Term
| What defines the abdomen? |
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Definition
| Part of the trunk between the thorax and the pelvis, consists of the abdominal wall enclosing the abdominal cavity |
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Term
| Why is the abdominal cavity larger than it appears externally? |
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Definition
| Respiratory diaphragm arches superiorly under the rib cage |
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Term
| The right dome of the diaphragm rises as high as what level? |
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Definition
| 5th rib during expiration |
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Term
| The left dome of the diaphragm rises as high as what? |
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Definition
| 5th intercostal space during expiration |
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Term
| What protects the upper abdominal organs such as the liver and the spleen? |
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Definition
| Lower ribs and their costal cartilages, may be injured by fractures of the lower ribs |
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Term
| What is in the upper right quadrant of the abdomen? |
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Definition
| Right lobe of liver, gallbladder, stomach pylorus, duodenum, head of pancreas, right suprarenal gland, right kidney, right colic (hepatic) flexure, ascending colon (superior part), transverse colon (right half) |
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Term
| What is in the upper left quadrant of the abdomen? |
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Definition
| Left lobe of liver, spleen, stomach, jejunum and proximal ileum, body and tail of pancreas, left kidney, left suprarenal gland, left colic (splenic) flexure, transverse colon (left half), descending colon (superior part) |
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Term
| What is in the lower right quadrant of the abdomen? |
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Definition
| Cecum, vermiform appendix, most of ileum, ascending colon (inferior part), right ovary, right uterine tube, right ureter (abdominal part), right spermatic cord (abdominal part), uterus (if enlarged), urinary bladder (if very full) |
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Term
| What is in the lower left quadrant of the abdomen? |
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Definition
| Sigmoid colon, descending colon (inferior part), left ovary, left uterine tube, left ureter (abdominal part), left spermatic cord (abdominal part), uterus (if enlarged), urinary bladder (if very full) |
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Term
| What are the two midclavicular planes? |
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Definition
| Vertical planes that goes through the middle of each clavicle and through the nipple down to the inguinal ligament |
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Term
| What are the two horizontal planes? |
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Definition
| Subcostal plane and Transtubercular plane |
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Term
| What does the subcostal plane travel through? |
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Definition
| 10th costal cartilages, also called the transpyloric plane |
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Term
| What does the transtubercular plane travel through? |
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Definition
| Tubercles of the iliac crest (L5) |
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Term
| What are the midline regions? |
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Definition
| Epigastric, umbilical, hypogastric (pubic) region |
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Term
| What are the lateral regions? |
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Definition
| Hypochondriac, lateral, and inguinal regions |
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Term
| The abdominal wall proper consists of what? |
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Definition
| The five lumbar vertebrae posteriorly and the wings (alae) of the ilia laterally |
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Term
| Lines of tension, aka cleavage lines or Langer's lines, are created from what? |
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Definition
| Predominant arrangement of collagen fibers within the dermis |
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Term
| How can surgeons use lines of tension? |
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Definition
| Dictates the direction of surgical incisions, incisions made parallel to tension lines typically heal well with little scarring |
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Term
| What cutaneous nerves, including lateral and anterior cutaneous branches, are contained in the superficial fascia of the anterolateral abdominal wall? |
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Definition
| Thoracoabdominal nerves, Subcostal nerve, Iliohypogastric and Ilioinguinal nerves |
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Term
| What are the roots of the thoracoabdominal nerve and how might pain be referred through them? |
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Definition
| T7-11, pain from disease of lower thoracic wall may be referred to the abdomen. T10 innervates umbilicus |
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Term
| What are the roots of the subcostal nerve? |
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Definition
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Term
| What are the roots of the iliohypogastric and ilioinguinal nerves |
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Definition
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Term
| What are the deep arteries of the abdominal wall? |
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Definition
| Superior epigastric arteries (from external iliac), deep circumflex artery and inferior epigastric (from external iliac) |
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Term
| What is an important source of potential collateral circulation in the deep abdominal wall? |
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Definition
| Inferior epigastric and superior epigastric arteries anastomosis |
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Term
| How is blood returned to the heart from the abdominal wall if superior or inferior vena cava is obstructed? |
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Definition
| Caval-caval shunts offer collateral routes of return |
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Term
| What is the thoracoepigastric vein? |
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Definition
| An anastomosis of the superficial epigastric and lateral thoracic vein, used if inferior/superior vena cava is obstructed |
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Term
| What route, other than the thoracoepigastric vein, is used for collateral return of blood to the heart if the superior/inferior vena cava is obstructed? |
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Definition
| Anastomosis of the inferior epigastric vein with the superior epigastric vein within the rectus sheath |
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Term
| Where are superficial lymphatic vessels located and where do they drain to? |
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Definition
| Above the umbilicus = drain to axillary lymph nodes, Below the umbilicus = drain to superficial inguinal lymph nodes |
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Term
| Deep lymphatic vessels accompany what? |
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Definition
| Veins in the abdominal wall |
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Term
| Where does the superficial fascia of the anterior abdominal wall become two layers? |
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Definition
| Single fatty layer above the umbilicus, two layers inferior to the umbilicus |
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Term
| What are the two layers of superficial fascia below the umbilicus? |
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Definition
| Campers fascia (superficial, fatty), Scarpa's fascai (deep, membranous) |
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Term
| Describe the boundaries of Scarpa's fascia |
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Definition
| Continuous with superficial penile fascia, dartos fascia of the scrotum, and Colle's fascia of the perineum, fuses with the fascia lata of the thigh just below the inguinal ligament |
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Term
| A ruptured penile uretha may cause what in the abdominal wall and why? |
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Definition
| Extravasated urine may spread upward into the abdominal wall due to penile fascia being continuous with Scarpa's fascia |
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Term
| What are the muscles located on each side of the anterolateral abdominal wall? |
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Definition
| 3 flattened muscles - external oblique, internal oblique, and transverse abdominis |
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Term
| What do the three anterolateral abdominal muscles develop from? |
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Definition
| Hypomere in the embryo, same 3 layers as intercostal muscles of the thoracic wall |
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Term
| Where is the rectus abdominis located? |
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Definition
| 6-pack muscles, in each half of the anterolateral abdominal wall, enclosed by the rectus sheath formed by the aponeuroses of the three flat layers of muscle |
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Term
| What doe the external oblique muscles originate from? |
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Definition
| Lower 8 ribs and courses inferomedially |
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Term
| Where does the external oblique muscle insert? |
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Definition
| Into the iliac creast and anteriorly creates an external oblique aponeurosis that is part of the rectus sheath, fibers meat at the linea alba (midline) |
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Term
| What are the boundaries of the external oblique aponeurosis? |
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Definition
| Between the anterior superior iliac spine and pubic tubercle, rolled over margin creates the inguinal ligament which contains the spermatic cord in its shallow gutter |
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Term
| The internal oblique muscle originates from what? |
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Definition
| Thoracolumbar fascia, iliac crest, and lateral 1/2 of the inguinal ligament, fibers travel superomedially |
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Term
| What does the interal oblique muscle insert into? |
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Definition
| Turns into the interal oblique aponeurosis |
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Term
| How are the anterior and posterior layers of the internal oblique aponeurosis formed? |
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Definition
| Medially splits around the rectus abdominis muscle above the arcuate line and intersects at the linea alba |
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Term
| What do the most inferior fibers of the internal oblique join with? |
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Definition
| The deeper transversus abdominis muscle |
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Term
| What forms the conjoint tendon? |
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Definition
| Joining of the most inferior fibers of the internal oblique and the deeper transversus abdominis muscle, arches over the spermatic cord to attach into the pubic crest and pecten pubis |
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Term
| Where does the transversus abdominus muscle originate? |
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Definition
| Costal cartilages 7-12, thracolumbar fascia, iliac crest, lateral 1/3 of the inguinal ligament |
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Term
| How do transversus abdominus muscle fibers run and what do they form? |
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Definition
| Trasversely, lowest fibers arch to help form the conjoint tendon above the pubic region, also helps to form the posterior layer of the rectus sheath above the arcuate line |
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Term
| What are the boundaries of the rectus abdominis muscle? |
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Definition
| Pubic crest to costal cartilages 5-7 |
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Term
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Definition
| The three or more tendinous intersections of the rectus abdominis muscle |
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Term
| What encloses the rectus abdominis muscle? |
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Definition
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Term
| What splits the rectus abdominis muscle into two halfs on each side of the body? |
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Definition
| Midline linea alba which lacks any major blood vessels or nerves, may be surgically incised for operations |
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Term
| What laterally binds the rectus abdominis muscle? |
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Definition
| Linea semilunaris, a shallow convex groove |
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Term
| What is the composition of the rectus sheath above the arcuate line? |
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Definition
| Internal oblique aponeurosis splits to contribute to both the anterior and posterior layers |
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Term
| What is the composition of the rectus sheath below the arcuate line? |
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Definition
| All three aponeuroses pass anterior to the rectus abdominis, posterior surface of the muscle is in contact with the transversalis fascia |
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Term
| What are the functions of the abdominal wall muscles? |
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Definition
| Support and protects abdominal organs, relaxes during inspiration and contracts during forced expiration |
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Term
| The anterolateral abdominal wall muscles can increase intra-abdominal pressure which is important for what? |
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Definition
| Emptying the uriniary bladder and rectum, coughing and sneezing, giving birth |
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Term
| The internal oblique and the contralateral external oblique contract to produce rotation of the trunk. Rotation is towards what side? |
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Definition
| Side of the internal oblique |
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Term
| Why is the inguinal (groin) region an area of weakness in the inferior part of the anteriolateral abdominal wall? |
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Definition
| Contains the inguinal canal which transmits the large spermatic cord in males and thin round ligaments of the uterus in females |
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Term
| What defines the inguinal canal? |
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Definition
| An oblique passage through the abdominal wall |
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Term
| What does the inguinal canal extend through? |
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Definition
| Extends inferomedially from the deep inguinal ring to the superficial inguinal ring within the external oblique aponeurosis and lies superior to the medial half of the inguinal ligament |
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Term
What are the boundaries of the inguinal canal?
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Definition
| Anteriorly bound by the external oblique aponeurosis, laterally by internal oblique aponeurosis, posteriorly by transversalis fascia reinforced medially by the conjoint tendon |
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Term
| Where do most hernias of the abdominal wall occur? |
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Definition
| Inguinal, umbilical, or epigastric region |
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Term
| What is the most common abdominal hernia? |
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Definition
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Term
| What causes inguinal hernias? |
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Definition
| Protrusions of viscera (small intestines) from abdominal cavity through the inguinal region |
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Term
| What is an indirect inguinal hernia? |
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Definition
| Hernia that follows the path of descent of the testis (most common type of hernia in both sexes and at all ages), leaves abdominal cavity lateral to the inferior epigastric artery |
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Term
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Definition
| Hernia that push directly through a weak area of abdominal wall more medially |
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Term
| What causes an indirect inguinal hernia? |
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Definition
| Persistance of an evagination of the peritoneum on each side, the processus vaginalis |
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Term
| And indirect inguinal hernia contains what three fascial coverings of the spermatic cord? |
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Definition
| Internal spermatic fascia, cremasteric fascia, external spermatic fascia, made from transversalis fascia, internal oblique muscle, and external oblique aponeurosis respectively |
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Term
| Why is an indirect inguinal hernia considered to be congenital? |
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Definition
| Represents a persistent processus vaginalis, may occur in women if the processus vaginalis persists as a peritoneal pouch known as a canal of Nuck |
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Term
| Where are indirect inguinal hernias palpated? |
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Definition
| Superficial inguinal ring |
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Term
| Why is surgery recommended to repair an indirect hernia? |
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Definition
| At risk of becoming entrapped with bowel obstruction and possible loss of its blood supply |
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Term
| A direct inguinal hernia pushes into where? |
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Definition
| Leaves abdominal cavity medial to the inferior epigastric artery, pushes directly into the inguinal canal through or around a weak conjoint tendon |
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Term
| What forms the inguinal triangle (Hesselbach's triangle)? |
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Definition
| Inferior epigastric artery, rectus abdominis, inguinal ligament |
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Term
| A direct inguinal hernia protrudes through what landmark? |
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Definition
| Inguinal triangle (Hesselbach's triangle) |
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Term
| What forms the hernial sac of a direct inguinal hernia? |
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Definition
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Term
| Which hernia is more likely to descend into the scrotum? |
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Definition
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Term
| What factors oppose inguinal hernia formation? |
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Definition
| Contraction of internal oblique and transversus abdominis muscle fibers, pressure of the posterior wall of the inguinal canal toward the anterior wall, location of the conjoint tendon |
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Term
| Umbilical hernias are common among what demographic and why? |
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Definition
| Newborns because the anterior abdominal wall is relatively weak at the umbilical ring |
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Term
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Definition
| Failure of the bowel to return to the body cavity following its normal embryonic herniation, covered by amnion |
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Term
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Definition
| Herniation of abdominal contents through the body wall lateral to the umbilicus into the amniotic cavity, viscera not covered by amnion, may be severe |
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Term
| What are inciscional hernias? |
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Definition
| Protrusions of omentum or organs through sites of surgical incisions, may result from improper healing of the abdominal wall following surgery or weakness of wall muscles following cutting of their motor nerve supply |
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