Term
| what is the superior boundary to the pelvic cavity? |
|
Definition
|
|
Term
| what is the inferior boundary to the pelvic cavity? |
|
Definition
pelvic outlet
closed by the muscular pelvic diaphragm |
|
|
Term
| which structures pass through the pelvic diaphragm? |
|
Definition
| rectum and urogenital structures |
|
|
Term
| where is the false pelvis located? |
|
Definition
part of abdomen
Related to upper part of pelvic bones and lower lumbar vertebrae |
|
|
Term
| where is the true pelvis located? |
|
Definition
Related to inferior parts of pelvic bones, sacrum and coccyx
Has an inlet and an outlet |
|
|
Term
| where is the pelvic peritoneum? |
|
Definition
Pelvic cavity is lined by peritoneum, which is continuous with the abdominal peritoneum.
Peritoneum is “draped” over the pelvic organs.
Blood vessels and nerves can be thought of as retroperitoneal, as can the pelvic organs. |
|
|
Term
| which bones form the pelvis? |
|
Definition
Right and left pelvic (hip) bones
Each is formed by three bones during development which fuse between 16 and 18 years of age.
Sacrum
Formed by 5 fused sacral vertebrae.
Coccyx
Formed by 4 fused coccygeal vertebrae |
|
|
Term
| where is the sacrospinous ligament located? |
|
Definition
| Extends from the ischial spine to the sacrum and coccyx |
|
|
Term
| where is the sacrotuberous ligament located? |
|
Definition
| Extends from a broad attachment to the sacrum to the ischial tuberosity |
|
|
Term
| what passes through the greater sciatic foramen? |
|
Definition
Piriformis muscle
Superior gluteal nerve and vessels (above piriformis)
Inferior gluteal nerve and vessels (below piriformis)
Sciatic nerve
Posterior femoral cutaneous nerve
Pudendal nerve
Internal pudendal artery and vein |
|
|
Term
| describe the lumbosacral joint |
|
Definition
Two zygapophyseal joints
Intervertebral disc between L5 and S1 vertebrae
Because the sacrum is angled posteriorly, the intervertebral disc between L5 and S1 vertebrae is thicker anteriorly than it is posteriorly.
This is the most common site of lumbar disc herniation |
|
|
Term
| describe the sacro-iliac joint |
|
Definition
Transmit force to lower limbs
Synovial joints that fibrose and may ossify with age |
|
|
Term
| what type of cartilage is found in the pubic symphysis? |
|
Definition
|
|
Term
| compare the general structure of the male and female pelvis |
|
Definition
Male – thick and heavy
Female – thin and light |
|
|
Term
| compare the greater pelvis in males and females |
|
Definition
Male – deep
Female – shallow |
|
|
Term
| compare the lesser (true) pelvis in males and females |
|
Definition
Male – narrow and deep
Female – wide and shallow |
|
|
Term
| compare the pubic arch in males and females |
|
Definition
Male – narrow
Female - wide |
|
|
Term
| what is the female pelvis adapted for? |
|
Definition
Female pelvis adapted for childbirth
Pelvic inlet is circular
Angle between two arms of pubic arch is greater in female pelvis (80-85°) than in male pelvis (50-60°)
Ischial spine in female do not project as far medially as in male pelvis |
|
|
Term
| which type of pelvic variation in females is most common? |
|
Definition
|
|
Term
| what is the ostetrical conjugate? |
|
Definition
| The narrowest fixed distance through which the baby’s head must pass in a vaginal delivery |
|
|
Term
| how would one perform an obstetric measurement? |
|
Definition
Through the vagina, palpate the sacral promontory with middle finger.
Use the other hand to mark the level of the inferior margin of the pubic symphysis.
This is a measure of the diagonal conjugate (≈13cm).
Distance from tip of index finger to point marked is an estimate of the obstetric conjugate and it should be ≈11.5cm or greater to predict a successful vaginal delivery. |
|
|
Term
| what composes the anterior wall of the true pelvis? |
|
Definition
| Bodies and rami of pubic bone and pubic symphysis |
|
|
Term
| what composes the lateral walls of the true pelvis? |
|
Definition
| Hip bones covered by obturator internus M |
|
|
Term
| what composes the posterior wall of the true pelvis? |
|
Definition
Sacrum and coccyx, adjacent parts of ilia and sacroiliac joints
Covered by piriformis posterolaterally |
|
|
Term
| what composes the floor of the true pelvis? |
|
Definition
Muscles of pelvic diaphragm
Levator ani m and coccygeus m |
|
|
Term
| what is the origin and insertion of the obterator internus muscle? |
|
Definition
Origin
Deep surface of obturator membrane and adjacent bone
Tendon exits lesser sciatic foramen
Insertion
Medial surface greater trochanter of femur |
|
|
Term
| what nerves innervate the obturator internus? |
|
Definition
|
|
Term
| what is the action of the obturator internus muscle? |
|
Definition
Laterally rotates extended hip joint
Abducts flexed hip |
|
|
Term
| what is the origin and insertion of the piriformis muscle? |
|
Definition
Origin
Anterior surface of sacrum between sacral foramina
Passes through greater sciatic foramen
Insertion
Medial side of superior border of greater trochanter of femur |
|
|
Term
| what nerves innervate the piriformis muscle? |
|
Definition
|
|
Term
| what are the actions of the piriformis muscle? |
|
Definition
Laterally rotates extended hip joint
Abducts flexed hip |
|
|
Term
| what is the origin and insertion of the coccygeus muscle? |
|
Definition
Origin
ischial spine and pelvic surface of sacrospinous ligament
Insertion
Lateral margin of coccyx and related sacrum |
|
|
Term
| what nerves innervate the coccygeus muscle? |
|
Definition
| branches from anterior rami of S3 and S4 |
|
|
Term
| what are the actions of the coccygeus muscle? |
|
Definition
| Contributes to floor of pelvis, helps support pelvic viscera, pulls coccyx forward after defecation |
|
|
Term
| what is the origin and insertion of the levator ani muscle? |
|
Definition
Origin
Posterior aspect of pubic bone, tendinous arch (thickening of obturator internus fascia), ischial spine via the tendinous arch
Insertion
Anteriorly to superior surface of perineal body, posteriorly meets partner of other side and attaches along the anococcygeal ligament |
|
|
Term
| what nerves innervate the levator ani muscle? |
|
Definition
| Direct branch of S4 and inferior rectal branch of pudendal (S2- S4) |
|
|
Term
| what is the action of the levator ani muscle? |
|
Definition
| Major part of pelvic floor, supports pelvic viscera, pulls coccyx forward after defecation |
|
|
Term
| where is an area of potential weakness in women who have given birth? |
|
Definition
|
|
Term
| where is the urogenital hiatus? |
|
Definition
| In the anterior portion of the pelvic floor, there is a gap between the medial borders of the levator ani muscles on each side, the urogenital hiatus |
|
|
Term
| what passes through the urogenital hiatus in males and females? |
|
Definition
In the male, this gap allows passage of the urethra.
In the female, it allows passage of the urethra and vagina.
This gap is filled, in part, by the perineal membrane and associated muscles.
These muscles serve as sphincters and help support the urogenital organs |
|
|
Term
| the urethra is embedded in which wall of the vagina? |
|
Definition
|
|
Term
| describe characteristics of the rectum |
|
Definition
Transition from sigmoid colon to rectum is at the S3 vertebral level.
While the sigmoid colon is suspended in the abdominal cavity by a mesocolon, the rectum lies retroperitoneally.
Rectum is continuous with the anal canal, which penetrates the pelvic floor to enter the perineum to end as the anus |
|
|
Term
| transition from the sigmoid colon to the rectum is at what vertebral level? |
|
Definition
|
|
Term
| the anorectal junction is pulled forward by the puborectalis portion of which muscle to form the perineal flexure? |
|
Definition
|
|
Term
| does the upper part of the anal canal have mucosa? |
|
Definition
|
|
Term
| what is the anal canal noteworthy for having? |
|
Definition
| is noteworthy for longitudinally-oriented anal columns that are joined inferiorly by crescent shaped folds called anal valves |
|
|
Term
| anal valves in the anal canal lie at which line? |
|
Definition
| Anal valves lie at the level of the pectinate or dentate line which marks the site of the proctodeal membrane. This is where embryonic endoderm and ectoderm meet |
|
|
Term
| describe sensory afferents above and below the pectinate line |
|
Definition
| Above the pectinate line, sensory afferents are visceral, below, they are somatic. |
|
|
Term
| the hymen and floor of urethra arise from which membrane? |
|
Definition
|
|
Term
| the middle portion of the anal canal is characterized by what type of epithelium? |
|
Definition
| characterized by stratified squamous, non-keratinized epithelium |
|
|
Term
| what is the name for the middle region of the anal canal? where does it end? |
|
Definition
the anal pectin
ends inferiorly at the anocutaneous line or the white line of Hilton where there is a transition from stratified squamous non-keratinized epithelium to skin |
|
|
Term
| what are the 3 major arteries which supply the rectum and anal canal? |
|
Definition
Superior rectal, the terminal branch of the inferior mesenteric.
Middle rectal, a branch of the the anterior division of the internal iliac artery.
Inferior rectal, a branch of the internal pudendal artery, which is a branch of the anterior division of the internal iliac artery |
|
|
Term
| if an individual had cancer in the upper rectum, through which artery would it metastasize? |
|
Definition
|
|
Term
| if an individual had cancer in the middle rectum, through which artery would it metastasize? |
|
Definition
|
|
Term
| the superior rectal vein drains into the portal system via which vein? |
|
Definition
| the inferior mesenteric vein |
|
|
Term
| the middle and inferior rectal veins drain into which system? |
|
Definition
|
|
Term
|
Definition
Varicosities of the internal or external rectal plexuses.
Internal are called piles.
Can prolapse and become strangulated.
External are covered by skin. |
|
|
Term
| where does the urinary bladder lie? describe its shape |
|
Definition
lies most anteriorly in the pelvis
Shaped like a 3-sided pyramid.
Apex is directed toward the top of the pubic symphysis.
The median umbilical ligament, a remnant of the embryologic urachus, continues from it superiorly up to the umbilicus.
Base, which is shaped like an inverted triangle, is directed posteroinferiorly.
Ureters enter bladder at upper corners of the base.
Urethra drain inferiorly from the lower corner of the base |
|
|
Term
| the urinary bladder is separated from the pubic bones by which space? |
|
Definition
|
|
Term
| describe the relationship of the fundus of the urinary bladder in males and females |
|
Definition
Fundus is posterior wall.
In male, fundus related to rectum.
In female, related to vagina |
|
|
Term
| pain afferents for the superior bladder, that part covered by the peritoneum, travel with sympathetics at what vertebral levels? |
|
Definition
|
|
Term
| describe the sympathetic innervation of the bladder |
|
Definition
Sympathetic fibers from inferior thoracic and upper lumbar levels via hypogastric plexuses and nerves.
Cause contraction of internal sphincter during ejaculation in the male to prevent reflux of semen in the male.
Pain afferents for the superior bladder, that part covered by peritoneum, travel with sympathetics to T11-L2 or L3 |
|
|
Term
| pain afferents from the inferior bladder travel with the __________. |
|
Definition
|
|
Term
| describe the parasympathetic innervation of the bladder |
|
Definition
Parasympathetics in pelvic splanchnics enter inferior hypogastric plexus.
Motor to detrusor muscle.
Inhibit internal sphincter.
Afferents signaling stretch travel with parasympathetics and cause reflexive contraction of the detrusor muscle and relaxation of the internal urethral sphincter.
Pain afferents from inferior bladder travel with parasympathetics |
|
|
Term
| describe the detrusor reflex |
|
Definition
Afferents signaling stretch travel with parasympathetics (S2-S4).
Efferents cause detrusor contraction and relaxation of the internal urethral sphincter.
Regulated by the pontine micturation center
Descending pathways from the medial frontal micturation centers activate the detrusor reflex |
|
|
Term
| the external urethral sphincter is controlled by what? |
|
Definition
| motor neurons in Onuf’s nucleus (S3, S4) in sacral cord |
|
|
Term
| at what point do the ureters enter the pelvic cavity? |
|
Definition
| Enter the pelvic cavity by crossing the pelvic brim at the bifurcations of the common iliac arteries |
|
|
Term
| where in males and females do the ureters pass? |
|
Definition
In the male, the ureter passes beneath the ductus deferens on its way to end in the ejaculatory duct.
In the female, the ureter passes beneath the uterine artery |
|
|
Term
| compare and contrast the urethra in males and females |
|
Definition
In females, the urethra is about 4cm long.
Opens anterior to the vaginal opening in the vestibule.
Skene’s glands are paired mucous glands which drain via ducts into the lateral margins of the urethral opening.
Male urethra is 20cm long and has 2 bends along its course.
Divided into 4 parts: preprostatic, prostatic, membranous and spongy |
|
|
Term
| describe the 4 parts of the male urethra |
|
Definition
Urethra in the bladder neck, preprostatic urethra (1-1.5cm in length)
Prostatic urethra (4cm long)
Receives the ejaculatory ducts.
Most distensible part of urethra
Membranous urethra (<1cm in length)
Passes through external urethral sphincter (voluntary)
Least distensible.
Spongy urethra
Within corpus spongiosum of penis |
|
|
Term
| what nerves innervate the testis? |
|
Definition
|
|
Term
| lymphatics from the testis drain where? |
|
Definition
| to lateral aortic and preaortic nodes |
|
|
Term
| the left testicular vein drains where? |
|
Definition
|
|
Term
| the right testicular vein drains where? |
|
Definition
|
|
Term
|
Definition
Long, coiled duct on posterolateral aspect of testis.
Efferent ductules form head of epididymis.
True epididymis is a single coiled duct made up of the body and the tail along the posterolateral aspect of the testis.
Storage site for sperm and place where they acquire motility |
|
|
Term
| what is the ductus (vas) deferens? |
|
Definition
Long tubular structure with a thick, smooth muscle wall.
Extends from the tail of the epididymis to the ejaculatory duct.
Enclosed within the spermatic cord distal to the superficial inguinal ring.
After it passes through the deep inguinal ring, turns medially around the inferior epigastric vessels and passes over the ureter on its way to join the duct of the seminal vesicle to form the ejaculatory duct.
Between the ureter and ejasculatory duct, the ductus deferens expands to form the ampulla of the ductus deferens |
|
|
Term
| where is the seminal vescile located? |
|
Definition
Develops as an outgrowth of the ductus deferens.
Lies between the bladder and the rectum.
Lies lateral to the ductus deferens.
Its duct joins the ductus deferens to form the ejaculatory duct |
|
|
Term
| describe the prostate and its features |
|
Definition
In young male, about the size of a walnut, the prostate is a midline gland that surrounds the urethra within the pelvic cavity.
Lies inferior to the bladder and anterior to the rectum.
Inferolateral aspects of the prostate are cradled by the levator ani muscles.
Fibrous capsule contains a plexus of veins and nerves (cavernous nerves), which innervate the erectile tissue of the penis |
|
|
Term
| urologists often refer to the seminal colliculus in the prostatic urethra as what? |
|
Definition
|
|
Term
| what occurs during benign prostatic hypertrophy (BPH)? |
|
Definition
hypertrophy blocks urethra
Affects men in their 50s and older
symptoms are nocturia and dysuria |
|
|
Term
| where is prostate carcinoma mostly found? |
|
Definition
70% involve peripheral zone
“Gold standard” treatment – radical prostectomy.
Nerve sparing radical prostectomy done to preserve erectile function |
|
|
Term
| true or false: all the organs in the female pelvis are retroperitoneal essentially |
|
Definition
|
|
Term
| what is the lowest point in the recto-abdominal cavity? |
|
Definition
|
|
Term
| where did the ovaries develop and where do they lie? |
|
Definition
Like the testes, the ovaries develop high in the abdominal cavity and descend into the pelvis before birth, bringing their blood supply and nerves with them.
Lie adjacent to the to the lateral pelvic wall, just below the pelvic brim.
Suspended by a mesentery (mesovarium) from the posterior aspect of the broad ligament of the uterus.
Suspensory ligament of the ovary contains the nerves and blood vessels of the ovary. |
|
|
Term
| the _____ _____ of the ovary contains the nerves and blood vessels of the ovary. |
|
Definition
suspensory ligament
The ovary is suspended by a mesentery (mesovarium) from the posterior aspect of the broad ligament of the uterus |
|
|
Term
| what is the broad ligament? |
|
Definition
The broad ligament is a sheet-like fold of peritoneum that extends from the lateral pelvic wall to the uterus.
Within this fold of peritoneum is the uterine (fallopian) tube.
The portion of the broad ligament between the origin of the mesovarium and the uterine tube is called the mesosalpinx. |
|
|
Term
|
Definition
Thick-walled, muscular organ which lies posterior to the bladder and anterior to the rectum.
Superior, rounded end, above the uterine tubes, is called the fundus.
The body is flattened anteroposteriorly and is continuous inferiorly with the cervix, which opens into the vagina. |
|
|
Term
| the lumen of the uterine tube connects what 2 regions? |
|
Definition
| connects the peritoneal cavity to the lumen of the uterus |
|
|
Term
| what encloses the uterine tube? |
|
Definition
| Enclosed in the upper margin of the mesosalpinx, a portion of the broad ligament |
|
|
Term
| describe the uterine tube |
|
Definition
Expanded end is the infundibulum, which has finger-like projections called fimbriae.
Fimbriae sweep up ovulated eggs that are released into the peritoneal cavity.
More medial is the ampulla.
Nearest the uterus is the isthmus |
|
|
Term
| the ligament of ovary and the round ligament are remnants of what? |
|
Definition
the gubernaculum
Ligament of the ovary
From the ovary to the uterus
Round ligament of the uterus
From the uterus to the labia majora
Passes through the inguinal ligament |
|
|
Term
| what is the broad ligament? |
|
Definition
| Sheet-like fold of peritoneum that extends from the lateral pelvic wall to the uterus. |
|
|
Term
| what are the 3 parts of the broad ligament? |
|
Definition
Mesometrium
Largest part
Serves as mesentery for the uterus
Mesosalpinx
Uterine tube lies in anterosuperior free boader of the broad ligament within this small mesentery
Mesovarium
Small mesentery in the posterior aspect of the broad ligament |
|
|
Term
| which blood vessels anastomose around the uterine tube? |
|
Definition
| ovarian and uterine vessels |
|
|
Term
| what is a hysterosalpingogram? |
|
Definition
At times the uterine tubes get block with mucus.
Blockage inhibits sperm from reaching and fertilizing ovum.
Hysterosalpingogram uses a water soluble radiopaque dye to visualize uterus and uterine tubes.
Dye should fill tubes and enter peritoneal cavities through the abdominal os |
|
|
Term
| true or false: infections in the vagina and uterus can spread into the peritoneal cavity and thereby cause peritonitis |
|
Definition
|
|
Term
| describe characteristics of the vagina |
|
Definition
Fibromuscular tube which extends from the vestibule, between the labia minora to the uterus.
Within the vestibule, the ostium of the vagina is surrounded by a ring-like fold of membrane, the hymen.
During development, the hymen separates the vagina from the urogenital sinus.
Within the anterior wall of the vagina is the urethra.
Upper end of the vagina surrounds the cervix.
Posterior wall of vagina related to the rectum and separated superiorly by the rectouterine pouch, pouch of Douglas
No muscularis mucosa
Some smooth muscle found
Hymen marks difference between visceral and somatic blood supply/innervation change |
|
|
Term
| the posterior vaginal fornix has a close relationship with what structure? |
|
Definition
|
|
Term
| where does the lymphatic drainage of the ovaries go? |
|
Definition
| drain to lumbar nodes along the ovarian vessels |
|
|
Term
| where does the lymphatic drainage from the middle and upper vagina, cervix and ody of the uterus drain? |
|
Definition
| to nodes along the internal iliac arteries |
|
|
Term
| where does the lymphatic drainage from the superolateral uterus near the attachment of the round ligament drain? |
|
Definition
| drains to the superficial inguinal nodes |
|
|
Term
| where does the lymphatic drainage from the ostium of the vagina, below the hymen and the vulva, drain? |
|
Definition
| to the superficial inguinal nodes |
|
|
Term
| what is the importance of the pelvic fascia? |
|
Definition
Continuation of extraperitoneal connective tissue of the abdomen.
Thickenings of the fascia form ligaments.
In the female, most important of these is the transverse cervical or cardinal ligament.
In the male, there is a condensation of fascia around the the anterior and lateral regions of the prostate. |
|
|
Term
| what is the most severe consequence of pelvic diaphragm weakness? |
|
Definition
vaginal prolapse; more common is stress incontinence
Kegel exercises were devised to strengthen the pelvic floor muscles |
|
|
Term
| what happens during stress incontinence? |
|
Definition
Some people believe that the female urethral sphincter is not as competent as that in the male. The idea for normal continence is that the architecture of the normal pelvic floor allows intra-abdominal pressure to exert a sphincter-like action at the neck of the bladder.
In stress incontinence, the neck of the bladder slips through the pelvic diaphragm, moving it below the effects of
intraabdominal pressure.
Childbirth weakens the pelvic diaphragm and thereby allows the neck of the bladder to slip inferior to the pelvic diaphragm |
|
|
Term
| pelvic structures are innervated by what nerves? |
|
Definition
S2, S3, and S4 and coccygeal nerves
S2 and S3 anterior rami emerge between digitations of piriformis and coccygeus muscles.
L4 and L5 form the lumbosacral trunk that unites with sacral plexus. |
|
|
Term
| which nerve supplies the perineum? |
|
Definition
| the pudendal nerve (S2,S3,S4) |
|
|
Term
| the sympathetics are associated with ______ splanchnics |
|
Definition
|
|
Term
| the parasympathetics are associated with _____ splanchnics |
|
Definition
|
|
Term
| describe the 2 divisions of the internal iliac artery |
|
Definition
Artery of the pelvis.
Has 2 divisions:
Anterior division – mainly to viscera
Umbilical artery
Obturator artery
Inferior vesical artery (only in males)
Middle rectal artery
Vaginal artery (female equivalent of inferior vesical)
Uterine artery
Internal pudendal artery
Inferior gluteal artery
Posterior division – mainly body wall
Superior gluteal artery
Iliolumbar artery
Lateral sacral arteries |
|
|
Term
| where is the perineum located and describe its divisions |
|
Definition
Anatomically defined as the entire outlet of the pelvis whereas clinically, the term is more restricted to the region between the scrotum and anus in the male or the vulva and the anus in the female .
Rhomboid-shaped region inferior to the pelvic diaphragm.
Divided into two triangles by a line joining the two ischial tuberosities.
Anterior triangle is the urogenital triangle.
Posterior triangle is the anal triangle.
These two triangles are not in the same plane.
In the anatomical position, the urogenital triangle is oriented horizontally and the anal triangle is oriented more posteriorly |
|
|
Term
| describe the orientation of the urogenital triangle |
|
Definition
In anatomical position, oriented horizontally.
In this region, the pelvic diaphragm has a u-shaped opening, the urogenital hiatus, which allows the passage of the urethra in the male and the urethra and vagina in the female.
The perineal membrane spans the urogenital triangle |
|
|
Term
| describe the perineal membrane |
|
Definition
Thick, fascial membrane attached to the bones of the pubic arch.
In anatomical position, it is oriented in a horizontal plane.
Has a free, posterior margin.
Superior to (deep to) the perineal membrane is a thin space, the deep perineal pouch or space.
Inferior to (superficial to) the perineal membrane is the superficial perineal pouch or space.
Inferiormost boundary of this space is Colles’ fascia. |
|
|
Term
| colle's fascia is tightly adherent posteriorly to the posterior edge of which membrane? |
|
Definition
|
|
Term
| the membranous layer of the superficial perineal space is which fascia? |
|
Definition
|
|
Term
| where is the perineal space located? |
|
Definition
| Lies between the perineal membrane and the membranous layer of superficial fascia |
|
|
Term
| describe what colle's fascia is continuous with and adherent to? |
|
Definition
Continuous with Scarpa’s fascia of the abdominal wall, Dartos (superficial ) fascia of the scrotum and the penis.
Tightly adherent, laterally, to the pubic and ischial rami and, posteriorly, to the posterior edge of the perineal membrane |
|
|
Term
| what is found in the superficial perineal space in males and females? |
|
Definition
Erectile tissues that form the penis in the male and clitoris in the female.
In the male, contains, the crura of the corpora cavernosa, corpus spongiosum and bulb of the penis.
In the female, it contains homologous structures and the greater vestibular glands (Bartholin glands).
Contains muscle associated with erectile tissues and the superficial transverse perineal muscle as well as the investing fascia of these muscles (Gallaudet’s fascia).
Branches of the internal pudendal vessels and pudendal nerve |
|
|
Term
| what are the 3 erectile masses of the penis? |
|
Definition
Two corpora cavernosa, each surrounded by a dense, fibrous capsule, the tunica albuginea.
One corpus spongiosum |
|
|
Term
| where is the root of the penis attached? |
|
Definition
| to the pubic arch and the perineal membrane |
|
|
Term
| describe characteristics of the penis |
|
Definition
Three erectile masses.
Two corpora cavernosa, each surrounded by a dense, fibrous capsule, the tunica albuginea.
One corpus spongiosum.
Root is attached to the pubic arch and the perineal membrane.
Ischiocavernosus muscles cover the crura.
Bulbospongiosus covers the bulb.
Body is the free part |
|
|
Term
| the skeletal muscle of the penis is innervated by which nerve? |
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Definition
| the perineal nerve, a branch of the pudendal nerve (S2-S4) |
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Term
| an erection involves which type of reflex? |
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Definition
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Term
| describe the afferents and efferents for erection of the penis |
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Definition
Afferents.
Sensation from the penis are carried in the dorsal nerve of the penis, the terminal branch of the pudendal nerve (S2-S4).
Damage to the pudendal nerve can cause penile insensitivity, but has no effect on psychogenic erection.
Psychogenic involves descending pathways from the cortex.
Plays a big role in human sexual behavior.
Efferents.
Parasympathetics travel in pelvic splanchnics.
Enter inferior hypogastric plexus, prostatic plexus and the cavernous nerves.
Release acetylcholine and nitric oxide (NO). |
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Term
| what happens during an erection? |
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Definition
Under the influence of acetylcholine and NO, helicine arteries relax, allow greater blood flow into penis.
Corpora cavernosa and corpora spongiosum become engorged with blood.
The ischiocavernosus muscles and bulbospongiosus muscle compress the veins and prevent venous return.
Tunica albuginea of the penis helps maintain turgidity. |
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Term
| sympathetics from which spinal segments causes peristalsis to move semen to the prostatic urethra via the ejaculatory ducts during ejaculation? |
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Definition
L1-L2
Sympathetics (L1-L2) close internal urethral sphincter of the bladder.
Contraction of urethral smooth muscle is parasympathetic (S2-S4).
Contraction of bulbospongiosum muscle is somatic reflex (pudendal nerve, S2-S4). |
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Term
| contraction of urethral smooth muscle during ejaculation is sympathetic or parasympathetic? |
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Definition
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Term
| describe the scrotum and its innervation |
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Definition
Cutaneous sac with 2 layers
Heavily pigmented thin skin
Dartos fascia
Fat-free fascial layer containing smooth muscle
When cold, dartos muscle contracts, reduces scrotal surface area and helps cremasteric muscle keep testes against the body
Innervation
Anterior scrotal nerve
Branches of Ilioinguinal and genitofemoral nerves
Posterior scrotal nerves from pudendal nerve |
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Term
| the labia majora are innervated by which nerves? |
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Definition
| Labia majora are innervated by the anterior labial nerves from ilioinguinal and the posterior labial nerves from the superficial perineal. |
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Term
| where is the deep perineal pouch located and what does it contain? |
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Definition
Immediately superior to the perineal membrane.
Contains skeletal muscle, blood vessels and nerves.
In the male, in addition to muscles, blood vessels and nerves, the deep pouch or space contains the bulbourethral glands or Cowper’s glands. |
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Term
| describe the muscles of the deep pouch of the perineum and their functions |
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Definition
Sheet of skeletal muscle functions as a sphincter for the urethra in the male and for the urethra and vagina in the female.
External urethral sphincter in male and female.
Two additional muscles in female.
Sphincter urethrovaginalis.
Compressor urethrae.
In males and females, deep transverse perineal muscles parallel the free margin of the perineal membrane and help stabilize the perineal body |
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Term
| where does the anal triangle face and what are its boundaries? |
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Definition
In anatomical position, faces postero-inferiorly.
Laterally, bordered by the medial margins of the sacrotuberous ligaments.
Anteriorly, bounded by the line between the ischial tuberosities, which marks the free posterior border of the perineal membrane.
Posteriorly, it is bounded by the coccyx |
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Term
| where is the ischioanal fossa? |
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Definition
Lie on either side of anal canal.
Large fascia-lined, wedge shaped spaces between the skin and the inferior fascia of the pelvic diaphragm.
Communicate with each other via the deep postanal space superior to the anococcygeal ligament |
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Term
| what happens if there is an abcess in the ischioanal fossa? |
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Definition
Can be very painful.
Inflammation in anal canal can lead to a fistula between the anal canal and the ischioanal fossa.
Can spread to the anterior recess and posteriorly through the deep postanal space to the opposite side. |
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Term
| what is the major blood supply to the perineum? |
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Definition
Internal pudendal artery
Branch of the anterior division of the internal iliac artery
Leaves the pelvic cavity via the greater sciatic foramen
Loops around the ischial spine lateral to the pudendal nerve
Enters the perineum through the lesser sciatic foramen
Enters the pudendal (Alcock’s) canal
Within anal triangle gives off Inferior rectal arteries
Within urogenital triangle gives off
Arteries to bulb of penis or vestibule
Deep dorsal artery of penis or clitoris
Dorsal artery of the penis or clitoris |
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Term
| does the pudendal nerve contain autonomics involved in erection and ejaculations? |
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Definition
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Term
| describe the major innervation of the perineum |
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Definition
Major somatic nerve is the pudendal nerve (S2-S4)
Exits the pelvic cavity via the greater sciatic foramen
Loops around the ischial spine to enter the lesser sciatic foramen
Enters the pudendal (Alcock’s) canal in the anal triangle
Gives off the inferior rectal nerve or nerves in the anal triangle
Continues as perineal nerve to supply urogenital triangle
Ends as dorsal nerve of the penis or clitoris |
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Term
| what is bicycle seat neuropathy? |
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Definition
One of the more common injuries reported by cyclists.
Complain of numbness.
Some complain of impotence.
Believed to be caused by compression of the pudendal nerve in Alcock’s canal.
Bicycle seat design is a factor.
Wider seats that support ischial tuberosities seem to reduce incidence. |
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Term
| what region would a physician use to locate the position of the pudendal nerve during a pudendal nerve block during childbirth? |
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Definition
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