lecture 7 imaging

Question 1

MRI vs CT; include abdomen and pelvic if requesting (not just abdomen)

Answer 1

CT: bones are white, marrow is grey, subcutaneous fat is black water is grey; MRI: bones black, white bone marrow, white subcutaneous fat, water is white on T2, grey on T1

Question 2

right external oblique muscle; include side of body if mentioning something which occurs in both

Answer 2

lateral muscles: external oblique, internal oblique, transversus abdominis; centre line is linea alba, with rectus abdominis either side, with linea semilunaris either side of these; underneath these is tranversalis fascia

Question 3

inferior epigastric artery (used as landmark to determine where hernia is on imaging; supplies blood to muscles of anterior abdominal wall e.g. rectus abdominis muscle, and to deep abdominal wall of pubic and lower umbilical regions)

Answer 3

runs medial to deep inguinal ring; deep inguinal ring (gap in transversalis fascia) is halfway along and 1cm above inguinal ligament, just lateral and superior to mid inguinal point; indirect inguinal hernias occur; posterior opening of inguinal canal

Question 4

direct inguinal hernias

Answer 4

cannot enter scrotal sac; indirect most common (comes down through deep inguinal ring into inguinal canal and into scrotum; lateral to inferior epigastric is peritoneal fold which forms tunica vaginalis lying next to testicle which should close off); direct inguinal hernia is weakness in abdominal wall medial to inferior epigastric artery so bulge medial

Question 5

fluid is in lesser sac

Answer 5

lies in between anterior pancreas and posterior stomach

Question 6

splenic artery provides blood supply to stomach

Answer 6

celiac axis: gives off left gastric, hepatic, splenic (close to cranial edge (head) of pancreas, runs just above pancreas); splenic give off short arteries which supply pancreatic body and tail, short gastric arteries which supply fundus of stomach, and large branch (gastroepiploic artery) which supplies left side of greater omentum; pancreatic head supplied mainly by gastroduodenal artery and part of superior mesenteric artery

Question 7

right and left liver lobes demarcated by plane between gall bladder fossa and IVC

Answer 7

fissure is for ligamentum teres where falciform ligament attaches to front of liver (anterior); fissure for ligamentum venosum (posterior on underside)

Question 8

renal veins drain directly into IVC

Answer 8

vein at front, then renal artery, then behind that is renal pelvis (left vein longer than right)

Question 9

vaginal lumen surrounding uterine cervix

Answer 9

fornix (recess formed between margin of cervix and vaginal wall, divided into 4 parts: posterior, anterior and lateral)

Question 10

if rectal exam on female, firm structure palpated in midline through anterior rectal wall is cervix of uterus

Answer 10

vagina is too soft; uterine cervix points posteriorly as anteverted uterus

Question 11

during hysterectomy, while uterine arteries are tied off, ureter may be damaged

Answer 11

ureter passes down bottom end of broad ligament to drain into bladder, which is very closely related to uterine vessels; ovarian arteries are within peritoneal fold of suspensory ligament of ovary

Question 12

female bony pelvis differs from males as females often has a larger subpubic angle

Answer 12

enough for baby to get out; larger diameter and ischial spines are less prominent and further apart

Question 13

urethra lies in corpus spongiosum of penis

Answer 13

3 compartments: corpus spingiosum, 2 corpus cavernosum

Question 14

cancer of penis is likely to spread to inguinal lymph nodes

Answer 14

lymphatic drainage tends to mirror arterial supply; external genitalia drain by inguinal lymph nodes; bladder and prostate drain to iliac lymph nodes; testis and ovary drain to para-aortic lymph nodes