The abdominal cavity has a complex and intricate anatomy. A physician must know in which area of the abdomen every major structure is located to understand the clinical presentation Presentation The position or orientation of the fetus at near term or during obstetric labor, determined by its relation to the spine of the mother and the birth canal. The normal position is a vertical, cephalic presentation with the fetal vertex flexed on the neck. Normal and Abnormal Labor of abdominal pathologies and/or in trauma situations to estimate which organs are most likely injured. The general surgeon, especially in emergency situations, uses this knowledge to execute the most advantageous surgical approach for a particular situation.
Last updated: 19 Jul, 2021
Superior:
Inferior:
Lateral:
Superficial anatomical landmarks of the abdomen
Image by Lecturio. License: CC BY-NC-SA 4.0The following divide the abdomen into its 9 regions:
Regions of the abdomen
Image by Lecturio. License: CC BY-NC-SA 4.0Abdominal quadrant regions:
There are (a) 9 abdominal regions and (b) 4 abdominal quadrants in the
peritoneal cavity
Peritoneal Cavity
The space enclosed by the peritoneum. It is divided into two portions, the greater sac and the lesser sac or omental bursa, which lies behind the stomach. The two sacs are connected by the foramen of winslow, or epiploic foramen.
Peritoneum: Anatomy.
Dermatomes Dermatomes Spinal Cord: Anatomy of the thorax, abdomen, and pelvis Pelvis The pelvis consists of the bony pelvic girdle, the muscular and ligamentous pelvic floor, and the pelvic cavity, which contains viscera, vessels, and multiple nerves and muscles. The pelvic girdle, composed of 2 “hip” bones and the sacrum, is a ring-like bony structure of the axial skeleton that links the vertebral column with the lower extremities. Pelvis: Anatomy
Image by Lecturio. License: CC BY-NC-SA 4.0Layers of abdominal wall
Image: “Gray399” by Henry Gray. License: Public Domain, edited by Lecturio.Ventral herniorrhaphy: surgical repair of hernias of abdominal wall
The surgically relevant structures of the right hypochondrium Hypochondrium Anterior Abdominal Wall: Anatomy include the liver Liver The liver is the largest gland in the human body. The liver is found in the superior right quadrant of the abdomen and weighs approximately 1.5 kilograms. Its main functions are detoxification, metabolism, nutrient storage (e.g., iron and vitamins), synthesis of coagulation factors, formation of bile, filtration, and storage of blood. Liver: Anatomy and the biliary tree Biliary tree The bile ducts and the gallbladder. Gallbladder and Biliary Tract: Anatomy.
Location:
Location of the liver Liver The liver is the largest gland in the human body. The liver is found in the superior right quadrant of the abdomen and weighs approximately 1.5 kilograms. Its main functions are detoxification, metabolism, nutrient storage (e.g., iron and vitamins), synthesis of coagulation factors, formation of bile, filtration, and storage of blood. Liver: Anatomy in the right hypochondrium Hypochondrium Anterior Abdominal Wall: Anatomy and epigastrium
Image by Lecturio. License: CC BY-NC-SA 4.0Limits:
Surfaces:
Anterior view of the diaphragmatic surface of the liver, featuring the falciform, triangular, round, and coronary ligaments:
Note that the round ligament extends from the free edge of the falciform ligament.
Image by Lecturio. License: CC BY-NC-SA 4.0Inferior view of the visceral surface of the liver:
Note the uneven structure that results from impressions of the neighboring organs. The colic impression is caused by the colon’s hepatic flexure. The descending portion of the duodenum forms the duodenal impression.
Image by Lecturio. License: CC BY-NC-SA 4.0Anterior view of the liver:
Gallbladder Gallbladder The gallbladder is a pear-shaped sac, located directly beneath the liver, that sits on top of the superior part of the duodenum. The primary functions of the gallbladder include concentrating and storing up to 50 mL of bile. Gallbladder and Biliary Tract: Anatomy:
Biliary tree Biliary tree The bile ducts and the gallbladder. Gallbladder and Biliary Tract: Anatomy:
Anatomy of the gallbladder Gallbladder The gallbladder is a pear-shaped sac, located directly beneath the liver, that sits on top of the superior part of the duodenum. The primary functions of the gallbladder include concentrating and storing up to 50 mL of bile. Gallbladder and Biliary Tract: Anatomy and the biliary tree Biliary tree The bile ducts and the gallbladder. Gallbladder and Biliary Tract: Anatomy
Image by Lecturio. License: CC BY-NC-SA 4.0Incisions for open (left) and laparoscopic (right) cholecystectomy Cholecystectomy Cholecystectomy is a surgical procedure performed with the goal of resecting and extracting the gallbladder. It is one of the most common abdominal surgeries performed in the Western world. Cholecystectomy is performed for symptomatic cholelithiasis, cholecystitis, gallbladder polyps > 0.5 cm, porcelain gallbladder, choledocholithiasis and gallstone pancreatitis, and rarely, for gallbladder cancer. Cholecystectomy
Image by Lecturio. License: CC BY-NC-SA 4.0The epigastrium contains the transverse colon Transverse colon The segment of large intestine between ascending colon and descending colon. It passes from the right colic flexure across the abdomen, then turns sharply at the left colonic flexure into the descending colon. Colon, Cecum, and Appendix: Anatomy, the duodenum Duodenum The shortest and widest portion of the small intestine adjacent to the pylorus of the stomach. It is named for having the length equal to about the width of 12 fingers. Small Intestine: Anatomy, and the pancreas Pancreas The pancreas lies mostly posterior to the stomach and extends across the posterior abdominal wall from the duodenum on the right to the spleen on the left. This organ has both exocrine and endocrine tissue. Pancreas: Anatomy.
Colon Colon The large intestines constitute the last portion of the digestive system. The large intestine consists of the cecum, appendix, colon (with ascending, transverse, descending, and sigmoid segments), rectum, and anal canal. The primary function of the colon is to remove water and compact the stool prior to expulsion from the body via the rectum and anal canal. Colon, Cecum, and Appendix: Anatomy in situ, covered by the greater omentum Omentum Peritoneum: Anatomy
Image by BioDigital, edited by LecturioDuodenum Duodenum The shortest and widest portion of the small intestine adjacent to the pylorus of the stomach. It is named for having the length equal to about the width of 12 fingers. Small Intestine: Anatomy and its relation with the pancreas Pancreas The pancreas lies mostly posterior to the stomach and extends across the posterior abdominal wall from the duodenum on the right to the spleen on the left. This organ has both exocrine and endocrine tissue. Pancreas: Anatomy and biliary ducts
Image by Lecturio. License: CC BY-NC-SA 4.0Segments:
Ducts:
Different parts of the pancreas Pancreas The pancreas lies mostly posterior to the stomach and extends across the posterior abdominal wall from the duodenum on the right to the spleen on the left. This organ has both exocrine and endocrine tissue. Pancreas: Anatomy and its surroundings
Image: “The pancreas Pancreas The pancreas lies mostly posterior to the stomach and extends across the posterior abdominal wall from the duodenum on the right to the spleen on the left. This organ has both exocrine and endocrine tissue. Pancreas: Anatomy” by OpenStax College. License: CC BY 3.0The most important structures of the left hypochondrium Hypochondrium Anterior Abdominal Wall: Anatomy are the spleen Spleen The spleen is the largest lymphoid organ in the body, located in the LUQ of the abdomen, superior to the left kidney and posterior to the stomach at the level of the 9th-11th ribs just below the diaphragm. The spleen is highly vascular and acts as an important blood filter, cleansing the blood of pathogens and damaged erythrocytes. Spleen: Anatomy and the stomach Stomach The stomach is a muscular sac in the upper left portion of the abdomen that plays a critical role in digestion. The stomach develops from the foregut and connects the esophagus with the duodenum. Structurally, the stomach is C-shaped and forms a greater and lesser curvature and is divided grossly into regions: the cardia, fundus, body, and pylorus. Stomach: Anatomy.
Location:
Relations:
Ligaments:
Blood supply: splenic artery and vein
Spleen
Spleen
The spleen is the largest lymphoid organ in the body, located in the LUQ of the abdomen, superior to the left kidney and posterior to the stomach at the level of the 9th-11th ribs just below the diaphragm. The spleen is highly vascular and acts as an important blood filter, cleansing the blood of pathogens and damaged erythrocytes.
Spleen: Anatomy in situ, anterior view (the
stomach
Stomach
The stomach is a muscular sac in the upper left portion of the abdomen that plays a critical role in digestion. The stomach develops from the foregut and connects the esophagus with the duodenum. Structurally, the stomach is C-shaped and forms a greater and lesser curvature and is divided grossly into regions: the cardia, fundus, body, and pylorus.
Stomach: Anatomy is faded):
Note the spatial relations with the neighboring abdominal organs.
Spleen
Spleen
The spleen is the largest lymphoid organ in the body, located in the LUQ of the abdomen, superior to the left kidney and posterior to the stomach at the level of the 9th-11th ribs just below the diaphragm. The spleen is highly vascular and acts as an important blood filter, cleansing the blood of pathogens and damaged erythrocytes.
Spleen: Anatomy in situ, posterior view:
Note the spatial relations with the neighboring abdominal organs.
Segments:
Anatomy of the stomach Stomach The stomach is a muscular sac in the upper left portion of the abdomen that plays a critical role in digestion. The stomach develops from the foregut and connects the esophagus with the duodenum. Structurally, the stomach is C-shaped and forms a greater and lesser curvature and is divided grossly into regions: the cardia, fundus, body, and pylorus. Stomach: Anatomy
Image by BioDigital, edited by LecturioThe stomach Stomach The stomach is a muscular sac in the upper left portion of the abdomen that plays a critical role in digestion. The stomach develops from the foregut and connects the esophagus with the duodenum. Structurally, the stomach is C-shaped and forms a greater and lesser curvature and is divided grossly into regions: the cardia, fundus, body, and pylorus. Stomach: Anatomy in situ
Image by BioDigital, edited by LecturioArterial supply:
Venous drainage:
Innervation:
Blood supply and innervation of the stomach Stomach The stomach is a muscular sac in the upper left portion of the abdomen that plays a critical role in digestion. The stomach develops from the foregut and connects the esophagus with the duodenum. Structurally, the stomach is C-shaped and forms a greater and lesser curvature and is divided grossly into regions: the cardia, fundus, body, and pylorus. Stomach: Anatomy
Image by BioDigital, edited by LecturioColon Colon The large intestines constitute the last portion of the digestive system. The large intestine consists of the cecum, appendix, colon (with ascending, transverse, descending, and sigmoid segments), rectum, and anal canal. The primary function of the colon is to remove water and compact the stool prior to expulsion from the body via the rectum and anal canal. Colon, Cecum, and Appendix: Anatomy in situ, anterior view, with the greater omentum Omentum Peritoneum: Anatomy and small intestines removed
Image by BioDigital, edited by LecturioLocation:
Renal capsule Renal capsule Pyelonephritis and Perinephric Abscess:
Relations:
Anterior view of the kidneys Kidneys The kidneys are a pair of bean-shaped organs located retroperitoneally against the posterior wall of the abdomen on either side of the spine. As part of the urinary tract, the kidneys are responsible for blood filtration and excretion of water-soluble waste in the urine. Kidneys: Anatomy and neighboring organs
Image by BioDigital, edited by LecturioPosterior view of the kidneys Kidneys The kidneys are a pair of bean-shaped organs located retroperitoneally against the posterior wall of the abdomen on either side of the spine. As part of the urinary tract, the kidneys are responsible for blood filtration and excretion of water-soluble waste in the urine. Kidneys: Anatomy and neighboring organs
Image by BioDigital, edited by LecturioExternal characteristics:
Blood supply: renal arteries and veins Arteries And Veins ACES and RUSH: Resuscitation Ultrasound Protocols
Transverse cross section of the abdomen focused on the
kidneys
Kidneys
The kidneys are a pair of bean-shaped organs located retroperitoneally against the posterior wall of the abdomen on either side of the spine. As part of the urinary tract, the kidneys are responsible for blood filtration and excretion of water-soluble waste in the urine.
Kidneys: Anatomy:
Note how the kidney is embedded in
adipose tissue
Adipose tissue
Adipose tissue is a specialized type of connective tissue that has both structural and highly complex metabolic functions, including energy storage, glucose homeostasis, and a multitude of endocrine capabilities. There are three types of adipose tissue, white adipose tissue, brown adipose tissue, and beige or “brite” adipose tissue, which is a transitional form.
Adipose Tissue: Histology within the gutters (paranephric and perinephric fat), which is continuous with the fat in the renal sinuses.
Blood supply:
Small intestine Small intestine The small intestine is the longest part of the GI tract, extending from the pyloric orifice of the stomach to the ileocecal junction. The small intestine is the major organ responsible for chemical digestion and absorption of nutrients. It is divided into 3 segments: the duodenum, the jejunum, and the ileum. Small Intestine: Anatomy and its parts
Image: “2417 Small IntestineN” by OpenStax College. License: CC BY 3.0Vascular branches:
Location variants of the vermiform appendix Appendix A worm-like blind tube extension from the cecum. Colon, Cecum, and Appendix: Anatomy
Image by Lecturio. License: CC BY-NC-SA 4.0Posterior view of the
cecum
Cecum
The blind sac or outpouching area of the large intestine that is below the entrance of the small intestine. It has a worm-like extension, the vermiform appendix.
Colon, Cecum, and Appendix: Anatomy:
Location of the vermiform
appendix
Appendix
A worm-like blind tube extension from the cecum.
Colon, Cecum, and Appendix: Anatomy at the
taenia
Taenia
Taenia belong to the Cestoda class of helminths. Humans are infected with these tapeworms by eating undercooked beef (T. saginata) or pork (T. solium and T. asiatica). Taeniasis is often asymptomatic, but the ingestion of larvae can cause abdominal discomfort, nausea, and constipation or diarrhea.
Taenia/Taeniasis confluence
McBurney’s point McBurney’s point Appendicitis:
McBurney’s and Rocky-Davis incisions
Image by Lecturio. License: CC BY-NC-SA 4.0Location of McBurney’s point McBurney’s point Appendicitis
Image by Lecturio. License: CC BY-NC-SA 4.0Boundaries:
Course:
The layers of the anterior abdominal wall Anterior abdominal wall The anterior abdominal wall is anatomically delineated as a hexagonal area defined superiorly by the xiphoid process, laterally by the midaxillary lines, and inferiorly by the pubic symphysis. Anterior Abdominal Wall: Anatomy, depicting the course of the inguinal canal Inguinal canal The tunnel in the lower anterior abdominal wall through which the spermatic cord, in the male; round ligament, in the female; nerves; and vessels pass. Its internal end is at the deep inguinal ring and its external end is at the superficial inguinal ring. Inguinal Canal: Anatomy and Hernias and the composition of the deep and superficial inguinal rings
Image by Lecturio. License: CC BY-NC-SA 4.0Contents:
Boundaries and contents of the male
inguinal canal
Inguinal canal
The tunnel in the lower anterior abdominal wall through which the spermatic cord, in the male; round ligament, in the female; nerves; and vessels pass. Its internal end is at the deep inguinal ring and its external end is at the superficial inguinal ring.
Inguinal Canal: Anatomy and Hernias
Note that the
ilioinguinal nerve
Ilioinguinal nerve
Inguinal Canal: Anatomy and Hernias runs along the
inguinal canal
Inguinal canal
The tunnel in the lower anterior abdominal wall through which the spermatic cord, in the male; round ligament, in the female; nerves; and vessels pass. Its internal end is at the deep inguinal ring and its external end is at the superficial inguinal ring.
Inguinal Canal: Anatomy and Hernias externally from the
spermatic cord
Spermatic Cord
Either of a pair of tubular structures formed by ductus deferens; arteries; veins; lymphatic vessels; and nerves. The spermatic cord extends from the deep inguinal ring through the inguinal canal to the testis in the scrotum.
Testicles: Anatomy.
Segments:
Broad ligament Broad Ligament A broad fold of peritoneum that extends from the side of the uterus to the wall of the pelvis. Uterus, Cervix, and Fallopian Tubes: Anatomy (ligamentum latum):
Blood supply:
Diagram of a
sagittal
Sagittal
Computed Tomography (CT) cross section of a female (a) and male (b)
pelvis
Pelvis
The pelvis consists of the bony pelvic girdle, the muscular and ligamentous pelvic floor, and the pelvic cavity, which contains viscera, vessels, and multiple nerves and muscles. The pelvic girdle, composed of 2 “hip” bones and the sacrum, is a ring-like bony structure of the axial skeleton that links the vertebral column with the lower extremities.
Pelvis: Anatomy:
In the female
pelvis
Pelvis
The pelvis consists of the bony pelvic girdle, the muscular and ligamentous pelvic floor, and the pelvic cavity, which contains viscera, vessels, and multiple nerves and muscles. The pelvic girdle, composed of 2 “hip” bones and the sacrum, is a ring-like bony structure of the axial skeleton that links the vertebral column with the lower extremities.
Pelvis: Anatomy, note the
bladder
Bladder
A musculomembranous sac along the urinary tract. Urine flows from the kidneys into the bladder via the ureters, and is held there until urination.
Pyelonephritis and Perinephric Abscess’s close proximity to the anterior vaginal wall. In the male
pelvis
Pelvis
The pelvis consists of the bony pelvic girdle, the muscular and ligamentous pelvic floor, and the pelvic cavity, which contains viscera, vessels, and multiple nerves and muscles. The pelvic girdle, composed of 2 “hip” bones and the sacrum, is a ring-like bony structure of the axial skeleton that links the vertebral column with the lower extremities.
Pelvis: Anatomy, note the
bladder
Bladder
A musculomembranous sac along the urinary tract. Urine flows from the kidneys into the bladder via the ureters, and is held there until urination.
Pyelonephritis and Perinephric Abscess’s close proximity to the
rectum
Rectum
The rectum and anal canal are the most terminal parts of the lower GI tract/large intestine that form a functional unit and control defecation. Fecal continence is maintained by several important anatomic structures including rectal folds, anal valves, the sling-like puborectalis muscle, and internal and external anal sphincters.
Rectum and Anal Canal: Anatomy.
Coronal
Coronal
Computed Tomography (CT) cross section of the
bladder
Bladder
A musculomembranous sac along the urinary tract. Urine flows from the kidneys into the bladder via the ureters, and is held there until urination.
Pyelonephritis and Perinephric Abscess:
The magnified histologic section (b) illustrates the innermost
transitional epithelium
Transitional epithelium
Surface Epithelium: Histology,
lamina propria
Lamina propria
Whipple’s Disease, and submucosa.
Location:
Lobes:
Related structures:
Accessory glandular structures:
Prostate
Prostate
The prostate is a gland in the male reproductive system. The gland surrounds the bladder neck and a portion of the urethra. The prostate is an exocrine gland that produces a weakly acidic secretion, which accounts for roughly 20% of the seminal fluid.
Prostate, Seminal, and Bulbourethral Glands: Anatomy gland and main
prostate
Prostate
The prostate is a gland in the male reproductive system. The gland surrounds the bladder neck and a portion of the urethra. The prostate is an exocrine gland that produces a weakly acidic secretion, which accounts for roughly 20% of the seminal fluid.
Prostate, Seminal, and Bulbourethral Glands: Anatomy zones:
Peripheral, transitional, and central zones in relation to other structures of the male genitourinary system
Note how the
prostate
Prostate
The prostate is a gland in the male reproductive system. The gland surrounds the bladder neck and a portion of the urethra. The prostate is an exocrine gland that produces a weakly acidic secretion, which accounts for roughly 20% of the seminal fluid.
Prostate, Seminal, and Bulbourethral Glands: Anatomy is positioned around the prostatic
urethra
Urethra
A tube that transports urine from the urinary bladder to the outside of the body in both the sexes. It also has a reproductive function in the male by providing a passage for sperm.
Urinary Tract: Anatomy.
Location:
Structure:
Superior view of the female pelvis Pelvis The pelvis consists of the bony pelvic girdle, the muscular and ligamentous pelvic floor, and the pelvic cavity, which contains viscera, vessels, and multiple nerves and muscles. The pelvic girdle, composed of 2 “hip” bones and the sacrum, is a ring-like bony structure of the axial skeleton that links the vertebral column with the lower extremities. Pelvis: Anatomy depicting the uterus Uterus The uterus, cervix, and fallopian tubes are part of the internal female reproductive system. The uterus has a thick wall made of smooth muscle (the myometrium) and an inner mucosal layer (the endometrium). The most inferior portion of the uterus is the cervix, which connects the uterine cavity to the vagina. Uterus, Cervix, and Fallopian Tubes: Anatomy in situ, its supporting ligaments, and relation to the ovaries Ovaries Ovaries are the paired gonads of the female reproductive system that contain haploid gametes known as oocytes. The ovaries are located intraperitoneally in the pelvis, just posterior to the broad ligament, and are connected to the pelvic sidewall and to the uterus by ligaments. These organs function to secrete hormones (estrogen and progesterone) and to produce the female germ cells (oocytes). Ovaries: Anatomy and neighboring organs
Image by Lecturio. License: CC BY-NC-SA 4.0Sectioned female pelvis Pelvis The pelvis consists of the bony pelvic girdle, the muscular and ligamentous pelvic floor, and the pelvic cavity, which contains viscera, vessels, and multiple nerves and muscles. The pelvic girdle, composed of 2 “hip” bones and the sacrum, is a ring-like bony structure of the axial skeleton that links the vertebral column with the lower extremities. Pelvis: Anatomy depicting the uterus Uterus The uterus, cervix, and fallopian tubes are part of the internal female reproductive system. The uterus has a thick wall made of smooth muscle (the myometrium) and an inner mucosal layer (the endometrium). The most inferior portion of the uterus is the cervix, which connects the uterine cavity to the vagina. Uterus, Cervix, and Fallopian Tubes: Anatomy in situ
Image by BioDigital, edited by LecturioSupporting structures:
Blood supply:
Blood supply of the
uterus
Uterus
The uterus, cervix, and fallopian tubes are part of the internal female reproductive system. The uterus has a thick wall made of smooth muscle (the myometrium) and an inner mucosal layer (the endometrium). The most inferior portion of the uterus is the cervix, which connects the uterine cavity to the vagina.
Uterus, Cervix, and Fallopian Tubes: Anatomy and
ovaries
Ovaries
Ovaries are the paired gonads of the female reproductive system that contain haploid gametes known as oocytes. The ovaries are located intraperitoneally in the pelvis, just posterior to the broad ligament, and are connected to the pelvic sidewall and to the uterus by ligaments. These organs function to secrete hormones (estrogen and progesterone) and to produce the female germ cells (oocytes).
Ovaries: Anatomy:
Note the ovarian artery traveling along the ovarian
suspensory ligament
Suspensory ligament
Ovaries: Anatomy, supplying both the
ovaries
Ovaries
Ovaries are the paired gonads of the female reproductive system that contain haploid gametes known as oocytes. The ovaries are located intraperitoneally in the pelvis, just posterior to the broad ligament, and are connected to the pelvic sidewall and to the uterus by ligaments. These organs function to secrete hormones (estrogen and progesterone) and to produce the female germ cells (oocytes).
Ovaries: Anatomy as well as the lateral â…“ of the uterine tube. The ovarian artery continues in the
mesosalpinx
Mesosalpinx
Uterus, Cervix, and Fallopian Tubes: Anatomy to anastomose with branches of the
uterine artery
Uterine Artery
A branch arising from the internal iliac artery in females, that supplies blood to the uterus.
Uterus, Cervix, and Fallopian Tubes: Anatomy.