Rectum, Anal Canal, Bladder, Etc.

Front 1

Rectum

Back 1

a. Begins at S3 as a continuation of sigmoid colon
b. Terminates anterior to the coccyx
c. Retroperitoneal
d. 15 cm long

Front 2

Rectosigmoid junction (teniae coli at junction)

Back 2

a. Teniae coli of the sigmoid become a complete outer muscle covering

Front 3

Upper 1/3 of rectum

Back 3

a. Peritoneum covers the rectum on its anterior and lateral side
b. Pararectal fossae→ areas lateral to rectum

Front 4

Middle 1/3 of rectum

Back 4

a. Peritoneum covers only the anterior surface of the rectum
b. Peritoneum is reflected anteriorly to form the rectovesical pouch in the male
c. Forms rectouterine pouch in the female

Front 5

Lower 1/3 of rectum

Back 5

a. Rectal ampulla
b. No peritoneal covering

Front 6

Rectovesical septum/rectovaginal septum

Back 6

i. Separates the rectum from the prostate or vagina, respectively
ii. Part of lower 1/3 of rectum

Front 7

Rectum shape

Back 7

a. Follows sacral curvature

Front 8

Transverse rectal folds

Back 8

a. 3 frontal plane curves
b. Occur at site where internally the rectum has mucosal infoldings

Front 9

Location of transverse rectal folds

Back 9

a. Upper and lower valves are on left side
b. Middle on right side
c. Help to support the fecal matter as it accumulates in the rectum

Front 10

Puborectalis muscle

Back 10

a. Forms a sling around the rectum at the rectoanal junction
b. Causes 90 degree bend between rectum and anal canal
c. “Perineal flexure”

Front 11

Anal canal

Back 11

a. Continuation of the rectum

Front 12

Anal columns

Back 12

i. Ridges in upper ½ of anal canal
ii. Separated by anal sinuses

Front 13

Anal valves

Back 13

i. Connect lower ends of anal columns

Front 14

Pectinate line

Back 14

i. Continuous, scalloped ring of anal valves

Front 15

Pecten

Back 15

i. Transition region just below the pectinate line
ii. Extends inferiorly to level of intersphincteric groove

Front 16

White line

Back 16

i. At level of intersphincteric groove
ii. Inferior border of pectin

Front 17

Anal verge

Back 17

i. Area below white line
ii. Extends to external opening

Front 18

Muscular coat of rectum

Back 18

i. Consists of inner circular layer and outer longitudinal layer
ii. Continues into anal canal

Front 19

Internal anal sphincter

Back 19

i. Made of lowermost fibers of inner circular coat
ii. Covers upper 2/3 of anal canal down to intersphincteric groove (white line)
iii. Involuntary

Front 20

Corrugator cutis

Back 20

i. Longitudinal muscle fibers that extend to the skin around anus
ii. Cause “puckered” appearance

Front 21

External anal sphincter

Back 21

i. Covers entire length of anal canal
ii. Voluntary striated muscle

Front 22

Subcutaneous part of external anal sphincter

Back 22

1. Inferior to internal sphincter
2. Encircles the anus
3. No bony attachments

Front 23

Intersphincteric groove of external anal sphincter

Back 23

a. White line
b. Formed by junction of subcutaneous part of external sphincter and internal sphincter

Front 24

Deep part of external anal sphincter

Back 24

1. Overlaps the internal sphincter
2. Encircles the anal canal
3. Fused to puborectalis

Front 25

Anorectal ring

Back 25

a. Portion of deep part of external anal sphincter
b. Palpable above intersphincteric groove

Front 26

Superior rectal artery

Back 26

i. Branch of inferior mesenteric artery
ii. Divides into a right and left branch to supply rectum
iii. Main supply to rectum
iv. Anastomose with branches of middle and inferior rectal arteries

Front 27

Terminal branches of superior rectal artery

Back 27

1. Form ridges under the mucosa that→ “anal columns”

Front 28

Middle rectal arteries

Back 28

i. Branches of internal iliac arteries
ii. Supply only muscle layers

Front 29

Inferior rectal arteries

Back 29

i. Branches of the internal pudendal arteries that cross the ischioanal fossa along the obturator internus muscle
ii. Supply the anal canal

Front 30

Venous drainage

Back 30

a. To both portal and caval systems

Front 31

Superior rectal veins

Back 31

i. Accompany arteries and help form anal columns
ii. Drain into IMV→ portal system

Front 32

Internal hemorrhoids

Back 32

1. Variscosities in the superior retal veins deep to anal columns frorm internal hemorrhoids
2. Not painful

Front 33

Middle rectal veins

Back 33

i. Drain musculature and empty into internal iliac vein→ caval system

Front 34

Inferior rectal veins

Back 34

i. In anal canal
ii. Drain via the internal pudendal vein→ caval

Front 35

External hemorrhoids

Back 35

1. Engorgement or thrombosis of inferior rectal veins
2. Painful

Front 36

Pelvic plexus

Back 36

i. Both motor and sensory innervation to rectum and anal canal

Front 37

Pelvic splanchnic nerves

Back 37

i. Parasympathetic fibers from S2-S4
ii. Join pelvic plexus
iii. Increase peristaltic activity

Front 38

Automatic emptying of bowel prevention

Back 38

i. Contraction of voluntary muscle fibers in external anal spincter
ii. Via branches of pudendal nerve

Front 39

Nerves in charge of reflex control in rectum/anus

Back 39

i. Sensory fibers arising form S2-S4
ii. Continence and defecation

Front 40

Upper 1/2 of anal canal innervation

Back 40

i. Pelvic autonomic fibers
ii. Sensitive to stretching but not cutting

Front 41

Lower 1/2 of anal canal innervation

Back 41

i. Branches of inferior rectal nerves from pudendal nerve
ii. Sensitive to pain, temperature, touch, pressure, cutting, and pricking

Front 42

Peritoneum on superior surface of bladder

Back 42

i. Covered by visceral peritoneum
ii. Reflected anteriorly over anterior abdominal wall as parietal peritoneum
iii. Female→ posteriorly over uterus
iv. Male→ covers base of bladder before reflecting over anterior surface of rectum

Front 43

Paravesical fossae

Back 43

1. Lateral reflections of peritoneum from bladder to lateral pelvic wall
2. Allow bladder to distend laterally

Front 44

Puboprostatic ligament/pubovesical ligament

Back 44

1. Male/female
2. Connects neck of bladder to pubic vone
3. Considered visceral pelvic fascia

Front 45

Base of male bladder

Back 45

1. Two ductus deferens
2. Seminal vesicles
3. Separated from rectum by rectoprostatic fascia

Front 46

Base of female bladder

Back 46

1. Base of bladder abuts anterior wall of vagina

Front 47

Vesical trigone

Back 47

1. Triangular area formed by 2 opeinings of ureters and their interconnecting ridge to internal orifice of urethra

Front 48

Interureteric ridge

Back 48

a. Runs between opening of each respective ureter

Front 49

Mucosa over trigone

Back 49

a. Smooth
b. Elsewhere in has numerous rugae

Front 50

Ureter entry to bladder

Back 50

a. Oblique angle
b. Contraction of bladder musculature functions as a physiological sphincter preventing urine reflex

Front 51

Uvula

Back 51

a. Projection on the trigone
b. Created by underlying median lobe of prostate

Front 52

Detrusor muscle

Back 52

1. Consists of smooth muscle with fibers coursing longitudinally, transversely, and obliquely
2. Motor innervation by pelvic splanchnic nerves

Front 53

Superior vesical arteries

Back 53

1. 2-3 small branches from umbilical arteries
2. Supply superior surface of bladder

Front 54

Inferior vesical arteries

Back 54

1. Usually branches of internal iliac artery in male
2. Prostate usually receives branches from inferior vesical artery
3. In female, it is usually an unnamed branch of vaginal artery

Front 55

Vesical venous plexus in males

Back 55

a. Continuous with the prostatic venous plexus
b. Drains mainly into internal iliac vein
c. May communicate with internal vertebral venous plexus

Front 56

Female urethra

Back 56

i. Short tube
ii. Fused to anterior wall of vagina

Front 57

Smooth muscle in female urethra

Back 57

1. Derived from bladder
2. Forms internal sphincter
3. Involuntary

Front 58

Striated muscle in female urethra

Back 58

1. In urogenital diaphragm
2. Forms external sphincter
3. Voluntary

Front 59

Prostatic male urethra

Back 59

1. First portion
2. Courses through the prostate
3. Urethral crest on posterior surface

Front 60

Prostatic sinuses

Back 60

a. Depression bilateral to urethral crest
b. Prostatic ducts open into urethra

Front 61

Seminal colliculus

Back 61

a. Enlargement of urethral crest 2/3 of distance down

Front 62

Prostatic utricle

Back 62

a. Blind depression about halfway down on colliculus

Front 63

Ejaculatory ducts

Back 63

a. Two
b. Open on either side of utricle

Front 64

Membranous urethra

Back 64

i. Passes through UG diaphragm and perineal membrane
ii. Shortest, narrowest, least distensible part
iii. Walls are the thinnest of entire urethra
iv. Enters the superior aspect of bulb of the penis

Front 65

Spongy urethra

Back 65

i. Extends through the bulb and corpus spongiosum from perineal membrane to external opening
ii. Makes 90 degree turn within the bulb anteriorly

Front 66

Navicular fossa

Back 66

1. Dilated part within the glans
2. May have a small mucosal valve proximally
3. Lacuna magna→ mucosal pit in roof (catheter)
4. Meatus→ external orifice

Front 67

Bulbourethral glands

Back 67

a. Embedded in deep perineal pouch
b. Lateral to membranous part of urethra
c. Associated ducts pass into the bulb of the penis to dump lubricating pre-ejaculates into spongy urethra
d. Greater vestibular glands in female

Front 68

Apex of prostate

Back 68

i. Rests on pelvic diaphragm

Front 69

Base of prostate

Back 69

i. Contact with neck of bladder

Front 70

Periurethral zone of prostate

Back 70

i. Surrounds prostatic urethra

Front 71

Central zone in prostate

Back 71

i. 25% of glandular tissue of prostate

Front 72

Peripheral zone of prostate

Back 72

i. 70% of glandular tissue

Front 73

Benign prostatic hypertrophy

Back 73

i. Enlargement of glands in posterior median lobe leads to compression of urethra
ii. Micturation becomes difficult
iii. Prostate cancer in glands of posterolateral lobes does not necessarily lead to micturition difficultiy

Front 74

Blood supply to prostate

Back 74

i. Branches of internal iliac artery
ii. Especially the inferior vesical

Front 75

Prostatic plexus

Back 75

1. Drains mainly into internal iliac vein
2. May drain into internal vertebral venous plexus (no valves)
3. Path for metastatic prostate cancer

Front 76

Deep dorsal vein of penis

Back 76

1. Drains into prostatic plexus
2. Provides direct access from outside of body to pelvic cavity

Front 77

Prostatic plexus of nerves

Back 77

1. Encircles and embeds within the prostatic fascial sheath
2. Derived from inferior hypogastric plexus
3. Innervation via sympathetic fibers

Front 78

Parietal pelvic fascia

Back 78

i. Membranous
ii. Continuation of transversalis fascia
iii. Covers walls and floors of pelvis
iv. Attaches to bones of lateral pelvic wall
v. Forms white line at superior edge of levator ani

Front 79

Visceral pelvic fascia

Back 79

i. Reflects onto and fully invests the pelvic viscera
ii. Continuous with parietal fascia
iii. Puboprostatic and pubovesical igaments

Front 80

Endopelvic fascia

Back 80

i. Loose areolar, fatty tissue with lymphatics and vessels
ii. Found in gaps between parietal and visceral pelvic fascia and pelvic walls

Front 81

Cardinal ligaments

Back 81

a. From cervix and upper vagina to pelvic walls
b. Rectovesical septum in males

Front 82

Lateral ligaments of rectum

Back 82

a. From cervix to ala of sacrum
b. Forms pouch of douglas

Front 83

Lateral ligaments of bladder

Back 83

a. From cardinal ligament to pubis to sling the bladder

Front 84

Testes

Back 84

a. Left lower than right
b. Scrotal ligament
i. Remnant of gubernaculum
ii. Attaches testes to scrotum

Front 85

Tunica albuginea

Back 85

i. Surrounds testes
ii. Send septa into testis to form lobules

Front 86

Seminiferous tubules

Back 86

i. 1-3 coiled tubules in each lobule

Front 87

Rete testis

Back 87

i. Opening of tubules
ii. Collecting chamber

Front 88

Efferent ductules

Back 88

i. Connect rete testis to epididymis

Front 89

Testicular descent

Back 89

i. Retroperitoneal
ii. Processus vaginalis-- testicle comes in behind it