Pelvis: Walls, floor, neurovascular supply Flashcards
(75 cards)
1
Q
What is the hip bone made out of?
A
- Ilium
- Ischium
- Pubis
2
Q
What makes up the pelvis?
A
- Hib bones
- Sacrum
- Coccyx
3
Q
What does the pelvic brim divide?
A
Greater and lesser pelvis
4
Q
What diivides the greater pelvis from the abdominal cavity?
A
Ala / wing of ilium
5
Q
What ligaments form the greater and lesser sciatic foramina?
A
- Sacrotuberous ligament and
- Sacrospinous ligament
6
Q
Where does the sacrotuberous ligament attach?
A
- Posterior- inferior iliac spine, sacrum and coccyx to
- Ischial tuberosity
7
Q
Where does the sacrospinous ligament attach?
A
- Sacrum, coccyx and sacrotuberous ligament to
- Ischial spine
8
Q
What are the pelvic gateways?
A
- Greater sciatic foramen
- Obturator foramen
- Retroinguinal space
- Lesser sciatic foramen
9
Q
What passes through the greater sciatic formaen?
A
- Sciatic nerve
- Gluteal neurovascular bundle
10
Q
What passes through the obturator formaen?
A
Obturator neurovascular bundle
11
Q
What passes through the retroinguinal space?
A
- Femoral neurovascular bundle
12
Q
What passes through the lesser sciatic foramen?
A
- Pudendal nerve
- Internal pudendal vessels
13
Q
What can the pelvic inlet also be known as?
A
- Pelvic brim
- Superior pelvic aperture
- Linea terminalis
14
Q
What is included in the pelvic brim?
A
- Pubic symphysis
- Pubic crest
- Pectineal line
- Arcuate line of ilium
- Sacral ala and promontory
15
Q
WHat is included in the pelvic outlet?
A
- Pubic symphysis
- Ischiopubic ramus
- Ischial tuberosity
- Sacrotuberos ligament
- Sacrum and coccyx
- Incompletely closed by muscles and membranes
16
Q
What are the greater and lesser pelvis also known as?
A
- Greater - false
- Lesser - True
17
Q
What is the difference between the general structure of the female and male pelvis?
A
- Female is thin and light
- Male is thick and heavy
18
Q
What is the difference between the greater pelvis of the male and female?
A
- Male - deep
- Female - shallow
19
Q
What is the difference between the lesser pelvis in men and women?
A
- Female - wide adn shallow, cylindrical
- Male - narrow and deep, tapering
20
Q
What is the difference between the pelvic inlet in men and women?
A
Female - oval and rounded; wide
Male - heart-shaped narrow
21
Q
What is the difference between the pelvic outlet in females and males?
A
Female’s is comparitavely larger
22
Q
What is the difference between the male and female pubic arch and suprapubic angle?
A
- Female’s is wide (>80deg)
- Males is narrow (<70deg)
23
Q
What is the difference in shape between male and female obturator foramen?
A
- Female - oval
- Male - round
24
Q
What gender has a larger acetabulum?
A
Men
25
What is the difference between the male and female greater sciatic notch?
- Female - Almost 90deg
| - Male - Narrow (-70deg); inverted V
26
What are the different pelvic inlet shapes?
- Android (males)
- Gynecoid (females)
- Anthropoid
- Platypelloid (males)
27
How long is the obstetric conjugate?
11 cm (measured off of diagonal), this diameter can decide if mother needs C section
28
How long is the diagonal conjugate?
12.5 cm
29
When would a C-section be done?
When the obstetric conjugate is less than 9 cm and the foetus is not underdeeloped, vaginal delivery is not possible
30
What is the antero-inferior wall made from?
- Pubic symphysis
| - Body and rami of pubis
31
What is the postero-superior wall made up from?
- Sacrum
- Piriformis
Divides greater sciatic foramen
32
What is the lateral wall made from?
- Obturator internus with obturator fascia
33
What is the most inferior region of the abdomino-pelvic cavity?
Pelvic floor/diaphragm
34
What does the perineal membrane divide?
Perineum into deep and superficial compartments
35
What shape is the pelvic diaphragm?
Ball / funnel shaped
36
What are the pelvic side walls and floor in contact with?
Central pelvic organs
37
What is the pelvic diaphragm formed by?
- Levator ani (iliococcygeus + pubococcygeus) and coccygeus (aka ischiococcygeus) muscles with their fasciae covering their superior and inferior surfaces
38
What is the coccygeus innervated by?
S4-5
39
What are the origins of the levator ani?
- Pubis
- Ischial spine
- Tendinous arch of levator ani
40
What are the medial gaps between levator ani called?
Urogenital hiatus and anal hiatus
41
What is the pubococcygeus subdivided into?
- Puborectalis
- Puboperineal
- Pubovaginalis or puboprostaticus
42
What is the levator ani innervated by?
S3-4
43
What does the puborectalis do?
Makes a sling posterior to the rectum therefore important in fecal continance
44
What are the functions of the levator ani?
- Supports the pelvic organs
- Makes the anorectal angle more acute and augments the external anal sphincter
Maintains faecal continence
- Augments the urethral sphincter
Maintains urinary continence
- Forms a vaginal sphincter
- Actively contracted coughing, sneezing, forced expiration
45
What can weakness of the levator ani cause?
Incontinence or prolapse of structures above i.e uterus (pelvic floor exercises needed) can be due to childbirth or menaupause
46
WHat do pelvic diaphragm muscles of each side meet to form?
The anococcygeal body (aka raphe or ligament) and perineal body (aka central tendon of perineum)
47
What is the pelvic floor supported anteriorly by?
- Perineal membrane
| - Muscles in the deep perinela pouch
48
What is the structure of the perineal membrane?
Thick, triangular fascial sheet that fills the space between the arms of the pubic arch, supports pelvic diaphragm
49
What is the lowest point in the pelvic cavity?
Rectouterine/rectovesical pouch
50
What are the recesses / pouches of the pelvic cavity?
- Supravesical fossa
- Paravesical fossa
- Vesico-uterine pouch
- Recto-uterine pouch (of douglas)
- Rectovesical pouch
- Pararectal fossae
51
What are the prevertebral plexuses formed around the abdominal aorta by?
- Preganglionic and postganglionic sympathetic fibres (T1-L2(3))
- Preganglionic parasympathetic fibres (vagus or S2-4)
- Visceral afferent fibres
52
What are the plexuses that condense around the origins of the branches of the abdominal aorta?
- Coeliac plexus
- Renal plexus
- Superior mesenteric plexus (aortic)
- Inferior mesenteric plexus (aortic)
- Superior hypogastric plexus
53
Where are cell bodies of postganglionic sympathetic cell bodies found?
- Randomly distributed
| - Ganglia which are clustered around roots of major branches of aorta
54
Where are the efferent postganglionic sympathetic ganglia found?
Branches of corresponding arteries
55
What are the pelvic autonomic nerves?
- Sacral sympathetic trunks
- Parasympathetic fibres from S2-4 spinal segments
- Hypogastric plexus
- Periarterial plexuses
56
What are the sacral sympathetic trunks?
- 4 pairs of sacral sympathetic gangli + ganglion impar
- Lumbar and sacral splanchnic nerves
- Both motor and sensory
57
What are the parasympathetic fibres from S2-4 spinal segments also known as?
```
Nervi erigentes (pelvic splanchnic nerves)
- both motor and sensory
```
58
What are the 2 plexuses that make up the hypogastric plexus?
- Superior hypogastric plexus
| - Inferior hypogastric plexus
59
What are the different periarterial plexuses?
Superior rectal, ovarian and internal iliac arteries all contain there own plexus (contain postsynaptic, sympathetic and vasomotor fibres)
60
Where does the superior hypogastric plexus lie?
In front of the inferior part of the abdominal aorta and its bifurication (promontory of the sacrum)
61
What is the superior hypogastric plexus formed as?
- Continuation of the aortic plexus
- Sympathetic fibres from L3 and L4 sympathetic ganglia
- Parasympathetic fibres from the pelvic splanchnic nerves
62
Where does the inferior hypogastric (pelvic) plexus lie?
On each side of the rectum, the base of the bladder and the vagina
- Seconday plexuses pass to the rectum, bladder, prostate, seminal gland, cervix and vagina
63
What is the inferior hypogastric (pelvic) plexus formed by?
Sympathetic fibres from:
| - HYpogastric nerves (from the superior hypogastric plexus) and parasympathetic fibres from the pelvic splanchnic nerves
64
When can the inferior hypogastric (pelvic) plexus become injured?
Surgical operations
65
What are the senses from the organs carried by?
AUtonomics (sympathetics or parasympathetics)
| sympathetics usually pain
66
What fibres do all visceral afferent fibres conducting unconscious (relexitive) sensation travel with?
Parasympathetic fibres
67
Where is the pelvic pain line?
- Inferior limit of the peritoneum
| - Middle of sigmoid colon
68
What do visceral pain impulses from organs superior to the the pain line travel with?
Sympathetic fibres
69
What do visceral pain impulses from organs inferior to the the pain line travel with?
Parasympathetic fibres
70
What is the somatic innervation of the pelvic muscles?
Pudendal nerve (S2-4)
71
Describe the course the pudendal nerve takes?
- Passes through greater sciatic foramen (infraperiform part)
- Curves posterior to the ischial spine and sacro-spinous ligament
- Medial to ischial tuberosity
- Runs forwards into the perineum inferior to levator ani
72
Where is the trochanteric anastomosis found?
Between lateral and medial circumflex femoral and superior and inferior gluteal arteries
73
What is the arterial supply of the pelvis?
- Common iliac artery -> internal iliac artery opposite the sacroiliac joint at the level of the L5 disc
- The internal iliac artery divides into anterior and posterior trunks
- Supplies buttock and medial thigh, posterior pelvic and abdominal walls, pelvic viscera, perineum
74
What does the internal artery supply?
The walls, floor and contents of the pelvic cavity
75
What are all the different lymph nodes around the pelvis?
- Lumbar (caval/aortic)
- Inferior mesenteric
- Common iliac
- Internal iliac
- External iliac
- Superficial inguinal
- Deep inguinal
- Sacral
- Pararectal
Tend to parallel the venous draonage, very interconnected
