1.2 Gross Anatomy & Imaging Of The Urinary System Flashcards
Urinary continence is maintained by ?
Urethral sphincters
What’s difference between which muscle and location of internal and external sphincter ?
Internal sphincter = smooth muscle at the urinary bladder neck
External sphincter = striated muscle , dismally at lvl of pelvic diaphragm
What is external sphincter acquired under ?
Voluntary control
What kind of organs are kidneys where are they situated ?
Paired retroperitoneal organs
Posterior part of the abdomen on each side of the vertebral column
urinary system is comprised of what ?
- kidneys
- ureters
- urinary bladder
- urethra
What is the urinary system contained within ?
the abdominopelvic cavity
shape of kidney organs ?
bean-shaped
Where do the kidneys lie ?
on the posterior abdominal wall
Why is right kidney normally found slightly lower than the left kidney ?
the liver is a large organ where its size and position push the R kidney downwards
posterior relations of kidney - muscular relations ?
- psoas
- quadratus lumborum
- transversus abdominis
- What is the perinephric fat also known as ?
- what is perinephric fat ?
- where can it be found relative to the kidney?
- perirenal fat
- accumulation of extraperitoneal fat that provides cushioning and protection for the kidney
- completely surrounds the kidney outside the renal capsule
What is the renal fascia and what role does it play in the anatomy of the kidney?
- a layer of connective tissue that surrounds the perinephric fat
- helps to anchor the kidney and the surrounding fat to the posterior abdominal wall
- providing structural support and stability
What is the anatomical significance of the renal fascia in relation to the kidneys?
it encases the perinephric fat and helps secure the kidneys in place by attaching them to the surrounding structures
What are the ureters ?
Thin, retroperitoneal, muscular tubes transport urine from kidneys to bladder
length and diameter of ureters ?
length = 25 - 30cm
diameter = 3-4 mm
Ureters are continous superiorly with what ?
renal pelvis
renal pelvis :
1. formed by ?
2. when does it become the ureter ?
- condensation of several minor calices
- at ureteropelvic junction
ureters descends on medial aspect of what ?
psoas major
ureters at pelvic brim cross …1…. arteries into …2… to bladder
- common/external iliac arteries
- pelvis
what are the 3 points of constriction ?
- utereopelvic junction
- pelvic inlet
- entrance into bladder
From where do the renal arteries branch off, and where are they located relative to the superior mesenteric artery (SMA)?
The renal arteries branch off laterally from the abdominal aorta and arise inferiorly to the superior mesenteric artery (SMA)
Describe the path and contributions of the renal veins to the inferior vena cava (IVC)
they receive multiple contributions from smaller veins within the kidneys. They pass anterior to the renal arteries and drain directly into the inferior vena cava
What anatomical feature makes the left renal vein longer than the right renal vein?
it has to travel across the midline of the body to reach the inferior vena cava (IVC), passing under the superior mesenteric artery (SMA)
Why is the fact that the left renal vein passes under the superior mesenteric artery (SMA) clinically significant?
it can be compressed between the SMA and the aorta, leading to a condition known as Nutcracker syndrome
causing symptoms such as : hematuria , left flank pain , varicocele in males due to impaired venous drainage
What is Nutcracker syndrome caused by ?
compression / entrapment of the left renal vein between the superior mesenteric artery and the abdominal aorta
The paired renal arteries take about …1…% of the cardiac output to supply organs that represent less than …2… th body weight
- 25
- 1/100
- main blood vessels that enter kidney and branch from where ?
- main blood vessels that exit kidney and drain into what ?
- renal arteries, which branch off from the aorta
- renal veins, which drain into the inferior vena cava (IVC).
Outline the pathway of arterial blood flow from the aorta to the glomerulus within the kidney.
Aorta
Renal artery
Segmental artery
Interlobar artery
Arcuate artery
Cortical radiate artery
Afferent arteriole
Glomerulus (capillaries)
Outline the pathway of venous blood flow from the peritubular capillaries or vasa recta to the inferior vena cava.
Peritubular capillaries or vasa recta
Cortical radiate vein
Arcuate vein
Interlobar vein
Renal vein
Inferior vena cava (IVC)
What is the significance of the segmental arteries in the kidney?
they are the first branches off the renal artery and provide blood to different segments of the kidney
Proper functionig of the segmental arteris in the kidney ensures what ?
that the entire kidney receives an adequate blood supply for filtration and urine production
which organ is the subperitoneal reservoir for urine ?
urinary bladder
urinary bladder is capable of holding up to approximately how many ml of urine ?
500
In what ways can the size, shape and wall thickness of the urinary bladder vary ?
It can vary greatly depending on the volume of urine it contains.
- when bladder empty
- when fills with urine
- it is smaller and has thicker walls.
- it expands, becoming larger and its walls thinner.
Describe the position of the urinary bladder when it is :
1. empty
2. full
- anteriorly in the lesser pelvis
- extends into the abdominal cavity , rising above the pelvic brim
Which anatomical structures cross over the ureter in males ?
ductus deferens (vas deferens) crosses over ureter posterior to urinary bladder
Why is it clinically significant that the ductus deferens crosses over the ureter in males and the uterine artery crosses over the ureter in females ?
anatomical relationships are clinically significant because they must be considered during surgical procedures in these areas to avoid damaging the ureter
in males - e.g. vasectomy
in females e.g. hysterectomy
Which anatomical structures cross over the ureter in females ?
uterine artery crosses over the ureter lateral to the cervix of the uterus
When is the urinary bladder only palpable ?
when adequately filled
Compare lengths of males and females urethra
Males is longer approx 18-20cm whilst females is approx 4cm (therefore an increased UTI risk )
In males what are the 2 major glands in the male pelvis associated with reproduction ?
prostate
seminal vesicles
female pelvis relationship to ..1… and …2..
- uterus
- rectum
Male pelvic cavity contains connection between what tracts ?
urinary & reproductive
What are the various zones of the prostate ?
- anterior fibromuscular
- preprostatic sphincter
- transitional
- central
- peripheral
Which zone of the prostate is most commonly associated with benign prostatic hyperplasia (BPH)?
Transitional Zone
Why is the Peripheral Zone significant in prostate health?
it is the most common site for prostate cancer development
Where is the Central Zone located, and what is its clinical significance?
located surrounding ejaculatory ducts
less comonly invovled in prostate cancer compared to the peripheral zone but can be involved in certain types of prostatitis and other conditions
What is the (1)location, (2) primarily composed of and (3) function of the Anterior Fibromuscular Zone?
- front of the prostate
- fibrous and muscular tissue
- structural support that has lesser role in glandular function
What is function of the preprostatic sphincter ?
Helps control the flow of urine from the bladder through the urethra, involved in urinary continence
How does the transitional zone change with age, and what symptoms might result ?
- enlarges due to benign prostatic hyperplasia (BPH)
- urinary symptoms e.g. difficulty starting urination , weak urine stream, frequent urination, incomplete bladder emptying
What is the prostatic venous plexus ?
a network of small veins that surrounds and drains the prostate gland of the male pelvis
what is the significance of the prostatic venous plexus ?
It surrounds the lateral and anterior parts of the prostate - it drains blood from the prostate into the internal iliac veins
it also has connections with the vertebral venous plexus, which can facilitate the spread of the prostate cancer to the spine
How does the prostatic venous plexus communicate with other venous systems?
internal iliac veins, inferior vesical veins, and the deep dorsal vein of the penis.
It also connects with the vertebral venous plexus through valveless veins,
Why are the veins of Batson (vertebral venous plexus) significant in the context of prostate cancer?
they lack valves, allowing for bidirectional blood flow which can facilitate the spread of prostate cancer cells to the spine and other parts of the skeleton
What role does the inferior vesical vein play in the venous drainage of the prostate?
drains blood from the bladder and the prostate, directing it into the internal iliac vein
it’s part of the venous drainage network that helps remove deoxygenated blood from the pelvic organs
Describe the pathway of venous blood from the prostate to the heart.
- venous blood from the prostate drains into the prostatic venoous plexus
- into inferior vesical veins and the internal iliac veins
- flows into the common iliac veins
- which merge to form the inferior vena cava
- blood travels through IVC to the RA of heart
What anatomical structures are involved in the venous drainage of the prostate ?
- prostatic venous plexus
- inferior vesical veins
- internal iliac veins
- common iliac veins
- external iliac veins
- vertebral venous plexus
