GA - Pelvic Viscera I Flashcards
(31 cards)
What is the Perineal Body?
Perineal body is a fibro-muscular mass in the midline of the perineum.
It serves as an attachment point for muscles.
Normally a bone would be used as an attachment point, but babies need to come through the pelvis, and a bone would block the way
What are the three Superificial Perineal Muscles, and what structure are they superior to?
Superificial Transverse Perineal M.
Bulbospongiosus M.
Ischiocavernosus M.
They are superficial to the Perineal membrane
Describe the erectile tissue in males
There are three cylindrical masses of erectile tissue in the penis.
1 ventral cylinder, and 2 (paired) dorsal chambers
Name the segments of the erectile tissue in males, and describe their location
The proximal portions of the paired dorsal cylinders of erectile tissue are called the Crura of the Penis (Left Crus of the Penis, Right Crus of the Penis).The crura fan out on either side of the penis along the Brim of the Pelvis.
The distal portions of the paired dorsal cylinders of erectile tissue are called the Corpora Cavernosa (plural) or Corpus Cavernosum (singular)
The proximal portion of the ventral cylinder of erectile tissue is called the Bulb of the Penis
The middle portion of the ventral cylinder of erectile tissue is called the Corpus Spongiosum
The distal portion of the ventral cylinder of erectile tissue is called the Glans Penis
Describe the erectile tissue in females
Erectile tissue compartments are not cylindrical like the male, but like the males, there are of these compartments
1 unpaired compartment is superior to the genitalia (clitoris)
2 (paired) compartments are i deep to the labia majora
Name the compartments of erectile tissue and females and describe their location
The clitoris has three parts to it:
- Glans Clitoris is the most superficial segment
- Body of the clitoris is just deep to the glans clitoris
- The Crura of the Clitoris fan out left and right along the pelvic brim
Bulbs of the Vestibule are a set of paired compartments of erectile tissue deep to the labia majora
Where is the Bulbospongiosus M. found in the male?
The Bulbospongiosus M. is a thin layer of muscle tissue found on top of the Bulbs of the Penis (proximal end of the ventral cylinder of erectile tissue) and on top of the Corpus Spongiosus (middle portion of the ventral cylinder of erectile tissue)
Where is the Ischiocavernosus M. found in the male?
Ischiocavernosus M. is a thin layer of muscle tissue found laying overtop the Crura of the penis.
Attaches somewhat to the ischium
Ischiocavernosus of the male is much larger than the ischiocavernosus of the female
Where is the Bulbospongiosus M. located in the female?
Bulbospongiosus muscle is a thin layer of muscle tissue found on top of the Bulbs of the Vestibule.
Where is the Ischiocavernosus M. found in the female?
The Ischiocavernosus M. is a thin layer of muscle tissue found laying overtop the Crura of the Clitoris
Ischiocavernosus of the female is much smaller than the ischiocavernosus of the male
What is the action of the Bulbospongiosus M. in the Female?
Holds the Perineal Body in place from the anterior direction.
Compress the vaginal vestibules as well as the vagina
What is the action of the Bulbospongiosus M. in the Male?
Holds the Perineal Body in place from the anterior direction.
Maintains erection by blocking venous drainage
Since the Bulbospongiosus surrounds the bulb of the penis, it is also capable of helping expel drops of urine/semen
What is the action of the Ischiocavernosus M. in the male?
Maintains erection of penis by compressing venous drainage
What is the action of the Ischiocavernosus M. in the female?
Maintains erection of the clitoris by compressing venous drainage
What is the action of the Superficial Transverse Perineal M.?
Supports and fixes the Perineal Body from both lateral directions
What are the Urogenital Diaphragm Muscles?
Deep Transverse Perineal M.
External Urethral Sphincter M.
These muscles are JUST DEEP TO THE PERINEAL MEMBRANE
What is different about the Deep Transverse Perineal M. in males and females?
In females, the Deep Transverse Perineal M. is composed of smooth muscle
In males the Deep Transverse Perineal M. is composed of skeletal M.
What are the components of the External Urethral Sphincter?
The Compressor Urethrae M. extends from the Ox Coxa wall to midline where it holds the External Urethral Sphincter in place.
The Urethrovaginal Sphincter M. is found only in womem. Muscle fibers extend from the External Urthra and wrap around the vagina.
What nerve innervates the External Urethral Sphincter M.?
Dorsal Nerve of the Penis (males)
Dorsal Nerve of the Clitoris (female)
This is an exception. All the other muscles of the Urogenital Diaphragm and the Superficial Perineal Muscles are innervated by Deep Perineal Nerves
What nerve innervates the muscles of the Urogenital Diaphragm and the Superficial Perineal Muscles (except for one muscle, name the exception)?
Deep Perineal Nerves innervate the muscles of the Urogenital Diaphragm and the Superificial Perineal Muscles.
The only exception is the External Urethral Sphincter M., which is innervated by the Dorsal Nerve of the Penis (males) or the Dorsal Nerve of the Clitoris (females)
What are the anal muscles?
Internal Anal Sphincter M. (smooth muscle)
External Anal Sphincter M. (skeletal muscle)
What are the actions of the External Anal Sphincter M. ?
Holds the Perineal Body in place from the posterior
Prevents feces from exiting the rectum
What nerve innervates the External Anal Sphincter M.?
The External Anal Sphincter M. is innervated by the Inferior Rectal N. (aka the Inferior Anal N.)
What does the Pelvic Diaphragm Separate?
The pelvis and the perineum
