pelvis Flashcards
week 1 (part 1)
What are the two bones of the pelvis that are components of the vertebral column?
Coccyx and sacrum
What are the three bones of the pelvis?
right and left pelvic bones (innominate bones) Coccyx and sacrum
What is the lowest vertebrae of the lumbar region?
vertebrae LV
What vertebrae does the Sacrum articulate superiorly with AND at what joint?
LV
lumbosacral joint
The Ala binds to the greater pelvis ….
laterally
what is the promontory of the pelvis?
anterior margin of first sacral vertebrae
The four anterior sacral formina are an exit for …. and entrance for…
exit= anterior divisions of sacral nerves
entrance = lateral sacral arteries
What does the pelvis bone ABOVE the linea terminalis represent?
represents the lateral wall of the false pelvis, which is part of the abdominal cavity
What does the pelvic bone BELOW the linea terminalis represent?
represents the lateral wall of the true pelvis, which contains the pelvic cavity.
What three elements form each pelvic bone?
llium, pubis and ischium.
Describe how the three components of the pelvic bone are connected throughout time.
At birth, these bones are connected by cartilage in the area of the acetabulum; later, at between 16 and 18 years of age, they fuse into a single bone.
What does the walls of the pelvic cavity consist of?
sacrum,
the coccyx,
the pelvic bones inferior to the linea terminalis,
two ligaments (sacrospinous and sacrotuberous)
two muscles (Obturator internus and piriformis)
What are the two ligaments of the Walls of the pelvic cavity?
sacrospinous and sacrotuberous
What are the two muscles of the Walls of the pelvic cavity?
(Obturator internus and piriformis)
Describe the Sacrospinious ligament
smaller of the two ligaments of the pelvic walls
triangular
apex attached to ischial spine and base attached to sacrum and coccyc.
Describe the Sacrotuberous ligament
also triangular and is superficial to the sacrospinous ligament.
Its base is broad and attaches from the posterior superior iliac spine of the pelvic bone, along the lateral margin of the sacrum, and onto the coccyx. Laterally, the apex of the ligament is attached to the ischial tuberosity.
Where do the two pelvic wall muscles originate from?
Originate from pelvic cavity but attach to femur
What is the shape of the Obturator internus and where does it originate from?
flat, fan-shaped muscle originating from the deep surface of the obturator membrane and the pelvic bone.
Function of Obtutator internus
The muscle fibers of the obturator internus form a tendon that leaves the pelvic cavity through the lesser sciatic foramen, and then passes to the greater trochanter of the femur.
forms a large part of the anterolateral wall of the pelvic cavity
What is the shape of the Piriformis and where does it originate from?
triangular and originates from the sacrum.
What are the three major apertures of the pelvic wall?
the obturator canal;
the greater sciatic foramen; and
the lesser sciatic foramen.
Obturator canal
at top of obturator foramen.
communication between pelvic cavity and adductor region
Greater sciatic foramen function
Major route of communication between the pelvic cavity and the lower limb.
Lesser sciatic foramen function.
acts as a route of communication between the perineum and the gluteal region.
What forms the pelvic floor?
Formed by the pelvic diaphragm, perineal membrane and muscles of the deep perineal pouch.
functions of the pelvic floor
Separates pelvic cavity (above) from the perineum (below)
Supports bladder, bowel and uterus.
What is the muscular part of the pelvic floor called?
Pelvic diaphragm
Structure of the pelvic diaphragm
Formed by the levator ani and coccygeus muscles
Attached superiorly to pelvic wall
Where does the levator ani join in females?
: join posterior to vagina and around anal aperture (both sexes).
…… to the anal aperture, levator ani muscles come together as the ….. …. an attach to the ….
posterior
anococcygeal ligament
coccyx
….., the levator ani is separated by a U-shaped defect called a….
Anteriorly…. urogenital hiatus
What does the urogenital hiatus allow for in men and women?
allows the urethra (in both men and women), and the vagina (in women), to pass through the pelvic diaphragm.
What are the three collections of muscles fibres within the levator ani?
the pubococcygeus, the puborectalis, and the iliococcygeus muscles.
what is the function of levator ani?
help support the pelvic viscera and maintain closure of the rectum and vagina.
Coccygeus
two triangular muscles (one on each side) that overlie the sacrospinous ligaments.
Together they complete the posterior part of the pelvic diaphragm. They are attached to ischial spines and to the lateral margins of the coccyx and the sacrum.
In the pelvic cavity, the Bladder is positined…. to the midline
anteriorly
in the pelvic cavity, the rectum is located…. to the midline
posteriorly
Function of the pelvic cavity
Contains and supports bladder, anal cabal, rectum and reproductive tracts
The pelvic cavity contains most of the reproductive tract in women and part of the reproductive tract in men.
What is the perineum?
space enclosed by the boundaries if the pelvic outlet and below the pelvic floor.
Describe the structures of the pelvis that make up the perinieum.
Peripheral boundry = pelvic outlet
Ceiling = pelvic diaphragm
Narrow lateral walls = walls of the pelvic cavity below attachment of levator ani.
What does the Anal triangle contain?
Anus and external anus sphincter (major muscle of area)
Where is the anal triangle located in refernce to the perinuem?
posterior
what is the ceiling of the anal triangle?
pelvic diphragm.
compare male and female pelvis in terms of Structure, lesser pelvis, pelvic inlet, pelvic outlet and subpubic angle
Male:
S-thick and heavy
LP- narrow and deep
PL-heart shaped
PO- small
A-greater then 70
female
S-thin and light
LP-wide and shallow
PL-oval-shaped
PO- large
A-less than 80
what are the two erictle tissues common to males and females and who to they form?
Corpus cavernosa and corpus spongiosum (forms bulbs of penis in males, bulbs of vestibule in females)
what are the superficial skeletal muscles found in the superficial perineal pouch in both males and females? what are they associated with?
(ischiocavernosous – associated with corpus cavernosa) and bulbospongious (associated with bulb of vestibule/penis)
What is the Epididymis
Long coiled duct along posterolateral side of testis
Tunica vaginalis
Serous membrane that allows movement to be lubricated
Cremaster muscle
Elevates and depresses testes to regulate scrotal temp
ductus deferens
muscular duct that transports spermatozoa from epididymis to ejaculatory duct
4 parts of male urethra
- preprostatic
- prostatic
- membranous
- spongy
pathway of urethtra
- begins (preprostatic)
- descends through the prostate gland (prostatic)
- descends through the deep perineal pouch and perineal membrane to enter the root of the penis, bends to course anteriorly in the root of the penis
(membranous) - continues in the body of the penis to open at the external urethral orifice (spongy)
male vs female accessory glands
Female: oviduct, uterus and vagina
Male: prostate, pair of seminal vesicles and pair of bulbourethral glands
