12. Adrenals, Ureter and Bladder Flashcards
paired endocrine glands situated over the medial aspect of the upper poles of each kidney.
adrenal glands
shape of right adrenal gland
pyramidal in shape
shape of left adrenal gland
semi-lunar
encloses the adrenal glands and the kidneys. This fascia attaches the glands to the crura of the diaphragm.
They are separated from the kidneys by the perirenal fat.
renal fascia /perinephric fascia
The adrenal glands consist of
capsule
cortex
medulla
Veins and lymphatics leave each adrenal gland via
hilum
arteries and nerves enter the glands at numerous sites.
adrenal cortex is derived from
embyronic mesoderm
adrenal medulla is derived from
ectodermal neural crest cells
this portion of adrenal gland is yellowish in color
cortex
cortex can be divided into 3 zones
superficial -> deep
- zona glomerulosa
- zona fasciculata
- zona reticularis
produces and secretes mineralocorticoids such as aldosterone.
Zona glomerulosa
produces and secretes corticosteroids such as cortisol. It also secretes a small amount of androgens.
Zona fasciculata
produces and secretes androgens such as dehydroepiandrosterone (DHES). It also secretes a small amount of corticosteroids.
Zona reticularis
dark brown in colour
portion of the adrenal gland
medulla
medulla contains this cells
chromaffin cells
secrete catecholamines (such as adrenaline) into the bloodstream in response to stress
also secrete enkephalins which function in pain control.
chromaffin cells
adrenal glands have a rich blood supply via three main arteries
Superior adrenal artery – arises from the inferior phrenic artery
Middle adrenal artery – arises from the abdominal aorta.
Inferior adrenal artery – arises from the renal arteries.
venous drainage of the adrenal glands
Right and left adrenal veins drain the glands.
The right adrenal vein drains into the inferior vena cava, whereas the left adrenal vein drains into the left renal vein.
innervation of the adrenal gland
coeliac plexus
greater splanchnic nerves.
Sympathetic innervation to the adrenal medulla - mainly from the T10 to L1 spinal cord segments.
lymphatic drainage of adrenal glands
lumbar lymph nodes by adrenal lymphatic vessels.
These vessels originate from two lymphatic plexuses – one deep to the capsule, and the other in the medulla.
a tumour of the adrenal medulla or preganglionic sympathetic neurones. It secretes adrenaline and noradrenaline uncontrollably, causing blood pressure to greatly increase.
Patients may present with palpitations, headaches and diaphoresis (profuse sweating).
pheochromocytoma
competitive, irreversible antagonist of adrenaline, can be used in treatment to reduce blood pressure by binding to adrenaline receptors, making less available for adrenaline to act upon.
phenoxybenzamine
adrenal gland
normal weight
4 grams
75% of the cortex is the
zone fasciculata
adrenocortical insufficiency characterized by : inc. pigmentation muscular weakness weight loss hypotension
Addison disease
cortical hyperplasia due to adenoma or carcioma of the cortex
cushing syndrome
cushing syndrome
manifestations
moon shaped face
truncal obesity
abnormal hairiness/ hirsutism
hypertension
•excessive androgen production during fetal period
•in femals -> masculinization of the external genitlia - enlargement of clitoris - virilization
- fused labia majora
Congenital Adrenal Hyperplasia
bronze tone of the skin
Addison disease
are two thick tubes which act to transport urine from the kidney to the bladder.
ureters
length of ureters
25 cm
arise in the abdomen as a continuation of the renal pelvis, and terminate in the pelvic cavity – where they empty into the bladder.
ureters
anatomical course of the ureters can therefore be divided into
- abdominal
* pelvic components
a funnel like structure located within the hilum of the kidney.
renal pelvis
The point at which the renal pelvis narrows to form the ureter is known as
ureteropelvic junction.
adrenal glands
and ureters are
a. intraperitoneal
b. retroperitoneal
b. retroperitoneal
Once within the pelvic cavity, the ureters travel down the lateral pelvic walls. At the level of the this structure, they turn anteromedially, moving in a transverse plane towards the bladder.
ischial spines
Upon reaching the bladder wall, the ureters pierce its lateral aspect in an ____ manner.
oblique
Ureters have a one way valve, where high ______ collapses the ureters – preventing the back-flow of urine.
intramural pressure
Approximately 2cm superior to the ischial spine, the ureters run underneath the____
uterine artery.
The ureter is a structure that has developed via this bud
ureteric bud from the mesonephric duct
The arterial supply to the ureters can be divided into abdominal and pelvic supply:
Abdominal – renal artery, testicular/ovarian artery, and ureteral branches directly from the abdominal aorta
Pelvic – superior and inferior vesical arteries.
nervous supply to the ureters
renal, testicular/ovarian and hypogastric plexuses.
Sensory fibres from the ureters enter the spinal cord at T11-L2, with ureteric pain referred to those dermatomal areas.
the presence of a solid stone in the urinary tract, formed from minerals within the urine. These can obstruct urinary flow, causing renal colic (an acute and severe loin pain) and haematuria (blood in the urine).
ureteric calculus
three locations where the ureters are at their narrowest – this is where a stone is more likely to become stuck:
Uretopelvic junction
Pelvic brim
Where the ureter enters the bladder
The gold standard investigation for suspected ureteric calculus is
CT scan of the kidneys, ureters and bladder (CT-KUB).
severe type of colicky pain and is referred through T11 - L2 dermatomes;
pain may radiate from the back above the iliac crest, through the ingunal region and into the scrotum or labia majora
renal colic
relation of ureter to the ovarian artery
below
water under the bridge
ureter lie ___ to ovarian vessels
medial
ureter passes ___ to uterine vessels
inferiorly
in vaginal hysterectomy, ureter lies ____ to uterine cervix
lateral
at the bifurcation, common iliac arteri on each side is crossed ___ by the ureter
anteriorly
right and left common iliac arteries arise at this level
L4
external iliac artery enters the thigh under the inguinal ligament to become
femoral artery
branches of external iliac atery
inferior epigastric
deep circumflex iliac banches
this artery passes down into pelvis in front of sacroiliac join to supply pelvic organs
internal iliac artery
The bladder is an organ of the urinary system. It plays two main roles:
- Temporary storage of urine
2. Assists in the expulsion of urine
folded internal lining of the bladder is known as
rugae
capacity of the bladder
400-600 mL
external features of the bladder
- apex
- body
- fundus/ base
- neck
Apex of the bladder – located superiorly, pointing towards the pubic symphysis. It is connected to the umbilicus by the
median umbilical ligament
a remnant of the urachus
median umbilical ligament
a triangular area located within the fundus of the bladder
trigone
Urine enters the bladder through the left and right ureters, and exits via the urethra. Internally, these orifices are marked by the
trigone
trigone is developed by the integration of two _______ at the base of the bladder
mesonephric ducts
In order to contract during micturition, the bladder wall contains specialised smooth muscle – known as
detrusor muscle
two muscular sphincters located in the urethra
Internal urethral sphincter
External urethral sphincter
In Male – consists of circular smooth fibres, which are under autonomic control. It is thought to prevent seminal regurgitation during ejaculation.
Internal urethral sphincter
In Females – thought to be a functional sphincter (i.e. no sphincteric muscle present). It is formed by the anatomy of the bladder neck and proximal urethra.
Internal urethral sphincter
has the same structure in both sexes. It is skeletal muscle, and under voluntary control.
External urethral sphincter
The vasculature of the bladder is primarily derived from
internal iliac vessels
Arterial supply is via the superior vesical branch of the internal iliac artery.
In males, supplemented :inferior vesical artery
females – vaginal arteries.
In both sexes, the obturator and inferior gluteal arteries may also contribute small branches.
Venous drainage of the blader
vesical venous plexus -> internal iliac veins
The vesical plexus in males is in continuity at the retropubic space with the prostate venous plexus (plexus of Santorini), which also receives blood from the dorsal vein of the penis
lymphatics of the bladder
The superolateral aspect of the bladder -> external iliac lymph nodes.
The neck and –> internal iliac, sacral and common iliac nodes.
Neurological control is complex, with the bladder receiving input from both the
Sympathetic – hypogastric nerve (T12 – L2). It causes relaxation of the detrusor muscle, promoting urine retention.
Parasympathetic – pelvic nerve (S2-S4). Increased signals from this nerve causes contraction of the detrusor muscle, stimulating micturition.
Somatic – pudendal nerve (S2-4). It innervates the external urethral sphincter, providing voluntary control over micturition.
is a primitive spinal reflex, in which micturition is stimulated in response to stretch of the bladder wall. It is analogous to a muscle spinal reflex, such as the patella reflex.
Bladder Stretch Reflex
In this case, the afferent signals from the bladder wall are unable to reach the brain, and the patient will have no awareness of bladder filling. There is also no descending control over the external urethral sphincter, and it is constantly relaxed.
There is a functioning spinal reflex
Reflex Bladder – Spinal Cord Transection Above T12
A spinal cord transection at this level will have damaged the parasympathetic outflow to the bladder. The detrusor muscle will be paralysed, unable to contract. The spinal reflex does not function.
In this scenario, the bladder will fill uncontrollably, becoming abnormally distended until overflow incontinence occurs.
Flaccid Bladder – Spinal Cord Transection Below T12
is a medical emergency, as the bladder has a “normal” functional capacity with is pushed to the limit due to accumulation of urine in an acutely obstructed reservoir. The patient feels increasingly excruciating pain and the placement of a urinary catheter alleviates the symptoms immediately.
Acute retention
is a gradual procedure due to incomplete obstruction of the urine outflow. This leads to accumulation of residual urine in the bladder through months or even years; the bladder is therefore progressively distended in volumes that exceed 1-1.5 lt of urine.
Chronic retention
empty bladder is in this shape
pyramidal
neck of the bladder is held in position by
- males : puboprostatic ligaments
* females: pubovesical ligaments
True ligaments of the bladder
pubo-vesical
recto-vesical
false ligaments of the bladder
medial umbilical
median umbilical
Ureteric bud/metanephric diverticulum or duct
is the primordium of
ureter
renal pelvis
renal calices
collecting tubules
Metanephric tubule forms the
nephron (renal corpuscle, PCT, Loop of Henle, DCT)
gives rise to the urinary bladder
vesical part of the urogenital sinus
divisible into a dorsal rectum, and ventral urogenital sinus thru urorectal septum
cloca
UG sinus 3 parts
- cranial VESICAL -> urinary bladder
- middle PELVIC ->urethra in the bladder nek
-> prostatic and membranous parts in males
and entire part in females
plus the lower part of vagina - caudal PHALLIC
-> genital tubercle
tubular sheath of fascia enclosing the three erectile tissue in the body of penis
Buck’s fascia
vessel responsible for transporting urine from the bladder to an external opening in the perineum
urethra
urethra is lined by
stratified columnar epithelium
•protected from the corrosive urine by mucus secreting glands.
male urethra approximate length
15-20 cm
a fluid containing spermatozoa and sex gland secretions.
semen
male urethra can be divided into 3 parts
- Prostatic urethra
- Membranous urethra
- Penile (bulbous) urethra
Begins as a continuation of the bladder neck and passes through the prostate gland.
Prostatic urethra
Receives the ejaculatory ducts (containing spermatozoa from the testes and seminal fluid from the seminal vesicle glands) and the prostatic ducts (containing alkaline fluid).
Prostatic urethra
It is the narrowest and least dilatable portion of the urethra.
Membranous urethra
It is the widest and most dilatable portion of the urethra.
Prostatic urethra
Passes through the pelvic floor and the deep perineal pouch.
Surrounded by the external urethral sphincter – which provides voluntary control of micturition.
Membranous urethra
Passes through the bulb and corpus spongiosum of the penis, ending at the external urethral orifice (the meatus).
Penile (bulbous) urethra
Receives the bulbourethral glands proximally.
Penile (bulbous) urethra
In the glans (head) of the penis, this dilates to form the navicular fossa
urethra
considered by some authors as a fourth anatomic part of the urethra.
part of the urethra that passes through the bladder neck
The arterial supply to the male urethra is via several arteries
Prostatic urethra – supplied by the inferior vesical artery (branch of the internal iliac artery which also supplies the lower part of the bladder).
Membranous urethra – supplied by the bulbourethral artery (branch of the internal pudendal artery)
Penile urethra – supplied directly by branches of the internal pudendal artery.
nerve supply to the male urethra is derived from the
prostatic plexus- contains a mixture of sympathetic, parasympathetic and visceral afferent fibres.
lymph drainage of the male urethra
- prostatic and membranous portions drain to the obturator and internal iliac nodes
- penile urethra drains to the deep and superficial inguinal nodes.
is the process of inserting a tube through the urethra and into the bladder.
urinary catherisation
this angle can be diminished by holding the penis upwards during urinary catheterisation.
prepubic angle
three constrictions in the male urethra
the internal urethral sphincter, external urethral sphincter, and external urethral orifice.
female urethra
length
4 cm
female urethra opens directly onto the
perineum
The distal end of the female urethra is marked by the presence of two mucous glands that lie either side of the urethra
skene’s glands
arterial supply to the female urethra is via the
internal pudendal arteries, vaginal arteries and inferior vesical branches of the vaginal arteries.
nerve supply to the female urethra arises from the
vesical plexus and the pudendal nerve
Lymphatic drainage of the female urethra
proximal female urethra is to the internal iliac nodes
distal urethra drains to the superficial inguinal lymph nodes
homologous to the prostate glands in males
skene’s glands / lesser vestibular glands
secrete a substance to lubricate the urethra opening
skene’s glands / lesser vestibular glands
are two pea sized compound alveolar glands located slightly posterior and to the left and right of the opening of the vagina. They secrete mucus to lubricate the vagina and are homologous to bulbourethral glands in males.
Bartholin’s glands (also called Bartholin glands or greater vestibular glands)
