Unit 4: The Abdomen and Pelvis Flashcards
what composes the liver and the hepatic portal system?
- liver (right, left, caudate, quadrate lobes)
- falciform ligament
- common hepatic artery
- hepatic vein
- portal vein
- right and left hepatic ducts
- cystic duct
- common bile duct
- gall bladder
what does the celiac trunk branch into?
- common hepatic artery
- splenic artery
- left gastric artery
what does the right gastric artery branch off of?
common hepatic artery
what does the common hepatic artery supply and what vertebral level does it originate?
- supplies the liver
- T12
what vertebral body does the celiac trunk originate at and supply?
- T12
- supplies foregut
what do the hepatic veins drain and at what vertebral level do they drain into the IVC?
- drain blood from liver
- drain into IVC at T8 (at IVC hiatus)
what is the function of the portal vein?
delivers oxygen-poor nutrient-rich blood to the liver
what veins does the portal vein collect blood from?
- superior mesenteric vein
- inferior mesenteric vein
- splenic vein
- gastric veins
- cystic vein (from gall bladder and cystic duct)
what are the functions of the right and left hepatic ducts?
carry bile from right and left lobes of liver; drain into common hepatic duct
what is the function of the cystic duct?
carries bile from gall bladder; joins with common hepatic duct to form common bile duct
what is the function of the common bile duct?
passage for bile into the hepatopancreatic ampulla
where is the gall bladder and what is its function?
- sits on inferior surface of right lobe of liver
- stores bile
what are the lobes of the liver?
- right lobe (larger than left)
- left lobe
- caudate lobe (superior)
- quadrate lobe (inferior)
what is the function of the falciform ligament?
separates right and left lobes of liver
where is the head of the pancreas?
- encircled by C-shaped duodenum
what is the hepatopancreatic ampulla and where does it travel?
- combination of common bile duct and pancreatic duct
- exits the head of the pancreas through the major duodenal papilla (sphincter of Oddi)
where is the tail of the pancreas?
- neighbours splenic hilum and left colic (splenic) flexure
- passes transversely anterior to the aorta and L2 vertebral body
- anterior surface covered in peritoneum
what is the pancreatic duct?
originates in the tail of the pancreas; joins common bile duct to form hepatopancreatic ampulla
where is the splenic artery and what does it supply?
- branches off celiac trunk @ T12
- squiggly, travels superior to pancreas
- supplies spleen, pancreas, and little stomach
what is the cardiac orifice?
distal opening of the esophagus
what is the cardia?
most proximal region of the stomach
what is the fundus of the stomach and how does it appear on CT?
superior portion of stomach; appears hypodense on CT because usually empty (air-filled)
what is the pylorus?
most distal part of the stomach; where chyme lies before dumped into duodenum
what is the function of the pyloric valve (and pyloric sphincter)?
prevents backflow from duodenum into stomach
what is the lesser curvature of the stomach?
superior, short, concave border of stomach; attachment for lesser omentum
what is the greater curvature of the stomach?
inferior, long, convex border of the stomach; attachment for greater omentum
what is the duodenum?
most proximal division of the small intestine; ends at duodenojejunal flexure
what is the jejunum?
second part of the small intestine, begins at duodenojejunal flexure
what is the ileum?
last part of the small intestine, terminates at the ileocecal junction
what is the mesentary and where is it?
- continuation of visceral and parietal peritoneum
- tethers organs (stomach, SI, pancreas, spleen) to posterior abdominal wall
- lies deep to greater omentum
what is the cecum?
proximal portion of the large intestine, continuous with the ascending colon
- connected to ileum by ileocecal valve
what is the appendix?
distal to the cecum, filled with lymphoid tissue (possible role in bacteria growth and development for gut microbiome)
- pouch
how does the colon travel?
- ascending colon on right side, turns into transverse colon and reflects left at right colic (hepatic) flexure, which is just inferior to the liver
- transverse colon runs from right colic flexure to left colic (splenic flexure) which is near the spleen
- descending colon on left side and turns into sigmoid colon at sigmoid flexure (at left iliac crest) to S3
- becomes rectum and then anus
what vertebral level is the rectum at?
S3
what are tenia coli?
thin ribbon of longitudinal muscle along large intestine
what does the superior mesenteric artery supply and at what vertebral level does it branch off the aorta?
- supplies duodenum to proximal 2/3s of transverse colon + pancreas; midgut
- L1
what does the inferior mesenteric artery supply and what vertebral level does it branch off the aorta?
- supplies distal 1/3 of transverse colon to rectum; hindgut
- L3
what are the suprarenal (adrenal) glands?
- sit on top of each kidney
- divided into cortex and medulla
what is the function of the suprarenal (adrenal) cortex?
secretes corticosteroids and androgens into the bloodstream
what is the function of the suprarenal (adrenal) medulla?
comprised of nervous tissue; functions like sympathetic ganglion (products epinephrine)
what level do the renal arteries branch off the abdominal aorta?
L2
what is the renal hilum?
medial aspect of the kidneys where the renal arteries, veins, nerves, and ureters enter
what is the function of the ureters?
carry urine to the urinary bladder from the renal pelvis
- travels in the retroperitoneal cavity
what is the function of the renal cortex?
contains majority of the nephron (primary site of filtration)
- outer portion of kidney
what is the function of the renal medulla?
contains the renal pyramids
what is the function of the renal capsule?
encloses the kidney
what are the renal columns?
space between pyramids
what are the renal pyramids?
within the medulla, triangular structures
what are the renal papillae?
apex of renal pyramids
- open to expel filtrate into the centre of the kidney
what are the minor renal calyces?
what renal papillae open into and are surrounded by
- merge to form the major renal calyx
how does urine travel after the minor renal calyces?
- major renal calyx
- renal pelvis
- ureter
what is the renal corpuscle?
where blood is filtered and filtrate enters the nephron
- made of the glomerulus (capillaries) and Bowman’s capsule
what is the function of the proximal convoluted tubule?
responsible for reabsorption and secretion of solutes and water
what is the function of the distal convoluted tubule?
regulates ECF and electrolyte homeostasis
what are the collecting tubules?
last part of nephron where filtrate becomes urine
what are the muscles of the abdominal wall?
- external obliques
- internal obliques
- transverse abdominus
- rectus abdominus
- quadratus lumborum
what are the OIAs of the external obliques?
O: ribs 5-12
I: iliac crest, inguinal ligament, linea alba, pubic tubercle
A: bilaterally - anterior flexion of the trunk and compression of the abdomen
unilaterally - lateral flexion of the trunk and rotation to the opposite side
what are the OIAs of the internal obliques?
O: iliac crest, inguinal ligament, thoracolumbar fascia
I: ribs 10-12, pectineal line, linea alba/abdominal aponeurosis
A: bilaterally - anterior flexion of the trunk and compression of the abdomen
unilaterally - lateral flexion of the trunk and rotation to the same side
what are the OIAs of transverse abdominus (corset muscle)?
O: iliac crest, thoracolumbar fascia, costal cartilages of ribs 7-12
I: abdominal aponeurosis
A: compression
what are the OIAs of rectus abdominus?
O: pubic crest and symphysis
I: costal cartilages 5-7, xiphoid process
A: flexion of the trunk
what are the OIAs of quadratus lumborum?
O: iliac crest
I: transverse processes of L1-L5, rib 12
A: extension of the trunk + lateral flexion, stability
what are the os coxae and how are they connected?
hip bones
- connected anteriorly by the pubic symphysis
- connected posteriorly by the sacrum
what bones compose the bony pelvis?
- sacrum
- coccyx
- bilateral os coxae
what are the landmarks of the ilium?
- iliac crest
- posterior superior iliac spine
- posterior inferior iliac spine
- anterior superior iliac spine
- anterior inferior iliac spine
- iliac fossa
- acetabulum
- acetabular notch
- greater sciatic notch
what is the function of the iliac crest?
attachment for internal oblique, transverse abdominus and external oblique (+ lat dorsi)
what landmark is colloquially known as the hip?
anterior superior iliac spine
what is the acetabulum?
cup-like fossa formed by all 3 os coxae bones; articulates with femur to form hip joint
what is the acetabular notch?
discontinuation of labrum and lunate surface of acetabulum (incomplete part of circle)
what is the greater sciatic notch?
between PIIS and ischium; forms the greater sciatic foramen
what are the landmarks of the ischium?
- ischial tuberosity
- body of ischium
- ramus of ischium
- obturator foramen
what bone of the os coxae bears weight while sitting?
ischium
what is the ischial tuberosity known as?
sit bones
what is the obturator foramen formed by?
ramus of ischium and pubis
what are the landmarks of the pubis?
- body
- arcuate line
- iliopubic (iliopectineal) eminence
- pubic tubercle
- superior ramus of pubis
- inferior ramus of pubis
- pubic symphysis
what does the arcuate line form?
pelvic brim
what forms the iliopubic eminence?
union of ilium and pubis
what is the function of the pubic tubercle?
where distal end of inguinal ligament binds to
what is the function of the superior ramus of the pubis?
attachment point for hip joint ligaments (obturator crest)
what are the muscles of the pelvic floor?
- puborectalis
- pubococcygeus
- iliococcygeus
- coccygeus
what are the levator ani muscles?
- puborectalis
- pubococcygeus
- iliococccygeus
what are the OIAs of puborectalis?
O: anteriorly, from the pubic symphysis
I: posteriorly; encircling the anorectal junction (integrating in part with the external anal sphincter)
A: inhibits defecation, recruited when you defecation, inhibits farting
what are the OIAs of pubococcygeus?
O: pubic bone, lateral to origin of puborectalis
I: coccyx
A: control urine flow; contract during orgasm
what are the OIAs of iliococcygeus?
O: ischial spine
I: coccyx
A: maintains position of pelvic organs
what are the OIAs of coccygeus?
O: spine of ischium, sacrospinous ligament
I: lateral margin of coccyx and sacrum
A: draws coccyx forward during childbirth and defecation; supports pelvic viscera
what are the hiatuses of the pelvic floor, from anterior to posterior?
- urethral canal
- vaginal canal (in females)
- rectal canal
what is the pelvic inlet?
roof of pelvic cavity; superior opening of pelvis
what does the pelvic cavity contain?
- urinary bladder
- rectum
- reproductive organs
what kind of uterus do rabbits have?
bicornuate duplex uterus
- 2 separate uterine horns and no uterine body
- each horn has its own cervix; 2 cervices open up into a single vagina
what are the male genital organs?
- testis
- epididymis
- vas deferens
- ejaculatory duct
- penis
what are male accessory glandular structures?
- seminal gland
- prostate
- bulbo-urethral gland
semen is a mix of secretions from what structures?
- testis
- seminal gland
- prostate
- bulbo-urethral gland
what is the function of the testis?
produce sperm + androgens (testosterone) which are responsible for sex drive, fertility, and development of bone and muscle mass
what is the function of the epididymis?
where sperm goes after production to mature
- head
- body
- tail
what is the function of the head of the epididymis?
above testis, acts as a reservoir until sperm are ready to undergo maturation
what is the function of the body of the epididymis?
long tube, site of maturation of sperm
how long does it take for sperm to mature?
~ 7 days
what is the function of the tail of the epididymis?
connects to vas deferens where sperm travels to the ejaculatory duct
what is the function of the vas deferens?
begins at the tail of epididymis, ascends to eventually join the duct of the seminal gland to collectively form the ejaculatory duct
what is the function of the seminal gland?
resides between fundus of bladder and the rectum, secretes fluid rich in fructose and a coagulating agent
what is the ejaculatory duct?
the combination of the vas deferens and the duct of the seminal gland; joins with urethra to create its distal continuation
what is the function of the prostate gland?
produces prostate fluid that helps sperm survive
what is the corpus cavernosa?
dorsal; facilitation of penile erection (fills with blood)
- does most of the work
what is the corpus spongiosum?
ventral; spongy tissue surrounding urethra, closes urethra to make it a channel for ejaculation
- continuous with the glans
what is the function of the bulbo-urethral (Cowper’s) gland?
secretes a mucus-like secretion during sexual stimulation
what are the female genital organs?
- ovaries
- fallopian tubes
- uterus
- vagina
what is the function of the uterus?
womb; facilitates development of embryo and fetus
what is the function of the round ligament?
connects anterior uterus (lateral horns) to labia majora (true ligament)
what is the cervix?
inferior portion of the uterus, between urinary bladder and rectum
- dilates during labour to admit the passage of the baby into the birth canal
- checked routinely for changes indicative of cervical cancer via pap smear
what are the functions of the ovaries?
location of female gamete development
- development of oocytes (female germ cells)
- endocrine function - produce estrogen, progesterone, and testosterone (for maintenance of reproductive organs, bone development, and fertility)
what is the function of the fallopian tubes?
facilitate fertilization between male sperm and female egg
- when fertilization is successful, tube transfers egg to uterus for transplantation
what is the function of the ovarian ligament?
tethers uterus to ovary
what is the function of the vagina?
projects from vaginal part of cervix to vaginal orifice; posterior to urinary bladder and urethra, anterior to rectum
what is the broad ligament?
a sheet-like fold of peritoneum
- extends from the sides of the uterus to the lateral wall and floor of the pelvis, holding the uterus in position
at what vertebral level does the abdominal aorta bifurcate into the common iliac arteries?
L4
at what vertebral level do the common iliac veins converge to form the IVC?
L5
what are the layers of the abdominal wall, from superficial to deep?
- skin
- Camper fascia
- Scarpa fascia
- superficial investing fascia
- external oblique
- intermediate investing fascia
- internal oblique
- deep investing fascia
- transverse abdominus
- endoabdominal fascia
- extraperitoneal fat
- parietal peritoneum
what is the rectus sheath formed by?
aponeuroses that are medial extensions of fascia covering the lateral abdominal muscles
- first layer after skin
- contains rectus abdominus
what is the linea alba?
band of connective tissue running from sternum to pubic bone
- midline
what is the arcuate line of the abdomen and its significance?
clinical landmark approx. halfway between umbilicus and pubic crest
- arrangement of fascia of rectus sheath changes at this line
how is the rectus sheath organized above the arcuate line?
- EO fascia runs anterior to RA
- IO fascia splits; half runs anterior to RA, half posterior
- TA fascia runs posterior to RA
how is the rectus sheath organized below the arcuate line?
- EO fascia runs anterior to RA
- IO fascia doesn’t split; runs anterior to RA
- TA fascia runs anterior to RA
what is the function of the inguinal ligament?
acts as a retinaculum for neurovascular structures passing into the lower limb
- forms floor of inguinal canal (site for vulnerability of an inguinal hernia - loop of SI can get stuck in there)
how are abdominal muscles innervated?
segmentally by branches of spinal nerves
- anterior rami branches into cutaneous nerve (sensory innervating dermatomes) and muscular nerve (motor innervating myotomes)
do muscles contain sensory receptors?
yes
what are the abdominopelvic regions?
- right hypochondriac region
- epigastric region
- left hypochondriac region
- right lumbar region
- umbilical region
- left lumbar region
- right iliac region
- hypogastric region
- left iliac region
what organs are in the right upper quadrant?
- liver (right lobe)
- gall bladder
- stomach (pylorus)
- duodenum
- pancreas (head)
- right adrenal gland
- right kidney
- right colic (hepatic) flexure
- ascending colon (superior part)
- right half of transverse colon
what organs are in the left upper quadrant?
- liver (left lobe)
- spleen
- stomach
- jejunum and proximal ileum
- pancreas (body + tail)
- left adrenal gland
- left kidney
- left colic (splenic) flexure
- left half of transverse colon
- descending colon (superior part)
what organs are in the right lower quadrant?
- cecum
- appendix
- most of ileum
- ascending colon (inferior part)
- right ovary
- right fallopian tube
- right ureter
- right spermatic cord
- uterus (if enlarged)
- bladder (if very full)
what organs are in the left lower quadrant?
- sigmoid colon
- descending colon (inferior part)
- left ovary
- left fallopian tube
- left ureter
- left spermatic cord
- uterus (if enlarged)
- bladder (if very full)
is the spleen a digestive organ?
NO
what are gastric rugae?
internal smooth muscle used for mechanical digestion (churning)
what forms the pyloric part of the stomach (pylorus)?
- proximally: pyloric antrum
- distally: pyloric canal
what is the hepatoduodenal ligament?
portion of the lesser omentum extending from the liver to the duodenum
what is the hepatogastric ligament?
portion of the lesser omentum extending from the lesser curvature of the stomach to the liver
how does the stomach lie in leaner individuals?
greater curvature of the stomach descends in an upright position
what is the omentum and its functions?
fold of peritoneum with protective functions:
- facilitates migration of immune cells into the peritoneal cavity
- physically walls off areas of inflammation by forming adhesions (walls off injury to prevent spreading)
- used as a source of tissue for wound repair
what is the greater omentum?
extends from the greater curvature of the stomach
- hangs in a fold, covering the SI
- doubles back and attaches to the transverse colon
what is the lesser omentum?
extends from the lesser curvature of the stomach
- attaches to liver and duodenum
what is the mesentery?
attaches to jejunum and ileum, it supplies them with nerves and vessels
- specialized peritoneum
what are haustra?
segmented pouches of bowel formed by contraction of the circular smooth-muscle layer
- bumps of LI
what are diverticula and their clinical importance?
tiny pouches that form in the colon with age
- can become inflamed = diverticulitis
what makes up the portal triad and what do they go through?
- hepatic artery
- hepatic portal vein
- common bile duct
go through the lesser omentum
how does bile enter the digestive tract when produced on demand?
liver -> left and right hepatic ducts -> common hepatic duct -> common bile duct -> hepatopancreatic ampulla -> major duodenal papilla -> duodenum
how does bile enter the gall bladder when it is produced by not required?
sphincter is closed at duodenum common bile duct -> cystic duct -> gall bladder
what is the path of portal blood supply?
celiac trunk -> common hepatic artery -> hepatic artery proper -> left and right hepatic arteries (going to their respective lobes)
why is their an accessory pancreatic duct and what structure does it pass through to enter the duodenum?
- only has pancreatic secretions for when fat is not being digested and bile is not required
- goes through the minor duodenal papilla
what is cholelithiasis?
gallstones
- hard deposits in the gall bladder
what are the functions of the spleen?
largest immunological organ
- contains a large reservoir for leukocytes
- retrieves and slowly filters blood, both to extract old/dysfunctional erythrocytes from circulation and perform immune surveillance
- highly variable in size and morphology
why is the spleen vulnerable to trauma?
superficial, right against the ribs (slightly lateral to left costal margin)
- commonly caused by blunt trauma
how does the abdominal aorta run relative to the IVC?
anterior and to the left
where do kidney stones form?
- calyces
- renal pelvis
- ureter
what are the most common muscles injured during vaginal delivery?
puborectalis and pubococcygeus, causing incontinence (loss of bladder control) and sexual dysfunction
what is the difference in risk of pelvic floor dysfunction of C-section vs vaginal delivery?
vaginal delivery is associated with 2 fold increase in risk of pelvic floor dysfunction
what connects the fundus of the uterus to the ovaries?
fallopian tubes
what connects the uterus to the vagina?
cervix
what are some complications of pregnancy due to compression of nearby organs caused by an enlarged uterus?
- shortness of breath
- heart burn
- reduced stomach capacity
- impaired intestinal transit and constipation
what is round ligament pain?
sharp pain in the pelvic floor due to pressure of uterus tugging on round ligament
what is a uterus prolapse?
the uterus collapses into the vagina (and in severe cases, outside of the vagina)
- when ligaments and/or pelvic floor muscles are damaged
what are the named portions of the fallopian tubes, from proximal to distal?
- intramural
- isthmus
- ampulla
- infundibulum
what is the most common form of ectopic pregnancy and its prevalence?
tubal pregnancy: once egg is fertilized and on its way to uterus, implants in fallopian tube
- 1/250 births
what can a tubal pregnancy be misdiagnosed as?
appendicitis
- appendix lies very close to the right ovary and right uterine tube
what is a tubal ligation?
surgical method of birth control (tubes tied)
- cut and cauterized
- placing clips on tubes
ova that are released degenerate and are absorbed
what is the cervical os?
small opening for women who have never given birth
what is the vulva?
collective term for external female genitalia
what is infibulation?
sewing up the vulva with some space left for urination and menstruation
what is tumescence?
erection
what part of the penis fills up with the most blood during an erection?
corpus cavernosum
what is the glans?
tip of penis
what are the divisions of the root of the penis?
- 2 crura (lateral)
- 1 bulb (medial)
what is the precpuce?
foreskin
- covers majority of glans
- attaches to fascia overlying body of penis
what are the potential benefits of male circumcision?
reduced risk of UTI, penile cancer, and STI (including HIV)
what are the risks of male circumcision?
infection, permanent disfiguration, impaired sexual pleasure of function
what is the urethra (males)?
extends from internal urethral orifice (bladder) to external urethral orifice (glans)
what are the 4 divisions of the urethra in males, from proximal to distal?
- preprostatic (intramural) urethra: surrounded by the internal urethral sphincter
- prostatic urethra
- membraneous urethra: surrounded by the external urethral sphincter
- spongy (penile) urethra
why is the prostatic urethra important?
- contains the urethral crest, where prostatic ducts open bilaterally
- contains the seminal colliculus, where the ejaculatory ducts open bilaterally
- affected by benign prostatic hyperplasia
what is benign prostatic hyperplasia?
a non-cancerous increase in prostate size
- waking up in the night to urinate
- urinary hesitancy
- intermittent urine flow
what runs alongside the spongy urethra?
cowper’s glands
what 2 openings increase the size of the urethra?
- ampulla (proximal)
- navicular fossa (distal, in the glans)
what is vas deferens ligation?
vasectomy
- cutting and ligating vas deferens in scrotum as a form of birth control
what organs are intraperitoneal?
SALTD SPRSS
- stomach
- appendix
- liver
- transverse colon
- duodenum (1st part only)
- small intestine (jejunum and ileum)
- pancreas (tail)
- rectum (upper 3rd)
- spleen
- sigmoid colon
what organs are retroperitoneal?
- adrenal glands
- aorta (IVC)
- duodenum (2nd and 3rd part)
- pancreas (except tail)
- ureters
- ascending and descending colon
- kidneys
- esophagus
- rectum (remaining)
