Anatomy Chapter 4 - Abdominal Regions

Skin of the Abdominal Wall

The 6 or 7 lower intercostal nerves, including subcostal nerve (12th intercostal), iliohypogastric nerve, and ilioinguinal nerve innervate the ________

Subcostal, Transtubercular, Umbilicus

The 9 abdominal regions are created by the ________ plane and ________ plane intersected by 2 midclavicular lines; 4 quadrants formed by lines crossing at the ________.

Right and Left Parietocolic (Paracolic) Recesses (Gutters)

The ________ ________ are situated between the ascending and descending colon and the lateral abdominal wall on each side

Abdominopelvic Cavity

The area between the thoracic diaphragm and pelvic diaphragm

Cremaster Muscle

The caudal section of the internal abdominal oblique muscle in males that reaches the spermatic cord

Cremaster Reflex

The contraction and lifting of the testis when the medial aspect of the upper thigh region is stroked in a male; Afferent limb: the femoral branch of the genitofemoral nerve and/or the ilioinguinal nerve Efferent limb: the genital branch of the genitofemoral nerve (L1-L2)

Scarpa's (membranous) Fascia

The deep later of the anterior abdominal wall, underneath the fatty fascia and above the external abdominal oblique, inferior to the arcuate line

Lesser Omentum

The double layer of the peritoneum, between the lesser curvature of the stomach and the porta hepatis of the liver.

Visceral Peritoneum

The greater omentum prevents the ________ from adhering to the parietal peritoneum.

Ascites

The peritoneum exudes fluid and cells in response to injury or infection such as peritonitis. Commonly seen in patients suffering from liver cirrhosis

Parietal Layer, Visceral Layer

The peritoneum has two layers: the ________ (outer) and the ________ (inner)

Greater Omentum

The section of the peritoneum that covers the anterior surface of the stomach and continues downward. Contains fat, lymphocytes, and other immune cells to protect against infection or inflammatory conditions in the abdominal cavity. Protects abdominal organs against injury, and acts as an insulator against loss of body heat

Camper's (fatty) Fascia

The superficial layer of the anterior abdominal wall, underneath the skin, inferior to the arcuate line

Axillary, Parasternal, Superficial Inguinal, Deep

The superficial lymph above the umbilicus drains into the ________ and ________ lymph nodes Lymph below the umbilicus drains into the ________ lymph nodes ________ Lymph drains into the lymph nodes around the deep pelvic and abdominal vessels

Paraumbilical Veins

The superficial veins around the umbilicus drain into the protal vein through the ________ (accompanying the round ligament of the liver)

Abdominal Cavity

The upper part of the abdominopelvic cavity as high as the 4th intercostal space

Portal Triad

Portal vein, hepatic artery, and common bile duct

Pyramidalis

Small, triangular muscle that lies anterior to the inferior section of the rectus abdominis, in the rectus sheath, attaches to the pubis; Function: tenses the linea alba

Posterior Superior Iliac Spine

feature of surface anatomy about 2 inches beneath the supracristal plane, seen as 2 dimples in the back on both sides of the midline

Iliac Tubercle

feature of the surface anatomy that can be palpated about 2 inches (5cm) posterior to the anterior superior iliac spine

Anterior Superior Iliac Spine

feature of the surface anatomy that runs backward from the iliac crest and can be palpated on either side

Mesenterocolic Recesses

right and left are below the transverse mesocolon, above the root of the mesentery

Parietal Peritoneum Innervation and Blood Supply

same vessels and nerves that innervate the underlying muscle Sensory information (i.e. Pain, laceration, cold/heat, and pressure) Pain is sharp and localized

Tunica Vaginalis

Double-layered sac of peritoneum covering the testis, derived from the processus vaginalis

Umbilical Hernias

Often occur in newborns due to weak abdominal walls May occur during pregnancy or in obese people (Aquired umbilical hernia)

Superficial Inguinal Ring

Opening in the aponeurosis of the external abdominal oblique (directly above the inguinal ligament bordered by medial crus, lateral crus, intercural fibers)

Deep Inguinal Ring

Opening in the transversalis fascia (lateral to the inferior epigastric vessels)

Epipolic Foramen (Foramen of Winslow)

Opening of the lesser sac between the liver and duodenum, beneath the portal triad

Greater Sac

main part of the peritoneal cavity. When the abdomen is open, almost everything can be seen in the peritoneal cavity.

Lower margin of rib cage, Pelvis

2 bony rings that enclose the upper and lower parts of the abdomen

Features on the Posterior Aspect of the Anterior Abdominal Wall

3 umbilical folds - Peritoneal voering of ligaments/vessels Medial - ligament; remnants of fetal umbilical arteries Median - ligament; remnant of urachal cord Lateral - over inferior epigastric vessels

Left Hypochonrial, Umbilical, Hypogastric (pubic)

9 ABDOMINAL REGIONS: Right hypochondrial, Epigastric, ________, Right lateral (lumbar), ________, Left lateral (lumbar), Right inguinal, ________, Left inguinal.

Sigmoid Mesocolon

A double layer of peritoneum suspending the sigmoid colon Attaches to the posterior pelvic wall on the left side in an inverted "v" shape structure. It attaches close to the sacroiliac joint area, extending medially to the middle of the sacrum (~S3 level)

Cryptochidism

Absence of one or both testes in the scrotum, due to failure of testic to descend through inguinal canal during development

Hydrocele

An accumulation of fluid due to abnormal closure of the processus vaginalis

Rectus Sheath

Aponeurosis of the lateral group of abdominal muscles (the oblique and transversus abdominis) that surrounds the rectus abdominis and pyramidalis muscles

Arcuate Line

Arch that is the termination point of the inferior layer of the aponeurosis about 5cm below the navel

Root of the Mesentery

Attaches to the posterior abdominal wall between the duodenojejunal flexure at the left side of the L2 vertebra, and extends downward, to the right of the posterior abdominal wall, finally reaching the ileocecal junction, about 6 inches (15cm) long Surrounds the small intestines for 150-700cm (variable small intestine length)

Inferior Epigastric Artery, Deep Circumflex Iliac Artery

Branches of the external iliac artery

Superficial Iliac Artery, Superficial Epigastric Artery

Branches of the femoral artery

Superior Epigastric Artery, Musculophrenic Artery

Branches of the internal (mammary) artery

Function of the Abdominal Muscles

Compress and support the visceral organs in the abdominal cavity Flex and rotate the trunk Forced expiration Force during defecation, urination, and childbirth

Round (teres) Ligament of the Uterus

Connection between the uterus and the subcutaneous tissue of the labium majus

Gastrocolic Ligament

Connects the transverse colon to the greater curvature of the stomach

Gastrosplenic Ligament

Contains the branches of the splenic artery to the stomach and the accompanying veins, and lies between the stomach and spleen.

Lineorenal Ligament

Contains the splenic vessels, is situated between the left kidney and spleen

T6/T7, T10, L1

Dermatome innervation of: 1. Xiphoid process is ________ 2. Umbilicus is ________ 3. Symphysis pubis is ________

Subphrenic Spaces

Found between the diaphragm and the liver on both sides of the falciform ligament

Vesicouterine Pouch

Found in females

Rectovesical Pouch

Found in males

Descendence of the Testis

Embryonic testes in abdominal cavity, vaginal process passes through inguinal canal to scrotum (7th week of gestation), testis begins to slide, in pelvis (12 weeks), in deep inguinal ring (28 weeks/7 months), passes through canal (+3~ days), in scrotum (+4 weeks)

Pubic Tubercle

Feature of the surface anatomy that can be palpated over the external genital area, about 1.5 inches (3-4cm) lateral to the midline

Linea Alba

Fibrous raphe (connecting ridge) formed from the aponeurosis of the interwoven right and left abdominal muscles; relatively avascular

Contents of Lesser Omentum

Hepatoduodenal ligament Hepatogastric ligament Portal Triad

Transtubercular Plane

Horizontal line at the iliac tubercles

Subcostal Space

Horizontal line at the lower border of the 10th costal cartilage

Transpyloric Plane

Horizontal line that passes from the tip of 9th costal cartilage anteriorly to L1 vertebra posteriorly in supine position; intersects pylorus of stomach, superior part of duodenum, duodejejunal flexure, fundus of galbladdar, origin of superior mesenteric artery

Rectouterine Pouch (Douglas Cul-De-Sac)

In females, between the rectum and uterus, a pouch is produced by the peritoneum, called the ________.

Rectouterine Pouch

In females, is a deep part of the pelvic cavity Site of fluid accumulation (e.g. pelvic inflammatory disease, PID)

Femoral Hernia

In the upper thigh region, more common in females

Peritonitis

Inflammation of the peritoneum following an abdominal injury (stab wound, perforated ulcer, appendicitis)

Iliohypogastric Nerve

Innervates: Skin of the anterior (hypogastric) and lateral (upper inguinal) regions of the abdomen

Ilioinguinal Nerve

Innervates: Skin of the lower parts of the ingiunal region, external genital areas (mons pubis and labium majus in females, anterior scrotum in males), medial aspect of the upper thigh

Retroperitoneal Organs

Kidneys, abdominal aorta Located behind the peritoneum and are partially covered by the peritoneum, usually only on one surface.

Inguinal (Poupart's) Ligament

Ligament between the anterior superior iliac spine and pubic tubercle

Falciform Ligamen

Ligament formed on the liver Produced by the peritoneum

Pectineal (Cooper's) Ligament

Ligament that continues laterally along the pectineal line (from lacunar ligament)

Peritoneum

Many of the abdominal visceral organs are suspended in a thin membrane called the ________.

Epigastric Hernia

May appear from small holes (defects) in the linea alba in infants Incisional hernia may develop at the site of a surgical scar

Herniation

May occur during increased intra-abdominal pressure, e.g. straining, coughing (bronchitis), or micturition (in people with benign prostatic hyperplasia, BPH)

Paracentesis

Medical procedure involving puncturing of the peritoneal cavity to drain fluids from the body cavity such as ascites.

Indirect Inguinal Hernia

More common than DIH. More common in both men and women due to a patent processus vaginalis. Condition can be congenital and/or aquired, often seen in younger people. IIH occur lateral to the epigastric vessels. Structure passes through the deep internal inguinal ring, traversing the inguinal canal and exiting through the superficial inguinal ring inside the spermatic cord. There is a higher risk of strangulation of the herniated structure. They commonly pass through the scrotum in males or the labium majus in females. Cooper's ligament repair

Direct and Indirect Inguinal Hernias

Most common type of hernia, result from herniation of the abdominal contents into the inguinal canal.

Recuts Abdominis

Muscle that lies within the rectus sheath, produced by the aponeurosis of the lateral group of abdominal wall muscles, extends between pubic crest and xiphoid process of the sternum and the puter surfaces of the costal cartilages 5-7; Function: Stabilizes the pelvis

Coarctation of Aorta

Norrowing of the aorta which would lead to dilation of an alternal blood supply (via the inferior thyroid artery p. 200)

Transversus Abdominis

Origin: 6 slips from internal surface of the 7-12th costal cartilages, deep layer of thoracolumbar fascia, inner lip of iliac crest, lateral thrid of the inguinal ligament Insertion: linea alba, pubic crest, pectin pubis via conjoint tendon Innervation: T7-T11 intercostal (thoracoabdominal), subcostal, L1 Ifrom iliohypogastric and ilioinguinal) possible T6 --Forms the posterior layer of the rectus sheath superior to the arcuate line, but only the anterior layer inferior to the arcuate line

External Abdominal Oblique

Origin: 8 slips from outer surface of ribs 5-12 Insertion: Flat aponeurosis

Internal Abdominal Oblique

Origin: intermediate line of the iliac crest, deep layer of thoracolumbar fascia, anterior superior iliac spine, inguinal ligament Insertion: lower margin of last three ribs, aponeurosis (superior and inferior to rectus abdominis), cremaster muscle/teres ligament, pectin pubis via conjoint tendon Innervation: T7-T11 intercostal (thoracoabdominal), subcostal, L1 (from iliohypogastric and ilioinguinal), sometimes T6 intercostal Function: --Has cranial, middle, and caudal fibers

Striae Gravidarum

Pregnancy lines that may show in lower sections of the lateral and anterior parts of the abdominal wall, caused by overstretching

Gastroschisis

Protrusion of abdominal viscera May occur as a result of a congenital defect in ventral abdominal wall

Contents of the Rectus Sheath

Rectus Abdominis Muscle Pyramidalis Muscles Inferior and Superior epigastric vessels some lymphatic vessels anterior primary rami of 5 lower intercostal nerves (including subcostal nerve)

Visceral Peritoneum Innervation and Blood Supply

Same vessels/nerves as visceral organs. Senses stretching, and chemical irritants (pain) Pain is often not sharp and radiates to the midline parts of the dermatomes

Abdomen

Section of trunk between the thorax and pelvis

Diastasis Recti

Separation of the rectus abdominis muscles in the midline) May be seen in newborns, during pregnancy, or postpartum

Inguinal Canal

Site of passage within the anterolateral abdominal wall muscles, between deep inguinal ring and superficial inguinal ring; contains spermatic cord (males) or round ligament of uterus (females)

Right Subhepatic Space (hepatorenal pouch of Morison)

Situated between the liver and the right Kidney. Lowest part of the abdominal cavity in supine position Second section of the duodenum lies posterior to it Site of fluid accumulation, which may lead to respiratory problems by irritating the diaphragm

Left Subhepatic Space

Situated on the left side of the right subhepatic space

Abdominal Wall Layers Inferior to Arcuate Line

Skin, camper's fascia, scarpa's fascia, external abdominal oblique aponeurosis, internal abdominal oblique aponeurosis, transversus abdominis aponeurosis, rectus abdominis, transversalis (deep) fascia S, CF, SF, EAOA, IAOA, TAA, RA, TF

Abdominal Wall Layers Superior to Arcuate Line

Skin, subcutaneous fat, external abdominal oblique aponeurosis, internal abdominal oblique aponeurosis (anterior layer), rectus abdominis, internal abdominal oblique aponeurosis (posterior layer), transversus abdominis aponeurosis, transversalis (deep) fascia, peritoneum S, SF, EAOA, IAOAA, RA, IAOAP, TAA, TF, P

Intraperitoneal Organs

Stomach, spleen, intestines, and others. Connected by the peritoneum to the lining of the body wall.

Innervation of the Internal Oblque and Transversus Abdominis Muscles

T7-T11 intercostal (thoracoabdominal), Subcostal, L1 (from iliohypogastric and ilioinguinal), possible T6 intercostal

Lacunar (Gimbernat's) Ligament

Triangular ligament at the angle between the medial insertion point of the inguinal ligament and the pectineal line of the pubic bone

Transverse Mesocolon

Turns upward and passes behind the transverse colon as the posterior layer of its mesentery, finally reaching the abdominal wall. The opposite layers of the greater omentum and transverse mesocolon then fuse The messentery surrounding the transverse colon

Subperitoneal (infraperitoneal) Organs

Urinary bladder Covered only on the superior border

Pelvic Diaphragm

What separates the pelvis from the perineum

Caput Medusae

When the paraumbilical veins become engorged with blood. Result of severe portal hypertension

Ovarian Ligament

connection between the ovaries and the uterus

Processus Vaginalis (vaginal process)

evagination (embryonic outpouching) of the peritoneum at the inguinal canal

Lesser Sac

formed by the peritoneum, lies behind the stomach and has a superior and inferior recess

Conjoint Tendon (falx inguinalis)

fusion of the lower end of the aponeurosis of the internal abdominal oblique and the transversus abdominis muscles

Lesser Sac (omental bursa)

is diverticulum of the peritoneal cavity to the left side, posterior to the stomach

Supracristal Plane

line that can be drawn on the back between the high points of the iliac crest; approximately at level of L4 spinous process (L4/L5) intervertebral discs; landmark for lumbar puncture/spinal tap

Direct Inguinal Hernia

occurs due to a weakness in the anterior abdominal wall. Usually a defect acquired from mechanical breakdown over the years, and the patients are typically middle-aged men. Herniation occurs medially to the inferior epigastric vessels or inside the inguinal/Hesselbach's triangle Direct inguinal hernias pass directly into the abdominal wall through or around the inguinal canal, but don't pass into the processus vaginalis, which parallels the spermatic cord. They exit through the superficial inguinal ring, and may rarely enter the scrotum. There is a lower risk of strangulation of the herniated structure in direct inguinal hernias.

Lumbar Puncture (Spinal Tap)

process in which needle is inserted into the back superior/inferior to spinous process (between L3-L5) in adults; used to withdraw CSF for analysis, measure CSF pressure, inject contrast medium for myelography and drugs (~block), into subarachnoid space

Cooper's Ligament Repair

surgical method for hernia repair, in which the transversalis fascia and the conjoint tendon are sutured to the periosteum of the pubic bone.

Teres Ligament

the caudal section of the internal abdominal oblique muscle in females that reaches the round (teres) ligament of the uterus

Mesentery

the double layer of peritoneum containing the blood and lymphatic vessels, nerves, and fat. Connects the intestines to the posterior abdominal wall, providing a neurovascular connection between the organ and the body wall, Usually fixed and more vascular

Serous Membrane, Mesothelium

the peritoneum is a ________ (________/simple squamous eptithelium) lining the abdominal and pelvic cavities