🥇 Anatomía de LOS URÉTERES. ¡Fácil Explicación!

Anatomy of the Ureters

Introduction to Ureters

• The video introduces the anatomy of the ureters, paired organs that transport urine from the renal pelvis to the bladder.

• It connects previous discussions on kidney irrigation and sets up for a future video on bladder anatomy.

Function and Structure

• Ureters are muscular, cylindrical tubes responsible for transporting urine; they connect the renal pelvis to the bladder.

• Both kidneys and ureters are retroperitoneal organs, meaning they lack visceral peritoneum and are confined within the retroperitoneal space.

Anatomical Characteristics

• The ureter measures approximately 25 to 30 centimeters in length with a diameter of 5 to 6 millimeters.

• There is no definitive anatomical point marking where the renal pelvis ends and where the ureter begins; however, it is generally considered to start around L3 vertebra.

Muscular Composition and Functionality

• Ureter walls consist of smooth muscle that facilitates peristalsis, allowing urine transport from kidneys to bladder for storage before excretion.

Retroperitoneal Context

• The parietal peritoneum covers only part of their anterior aspect while they remain in contact with retroperitoneal fat.

• Ureters do not come into contact with the abdominal cavity due to their retroperitoneal positioning.

Classification of Ureters

Divisions of Ureter Anatomy

• Some authors classify ureters into three thirds; however, urology uses a more precise four-part classification: lumbar, iliac, pelvic, and bladder portions.

Lumbar Portion

• The lumbar portion extends from the pelvicalyceal junction (renal pelvis area) until crossing over iliac vessels. It measures about 9 to 11 centimeters long.

Relationships with Surrounding Structures

• This portion has significant relationships with surrounding structures such as psoas major muscle and associated nerves.

Anatomy of the Ureters and Their Relationships

Medial Relations of the Ureters

• The genitofemoral nerve is a branch of the lumbar plexus, with specific medial relationships depending on whether discussing the right or left ureter. The inferior vena cava is approximately 2 cm from the right ureter.

• For the left ureter, it is located about 2 to 2.5 cm medially from the abdominal aorta. Additionally, both ureters are associated with the abdominal sympathetic trunk and nearby lymph nodes.

Lateral Relations of the Ureters

• The right ureter has lateral relations with the ascending colon, while the left ureter relates laterally to the descending colon. This anatomical positioning varies significantly between sides due to abdominal asymmetry.

Anterior Relationships

• In terms of anterior relationships, for the right ureter, it is positioned anteriorly to the second portion of the duodenum (prerenal portion). It also crosses paths with gonadal vessels (gonadal artery and vein). If female, these would be termed ovarian vessels; if male, they are spermatic or testicular vessels.

• The left ureter shares similar crossings with gonadal arteries but also interacts with branches from the inferior mesenteric artery such as sigmoid and left colic arteries.

Iliac Portion Characteristics

• The iliac portion of each ureter crosses over iliac vessels and typically does not exceed four centimeters in length. There are variations in literature regarding which iliac vessel (common or external) it crosses first; however, most sources agree on crossing primitive iliac vessels.

Anatomy of the Ureter and Its Relationships in Women

Overview of Ureter Anatomy

• The ureter's anatomy is crucial, particularly its relationship with the vas deferens in men and its more complex structure in women.

• In females, the ureter crosses the iliac region and relates to various pelvic structures, including the ovary.

Ligamentous Relationships

• The ureter interacts closely with several ligaments:

• It passes through the uterine sacral ligament and broad ligament before reaching the bladder.

• The transverse cervical ligament supports both ureters as they approach the bladder.

Clinical Significance

• Understanding these relationships is vital during surgical procedures like hysterectomies, where ligation of uterine arteries can inadvertently damage nearby ureters due to their proximity.

Bladder Interaction

• Both male and female ureters penetrate the bladder at a similar location, approximately 5 cm apart, entering obliquely from behind. This anatomical detail is essential for understanding urinary function.

• The detrusor muscle of the bladder plays a significant role in urine storage and expulsion; it measures about 2 cm thick at rest.

Vascular Supply and Drainage

• The upper portion of each ureter receives blood supply from branches off renal arteries, while gonadal arteries may also contribute occasionally.

• Venous drainage varies: upper portions drain into gonadal veins while lower sections empty into iliac veins leading to inferior vena cava. This vascular knowledge is critical for surgical planning and understanding potential complications.