Week 21 & 22 - Male & Female Pelvis Flashcards
(123 cards)
What two groups of muscles make up the pelvic floor?
- Levator ani
- Coccygeus
What are the functions of the pelvic floor?
- Separates pelvic cavity from perineum
- Supports pelvic viscera
- Reinforces external anal sphincter
Describe the perineum and its borders.
- Diamond-shaped region inferior to pelvic floor with anatomical borders including:
- Anterior – pubic symphysis
- Posterior – tip of the coccyx
- Laterally – inferior pubic rami and inferior ischial rami, and the sacrotuberous ligament
- Roof – pelvic floor
- Base – skin and fascia
What are the surface borders of the perineum?
- Anterior – mons pubis in females, base of the penis in males
- Laterally – medial surfaces of the thighs
- Posterior – superior end of the intergluteal cleft
What are the two triangular areas formed by the line between ischial tuberosities in the perineum?
- Urogenital triangle
- Anal triangle
What are the contents of the anal triangle?
- Anal aperture
- External anal sphincter muscle
- Ischioanal fossae (x2)
- Pudendal nerve
List the layers of the urogenital triangle from deep to superficial.
- Deep perineal pouch
- Perineal membrane
- Superficial perineal pouch
- Perineal fascia
- Skin
Describe the contents & boundaries of deep perineal pouch.
Boundaries:
- Superior – pelvic floor
- Inferior – perineal membrane
Contents:
- Part of urethra
- External urethral sphincter
- Vagina / bulbourethral glands
- Deep transverse perineal muscles
What is the function of the perineal membrane?
Provides attachment for muscles of external genitalia
What are the boundaries of the superficial perineal pouch?
- Superior – perineal membrane
- Inferior – superficial perineal fascia
- Posterior – perineal body
What are the contents of the superficial perineal pouch?
- Erectile tissues forming penis & clitoris
- 3 muscles - ischiocavernosus, bulbospongiosus & superficial transverse perineal muscles
- Greater vestibular glands
Describe the perineal fascia.
Continuity of abdominal fascia with two components:
- Deep fascia – covers superficial perineal muscles and protruding structures
- Superficial fascia – composed of two layers:
- Superficial layer – continuous with Camper’s fascia
- Deep layer (Colles’ fascia) – continuous with Scarpa’s fascia
What is the perineal body and its functions?
- Irregular fibromuscular mass located at junction of triangles
- Functions as a point of attachment for muscle fibres from the pelvic floor and perineum
How can infection spread from the anal aperture to the ischioanal fossa?
Infection can track laterally from anal mucosa through external anal sphincter, or from perianal hair follicles or sweat glands.
What is the pelvic pain line?
Divides pelvic pain into visceral (above the line) and somatic (below the line); corresponds to the peritoneum.
Describe the trigone of the bladder.
- Smooth triangular shaped segment of the urinary bladder wall
- Located along the posterior surface of the bladder and marks the point of opening for the two ureters
- Sensitive to stretch and expansion, which signals the brain to become aware of the “need” to urinate
What is the content of the spermatic cord?
- Vas deferens
- Testicular artery
- Cremasteric Artery & Vein
- Artery to Vas deferens
- Pampiniform plexus of veins
- Genital branch of Genitofemoral nerve
- Autonomic nerves
- lymphatics
- Processus vaginalis - fused in adults/projection of peritoneum forming pathway for testes decent
What are the layers of the spermatic cord?
- Internal spermatic fascia: derived from the transversalis fascia
- Cremasteric fascia: derived from the investing fascia of the internal oblique muscle
- External spermatic fascia: derived from the external oblique aponeurosis
What is the scrotum?
A cutaneous sac consisting of heavily pigmented skin and dartos fascia, which includes smooth muscle fibers responsible for its wrinkled appearance.
What is the purpose of testicular thermoregulation?
To maintain a temperature 3 degrees lower than abdominal temperature.
What roles do the cremaster and dartos muscles play in testicular thermoregulation?
- Cremaster muscle: pulls testes close to body
- Dartos muscle: wrinkles skin to reduce surface area for heat exchange
Describe the course of the ductus deferens.
- Begins in the tail of the epididymis
- Ascends posterior to the testis
- Penetrates the anterior abdominal wall via the inguinal canal
- Crosses over the external iliac vessels
- Enters the pelvis
- Passes along the lateral wall of the pelvis
- Joins the duct of the seminal gland to form the ejaculatory duct
Where are the seminal glands located?
Posterior to the prostate in the rectovesical pouch.
What do the seminal glands secrete?
A thick alkaline fluid with fructose and a coagulating agent.