Abdomen, Pelvis, Perineum 4 DR

Question 1

what is the pelvic girdle

Question 2

what is the function of the pelvic girdle

Answer 2

primary functions:

bear the weight of upper body when sitting + standing

transfer the weight of body from axial to lower appendicular skeleton for standing + walking

provide attachment for muscles of locomotion, posture and abdominal wall muscles → needs to be able to withstand the force generated by their actions → pelvic girdle is strong and rigid

other functions:

contain and protect pelvic viscera (inferior parts of urinary tract + reproductive organs) and inferior abdominal viscera (intestines) whilst permitting the passage of their terminal parts (and fetus) via perineum

support abdominopelvic viscera and pregnant uterus

provide attachemnt for erectile bodies of external genitalia

provide attachment for muscles + membranes that form the pelvic floor

Question 3

what bones make up the pelvic girdle

Answer 3

3 bones in adults

right and left hip bones - made up of ilium, ischium, pubis fused together

sacrum - formed by fusion of 5 originally separate vertebrae

Question 4

where do each of the bones begin and end in pelvic girdle

Question 5

what are the palpable landmarks of the iliac bone

Question 6

what are the joints which make up the pelvic girdle

Answer 6

right and left hip bones joined by pubic symphysis (fibrocartilaginous)

right and left hip bones join with sacrum at sacro-iliac joint (synovial)

Question 7

what are the different parts of the ilium

Question 8

what are the different parts of the ischium

Question 9

what are the different parts of the pubis

Question 10

how is the pelvis divided

Answer 10

greater and lesser

separated by pelvic inlet (bony edges of pelvic inlet = pelvic brim)

Question 11

what is the pelvic brim

what forms it

Question 11

what is the pelvic brim

what are the borders of it

Answer 12

greater and lesser

separated by pelvic inlet (bony edges of pelvic inlet = pelvic brim)

Question 13

what is the difference between the pelvic inlet and outlet

Answer 13

Question 14

what are the borders of the pelvic outlet

Question 15

where is the greater/false pelvis

what are its borders

what does it contain

Question 16

where is the lesser/true pelvis

what are its borders

what does it contain

Question 17

how does the true pelvic cavity relate to the perineum

Question 18

describe the orientation of the pelvic girdle

Question 19

what is the sacral promontory

Question 20

what is the sciatic notch

Question 21

what are the differences between the male and female pelvis

Answer 21

female pelvis is:

wider and broader but lighter in weight

oval shaped pelvic inlet compared to heart shaped in men

less prominent ischial spines → greater bispinous diameter

larger angle of sub-pubic arch

shorter more curved sacrum + less pronounced sacral promontory

Question 22

what are the differences between the male and female pelvis

Answer 22

female pelvis is:

wider and broader but lighter in weight

oval shaped pelvic inlet compared to heart shaped in men

less prominent ischial spines → greater bispinous diameter

larger angle of sub-pubic arch

shorter more curved sacrum + less pronounced sacral promontory

Question 23

what are the primary joints of the pelvic girdle

what is their function

Answer 23

sacroiliac joints

pubic symphysis

other joints - sacrococcygeal and lumbosacral joint

all supported + strengthened by ligaments

Question 24

what is the significance of the sacral-iliac joints how are they unique compared to other similar joints

Answer 24

connect the axial skeleton to the inferior appendicular skeleton - transmits weight from vertebral column to hip bone synovial joint but has much more limited mobility compared to other synovial joints → because they have to transmit so much bodyweight onto hip bones

Question 25

what ligaments support the sacro-iliac joints where do they attach

Answer 25

anterior sacro-iliac ligament - thin ligament between sacrum and iliac joint posterior sacro-iliac ligament - interosseous sacro-iliac ligament sacrospinous ligament - between sacrum and ischial spine sacrotuberous ligament - between sacrum and ischial tuberosity sacrospinous ligament is anterior and medial to sacrotuberous

Question 26

how is the sciatic notch divided

Answer 26

divided by sacrospinous and sacrotuberous ligaments (which stabilise sacro-iliac joint) into greater and lesser sciatic foramen

Question 27

what is the structure of the pubic symphysis

Answer 27

fibrocartilaginous interpubic disc between the bodies of the pubic bones supported by ligaments

Question 28

how does the pubic symphysis vary between sexes

Answer 28

interpubic disc is generally wider in women

Question 29

what ligaments support the pubic symphysis

Answer 29

superior pubic ligament inferior pubic ligament decussating fibres of tendinous attachment of rectus abdominis and external oblique also strengthen pubic symphysis anteriorly

Question 30

what are the lumbosacral joints

Answer 30

articulations between L5 and S1 intervertebral joint - formed by intervertebral disc between their bodies joints between inferior articular processes of L5 and facets of S1 strengthened by fan-like iliolumbar ligaments radiating from from transverse processes of L5 to ilia

Question 31

what is the sacrococcygeal joint

Answer 31

joint between apex of sacrum and base of coccyx - fibrocartilaginous stabilised by anterior and posterior sacrococcygeal ligaments

Question 32

which parts of the abdominopelvic cavity are the best protected why

Answer 32

superior - protected by ribcage inferior - protected by pelvis

Question 33

what part of the abdominopelvic cavity is the pelvic cavity what does the pelvic cavity contain

Answer 33

funnel shaped inferior and posterior section pelvic viscera: terminal parts of ureter bladder genital organs blood vessels, lymphatics, nerves “overflow” abdominal viscera: loops of small intestine - mainly ileum loops of large intestine - appendix and transverse and/or sigmoid colon

Question 34

what are the borders of the pelvic cavity

Answer 34

inferior border - pelvic diaphragm (group of muscles + their fascia) superior border - pelvic inlet anteroinferior wall - pubic symphisis and pubis bones lateral walls - right and left hip bones + obturator internus posterior wall - inferiormost/apex part of sacrum + coccyx + piriformis superior part of sacrum forms posterior-superior wall of pelvic cavity

Question 35

what is important to note about the inferior border of the pelvic cavity

Question 36

what is the significance of the pelvic floor attachments

Answer 36

they attach in the pelvic cavity (above the pelvic outlet), but descends below the pelvic outlet → forms bowl like floor to the cavity