Pelvis

Overview of Pelvic Anatomy

Internal Iliac Artery

• The internal iliac artery is responsible for supplying blood to the pelvic region's organs, including the urinary and digestive systems.

• It branches into multiple arteries, particularly the internal pudendal artery, which has various avenues of distribution.

Arterial Branches of Internal Iliac

• Internal Pudendal Artery:

  • Supplies blood to perineal structures.

  • Gives off branches such as:

  • Vaginal or prostatic artery (depending on sex).

• Main Uterine Artery:

  • Arises from the internal iliac artery and provides blood supply to the uterus and vagina.

  • It runs deep to the peritoneum, reaching upwards towards the broad ligament of the uterus.

  • Supplies blood to:

  • Cranial part of the vagina.

  • Uterine horns inside the mesosphere (broad ligament).

• Ureterine Artery:

  • Blood supply to the ureter.

• Middle Rectal Artery:

  • Supplies blood to the middle part of the rectum and has cranial and caudal branches.

  • Cranial Directed Branch:

  • Extends along the middle and descending colon.

  • Causally Directed Branch:

  • Runs towards the caudal rectal region.

Differences in Male and Female Blood Supply

• In males:

  • The ductus deferens artery is replaced by the prostatic artery.

• In females:

  • Blood supply includes structures such as the vaginal and uterine arteries.

Notable Arteries in Pelvic Region

• Ventral Perineal Artery:

  • Terminates into clitoral or penile arteries, supplying the respective genitalia.

• Colorectal Artery:

  • Supplies blood to colorectal structures and can vary anatomically among species.

Practical Considerations for Surgical Procedures

• Caution is advised during pelvic surgeries to avoid damaging nerves and blood vessels while manipulating the peritoneum and other structures.

• The process often involves careful dissection around the pelvis, guided by an experienced surgeon.

Anatomical Structures Associated with the Pelvic Cavity

Sensory Innervations and Muscles

• Sensory innervations to various regions, such as:

  • Mammary glands.

  • Scrotum.

  • Medial side of the thigh.

• Discussed muscles include:

  • Deep abdominal oblique's role in muscular attachments and extensions.

Inguinal Canal vs. Anal Canal

• Distinction in passageways within the pelvic cavity where various structures travel:

  • The inguinal canal serves as a minimal space.

  • The anal canal is described in functional context regarding contents passing through.

Stomach Anatomy and Related Lymph Nodes

Key Stomach Regions

• Regions of the Stomach:

  • Antrum

  • Pylorus

  • Body

  • Cardiac region (difficult to identify)

  • Angular notch

• Detailing connections:

  • Transitions and bends connecting to the duodenum and jejunum.

Lymphatic Structures

• Lymph nodes in the mesentery:

  • Mesenteric lymph nodes associated with specific bowel segments, such as the jejunum.

• Major Mesenteric Lymph Node Location:

  • Related to descending colon area where mesenteric arteries converge.

Hepatic and Biliary Structures

• Cystic Duct:

  • Extends towards the cranial part of the descending duodenum and receives hepatic ducts.

• Bile Production and Flow:

  • Bile is secreted from the liver into hepatic ducts, combined into the cystic duct, and then into the common bile duct.

• Pancreatic Duct Variations:

  • Not all species have an accessory pancreatic duct, emphasizing anatomical variances.

Peritoneal Structures

Peritoneum Description

• Divided into:

  • Parietal Peritoneum:

  • Extends down and reflects off organ surfaces within the pelvic cavity.

• Various Pouches:

  • Consideration of anatomical receses from ventral to dorsal:

  • Ventral vesicle pouch associated with the bladder.

  • Middle pouch related to urinary pathways.

Practical Application for Procedures

• Understanding anatomical significance aids in surgical planning, particularly on how to navigate and approach organs while minimizing risk to blood vessels and nerves.