WEEK 3 LECTURE FINISHED Flashcards
What are the 2 parts of the autonomic nervous system?
SNS
PNS
Hypogastric plexi: How many are there and what are their names?
3
1 x Superior hypogastric plexus
2 x inferior hypogastric plexi
Superior hypogastric plexus:
What type of nerves?
Location?
What spinal nerves make it?
Just SNS
Just below bifurcation of abdominal aorta, just below L4
Sympathetic nerves T10-L2
Hypogastric nerves - 2 of these come off the plexus and descend down to join with inferior hypogastric plexi
Inferior hypogastric plexi:
Location?
Formed by?
Both SNS and PNS
Paired
Male - beside the rectum
Female - beside rectum and vagina
Former by:
- Hypogastric nerves from SHP
- Nerves from sacral ganglia (S3-S4) (Sympathetic)
- Pelvis splanchnic nerves (S2-S4 (Parasympathetic)
Ureters: What do they do? Length? Location? What do they look like?
- They convey urine form the kidneys to the bladder
- 1200ml - average amount of urine per day
- 25cm long
- Upper half is in the abdomen and half in the pelvis (changes where the common iliac artery divides)
- Long thin tubes with a thick muscular wall (Transitional epithelium in the walls)
Are the ureters retroperitoneal?
Yes
Where does the ureters travel in relation to psoas? What about in relation to the genitofemoral nerve?
Along the anterior part of psoas.
They cross in front of the genitofemoral nerve
What vessels cross the ureters?
Gonadal
What is the pathway of the ureters?
They pass down on psoas under the cover of the peritoneum
They cross in front of the genitofemoral nerve (L1,2 skin genital region, thigh)
They are crossed by the gonadal vessels.
They leave the psoas muscle at the level of the bifurcation of the common iliac artery and pass over the S/I joint to enter the pelvis
The terminal parts pierce the posterior lateral angle of the bladder
In males just before they enter the bladder they are crossed by the vas deferens.
How many parts does the ureter have in terms of arterial supply? What are these parts called and what arteries supply each of these parts?
3
Upper Part - ureteric branch of renal artery
Middle part - AA, gonadal, common iliac, internal iliac
Lower part - branches from sup and inf vesicle arteries and uterine arteries.
Lymphatic drainage of ureters:
Abdominal portion - para aortic lymph nodes
Pelvic portion - common iliac and internal iliac lymph nodes
What is the nerve supply of the ureter:
Sympathetics: T10-L1
Parasympathetic - pelvic splanchnic
What is the structure of the ureters? What is it lined with and what are the layers of muscle?
Smooth muscle lines by mucous membrane
Inner and outer longitudinal later of muscle
Middle circular layer
Lined with transitional epithelium - (4-5 layers) 2 layers of cuboidal, 1 layer of polygonal, 2 layers of squamous which are large, more circular that stratified squamous and can be bi-nucleated.
The Bladder:
Describe
Location full and empty
A hollow organ with strong muscular walls.
When empty it is entirely within the pelvic
When it is full it can distend and dome up into the abdomen, even to the level of the umbilicus
What is the shape when empty
Tetrahedral
What are the surfaces and angles of the bladder
Inferior/posterior surface = base (1) Inferior/lateral surfaces (2) superior surface (1)
Where does the urethra come out of the bladder
Where the base and the inferior/lateral surfaces meet
Which direction of the apex point and where does it point?
Anteriorly to the top of the pubic symphysis
What separates the apex and the pubic bone?
Retropubic space
What forms the fundus of the bladder?
The posterior aspect
Where is the neck of the bladder formed:
Where the fundus/ base and inferiolateral surfaces meet.
What is the bladder neck pierced and what is it pierced by?
It is pierced by the urethra at the internal urethral orifice
What is the trigone?
What shape?
The region at the base of the bladder lying between the 2 ureteral orifices and the internal urethral orifice.
Triangular
What does uvula mean?
Grape
What is the uvula of the bladder?
A projection of the trigone. Made of the smooth muscle fibres that form the bladder converge, mostly seen in males. More common in older men because
What parts of the bladder are covered with peritoneum?
The superior surface and 1cm of the base
What surrounds the whole organ?
Vesicle fascia
What does vesicle mean?
Bladder
Where does the vesicle plexus lie? What is it?
Lies within the vesicle fascia on the side of the bladder
It is a dense plexus of veins
What lies on the superior surface of the bladder?
Portions of the sigmoid colon and ileum
In males, where does the prostate lie?
Under the bladder
In males, what separates the base/inferior surface of the bladder from the rectum?
By seminal vesicles and vas deferens
Where is the rectovesicle pouch?
Who is it found in?
Separates the upper 1cm of the bladder from the rectum
Only found in males
What is the uterovesicle pouch?
Separates the uterus from the bladder in females.
Can the bladder move? Which parts can’t move and why?
Relatively free to move except for its neck, where it is firmly attached by the puboprostatic ligaments in males and the pubovesical ligaments in females
What are the names of the ligaments that hold the neck of the bladder in place?
Males - puboprostatic ligaments
Females - pubovesical ligaments
Where does the bladder sit in terms of the peritoneum?
Below - subperitoneal
What is the detruser muscle?
Involuntary internal sphincter
What does the internal uretheral sphincter also stop?
Ejactulatory reflux
What is the arterial supply of the bladder?
Braches of the internal iliac arteries
Superior vesicle artery
xxxx
Lymphatic drainage of the bladder
Superior surface of the bladder to the external iliac lymph nodes
Innervation of the bladder
Parasympathetics from the pelvic splanchnic nerves (S2,3,4)
• They are motor to the detruser mm and inhibitory to the internal sphincter
• When the visceral afferents are stimulated by stretching of the bladder, the bladder contracts reflexly, the internal sphincter relaxes and urine flows into the urethra
• With toilet training we learn to suppress this reflex when we do not wish to void
Sympathetics (T11 - L2)
• The parasympathetic nerves and the sympathetic
nerves form the vesicle plexus
• This is continuous with the hypogastric plexus
What is the structure of the bladder?
• Similar structure to the ureters
• Three layers of smooth muscle
- inner and outer layers of longitudinally arranged mm fibres
- middle layer of circular arranged mm fibres
• As in the ureters, these layers may be difficult to identify
• Lined with transitional epithelium
• This is thrown into numerous folds in the relaxed state (rugae)
Urethra in males:
- Is much longer than the female urethra
- Approx. 20 cm long
- Extends from the bladder neck to the tip of the penis (urethral orifice, the narrowest part of the urethra)
- Passes through the prostate and the entire corpus spongiosum
What are the 4 parts of the male urethra?
Preprostatic ? part
Prostatic ( 2 - 4 cm )
Intermediate (membranous) (1 - 2 cm long)
Spongy (penile) (15 cm long)
Describe the prostatic urethra
Runs closer to the anterior surface compared to the posterior surface of this gland.
Receives the openings of the ejaculatory ducts (the union of the vas deferens and ducts of the seminal vesicles bilaterally)
Describe the intermediate/ membranous urethra
Shortest section
Begins at the apex of the prostate, ends at the bulb of the penis where it is continuous with the spongy urethra.
It is surrounded by the external urethral sphincter and perineal membrane
Posterior laterally are the bulbourethral glands and their ducts which open into the beginning of the spongy urethra open.
Describe the spongy urethra
Longest section
Passes through the bulb and the corpus spongiosum of the penis
Starts at the end of the intermediate part of the urethra and ends at the end of the external urethral orifice (the narrowest part of the urethra)
Below the perineal membrane the urethra is dilated within the substance of the corpus spongiosum to form the bulbous urethra
It is here where the bulbourethral ducts open into the promixal region of the spongy urethra
There are many mucous secreting urethral glands along the length of the spongy urethra
Just proximal to the external urethral meatus at the tip of the glans is a short dilated region called the navicular (boat shaped) fossa
Describe the external urethral sphincter?
- The external sphincter is composed of striated muscle and is under voluntary control. Mainly slow twitch muscle fibres.
- Innervated by the perineal branch of the pudendal nerve
- Maintains constant muscular tone and only relaxes during micturition
- It is roughly pear shaped
- Lies between the levator ani mm and perineal membrane
- It surrounds the intermediate / membranous urethra
- Found around the mid portion of the urethra where it passes through the striated muscle of the pelvic floor.
The urethra is narrowest at the external meatus and shows dilations in the prostate, bulb and navicular fossa
What is the arterial supply of the urethra in men?
- Branches from the internal pudendal arteries (branch of the anterior division of the internal iliac artery)
- The blood supply comes from the adjacent vessels as it passes through the prostate, urethral sphincter and corpus spongiosum
What is the lymph and venous supply to the urethra?
- Internal pudendal veins
- Internal iliac lymph nodes (intermediate)
- Deep inguinal lymph nodes (spongy)
- External iliac lymph nodes
What is the innervation of the urethra?
- Pudendal nerve (S2-4) somatic nerve
* Autonomic nerve supply from the inferior hypogastric plexus
What is the structure of the tissue in the male urethra?
- Most of the male urethra is lined by transitional epithelium (this is typical of the urinary tract)
- In the membranous and spongy urethra it may change to unspecialised, pseudostratified columnar epithelium
- An exception is the navicular fossa where the epithelium is stratified squamous epithelium
- This is continuous with the stratified squamous epithelium of the glans penis
- In the urethral mucosa are numerous mucous secreting glands.
- This produces a protective mucous layer.
- The urethral smooth muscle is a continuation of the involuntary smooth muscle of the bladder
The female urethra
Length
Position
Direction
• Is relatively short approx. 4 cm long
• A straight muscular walled tube which passes downward and a little forward
(anterior / inferior direction )
• Extends from the bladder neck to the external urethral orifice (an A-P slit)
What is the arterial supply of the female urethra?
• Upper part
- Vaginal arteries
• Lower part
- Internal pudendal arteries
What is the nerve supply to the female urethra?
Nerve supply
• Branches from the inferior hypogastric plexus
• Perineal branch of the pudendal nerve
What is the structure of the female urethra?
- Lined by non-keratinized stratified squamous epithelium
- There are a few mucous glands in the wall of the urethra
- The largest of these is the paraurethral glands which open by a single duct on each side just inside the external meatus or orifice
- The female urethral smooth muscle is orientated mainly in a longitudinal direction
- It is a continuation of the involuntary smooth muscle of the bladder
- When it contracts during micturition it shortens and widens the urethral lumen
- Outside the smooth muscle is the striated circular muscle of the external urethral sphincter
- This is thickest near the middle of the urethra
- Where it passes through the striated muscle of the pelvic floor
- It is thicker in front then at the sides
- It is supplied by the pudendal nerve
