Final Exam- Weeks 10-11 Flashcards
cecum
- blind-ended pouch
- covered in peritoneum, but not mesentery
- contains ileocecal (ileocolic) valve (1-way)
vermiform appendix
- 8-10 cm long
- aggregations of lymphoid tissue
- no longer necessary - more trouble than functional
- suspended by mesoappendix (houses arteries/veins)
variable positions: retrocecal, retrocolic, pelvic
McBurneys Point of the vermiform appendix
point on anterior ab wall that is the lateral 1/3 of the distance from the ASIS to umbilicus
1. dull pain - doctors visit
2. sharp pain - emergency
4 parts of the colon
- ascending - right upper
- transverse
- descending - left upper
- sigmoid (pelvic)
structures of colon
- left colic flexure (splenic)
- right colic flexure (hepatic)
features of colon
- teniae coli
- haustra
- epiploic appendages
muscular components of the colon
- taeniae coli
- haustra
taeniae coli
3 longitudinal bands of smooth muscle that run along the outer layer of the entire colon
haustra
- series of pouches in the wall of colon
- created by muscle tone in taeniae coli
- permit expansion and elongation of colon
peritoneal coverings of the colon - mesocolon
- complete covering
- partial covering
- mesoappendix
complete covering
transverse & sigmoid mesocolons (intraperitoneal)
partial covering
ascending, descending & rectal mesocolons (retroperitoneal)
mesoappendix
connects appendix to ileum & cecum
what feature does the cecum not contain?
mesenteric attachment
where does the midgut transfer to the hindgut
distal 1/3 of the transverse colon
large intestine blood supply (SMA)
SMA
- ileocolic
- right colic
- middle colic
***MRI
large intestine blood supply (IMA)
IMA
- left colic
- sigmoidal
- superior rectal (hemorrhoidal)
I Love Singing Songs
large intestine blood supply (marginal artery of drummond)
anastomoses between right, middle, and left colic arteries
- key for collateral circulation of alternative supply
parts of pancreas
- tail
- body
- neck
- head
- uncinate process
large intestine venous drainage - splenic vein
- hilum of spleen
- posterior to tail and body of pancreas
- join superior mesenteric vein
what does the splenic vein drain
- spleen
- lower esophagus
- part of stomach
- pancreas
large intestine venous drainage - superior mesenteric vein
- ascends in root of mesentery
- pass anterior to 3rd part of duodenum (transverse)
- joins splenic vein posterior to neck of pancreas
what does the superior mesenteric vein drain
areas supplied by the SMA
1. iliocecum
2. left colic
3. middle colic
large intestine venous drainage - inferior mesenteric vein
- ascends on left posterior ab wall
- join splenic vein posterior to pancreas
what does the inferior mesenteric vein drain
areas supplied by the IMA
1. left colic
2. sigmoidal
3. superior rectal
hepatic portal vein
- created by splenic vein and superior mesenteric vein uniting
- carries nutrients from digestive tract to liver
portosystemic obstruction
result of obstructed venous return to liver
accessory digestive organs
- liver
- gallbladder
- pancreas
- salivary glands
function of the accessory digestive organs
produce, store, and secrete digestive enzymes and buffers
liver
largest visceral organ
metabolic function of the liver
hepatocytes regulate circulating levels of nutrients; remove metabolic wastes and toxins
hematological function of the liver
- acts a blood reservoir
- filters circulating debris
digestive function of the liver
synthesizes and secretes bile
“hepato”
related to liver
location of the liver
- immediately inferior to diaphragm
- in right upper abdomen
- sits superior and lateral to stomach, right kidney and intestines
diaphragmatic surface of the liver
- superior and anterior surfaces
- smooth and follows curve of diaphragm and body wall
bare area of the diaphragmatic surface
area of liver in direct contact with diaphragm
- no visceral peritoneum (shiny)
visceral surface of diaphragmatic surface
- posterior and inferior surfaces
- has impressions from stomach, small intestine, right kidney, and large intestine
lobes of liver
- right lobe
- left lobe
- caudate lobe (adjacent to IVC)
- quadrate lobe (adjacent to gallbladder)
ligaments of liver
made up of double folds of peritoneum - anchor liver
1. falciform lig
2. coronary lig
3. right & left triangular ligs
4. round lig
falciform ligament
attaches liver to anterior body wall and divides liver into left and right lobes
coronary ligament
suspends liver from the diaphragm
- superior
right and left triangular ligaments
on superior aspect, towards lateral body wall
round ligament (ligamentum teres)
thickening of inferior margin of falciform ligament, embryological remnant of umbilical vein
bile
- gallbladder stores and concentrates bile produced by liver
- bile helps in digestion of dietary lipids through emulsification
gallbladder location
- hollow, pear-shaped, muscular sac on the right visceral surface of liver
- lateral to stomach
- closely related to the duodenum
gross anatomy of the gallbladder
- cystic duct
- neck
- infundibulum
- fundus
ducts connecting the liver and gallbladder
- right and left hepatic duct
- common hepatic duct
- cystic duct
- common bile duct
common hepatic duct
joins the cystic duct to form common bile duct
common bile duct
empties into duodenum
arterial supply of the gallbladder
cystic artery (branch of hepatic artery proper)
venous drainage of the gallbladder
cystic vein into the hepatic portal vein
the porta hepatis contents - doorway to liver
also known as hilum of the liver
1. hepatic portal vein
2. hepatic artery proper
3. common hepatic duct
origin of the artery in porta hepatis (hepatic proper artery)
abdominal aorta>celiac trunk>common hepatic artery>hepatic proper artery
origin of the vein in the porta hepatis (hepatic portal vein)
formed by the union of the SMV and splenic vein, posterior to pancreas
hepatic portla vein pathway
carries blood from…
1. small intestine
2. large intestine
3. stomach
4. pancreas
5. gallbladder
6. spleen
hepatic portal system
- connection between two capillary beds
- nutrient-rich venous blood drains from the stomach and intestines and travels to the liver for processing
steps of hepatic portal system
- small intestine absorbs products of digestion
- nutrient molecules travel in hepatic portal vein to liver
- liver monitors the blood content
- blood enters general circulation by way of hepatic veins
- hepatic veins empty into the IVC
processing at liver
done via lobules
lobules of liver
- functional unit of the liver for processing
- hexagonal in shape
- contain a central vein at the centre of each lobule
contain a portal area with a portal triad at each corner of the lobules
portal area of the lobule (triad)
triad of portal area contains:
1. small branch of the hepatic portal vein
2. s small branch of the hepatic artery proper
3. a bile duct
blood flow towards the central vein
- blood provided by hepatic artery proper and hepatic portal vein flows from portal area towards central vein
- as blood flows towards centre, hepatocytes absorb and secrete substances altering blood entering systemic circulation
- central veins coalesce into hepatic veins
hepatic veins
drain each segment of the liver into IVC and eventually empties filtered blood into right atrium of the heart to be pumped to rest of body
alcohol consumption
- stomach and SI absorb alcohol
- hepatic portal vein carries blood to liver
- enzymes metabolize alcohol in liver
- hepatic veins carry the blood to IVC to go back into systemic circulation
origin of the duct in porta hepatis (common hepatic duct)
formed by the fusion of the left and right hepatic ducts
bile flow towards the portal areas
- hepatocytes produce bile and bile flows outward to portal areas
- bile canaliculi carry bile to bile duct of closest portal area
- bile duct branch which leads to the rest of the duct system
hepatic artery proper
delivers oxygenated blood to liver
- has a right and left branch
hepatic portal veins
delivers deoxygenated, but nutrient-rich blood from the digestive tract
common hepatic ducts
carries bile produced by the liver aways
exocrine function of the pancreas
- produces digestive enzymes and alkaline buffers to neutralize acidic chyme
- duct system within pancreas carries the fluid to duodenum
endocrine function of the pancreas
produces hormones such as insulin
exocrine
substances secreted into duct system to an epithelial surface
endocrine
substance is secreted into interstitial fluid and then into bloodstream
pancreas
- approx 15 cm long
- pinkish, greyish colour
location of pancreas
- posterior to stomach
- head of pancreas is nestled in curve of duodenum
- extends left, towards the spleen
greater omentum
drapes over the rest of abdominal contents like an apron
anatomy of the pancreas
- neck
- body
- tail
- uncinate process of pancreas (hooks)
- head
- pancreatic duct
- accessory pancreatic duct
what anastomosis occurs behind the head of the pancreas
superior mesenteric vein + splenic vein form the portal veins
arterial blood supply to pancreas
branches of splenic artery and pancreaticoduodenal artery
venous drainage to the pancreas
splenic veins
what does the pancreas empty into
secretions from gallbladder and pancreas are transported to duodenum via duct systems
how does fluid from gallbladder and pancreas enter the duodenum
papilla
papilla
small, rounded protuberance on an organ
minor and major duodenal papilla
empty secretions from the gallbladder and pancreas into the duodenum
spleen
- lymphatic organ
- triangular shaped
- intraperitoneal
function of spleen
- filtration of red blood cells to remove old, larger and deformed cells
- prevention of infection
location of spleen
- upper left quadrant of abdomen
- between ribs 9-11 at the midaxillary line
- superior to the large intestine and kidney
- anterior to diaphragm
- tail of pancreas inserts to central area of spleen
posterior surface of the spleen
diaphragmatic area
superior surface of the spleen
gastric area (close to stomach)
anterior surface of the spleen
colic area
inferior surface of the spleen
renal area (spleen comes into contact with left kidney
blood supply to the spleen
via splenic artery
hilum of spleen
- medial concave area of spleen
- vascular attachment site
hilum of the spleen contents
- splenic artery
- splenic vein
peritoneum of spleen - hilum lines
- splenogastric ligament
- pocket for tail of pancreas
- splenorenal ligament
splenogastric ligament
connects stomach and gastric area of spleen
splenorenal ligament
connects left kidney to renal area of spleen
what surface of the spleen is associated with the large intestine
the anterior surface
the kidneys
- retroperitoneal organs
- kidney-bean shaped
position of the kidneys
- posterior abdominal wall
- right kidney sits lower than left (cause liver is so big)
- T12-L3/L4 (L3=left, L4=right)
functions of kidneys
- urine production
- regulation of blood ionic concentration
- regulation of blood pH
- regulation of blood volume and pressure
- production of hormones
- regulation of blood glucose
- excretion of waste and foreign substances
protective coverings of the kidney
- PERIrenal fat
- renal capsule
- renal fascia
- PARArenal fat
PERIrenal fat
fatty mass that protects from trauma and holds in place
renal capsule
connective tissue that is the deepest form of protection
renal fascia
anchor kidneys to surrounding structures and abdominal wall
PARArenal fat
thinner and most superficial protective layer
blood supply to the kidneys
renal artery
- comes directly off the abdominal aorta to kidneys
venous drainage of the kidneys
renal veins directly to IVC
vasculature relationships between both sides
- right renal artery= longer than left renal artery cause its further from AA
- right renal vein is shorter than left renal vein cause shorter pathway to IVC
hilum of kidney
- medial concave area of the kidneys
- 3 main structures
3 main structures of hilum of kidney
- renal artery
- renal vein
- ureter
ureter
runs from the kidney to the urinary bladder POSTERIOR to renal veins and artery
2 main components of kidney
- cortex
- medulla
cortex of kidneys
- outer component
- main filtering area
medulla of kidneys
- many columns and tubes
- beginning of urine production
components of medulla
- renal pyramid
- renal papilla
- minor calyx (calyces)
- renal pelvis
- major calyx (calyces)
- ureter
pathway of urine
- renal pyramid
- renal papilla
- minor calyx
- major calyx
- renal pelvis
- ureter
adrenal glands (suprarenal glands)
- endocrine organs (produce hormones)
- retroperitoneal organs
- sits directly superior to kidneys
function of the adrenal glands
- produce adrenaline
- produce cortisol
- produce aldosterone
components of adrenal glands
- medulla
- cortex
3 inner layers of cortex of adrenal glands
- zona glomerulosa
- zona fasciculata
- zona reticularis
zona glomerulosa
secretes hormones (aldosterone for blood pressure)
zona fasciculata
secretes glucocorticoids (cortisol)
zona reticularis
synthesize weak androgens
3 branches of blood supply to the adrenal glands
- superior suprarenal arteries
- middle suprarenal artery
- inferior suprarenal artery (from renal artery - supplies inferior AG)
superior suprarenal arteries
extends from the inferior phrenic artery
- supplies superior adrenal glands
middle suprerenal artery
extends directly from abdominal aorta
- supplies middle adrenal
venous drainage of the adrenal glands
- right suprarenal vein
- left suprarenal vein
- left renal vein
***asymmetrical drainage
right suprarenal vein
drains directly into IVC on right hand side (direct drainage)
left suprarenal vein
drains into left renal vein and then into IVC (indirect drainage)
why would a horseshoe kidney not sit as high up in abdomen than regular kidneys
it gets hooked on the inferior mesenteric artery
branches off the abdominal aorta for the kidneys
- celiac trunk (T12)
- left renal a (T12)
- superior mesenteric a (L1)
- inferior mesenteric a (L3)
- right renal a (L1)
- middle suprarenal a
pelvic girdle
- sacrum
- innominate bones
- coccyx
innominate bone
- ilium
- ischium (infero-posterior)
- pubis (infero-anterior)
features of the innominate bones
- auricular surface
- iliopectineal line
- ischial spine
- ischial tuberosity
- symphyseal surface (joins pelvises)
features of sacrum
- sacral promontory
- sacral ala
- anterior sacral foramina
- auricular surface
- coccyx (4 fused bones)
joints of the pelvic girdle
- sacroiliac joints
- symphysis pubis
sacroiliac joints
joins auricular surfaces of sacrum and ilium
symphysis pubis
fibrocartilaginous disc between left and right pubis (symphyseal surface)
pelvic inlet
anterior border: symphysis pubis + iliopectineal line
posterior border: sacral promontory
lateral border: sacral ala
pelvic outlet
anterior border: symphysis pubis
posterior border: coccyx
lateral border: ischial tuberosities
true and false pelvis
true pelvis: pelvic viscera (space between pelvic inlet + outlet)
false pelvis: abdominal viscera
male vs female pelvis
female: larger subpubic angle + interspinous distance
male: smaller subpubic angle + interspinous distance (space between the ischial spines)
function of the pelvic diaphragm
supports pelvic viscera
features of the pelvic diaphragm
- urogenital hiatus (anterior)
- anal aperture
muscles of the pelvic diaphragm
- levator ani group (support anal canal)
- ischiococcygeus
levator ani muscles
- puborectalis
- pubococcygeus
- iliococcygeus
puborectalis
extends from pubis to the rectum
- wraps around the anal aperture forming the anal sling
pubococcygeus
extends from the pubis to the coccyx
iliococcygeus
extends from the ilium to the coccyx
ischiococcygeus
extends from the ischium to the coccyx
what pelvic diaphragm muscles do not form the urogenital hiatus
all except the puborectalis
male pelvic viscera
- vas deferens/ ductas deferens
- seminal vesicles
- ejaculatory ducts
- prostate gland
female pelvic viscera
- uterus
- uterine tubes
- ovaries
- vagina
shared pelvic viscera between both male and females
- bladder
- ureters
- sigmoid colon
- rectum
broad ligament
double fold of peritoneum that covers female pelvic viscera
- covers ovary, bladder directly and vagina indirectly
3 divisions of the broad ligament
- mesometrium
- mesovarium
- mesosalpinx
mesometrium
- reference to uterus
- largest division of the broad lig
- covers the uterus and bladder
mesovarium
- reference to ovaries
- suspends ovaries from the uterine tubes
mesosalpinx
- reference to tubes
- surrounds uterine tubes and drapes posteriorly
features of the uterus
- fundus
- uterine cavity
- cervix
- cervical canal
- internal os
- external os
ligaments of the uterus
- uterosacral lig
- cardinal lig
- round lig
***suspend and holds uterus in place
uterosacral lig
extends from uterus to sacrum posteriorly
cardinal lig
- looks like wings
- extends lateral from the uterus to side wall of the pelvic cavity
round lig
attaches uterus anteriorly to the pelvic cavity
features of the uterine tubes
- infundibulum
- isthmus
- ampulla
- fimbriae
infundibulum of uterine tube
cone shaped
- fans out into fimbrae
isthmus of uterine tube
attaches uterine tube to uterine cavity
fimbriae of uterine tube
scoops eggs into the uterus
ovaries
- paired almond shaped organs
- produce ova (eggs)
- secrete estrogen and progesterone
features of the ovaries
- mesovarium
- suspensory lig of the ovary
- ovarian lig
ovaries in situ
- suspensory ligament anchors ovaries to pelvic side wall
- ovaries are located superior to uterus
vagina
- open to external environment
- begins at the external os of the cervix
- posterior to bladder
- protrusion of cervix creates fornixes
ductus (vas) deferens
carries sperm from testicles to inguinal canal then to bladder
seminal vesicles
- posterior surface of bladder
- lateral to ductas deferens
- glandular structures
- store & produce fluid that makes up a majority of semen
ejaculatory ducts
formed by union of seminal vesicles and vas deferens
prostate gland
- inferior to bladder
- walnut shaped
- traversed by prostatic urethra
- prostatic utricle contracts to widen the openings of ejaculatory ducts
utricle of the prostate gland
helps open the ejaculatory duct
opening of ejaculatory ducts
semen enters urethra via prostate gland
sigmoid colon
- ‘S’ shaped
- distal end of the colon
- continuous with the rectum distally
rectum
continuous with the anal canal distally
two flexures of the rectum
- sacral flexure
- anorectal flexure (via anal sling)
internal anatomy of the rectum
- 3 transverse folds
- superior rectal folds
- middle rectal folds
- inferior rectal folds - 3 lateral flexures
ureters pathway
- exit renal pelvis
- pass posterior to gonadal vessels and anterior to psoas major
- pass anterior to iliac vessels
- enter the posterior aspect of the bladder
bladder features
- apex
- body
- ureters
- urethra
- internal urethral orifice
- trigone
- ureteric orifices
internal urethral orifices
opening from bladder to urethra
male relational anatomy - prostate gland
superior: bladder
inferior: pelvic diaphragm
anterior: symphysis pubis
posterior: seminal vesicles
female relational anatomy - bladder
superior: uterus
inferior: pelvic diaphragm
anterior: symphysis pubis
posterior: vagina/vaginal canal
blood supply to the uterus
internal iliac artery gives off the uterine artery to supply the uterus
blood supply to the ovaries
abdominal aorta gives off the right and left ovarian arteries to supply the ovaries
blood supply to the sigmoid colon
IMA gives off the sigmoidal artery to supply the sigmoid colon
blood supply to the rectum
- IMA gives off the superior rectal artery to supply superior rectum
- the internal iliac artery gives of the middle and inferior rectal arteries to supply the middle and inferior rectum
what is the pelvic viscera innervated by
ANS
sympathetic innervation pathway to the pelvic viscera
preganglionic neurons in L1 and L2 either go to
1. inferior mesenteric ganglion
2. inferior hypogastric plexus
which supply the pelvic viscera
sympathetic innervation of the pelvic viscera
- inhibits bladder, excited internal urethral sphincter to PREVENT urination
- inhibits peristaltic contraction, excited internal anal sphincter to PREVENT defecation
- excites uterine contraction
parasympathetic innervation pathway to pelvic viscera
- preganglionic neurons in S2, S3, S4
- pelvic splanchnic nerves
- to innervate the pelvic viscera
parasympathetic innervation of the pelvic viscera
- excites bladder, inhibits internal urethral sphincter to ALLOW urination
- excited peristaltic contraction, inhibits internal anal sphincter to ALLOW defecation
- inhibits uterine contraction
perineum
- lies inferior to pelvic floor, between lower limbs
- formed from soft tissue inferior to pelvic floor, ending with skin
orientation of perineum
superficial = inferior, closer to skin
deep = superior, closer to pelvic diaphragm
pelvic floor
forms roof of the perineum
borders of perineum
anterior border: pubic symphysis
posterior border: coccyx/sacrum
lateral border: ischial tuberosity
ischiopubic ramus
connects pubic symphysis to ischial tuberosity
triangles of perineum
- urogenital triangle
- anal triangle
- functional units of the perineum
urogenital triangle
- anterior portion of perineum
- bounded by:
- pubic symphysis anteriorly
- ischial tuberosity laterally - has opening for urogenital hiatus
anal triangle
- posterior portion of perineum
- bounded by:
- ischial tuberosities laterally
- coccyx posteriorly - contains rectal hiatus
male genitalia
- penis
- scrotum
- urethra
contents of scrotum
- testes
- epidydmis
- external spermatic cord
root of penis
- crus
- bulb
body of penis
- glans
- corpus covernosum
- corpus spongiosum
bulb of penis
single erectile cylinder surrounded by crus
crus of penis
“legs”
- paired legs surrounding the bulb
corpus spongiosum
- single tissue
- extension of bulb into body of penis surrounded by corpus cavernosum
- houses the urethra
corpus cavernosum
- paired tissue
- extension of crus into body of penis
glans of penis
- expanded corpus cavernosum
- where semen is expelled during ejaculation
deep penile artery
one deep penile artery in each corpus cavernosum
urethra features - male
- bladder (urethra begins after the bladder)
- prostate
- prostatic urethra
- membranous urethra
- corpus spongiosum
- spongy urethra
- external urethral orifice
prostatic urethra
in prostate
membranous urethra
after the prostate at seminal vesicles
spongy urethra
becomes this once the urethra enters the corpus spongiosum
external urethral orifice
exit point - where urethra terminates to external world
female genitalia
- mons pubis
- clitoris
- prepuce of clitoris
- labia majora
5.labia minora
pudenal cleft
space between labia majora and labia minora
mons pubis
fatty tissue covering that acts as a cushion for protection
clitoris
erectile tissue
labia majora
“major lip”
- protect from external environment
labia minora
“minor lip”
- inner lip responsible for lubrication
female genitalia - vestibule borders
anterior border: clitoris
lateral border: labia minora
posterior border: fourchette
female genitalia - vestibule contents
- external urethral orifice
- vaginal orifice
- bulb of vestibule
- greater vestibular glands
vaginal orifice
opening of vagina
bulb of vestibule
- erectile tissue - clitoris
- gorged with blood during arousal
greater vestibular glands
lubrication function
erectile tissue - root
- crus of clitoris
- bulb of vestibule
- greater vestibular gland (secretions + lubrication)
erectile tissue - body
- body of clitoris (corpora cavernosa)
- glans of clitoris (distal portion)
urethra features - female
- external urethral sphincter
- urethrovaginal sphincter
- compressor urethrae
external urethral sphincter
surround entire urethra
- when contracts, it puts pressure on the entire urethra
urethrovaginal sphincter
surrounds urethra and vagina
- when contracts it puts pressure on vagina and urethra
compressor urethrae
surrounds anterior urethra
- when contracts, puts pressure on anterior urethra
urogenital triangle contents
superficial to deep
1. skin
2. perineal fascia (directly under skin)
3. superficial perineal pouch
4. perineal membrane
5. deep perineal pouch
6. pelvic floor
deep perineal pouch
- between pelvic floor superiorly and perineal membrane inferiorly
- lies superior to perineal membrane
- forms the external urethral sphincter
deep perineal pouch - males
- deep transverse perineal muscle
- external urethral sphincter
deep transverse perineal muscle
supports perineal region
external urethral sphincter
- voluntary control to control when to urinate
- surround membranous urethra
deep perineal pouch- females
- external urethral sphincter
- urethrovaginal sphincter
- compressor urethrae
- deep transverse perineal muscle
perineal membrane
only present in urogenital triangle not anal triangle
superficial perineal pouch
- between perineal membrane superiorly, and deep perineal fascia inferiorly
- lies inferior to perineal membrane
- superior limit= perineal membrane
- inferior limit= colle’s fascia
superficial perineal pouch- males
- bulbospongiosum
- ischiocavernosus
- superficial transverse perineal muscle
bulbospongiosus
compresses bulb of penis during erection
- covers bulb
ischiocavernosus
compresses crus of penis during erection
- covers crus
- paired
superficial transverse perineal muscle
supports perineum
superficial perineal pouch- females
- bulbospongiosus
- ischiocavernosus
- superficial transverse perineal muscle
perineal fascia - superficial layer
- close to skin
- continuous with campers fascia of anterior abdominal wall
perineal fascia - deep layer
- forms part of the superficial pouch
- continuous with scarpas fascia of the anterior abdominal wall
- colle’s fascia
perineal body
convergence/interlacing of
1. bulbospongiosus
2. superficial/deep perineal muscles
3. external anal sphincter
4. pelvic floor muscles
which triangle lacks the perineal membrane
anal triangle
anal triangle contents
- anal aperture
- external anal sphincter (controls anal canal)
- ischiorectal fossa
- pudenal canal
ischiorectal fossa
paired - on both sides of the perineum
lateral border: obturator internus
medial border: external anal sphincter
superior border: levator ani
inferior border: perineal fascia
pudendal canal - neurovasculature
- pudendal nerve (supply of innervation to perineal region)
- internal pudendal artery
- infernal pudendal vein
external vs internal anal sphincter
external: voluntary; compresses to keep sphincter shut
internal: involuntary; relaxed during normal defecation
blood supply
- abdominal aorta bifurcates at L4 into left + right common iliac artery
- common iliac artery bifurcates at sacroiliac joint into external +internal iliac artery
external iliac artery
blood supply to lower limbs
internal iliac artery
blood supply to the pelvis
blood supply to the perineum
internal iliac artery gives off the internal pudendal artery to supply the perineum