Pelvis and Perineum Flashcards
1
Q
What are the functions of the pelvis? (2)
A
- Weight-bearing
2. Attachment of the lower limbs
2
Q
What does the head of the femur attach to?
A
Acetabulum
3
Q
What does the pelvis consist of? (3)
A
- 2 hip bones
- 1 sacrum
- 1 coccyx
4
Q
What are the bones of pelvis? (3)
A
- Hip (inominate)
2. Greater and Lesser Pelvis
5
Q
What is the hip comprised of?
A
A pair of bones joined anteriorly to each other at the pubic sympysis and posteriorly to the sacrum.
6
Q
What are the 3 parts of the hip?
A
- Ilium
- Ischium
- Pubis
7
Q
Where do the junctions of the hip go through?
A
Acetabulum
8
Q
What is the acetabulum?
A
Cup shaped cavity for articulation with head of femur
9
Q
What does the greater pelvis consist of?
A
- Upper larger cavity
- Surrounded ilium
- Upper sacrum
10
Q
What does the lesser pelvis consist of?
A
- Lower, smaller cavity closed by soft tissue of pelvic floor
- Junction between greater and lesser pelvis is pelvic brim/pelvic inlet
11
Q
What is the function of the head of femur?
A
The ball and socket joint with the pelvis called the hip joint
12
Q
What is the function of the less trochanter?
A
Where muscles attach that move thigh inwards at the hip joint. Adductor muscles.
13
Q
What is the function of the greater trochanter?
A
Where muscles attach that move thigh outwards at the hip joint. Abductor muscles
14
Q
What is the function of the medial condyle?
A
The medial part of the hinge joint with the tibia called the knee joint.
15
Q
What is the function of the lateral condyle?
A
The lateral part of the hinge joint with the tibia called the knee joint.
16
Q
What is the iliac crest?
A
Upper extent of ilium.
17
Q
What are the two ways the iliac crest ends?
A
- Anteriorly as the ANTEROSUPERIOR ILIAC SPINE (ASIS)
2. Posteriorly as the POSTEROSUPERIOR ILIAC SPINE (PSIS)
18
Q
What is the AIIS adjacent to?
A
Acetabulum
19
Q
Where is the PSIS located?
A
PSIS is located on the posteromedial part of ILIAC TUBEROSITY
20
Q
What attaches to the iliac tuberosity?
A
Interosseous ligament and of posterior sacroiliac ligament
21
Q
What is the tubercle of iliac crest?
A
A thickening of the central part of the crest
22
Q
Where does the tubercle of the iliac crest lie?
A
- Above greater sciatic foramen
2. Not palpable but location is recognisable in some individuals as a surface dimple
23
Q
What is the gluteal surface?
A
Outer, posterior surface of ilium. Attachment of gluteal muscles.
24
Q
What is the iliac fossa?
A
Inner/anterior concave surface, attachment of iliacus
25
What are the features of the pubis?
1. Pubic symphysis
2. Pubic crest and pubic tubercle
3. Pecten pubis
4. Obturator foramen
5. Superior pubic ramus
6. Inferior ramus
7. Ileopubic eminence
26
What is the pubic symphysis?
Cartilaginous joint between anteromedial parts of BODY of each pubic bones
27
What is the pubic crest?
Short rounded upper part of the body of the pubis about 2.5 cms long, ending laterally as pubic tubercle (for attachment of inguinal ligament)
28
What is the pecten pubis?
1. A sharp ridhe running posteriorly from pubic tubercle
2. For attachment of lacunar ligament
3. Forms part of pelvic brim
29
What is the obturator foramen?
Anterior opening in pelvis bounded by pubis and ilium
30
What is the superior pubic ramus?
Above obdurator foramen to acetabulum
31
What is the inferior ramus?
Below obdurator foramen to join ISCHIAL RAMUS to form ISCHIOPUBIC RAMUS
32
Where is the ileopubic eminence?
At junction of ilium and pubis
33
What are the features of the ischium?
1. Body
2. Ischial tuberosity
3. Ischial spine
34
Where is the ischium body located?
Adjacent to acetabulum
35
Where is the ischial tuberosity located?
On thelower posterior surface (attachment of sacrotuberous ligament)
36
Where is the ischial spine?
Above ischial tuberosity, at junction of GREATER AND LESSER SCIATIC NOTCHES
37
What are the other features of the pelvis?
1. Greater sciatic notch
2. Lesser sciatic notch
3. Acetabulum
38
Where is the greater sciatic notch and what is its function?
Between PIIS and ischial spine.
| Transmits piriformis
39
Where is the lesser sciatic notch and what is its function?
Below ischial spine.
| Transmits tendon of obdurator internus, obdurator nerve, internal pudenal vessels and nerve.
40
Where is the acetabulum?
A hemispherical cavity on the lateral side of the pelvis directed anteroinferiorly.
41
What joins onto the acetabulum?
Ilium, ischium, pubis form a junction in this cavity.
42
What is the acetabulum lined with?
Cartilage and articulates with the head of the femur (also covered with articular cartilage) to form the acetbulofemoral joint (hip joint)
43
What is the hip joint supported by?
Capsule, ligaments and some of the pelvic muscles
44
What are the features sacrum? (6)
1. Five fused vertebrae
2. Anterior and posterior sacral foramina - anterior (pelvic) and posterior (dorsal) foramina communicate
3. Median sacral crest - fused spines of vertebrae
4. Anteriorsuperior margin forms sacral promontary
5. Sacral canal - continuous with vertebral canal (contains spinal nerves and meninges but no spinal cords - ends at L2)
6. Auricular surface for sacroiliac joint, roughened area posterior to this for interosseous ligament
45
What are the features of the coccyx? (2)
1. 4 fused rudimentary vertebrae
| 2. Tip of coccyx level with pubic symphysis
46
What type of joint is the sacroiliac joint?
A synovial joint
47
Where is the sacroiliac joint recognisable?
Recognisable on ilium and sacrum as smooth auricular surfaces
48
What cartilage lines the sacroiliac joint?
Hyaline cartilage
49
The movement of sacroiliac joints is limited. True or false?
True. Limited movement due to the way articulating bones interlock (slight sliding and rotation only).
50
What may happen to the sacroiliac joint at old age?
Adhesions are common across joint cavity and joint may fibrose or ossify in old age.
51
Where is the lumbosacral joint located?
Interveterbral disc between L5 and sacrum.
52
What is the lumboscarl joint stabilised by?
Iliolumbar ligament
53
Where is the acetabular joint and what type of joint is it?
Synovial joint between acetabulum of hip and head of femur.
54
Where is the interosseous ligament located?
Posteriorsuperior to sacroiliac joint.
55
Where is the interosseous ligament recognisable?
It is recognisable on the ilium and sacrum as roughened regions superior to smooth auricular parts.
56
Where is the iliolumbar ligament located?
5th lumbar vertebra to iliac crest
57
What does the iliolumbar ligament prevent?
Prevents L5 from slipping anterioly and also transmits some of the weight directly to ilium thus partly bypassing sacroiliac joint.
58
What are the sacroiliac ligaments?
Collagenous bands of various lengths conneting sacrum to ilium on both anterior and posterior surfaces.
59
What is the difference between the anterior and posterior bands?
Posterior are interlacing bands, anterior part runs from sacrum to iliac fossa.
60
Where does the sacrotuberous ligament extend? What else does it include?
Ischial tuberosity to sacrum. Blends with sacroiliac ligament. Also includes a band of fibres which extend upwards to both PSIS and PIIS.
61
Where the sacrospinous ligament extend?
Ischial spine to lateral; sacrum and coccyx. It is anterior to the sacrotuberous ligament, anterior surface is coccygeus muscle
62
What does the sacrospinous ligament prevent?
Prevent rotation of sacrum in the vertical plane.
63
What are the apertures of pelvis?
1. Superior aperture of lesser pelvis (Pubic symphysis and crest, arcuate line, pecten pubis, sacral promontary)
2. Inferior pelvic apertue (Pubic symphysis, ischiopubic ramus, ischial tuberosity, sacrotuberous ligament, coccyx)
64
What are the attachments of the obturator internus?
1. Ilium and ischium surrouding obturator foramen
2. Obturator fascia - covers medial surface of muscle, thickened to form tendinous arch below obturator foramen - part of attachment of levator ani
65
What does the obturator internus pass?
Obturator internus passes around anterolateral wall of true pelvis and through lesser sciatic foramen as tendinous bands which bend through a right angle around the foramen.
66
Where does the tendon attach to?
Tendon attaches to greater trochanter of femur (below attachment of piriformis)
67
What action is the obturator internus responsible for?
Rotates thigh laterally.
68
Where is the piriformis located?
Pelvic surface of S2-4.
69
What is the piriformis pierced by?
Often piereced by sacral ventral rami arising from anterior sacral foramina (forming among other structures the sciatic nerve).
70
Where does the piriformis pass through?
Pases through the greater sciatic notch.
71
What action is the piriformis responsible for?
Rotates thigh laterally.
72
What is the levator ani?
1. Extensive attachment to bones of lesser pelvis
| 2. Tnedinous arch of obdurator fascia
73
What is the function of the levator ani?
Suppots pelvic viscera. Raises pelvic floor - important in forced expiration, coughing, urination defecation, heavy lifting etc.
74
What are the attachments coccygeus?
Ischial spine
Coccyx
Sacrum
75
What is the function of the coccygeus?
Part of the pelvic diaphragm
76
Where is the obdurator internus located?
Deep to obturator membrane and arises partly from it. Also from adjacent ilium and ischium. Inserts into greater trochanter of femur. Crossed by obturator canal.
77
What is the obdurator fascia?
Fascia of medial surface of obdurator internus. Thickened infrior part is tendinous arch - origin of levator ani.
78
How are the levator ani muscles arranged?
Muscles are paired and unite in midline.
79
What does the levator ani consist of?
Iliococcygeus, pubococcygeus, puborectalis, pubovaginalis
80
What is the pubococcygeus?
Back of body of pubic bone and anterior half of tendinous arch to coccyx.
81
Where is the puborectalis located? What is its function?
Originates with pubococcygeus and extends below it to pass around anorectal junctin. Joins puborectalis from opposite side to form a sling around anorectal junction.
Role in fecal continence.
82
Where is the pubovaginalis?
Attached to the back of body of pubis to form a sling attach to walls of vagina or prostate and then passes into perineal body. Also relates to spingter urethrae and thus plays a role in urinary continence.
83
What is the function of the anococcygeal ligament?
It is a musculotendinous raphe extending from coccyx to anal margin.
84
What inserts into the anococcygeal ligament?
Fibres from the left and right iliococcygeus and pubococcygeus, puborectalis and external anal sphincter insert into the anococcygeal ligament.
85
What is the pelvic diaphragm consist of?
Consists of levator ani, coccygeus and their superior and inferior fasciae
