Abdomen, Pelvis and Perineum 4 Flashcards
(91 cards)
1
Q
What is the perineum?
A
the anatomical region which is located inferior to the main pelvic cavity
2
Q
What separates the perineum from the main pelvic cavity?
A
The pelvic diaphragm (levator anii and coccygeus)
3
Q
Which processes does the perineum play a part in?
A
- defacation
- micturition
- intercourse
- partuition
4
Q
How is the perineum best viewed and what is its shape from this angle?
A
Inferiorly with the thighs abducted
Diamond shaped
5
Q
What two triangles can the perineum be divided into?
A
- anterior urogenital triangle
- posterior anal triangle
6
Q
What structre lies in the centre of the perineum, between the urogenital and anal triangles?
A
The perineal body
7
Q
Where is the perineal body located in men vs women?
A
- men = between the bulb of the penis and the anus
- women = between the vagina and anus
8
Q
What is the perineal body?
A
- small fibromuscular structure
- site of attachment for the muscles and fascia of the perineum
- provides support and function
9
Q
What does the urethra pass through in the perineum in women?
A
Deep perineal pouch > perineal membrane > superficial perineal pouch > vestibule in front of vagina
10
Q
What does the urethra pass through in the perineum in men?
A
Deep perineal pouch > perineal membrane > superficial perineal pouch > penis > external urethral orifice in the glans
11
Q
What do the ejaculatory ducts do?
A
drains sperm cells and ejaculatory fluid from the ductus deferens and seminal vesicles into the prostatic part of the urethra
12
Q
What happens to the internal urethral sphincter during ejaculation?
A
Closes to prevent sperm moving into the bladder
13
Q
What does the urogenital triangle contain?
A
The urethra and external genitalia
14
Q
What are the boundaries of the urogenital triangle?
A
- pubic symphysis anteriorly
- ischiopubic rami laterally
- (imaginary) line between the ischial tuberosities posteriorly
15
Q
What are the layers of the urogential triangle from deep to superficial?
A
- Pelvic diaphragm muscles (not in perineum)
- Deep perineal pouch
- Perineal membrane
- Superficial perineal pouch
- Perineal fascia (deep and superficial)
- Skin
16
Q
What does the deep perineal pouch contain?
A
- deep transverse perineal muscles
- external urethral sphincter
- urethra
- vagina or bulbourethral glands
17
Q
What is the function of the perineal membrane?
A
provides attachment sites for the roots of the external genitalia
18
Q
What does the superficial perineal pouch contain?
A
- ischiocavernosus muscle
- bulbospongiosus muscle
- superficial transverse perineal muscle
- erectile tissue for penis or clitoris
- greater vestibular glands (women)
19
Q
What are the urethral sphincter muscles in the deep perineal pouch?
A
- female = external urethral sphincter, sphincter urethrovaginalis, compressor urethrae
- male = external urethral sphincter
20
Q
What are the muscles in the deep perineal pouch innervated by?
A
Pudendal nerve (S2-S4)
21
Q
What are the bulbourethral glands?
A
Pea-sized glands that sit one either side of the urethra and secrete a mucous like substance to lubricate the urethra (male only)
22
Q
What is the perineal membrane?
A
- a thickened fascia which separates the deep and superficial perineal pouches
23
Q
What is the function of the perineal membrane?
A
- attachment point for the roots of the external genitalia and superficial perineal pouch muscles
- transmits urethra and vagina ro the superficial perineal pouch
- supports the pelvic floor muscles
24
Q
What is the structure of the erectile tissues (penis and clitoris)?
A
Core of expandable tissue surrounded by a connective tissue capsule
25
What is the structure of the clitoris?
- two corpora cavernosa converge near the pubic symphysis to form the body of the clitoris
- two vestibular bulbs in the superficial perineal pouch converge to form the glans of the clitoris
26
How can the clitoris be observed?
- glans is the only visible part
- body can be palpated under the skin
27
What are the greater vestibular glands and where are they located?
- secrete mucous into the vestibule of the vulva and around the opening of the vagina
- located in the superficial perineal pouch
28
What is the structure of the penis?
- two corpora cavernosa forming the dorsal side
- corpus sponginosum which forms the ventral side and contains the penile urethra
- the CS also expands distally to form the glans of the penis
29
What are the two regions of the penis?
The root and the body
30
What does the root of the penis consist of?
The fixed ends of the copora cavernosa and the corpus sponginosum
31
What does the body of the penis consist of?
The free parts of the corpora cavernosa and corpus sponginosum covered by skin
32
What is the innervation of the erection of the clitoris and penis?
Parasympathetic fibres of the pelvic splanchnic nerve
33
Where does blood flow for erections arise from?
Internal pudendal artery
34
What is the action of the ischiocavernosus muscle?
Moves blood from the corpora cavernosa of the clitoris/penis into the body during erection
35
What is the action of the bulbosponginosus muscle?
- moves blood from the glans of the clitoris/penis
- assists with movement of residual urine or semen from the penile urethra
36
What is the action of the superficial transverse perineal muscle?
Stabilising the perineal body
37
What does the deep perineal fascia cover?
The muscles and erectile tissue of the superficial perineal pouch
38
What is the superficial perineal fascia continuous with?
The superficial fascia of the anterior abdominal wall
39
What forms the vulva?
- clitoris
- vestibular bulbs
- connective tissue
- skin folds
40
What is the vestibule?
The area where the urethra and the vagina open
41
What are the labia minora?
Two folds of hairless skin on either side of the vestibule
42
What do the labia minora unite to form?
- anteriorly = frenulum and prepuce of the clitoris
- posteriorly = frenulum of the vagina
43
What are the labia majora?
Larger folds of skin with hair, lateral to the labia minora
44
What do the labia majora unite anteriorly to form?
Mons pubis
45
What is the posterior commisure?
A surface marking for the perineal body lying deep to this area
46
Where do paraurethral glands drain?
Via their ducts at the urethral opening
47
Where do the greater vestibular glands drain?
At the opening of the vagina
48
How does the scrotum differ to the labia majora?
The scrotum fuses in the midline so there is only a single scrotum
49
Which structres are found within the scrotum?
The testes and the coverings and neurovasculature
50
What does the line of fusion in the scrotum form?
The raphe, which extends from the anus, over the scrotal sac and to the inferior aspect of the penis
51
Where is the external urethral orifice located?
In the glans of the penis
52
What is the corona of the glans?
A raised circular margin formed by the base of the glans
53
What is the neck of the glans?
Depression just below the corona of the glans
54
What arises from the neck of the glans?
The prepuce of the glans (foreskin)
55
Where do the testes descend from?
Posterior from the abdomen, through the inguinal canal and into the scotal sac
56
What is the tunica vaginalis?
A covering of the testes formed from the peritoneum of the abdominal wall
57
What is the tunica albuginea?
Thick covering of the testes
58
What is the epidiymus?
A highly convoluted tubule which connects the testes to the ductus deferens
59
What are the borders of the anal triangle?
- coccyx posteriorly
- sacrotuberous ligaments laterally
- (imaginary) line between the two ischial tuberosities anteriorly
60
What are the main components of the anal triangle?
* Anal canal
* Anal sphincter muscles (internal and external)
* Ischioanal fossae
* Pudendal nerve
* Internal pudendal artery and vein
61
What is the anal canal?
- final part of the GIT
- role in defacation
- continuous with the inferior rectum
- 4cm long
62
What role do the levator ani muscles play in defaction?
Hold the walls of the anal canal closed until defacation occurs and the muscles relax
63
How does the anal canal open into the perineum?
Via the anal aperature
64
What is the anal canal divided into and how?
- upper and lower halves
- divided by the pectinate line of the anus
65
How is the pectinate line of the anus formed?
By the collection of anal valves which secrete mucous
66
What is the upper half of the anal canal innervated by?
- the autonomic nervous system via the hypogastric plexus
- only sensitive to stretch
67
What is the lower half of the anal canal innervated by?
- somatic nervous system via the inferior rectal nerve of the sacral plexus
- sensitive to pain, temperature, touch and pressure
68
What is the internal anal sphincter muscle?
- smooth muscle
- involuntary control by the autonomic nervous systme
69
What is the external anal sphincter muscle?
- skeletal muscle
- voluntary control by the somatic nervous system
70
What is the internal anal sphnicter formed from?
Thickening of the smooth muscle wall of the anal canal
71
What does the external anal sphincter blend with to form?
Blends with the puborectalis muscle to form the anorectal ring
72
What is the puborectalis muscle?
a strong ring of muscle which assists with maintaining faecal continence by creating the anorectal junction
73
What are the ischioanal fossae?
Two fat-filled spaces on either side of the anal canal which allow it to expand during defaction
74
Which vessels run within the ischioanal fossae?
- pudendal nerve
- internal pudendal artery and vein
75
Where does the internal pudendal artery branch from?
Internal iliac artery
76
What does the internal pudendal artery give rise to?
Inferior rectal artery
77
Label 1-6
1. Femoral nerve
2. Spermatic cord with genital branch of
genitofemoral nerve
3. Great saphenous vein
4. Superficial inguinal ring
5. Ilioinguinal nerve
6. Glans penis
78
Label 1-5
1. Deep dorsal vein of penis (unpaired)
2. Tunica albuginea of corpora cavernosa
3. Dorsal artery of penis (paired)
4. Corpus cavernosum of penis
5. Spongy (penile) urethra
79
Label 1-7
1. Bulbospongiosus muscle
2. Perineal branches of pudendal nerve
3. Inferior rectal arteries and nerves
4. Posterior scrotal nerves and superfi cial perineal
arteries
5. Deep transverse perineal muscle
6. External anal sphincter muscle
7. Gluteus maximus muscle
80
Label 1-8
1. External anal sphincter muscle
2. Anal canal
3. Bulb of penis
4. Testis (cut surface)
5. Internal urethral orifi ce and sphincter
6. Prostate gland
7. Corpus cavernosum of penis
8. Corpus spongiosum of penis
81
Label 1-7
1. Glans of clitoris
2. Frenulum of clitoris
3. Labium majus
4. Labium minus
5. Prepuce of clitoris
6. External urethral orifi ce
7. Vaginal orifice
82
Label 1-6
1. Labium minus
2. Perineal branch of pudendal nerve
3. Mons pubis
4. Greater vestibular gland
5. Superficial transverse perineal muscle
6. Inferior rectal nerves
83
Label 1-7
1. Body of clitoris
2. Prepuce of clitoris
3. Labium minus
4. Posterior labial nerve
5. Deep artery of clitoris and dorsal nerve of clitoris
6. Crus of clitoris
7. Bulbospongiosus muscle
84
Label 1-8
1. Corpus spongiosum of penis
2. Corpus cavernosum of penis
3. Ischiocavernosus muscle overlying crus of penis
4. Perineal body
5. External anal sphincter muscle
6. Gracilis muscle
7. Bulbospongiosus muscle
8. Anococcygeal ligament
85
Label 5-7
5. Testicular artery
6. Ductus deferens
7. Epididymis
86
Label 1-8
1. Urogenital triangle
2. Levator ani
3. Anal triangle
4. Coccyx
5. Sacrotuberous ligament
6. Ischial tuberosity
7. Ischiopubic ramus
8. Pubic symphisis
87
Label 1-4
1. Preprostatic urethra
2. Prostatic urethra
3. Membranous urethra
4. Spongy/penile urethra
88
Label 1-6
1. Pubic symphisis
2. Inferior pubic ligament
3. Ischial tuberosity
4. Perineal membrane
5. Obturator foramen
6. Ischiopubic ramus
89
Label 1-5
1. Suspensory ligament of clitoris
2. Superficial transverse perineal muscle
3. Perineal body
4. Bulbospongiosus muscle
5. Ischiocavernosus muscle
90
Label 1-7
1. Fundiform ligament of penis
2. Suspensory ligament of penis
3. Midline raphe
4. Superficial transverse perineal muscle
5. Perineal body
6. Bulbospongiosus muscle
7. Ischiocavernosus muscle
91
Label 1-6
1. Prepuce
2. Glans penis
3. External urethral orifice
4. Frenulum of glans
5. Neck of glans
6. Corona of glans
