Anatomy - Pelvic Floor and Perineum Flashcards
1
Q
What 2 parts of the pelvis are on the same vertical plane in the anatomical position? Why is this important?
A
ASIS and pubic tubercle => 1. Pelvic outlet: urogenital part with bodies of pubic bones and pubic arch are positioned in a nearly horizontal plane and posterior part of outlet is positioned more vertically 2. Pelvic inlet is tilted to face anteriorly => pelvic cavity projects posteriorly from the abdominal cavity
2
Q
What are the 2 diameters that restrict the pelvis? Describe each.
A
- Conjugal diagonal diameter of the pelvic inlet: distance from sacral promontory to the superior border of pubic symphysis2. Ischial diameter of the pelvic outlet: distance between the 2 ischial spines
3
Q
Other name for conjugal diameter of the pelvis?
A
Anteriorposterior (AP) diameter
4
Q
Why are the 2 diameters that restrict the pelvis important? What to note?
A
Because they are the 2 narrowest points of the pelvis, so in order for a baby’s head to pass through the conjugal diameter has to be more than 11 cm and the ischial diameter has to be more than 10 cmNote: hormones like estrogen and relaxin released during labor help to relax the pelvic joints in order to help expand these diameters by about 15%
5
Q
What is parturition?
A
Action of giving birth
6
Q
What is pelvimetry? What to note?
A
The assessment of the female pelvis in relation to the birth of a baby Not really used much anymore
7
Q
What part of the pelvis are the internal genital organs and the lower parts of the intestinal and urinary tracts found in?
A
Within the true pelvis
8
Q
3 elements forming each pelvic bone?
A
- Ilium2. Pubis3. Ischium
9
Q
5 differences between male and female pelvises?
A
- The pelvic inlet in women is circular compared with the heart-shaped pelvic inlet in men. The more circular shape is partly caused by the less distinct promontory and broader alae in women 2. The angle formed by the two arms of the pubic arch is larger in women (80°–85°) than it is in men (50°–60°)3. The ischial spines generally do not project as far medially into the pelvic cavity in women as they do in men4. Pelvis is thick and heavy in men and thin and light in women 5. Pelvic inlet is small in males and large in females
10
Q
What 3 structures pass below the inguinal ligament?
A
AVC:1. Femoral artery2. Femoral vein3. Femoral canal
11
Q
Through what structure does the lymphatic drainage from the external genitalia in males and females pass?
A
Through the femoral canal
12
Q
What is the most prominent feature of the ischium? Why is it important?
A
Large ischial tuberosity on the posteroinferior aspect of the bone Important site for attachment of lower limb muscles and for supporting the body when sitting
13
Q
What nerve innervates the perineum (both somatic sensory and motor)?
A
Pudendal nerve
14
Q
Spinal cord levels of the pudendal nerve?
A
S2 to S4
15
Q
Describe the pathway of the pudendal nerve.
A
Originate from S2-S4 anterior rami => leaves pelvic cavity through the greater sciatic foramen => passes around the ischial spine (posterolaterally) and medially through the lesser sciatic foramen to enter perineum => travels along the lateral wall of the ischio-anal fossa in the pudendal canal => enters the anal triangle of the perineum
16
Q
What is the sacrospinous ligament?
A
Triangular ligament 1. Apex: attached to the ischial spine 2. Base: attached to the related margins of the sacrum and coccyx
17
Q
What is a pudendal block? How is it administered? For what purpose?
A
Anesthesia of the pudendal nerveIschial spine can be palpated transvaginally in women and is the landmark to administer the block for vaginal childbirth or for minor surgeries of the vagina and perineumOR a perineal approach is also possible by injecting through the skin at the points where the ischial spines project (2” above ischial tuberosities), but this is less reliable and is typically only preferred when a baby’s head prevents the transvaginal approach
18
Q
What is a pudendal nerve entrapment syndrome? Symptom? Treatment?
A
Pudendal nerve is compressed against the sacrospinous ligament Symptom: pain in genital area and between upper thighs; worse when sitting and often relieved when standingLast resort is surgical treatment
19
Q
What is the sacrotuberous ligament?
A
Triangular ligament Base: broad attachment that extends from the posterior superior iliac spine of the pelvic bone, along the dorsal aspect and the lateral margin of the sacrum, and onto the dorsolateral surface of the coccyxApex: medial margin of the ischial tuberosity
20
Q
Where is the greater sciatic foramen? Purpose?
A
Superior to the sacrospinous ligament and the ischial spine, superior to pelvic floorPurpose: route of communication between the pelvic cavity and the gluteal region of the lower limb
21
Q
Where is the lesser sciatic foramen? Purpose?
A
Inferior to the ischial spine and sacrospinous ligament between the sacrospinous and sacrotuberous ligaments, below the pelvic floor Purpose: route of communication between the gluteal region of the lower limb and the perineum
22
Q
Other name for perineal approach to a pudendal block?
A
Transutaneous approach
23
Q
Other name for pudendal nerve entrapment syndrome?
A
Alcock canal syndrome
24
Q
Is pudendal nerve entrapment syndrome common?
A
NOPE - rare
25
What do we call the male pelvis?
Android pelvis
26
What do we call the female pelvis?
Gynecoid pelvis
27
What is the cause of much lower back pain? What to note about these?
Sacroiliac ligaments because they're role is to displace some of the weight associated with vertebral column, head, and neck to the hip (without which the sacrum would move posterosuperiorly)Some of the strongest ligaments of the body
28
Why are pelvic fractures common? What to note?
1. Anteroposterior compression in auto accidents2. Falls from a height may drive the femoral head through the floor of the acetabulum In pelvic fractures there is often soft tissue injury
29
What is the acetabulum? What does it form?
Large articular socket on the lateral surface of the pelvic bone formed by ilium, ischium, and pubis all coming together, which, together with the head of the femur, forms the hip joint
30
What is the pelvic diaphragm?
Muscular part of the pelvic floor, is shaped like a bowl/funnel, and is attached to pelvic walls Consists of:1. Levator ani muscles2. Coccygeus muscle
31
What is the pelvic floor? Purpose?
Composed of:1. Pelvic diaphragm2. Perineal membrane3. Muscles in the deep perineal pouch Separates the pelvic cavity from the perineum
32
Levator ani muscles:1. Origin2. Insertion3. Innervation4. Function
1. In a line around the pelvic wall: from the posterior aspect of the pubic bone => tendinous arch of obturator internus muscle (thickening of the obturator internus fascia) => ischial spine 2. - Anterior part: superior surface of the perineal membrane- Posterior part: meets its partner on the other side at the perineal body, around the anal canal, and along the anococcygeal ligament 3. Branches direct from the anterior ramus of S4, and by the inferior rectal branch of the pudendal nerve (S2 to S4) 4. - Contributes to the formation of the pelvic floor, which supports the pelvic viscera- Maintains a 90 degree angle between the rectum and anal canal- Reinforces the external anal sphincter - In women: functions as a vaginal sphincter (sphincter vaginae) during orgasm- In men: principal support for the prostate (levator prostatae)
33
Coccygeus:1. Origin2. Insertion3. Innervation4. Function
1. Ischial spine and pelvic surface of the sacrospinous ligament 2. Lateral margin of coccyx and related border of sacrum 3. Branches from the anterior rami of S3 and S4 4. Contributes to the formation of the pelvic floor, which supports the pelvic viscera; pulls coccyx forward after defecation
34
Why is it important the the levator ani muscles maintain an angle between the rectum and anal canal?
Major factor in anal canal continence
35
Shape of true pelvis?
Cylindrical
36
4 parts of bony pelvis?
2 pelvic bones1 sacrum1 coccyx
37
Borders of the pelvic inlet?
1. Posteriorly: body of vertebra SI, which projects into the inlet as the sacral promontory + on each side of this vertebra, wing-like transverse processes called the alae (wings) which connect with each other2. Laterally: linea terminalis = arcuate line + pectineal line + pubic crest3. Anteriorly: pubic symphysis, where the two pelvic bones are joined in the midline
38
Passage of baby during childbirth?
Abdomen => pelvic inlet => pelvic outlet
39
Borders of the pelvic outlet?
1. Posteriorly/laterally: sacrotuberous ligament 2. Antero/laterally: pubic arch = inferior margin of the body of pubis + inferior ramus of pubis + ramus of ischium + ischial tuberosity 3. Anteriorly: pubic symphysis4. Laterally: ischial tuberosities5. Posteriorly: coccyx and sacrum
40
4 main purposes of pelvic diaphragm?
1. Supports the pelvic viscera2. In conjunction with the thoraco-abdominal diaphragm, increases intra-abdominal pressure3. Resists downwards thrust, e.g., in forced expiration and coughing. 4. Assists the anterior abdominal wall muscles in compressing the abdominal contents and even helps to fix the trunk during weight lifting
41
When does injury to pelvic floor muscles most often occurs? Explain. Recovery?
During parturition: 1. The most common complaint of women after delivering a baby is that "my bottom is falling out" => in essence, the pelvic contents are now supported mostly by skin and fascia since the muscle was completely spread apart during the delivery => as the muscles slowly "recover" and adopt their normal position and integrity, they can once again assume their role of supporting the pelvic viscera2. Weakness of the muscles (stretching or tearing) may alter the position of the neck of the bladder or the urethra causing urinary stress incontinence => there may be dribbling of urine when intra-abdominal pressure is increased (coughing, lifting)
42
What are the Kegel muscles? What is their purpose?
Include the pelvic floor muscles as well as other muscles in the perineumPurpose: women patients who have just given birth and leak urine should exercise them
43
Connection between main diaphragm and pelvic diaphragm?
They often act synergistically
44
What is located below the pelvic diaphragm?
Perineum
45
What 3 parts of the pelvic outlet can be palpated?
1. Pubic symphysis2. Ischial tuberosities3. Coccyx (*not technically part of pelvic outlet)
46
What are the 3 levator ani muscles?
1. Iliococcygeus muscle2. Pubococcygeus muscle3. Puborectalis muscle
47
What surrounds the true pelvis?
Pelvic inlet and outlet
48
What is cyclists’ syndrome?
Condition caused by sitting on a bike seat for too long causing person to lose sensation in the perineum because the pudendal nerve gets pressed against the pelvic bone in the ischium region
49
Is cyclists’ syndrome common?
YUP
50
What is the pudendal canal? Other name? What does it contain?
Tubular compartment formed in the fascia that covers the obturator internus muscle= Alcock canal Contains the internal pudendal artery and accompanying vein and the pudendal nerve
51
Describe the pathway of the inferior rectal nerve and its function.
Penetrates through the fascia of the pudendal canal, and courses medially across the ischio-anal fossa 1. Innervates the external anal sphincter and related regions of the levator ani muscles 2. Provides general sensory for the skin of the anal triangle
52
Describe the pathway of the perineal nerve and its function.
Passes into the urogenital triangle and gives rise to motor and cutaneous branches1. The motor branches supply skeletal muscles in the superficial and deep perineal pouches2. The largest of the sensory branches is the posterior scrotal nerve in men and the posterior labial nerve in women
53
Describe the pathway of the dorsal nerve of the penis/clitoris and its function.
Enters the deep perineal pouch => passes along the lateral margin of the pouch => exits by passing inferiorly through the perineal membrane in a position just inferior to the pubic symphysis where it meets the body of the clitoris or the penis => courses along the dorsal surface of the body to reach the glansSensory to the penis and clitoris, particularly to the glans
54
3 branches of the pudendal nerve?
1. Inferior rectal nerve2. Perineal nerve3. Dorsal nerve of the penis/clitoris
55
What are the sacroiliac ligaments?
1. Sacrospinous ligament2. Sacrotuberous ligament
56
What is the lithotomy position?
A supine position of the body with the legs separated, flexed, and supported in raised stirrups
57
Describe the position of the puborectalis muscle. Function?
Originates, in association with the pubococcygeus muscle, from the pubis and passes inferiorly on each side to form a sling around the terminal part of the GIT to form a muscular sling to maintain an angle or flexure, called the perineal flexure, at the anorectal junction (part of the mechanism that keeps the end of the GIT closed)
58
What organs are both pelvic and perineal?
1. Urethra2. Anal canal 3. Vagina
59
What is the perineum? 2 parts?
Diamond-shaped region below the pelvic floor between the lower limbs bound by the pelvic outletAn imaginary line between the ischial tuberosities divides the perineum into two triangular regions:1. Urogenital triangle anteriorly 2. Anal triangle posteriorly
60
What does the urogenital triangle contain?
1. Roots of the penis/clitoris2. Openings of the urogenital system3. Urethral sphincter4. Vaginal sphincter in women 3+4=urogenital diaphragm muscles
61
What does the anal triangle contain?
1. The anal aperture and external anal sphincter2. Ischioanal fossa on both sides
62
What does the perineum contain?
1. The terminal openings of the gastrointestinal and urinary systems2. The external opening of the reproductive tract3. The roots of the external genitalia
63
Are both perineal triangles on the same plane?
NOPE: in the anatomical position, the urogenital triangle is oriented in the horizontal plane, whereas the anal triangle is tilted upward at the transtubercular line so that it faces more posteriorly
64
Is the external urethral sphincter under voluntary control?
YUP
65
What are the 5 layers in the perineum below the pelvic floor muscles? List from above to below.
1. Superior fascia of the urogenital diaphragm 2. Deep perineal pouch with urogenital diaphragm muscles 3. Inferior fascia of the urogenital diaphragm = perineal membrane 4. Superficial perineal pouch 5. Skin and superficial fascia
66
Other name for inferior fascia of the urogenital diaphragm?
Perineal membrane
67
What does the superficial perineal pouch contain?
1. Erectile structures that join together to form the penis in men and the clitoris in women2. Skeletal muscles that are associated mainly with parts of the erectile structures attached to the perineal membrane and adjacent bone3. Proximal part of the spongy urethra in MALES4. Bartholin's glands in FEMALES
68
What does each erectile structure of the superficial perineal pouch consists of?
Central core of expandable vascular tissue and its surrounding connective tissue capsule
69
What are the 3 muscles of the superficial perineal pouch?
1. Ischiocavernosus2. Bulbospongiosus3. Superficial transverse perineal muscles
70
Ischiocavernosus muscle:1. Origin2. Insertion3. Innervation4. Function
1. Ischial tuberosity and ramus2. Crus of penis and clitoris3. Pudendal nerve 4. Move blood from crura into the body of the erect penis and clitoris
71
What are the 2 erectile structures of the superficial perineal pouch?
1. Corpora cavernosa2. Second structure surrounds the openings of the urogenital system:WOMEN: bulbs of the vestibule MEN: corpus spongiosum
72
What are the crura of the corpora cavernosa?
Proximal attached parts of the corpora cavernosa to the pubic arch
73
Where is the glans clitoris?
In the midline at the end of the body of the clitoris and anterior to the opening of the urethra
74
What are ischio-anal fossae?
Inverted wedge-shaped gutters in the anal triangle on each side of the anal aperture between the levator ani muscles and adjacent pelvic walls (obturator internus muscles) as the two structures diverge inferiorly
75
What do the ischio-anal fossae contain? Purpose? Issues?
Liquid fat Purpose: allows for expansion of the anal canal as fecal material passes down the anal canal + safe passage of pudendal nerve and internal pudendal vessels in the canal to reach perineumIt is a site of frequent infections and abscesses, which is painful because of irritation of inferior rectal nerve
76
When can urethral rupture occur in males? Consequence?
Following a severe blow to the perineum => urine may extravasate into the superficial perineal pouch and under Scarpa's fascia => yellowing of the skin
77
When can scrotal distention occur in males? Consequence?
Can occur from a hernia or from fluid production (orchitis) or from bleeding => scrotum can become the size of a grapefruit, even after a vasectomy
78
What is palpation of the testes and epididymis important for?
Important in differential diagnosis between testicular cancer and inflammation of the epididymis
79
What are bulbo-urethral glands?
Small pea-shaped mucous glands in the deep perineal pouch in men on either side of the membranous urethra just as it enters the base of the penis
80
Other name for bulbo-urethral glands?
Cowper's glands
81
What are the greater vestibular glands? Role?
Small pea-shaped mucous glands in the superficial perineal pouch on each side of the vaginal opening in women that open into the vestibule of the perineum along the vaginal openingProduces secretion during sexual arousal
82
Other name for greater vestibular glands?
Bartholin's glands
83
What is the perineal body?
Poorly defined fibromuscular node at the center of the perineum, approximately midway between the two ischial tuberosities at which the following converge:1. The levator ani muscles of the pelvic diaphragm2. Muscles in the urogenital and anal triangles of the perineum, including the skeletal muscle sphincters associated with the urethra, vagina, and anus Total = 8 muscles
84
Why is the perineal body important? Eg?
It is essential to the integrity of the perineumDuring childbirth, the obstetrician will make sure it does not tear
85
What is an episiotomy? 2 types?
Procedure in which an incision is made in the perineum and lower vaginal wall between the vagina and anal canal to allow the head of the fetus to pass through the vagina1. Median episiotomy cuts through the perineal body2. Mediolateral episiotomy is an incision 45° from the midline
86
4 benefits of episiotomy?
1. Speeds up the birth2. Prevents tearing3. Protects against incontinence4. Heals easier than tears
87
4 dangers of episiotomy?
1. Infection2. Increased pain3. Longer healing times4. Increased discomfort when intercourse is resumed
88
What can tearing of the perineal body lead to?
Prolapse of the bladder, uterus, or vagina
89
Other than by childbirth, what can the perineal body be disrupted by?
1. Trauma2. Inflammatory disease3. Infection
90
Why is the female perineum prone to infections?
Because it contains many glands and ducts that open onto the surface
91
In what women are Bartholin's cysts more common?
Women aged 20-29
92
In what % of women do Bartholin's cysts develop?
2% of women
93
What does the deep perineal pouch contain?
1. Urogenital diaphragm2. Membranous part of urethra in MALES3. Bulbo-urethral glands in MALES4. Vagina in FEMALES5. Deep transverse perineal muscle6. Internal pudendal vessels7. Dorsal nerve of the penis/clitoris8. External urethral sphincter in MALES
94
Where is the prostate located in men?
Right above the urogenital diaphragm and right below the bladder
95
What structures are suspended from the urogenital diaphragm?
Roots of the external genitalia: including crura and bulbs of the vestibule/corpus spongiosum
96
Vertebral levels of abdominal aorta?
T12 to L4
97
Describe the pathway of the common iliac artery.
Common iliac artery => internal iliac artery branches => continuation is the external iliac artery => passes posterior to the inguinal ligament => femoral artery
98
What artery is termed the mother artery of the pelvis?
Internal iliac artery
99
2 trunks/divisions of the internal iliac artery?
Anterior and posterior
100
3 branches of the posterior trunk of the internal iliac artery? Which 2 are useless?
1. Iliolumbar artery*2. Lateral sacral artery*3. Superior gluteal artery
101
8 branches of the anterior trunk of the internal iliac artery?
1. Umbilical artery2. Superior vesicle artery (branches from #1)3. Inferior vesicle OR vaginal artery4. Middle rectal artery5. Obturator artery6. Internal pudendal artery7. Inferior gluteal artery8. Uterine artery in FEMALES
102
Describe the pathway of the umbilical artery.
Gives origin to the superior vesical artery and then travels forward just inferior to the margin of the pelvic inlet => anteriorly, the vessel leaves the pelvic cavity and ascends on the internal aspect of the anterior abdominal wall to reach the umbilicus
103
How does the umbilical artery change from fetus to after birth?
Fetus: umbilical artery is large and carries blood from the fetus to the placenta. After birth: the vessel closes distally to the origin of the superior vesical artery and forms a fibrous remnant, the medial umbilical ligament, which raises a fold of peritoneum termed the medial umbilical fold on the anterior abdominal wall
104
Describe the pathway of the superior vesical artery. What does it supply? What to note?
Originates from the root of the umbilical artery and courses medially and inferiorly to supply the superior aspect of the bladder and distal parts of the ureterNote: in men, it also may give rise to an artery that supplies the ductus deferens
105
What does the inferior vesical artery supply in men?
Supplies branches to the bladder, ureter, seminal vesicle, and prostate
106
What does the vaginal artery supply in women? What does it anastomose with?
Supplies branches to the vagina and to adjacent parts of the bladder and rectumAnastomoses with other side to form azygos arteries of cervix and vagina
107
Pathway of the middle rectal artery? What does it supply? What to note?
Courses medially to supply the rectumNote: it anastomoses with the superior rectal artery, which originates from the inferior mesenteric artery in the abdomen, and the inferior rectal artery, which originates from the internal pudendal artery in the perineum
108
Pathway of the obturator artery? What does it supply?
Courses anteriorly along the pelvic wall and leaves the pelvic cavity via the obturator canal and supplies the adductor region of the thigh
109
What courses above and below the obturator artery?
Above: obturator nerveBelow: obturator vein
110
Pathway of the internal pudendal artery? What does it supply?
Courses inferiorly to leave the pelvic cavity through the greater sciatic foramen inferior to the piriformis muscle => passes laterally to the ischial spine and then through the pudendal canal => through lesser sciatic foramen to enter the perineumMain artery of the perineum supplying the erectile tissues of the clitoris and the penis
111
What runs on the medial side of the internal pudendal artery?
Pudendal nerve
112
Pathway of the inferior gluteal artery? What does it supply? What to note?
Large terminal branch that passes between the anterior rami S1 and S2 or S2 and S3 of the sacral plexus => leaves the pelvic cavity through the greater sciatic foramen inferior to the piriformis muscle => enters and contributes to the blood supply of the gluteal region Note: it anastomoses with a network of vessels around the hip joint
113
Pathway of the uterine artery in females? What does it supply? What to note?
Courses medially and anteriorly in the base of the broad ligament to reach the cervix and crosses the ureter anteriorly and passes superiorly to the lateral vaginal fornix => once the vessel reaches the cervix, it ascends along the lateral margin of the uterus to reach the uterine tube => curves laterally and anastomoses with the ovarian arteryMajor blood supply to the uterus + through anastomoses with other arteries, the vessel contributes to the blood supply of the ovary and vagina
114
Pathway of the superior gluteal artery? What does it supply? What to note?
Courses posteriorly, usually passing between the lumbosacral trunk and anterior ramus of S1 => leaves the pelvic cavity through the greater sciatic foramen above the piriformis => enters the gluteal region of the lower limbSubstantial contribution to the blood supply of muscles and skin in the gluteal region and also supplies branches to adjacent muscles and bones of the pelvic walls + hip joint + travels with superior gluteal nerve
115
Largest branch of the internal iliac artery?
Superior gluteal artery
116
What artery enlarges significantly during pregnancy?
Uterine artery
117
3 issues that can arise with the superior gluteal artery?
1. May be compressed2. May have an aneurysm3. May have atherosclerotic involvement
118
What is important to note about the blood vessels to the pelvis?
Subject to wide variation
119
How to remember that the ureter passes posteriorly to the uterine artery?
Water under the bridge
120
How to identify the branches of the internal iliac artery with certainty?
Note where the vessels distribute
121
2 types of lymph nodes associated with the aorta? What do we call all of them?
1. Pre-aortic nodes associated with celiac artery, SMA, and IMA2. Para-aortic lymph nodes= aortic-caval nodes
122
Other name for para-aortic lymph nodes?
Lumbar lymph nodes
123
What do we call the lymph nodes associated with all iliac arteries?
Iliac lymph nodes
124
What structure is at risk during a hysterectomy? Why?
Ureter because it may be divided when clamping the uterine vessels
125
What do internal iliac lymph nodes drain?
Deep parts of the perineum
126
Location of superficial inguinal nodes?
T shape:- Horizontal bar: below inguinal ligament between ASIS and pubic tubercle - Vertical bar: along and lateral to the great saphenous vein
127
What do superficial inguinal nodes drain?
1. Scrotum2. External genitalia in male and female3. Buttock4. Lower 1/3 of vagina5. Part of uterus via round ligament6. Leg7. Lower trunk 8. Back below umbilicus9. Superficial aspects, lower part of the anal canal10. Urethra
128
Lymph pathway from the superficial inguinal nodes?
Through the saphenous opening => deep inguinal nodes => deep to the inguinal ligament, mostly via the femoral canal => external iliac nodes => common iliac nodes => para-aortic nodes
129
What do the para-aortic lymph nodes drain?
1. Kidneys2. Abdominal ureters3. Posterior abdominal wall4. Testes5. Ovaries6. Uterine tubes7. Upper part of uterus including fundus
130
What do the deep inguinal and external iliac nodes drain?
1. Glans penis2. Glans clitoris3. Labia minora4. Terminal inferior end of the vagina
131
What does the sacral plexus consist of?
Ventral rami of L4 to S4
132
Largest nerve in the body?
Sciatic nerve
133
2 causes of sacral plexus compression?
1. Malignant tumors from neighboring viscera (e.g. carcinoma of the rectum can cause severe intractable pain down the lower limbs)2. Fetal head (producing pain in the lower limb)
134
What is the lumbosacral trunk? Pathway?
Consists of part of the anterior ramus of L4 and all of the anterior ramus of L5Courses vertically into the pelvic cavity from the abdomen by passing immediately anterior to the sacro-iliac joint
135
What do lymph vessels run with?
Corresponding arteries
136
In what orientation does the urogenital triangle face?
Inferiorly
137
In what orientation does the anal triangle face?
Posteriorly
138
What are the corpus cavernosa?
Pair of cylindrically shaped structures on each side of the urogenital triangle, that are anchored by their proximal ends to the pubic arch and form the body of clitoris/dorsal parts of the body of the penis with their distal ends which are not attached to bone
139
What are the bulbs of the vestibule in women?
Bulbs on each side of the vaginal opening firmly anchored to the perineal membrane and are connected anteriorly by small bands of erectile tissues to form a single, small, pea-shaped erectile mass, the glans clitoris
140
What is the corpus spongiosum in men?
Single large erectile mass surrounding the urethra, which is anchored at its base to the perineal membrane with its proximal end, forming the ventral part of the body of the penis and expanding over the end of the body of the penis to form the glans penis
141
Other than from the internal iliac artery, from what artery can the vaginal artery originate?
Uterine artery
142
Superficial transverse perineal muscle:1. Origin2. Insertion3. Innervation4. Function
1. Ischial tuberosity and ramus 2. Perineal body 3. Pudendal nerve (S2 to S4) 4. Stabilize the perineal body
