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85 Cards in this Set

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  • Back
What two major features of the pelvis are in the same vertical plane when the pelvis is tipped forward into anatomical position?
The ASIS is above the pubic tubercle.
How far forward is the pelvis tipped in anatomical postion?
50-60 degrees.
What does each hip bone articulate with? (2 things) What is the junction called?
Sacrum - Sacroiliac joint
Other hip bone - Pubic symphysis
What are the 3 bones of the bony pelvis?
2 hip bones and 1 sacrum.
What part of the skeleton does the hip bone belong to?
The appendicular skeleton, like the scapula for the upper limb.
What is the pelvis considered a part of?
The trunk
Compare/contrast male and female pelvises.
Male - Not as wide, subpubic angle = 60 degrees

Female pelvis - Wider, lighter (smaller muscle mass to support), and subpubic angle near pubic symphysis = 90 degrees.

See plate 354
What is the acetabulum? What meets here?
A cuplike recess in the hip bones. 3 bones unite here: Ischium, pubis and the ilium.
What is the anteriormost bone of the hipbone?
The pubis
What is the most inferior/posterior bone of the hipbone?
The ischium.
What 2 major processes does the ischium have? Which is more superior?
The ischial spine as superior to the ischial tuberosity.
What is the most superior bone of the hipbone?
The ilium
What is the large foramen that can be seen prominently from a lateral view of the pelvis? What two bones make up its borders?
The obturator foramen is bordered by the pubis and ischium
What 2 features does the ischial spine separate? Which is most superior? Which bones do these belong to?
The ischial spine sperates the superior greater sciatic notch of the ilium and the inferior lesser sciatic notch of the ischium.
Why are the lesser/greater sciatic notches so important?
Structures leave pelvis through these notches.
What 2 ligaments connect the sacrum to the hip bone inferiorly?
The sacrotuberous ligament and the sacrospinous ligament.
What does the sacrotuberous ligament run to/from?
Sacrum to ischial tuberosity.
What does the sacrospinous ligament run to/from?
Sacrum to spine of schium (ischial spine)
What do the sacrotuberous ligament and sacrospinous ligament form?
The greater and lesser sciatic foramen.
What closes the pelvis inferiorly?
A musculofascia diaphragm.
Why are the greater/lesser sciatic foramen so important?
They allow structures to go through to the perineum without passing through the pelvic floor (diaphragm)
What forms the pelvic brim?
A circumferential ridge of bone all the way around the ala to the pelvis.
What is the space superior to the pelvic brim/bone pelvis called? What is contained here?
The false or greater pelvis. The abdominal rim may be found here.
What is the space inferior to the pelvic brim called?
The lesser or true pelvis.
Where are most structures of the pelvis found?
In the true pelvis
What does the pelvic brim serve as a junction between?
The false (greater) and true (lesser) pelvis
Which two facets of the human body can extend from the true pelvis into the false pelvis?
The pregnant uterus and the urinary bladder when filled.
What 3 facets of the pelvis form the pelvic outlet?
The inferior aspect of the pubic symphysis, ischial tuberosity, and tip of the coccyx.

See plate 354
What is the conjugate or obstetrical dimension? How long is it normally? How do you determine its length? Is this distance fixed or variable?
The conjugate or obstetrical dimension is usually 11 cm and goes from the sacral promontoroy to the pubic symphysis (superior part). This distance is usually measured with imaging and is fixed.

See plate 354
What is the diagonal conjugate dimension? How long is it normally? How do you determine its length? Is this distance fixed or variable?
The diagonal conjugate runs from the the sacral promonotory to the inferior pubic symphysis. This distance is variable and can be measured by inserting 2 finges into the vagina and palpating it along the posterior abdominal wall. If you can't feel it then the distance is appropriate for vaginal delivery.
What is the smallest/narrowist point of the birth canal/pelvis? How is this area widened during pregnancy?
Area between the ischial spines. Relaxin is a hormone that targets the joints of pelvis and causes these to move apoart, mainly by acting on the pubic symphysis.
What does the pelvic diaphragm close?
The pelvic outlet in the true pelvis.
Give the inferior attachment and pathway of the piriformis? What musculoskeletal area does this muscle act on? When viewed from a superior view what is its proximity to the pelvic diaphragm?
The piriformis goes through the greater sciatic foamen and attaches to the femur. It is a muscle of the lower limb. It is the furthest muscle from the pelvic diaphragm that is part of that "group" of muscles andis right against the posterior wall/vertebrae of the body.

See plate 356
What musculoskeletal area does the obturator internis (paired) act on? Relative to the pelvic diaphragm where is it?
It acts on the hip joint and is a muscle of the lower limb.
It is lateral to the pelvic diaphragm.

See plate 356
Which two muscles are specifically not part of the pelvic diaphragm?
Piriformis and Obturator internis (paired).
How many aperatures does the male pelvic diaphragm have medially? What are they called? What is the general shape of the male pelvic diaphragm?
The 2 aperatures are the hiatus for urethra and the anorectal hiatus. The male pelvic diaphragm is roughly shaped like a funnel.

See Plate 358
From where to where does the pelvic diaphragm extend?
From the lateral wall of the true pelvis to the pelvic outlet.
What is the space confined between the pelvic brim and the pelvic diaphragm?
The true pelvis.
Once you go inferior to the pelvic diaphragm what space are you in?
The perineum.
What is the line of deliniation between the pelvis and perineum?
The pelvic diaphragm.
What 2 triangles can be found inferior to the pelvic outlet?
The Anal triangle posteriorly and the urogenital triangle anteriorly.
When does the perineum take on a diamond shape? What is the clinical term for this position?
Only when the thighs are abducted. Called the lithotomy position.
Fill in the blank!

The anus and scrotum are considered _________ of triangles.
What are the 3 dermatomes found in the perineum?
S3 S4 S5
Which dermatome is dominant in the perineum?
Which dermatomes make up mostly the anal triangle?
S4 S5
IF you remove the skin from the anal triangle what is the first muscle you will see?
The gluteus maximus muscle

See Plate 379
What are the recesses to the side of the anal driangle called? What is in them? What is their purpose?
The recesss are the ischial anal fossa (paired) they are full of fat and maintain the integrity of the GI tract by helping to keep the anal canal closed. This is also the last fat to be used in starvation conditions.
Differentiate between the anus and the anal canal.
The anus is only the inferior aperture of the GI tract. The last 4 cm of the GI tract is the anal canal.
Describe the tissue of the anal coccygeal body.

See plate 382
Do the ischial anal fossa communicte?
YES! The abcess extends across the midline.
What is the perineal body? What does this serve as?
A fibrous tuft just deep to the skin. It serves as a point of attachment for muscles in the perineum.

See plate 382
What is it called when you cut the perineal body? Why would you do this?
This is called an episiostomy.
This is done to prevent excessive or irregular vaginal tearing during delivery.
What is the perineal body called in clinical setting?
The perineum.
What is the general shape of the ischioanal fossa from a front section?
What makes up the base of the pyramid of the ischioanal fossa? How about the apex?
Base = Skin, the apex is the deepest part of the fossa and is formed where 2 muscles meet. The pelvic diaphragm and the obturator internus.
What makes up the medial wall of the pyramid of the ischioanal fossa?
The pelvic diaphragm.
What makes up the lateral wall of the pyramid of the pelvic diaphragm?
The obturator internus.
From what muscle do some of the muscles of the pelvic diaphragm take origin?
The obturator internus.
What goes through the fibers of the obturator interis?
The Pudendal canal.
What can be found within the pudendal canal?
The Internal pudendal arteries and veins as well as the pudendal nerve and the perineal nerve.

See plate 392
Where do the pudendal arteries arise from?
The internal iliac.
In which direction does the internal pudendal artery branch?
From lateral to medial, it cuts across the fat of the midline.

See plate 404
What is the first branch of the pudendal nerve? What sort of nerve is it and what does it do?
The inferior rectal branch. This nerve is a mixed nerve and is sensory to the perianal skin and motor to the external anal sphincter.

See plate 404
What is the 1st branch of the internal pudendal artery?
The inferior rectal artery with the vein just above it.
What sort of things can the external anal sphincter distinguish?
Fluid, gas and solid
What sort of muscle is the internal anal sphincter? Describe its action and nervous control.
The internal anal sphincter is smooth muscle and is under taunt contraction except for during fecal release. It is under control of sympathetic nervous system.
What are the longitudinal ridges of the upper portion of the anal canal called?
Anal columns.
What forms anal columns? Where do these arise from? What about the origin of their origin? (2 steps back)
Blood vessels in the submucosa from the superior rectal artery form the anal columns. The superior rectal artery comes from the inferior mesenteric artery.
What connects adjacent anal columns?
Anal valves.
What collects in anal valves? What is their purpose?
The anal valves collect mucus in the sinuses. This heps to lubricate the anal canal during defecation.
Where is venous blood form the upper end of the anal canal going?
The portal system
Where can the internal venous plexus of the anal canal be found?
External to the anal columns.
What sort of things anastamose in the internal venous plexuses of the anal columns? What is the clinical significance of this?
There are both venous and arteriole anastomoses in columns. The significance of this is that it will be bright red (oxygenated) blood if this plexus is torn.
Below what is the surface of the anal canal smooth?
The pectinate line.
What divides the upper and lower anal canal?
The pectinate line
What is the origin of the lower anal canal? What sort of sensations can be felt here?
The proctodeum or ectodermal in origin. All sensations can be felt here (touch, temperature etc.)
What is the origin of the upper anal canal? What sort of sensations can be felt here?
From hindgut endoderm. Is only sensitive to distension.
What is the blood supply of the upper and lower anal canal?
The upper = superior rectal
The lower = inferior rectal
What is the vain of the upper anal canal? Follow this back all the way to the vena cava.
The internal pudendal to the internal iliac to the common iliac to the IVC.
What is vein of the lower anal canal?
The inguinal vein.
Are there valves in the internal pudendal or inginal veins?
What are anal fissures and where do they occur?
Anal fissures are tears in the ining of the mucosa of the anal canal. They occur in the posterior wall of the lower anal canal.
What are 2 possible sources/causes of anal fissures?
Dehydration makes stools extremely hard or foreign object insertion.
What is one of the complications associated with anal fissures?
Feces can get to the ischioanal fossa and form pus filled abcesses.