep laceration within the inguinal canal, along with a tender, reducible mass. Which structure is likely to have been lacerated in this case?
round ligament of the uterus
