1003 Final Review - Anatomy PDF

08/21/23 1003 FINAL REVIEW PANCREAS URINARY SYSTEM SPLEEN ADRENAL GLANDS ABDOMINAL CAVITY AND WALL LYMPHATIC SYSTEM SAGITTAL IMAGE DIRECTIONS  COMMON BILE DUCT (CBD) LOCATION Extends inferiorly from the union of the CHD and cystic...

08/21/23 1003 FINAL REVIEW PANCREAS URINARY SYSTEM SPLEEN ADRENAL GLANDS ABDOMINAL CAVITY AND WALL LYMPHATIC SYSTEM SAGITTAL IMAGE DIRECTIONS  COMMON BILE DUCT (CBD) LOCATION Extends inferiorly from the union of the CHD and cystic duct to enter the duodenum near the head of the pancreas CBD travels along the posterolateral aspect of the pancreatic head Enters duodenum at the ampulla of prox Vater through a muscle called the sphincter of Oddi dist Main pancreatic duct joins the CBD When foodinisentering ingested,the the duodenum duodenal at the ampulla mucosa of Vater releases the cholecystokinin (CCK) peptide hormone of the gastrointestinal system. CCK relaxes the Sphincter of Oddi. The gallbladder and pancreas release digestive juices and bile PORTAL SYSTEM  Portal Venous System Intraabdominal location Unique venous system that drains spleen, stomach, pancreas, and intestines Supplies liver with nutrients-rich blood drained from intestines Consists of the following veins: 1. Splenic vein 2. Inferior Mesenteric vein 3. Superior Mesenteric vein 4. Main Portal vein Portal Venous System 1. From the splenic hilum, the Splenic vein runs medially to the right, along the posterior aspect of the pancreatic tail and body, to join the SMV at the confluence 2. Inferior Mesenteric vein (IMV) joins Splenic vein close to Confluence 3. Superior Mesenteric vein (SMV) runs superiorly toward the confluence 4. The confluence is located posterior to the pancreatic head 5. Main Portal Vein – main vessel, formed by the CONFLUENCE OF THE SPLENIC AND SUPERIOR MESENTERIC (SMV) VEINS PANCREAS Pancreas Location Surroundin g Landmarks Posterior to pancreas Peri-vertebral connective tissue IVC and Aorta Left kidney Diaphragm 8 The pancreas is Pancrea posterior to the s Fluid in stomach Stomach LESSER SAC IS A POTENTIAL SPACE FOR FLUID COLLECTIONS Prominent peritoneal folds – greater omentum and lesser omentum; these two form the greater and lesser sacs Lesser sac, perihepatic and subphrenic spaces are common places for free fluid to pool Lesser sac located between pancreas and stomach  Primary duct, extending the entire length of Pancreatic the gland Enters the medial second part of the duodenum Ducts with the common bile duct at the ampulla of Vater (guarded by the sphincter of Oddi) Measure less than 2mm Secondary duct that drains the upper anterior head Pancreas Congenital Anomalies Pancreas Divisum : Failure of the dorsal and ventral pancreatic ductal system to fuse properly during embryonic development results in a smaller Santorini duct draining the pancreas. Inadequate pancreatic enzyme drainage may result in pancreatitis Annular pancreas: Uncommon congenital anomaly where a ring of normal pancreatic tissue encircles the duodenum secondary to abnormal migration of the ventral pancreas. 11  Physiology Exocrine Function of Pancreas Endocrine Function of the Exocrine function is carried out by Pancreas Acini cells Endocrine function is carried out Acini cells produce pancreatic by Isles of Langerhans enzymes of the pancreatic juice Groups of cells – Alpha, Betta, and 2 liters of pancreatic juice per day Delta Sodium Neutralizes stomach Betta Conversion of glucose into Bicarbonate acid cells glycogen with INSULIN (largest (lowers serum glucose) component of Alpha Conversion of glycogen pancr. juice) cells into glucose with Amylase Digestion of GLUCAGON (raises carbohydrates serum glucose) Lipase Digestion of fats Delta Inhibitors for Alpha and cells Betta cells Trypsin Digestion of proteins 12  BODY NECK HEAD UNCINATE PROCESS Pancreas TAIL Sono- anatomy Uncinate process is a posteromedial extension of the head Uncinate process lies anterior to IVC and posterior to SMV 13  SV SC IVC AO Splenic vein runs posterior to the body and tail of the pancreas Splenic vein and SMV form portal confluence, which is posterior to the neck of the pancreas IVC located posterior to the head of the Pancreas SMA marks the body 14 In the head – GDA and CBD may be found  Short sections of the pancreas - HEAD Sagittal scanning plane images just to the right of the midline show short sections of the pancreas head and portal vein (PV) anterior to a longitudinal section of the inferior vena cava (IVC) 15  Short sections of the pancreas – NECK and UNCINATE PROCESS The sagittal scanning plane image is just medial to the level of the head of the pancreas. Note the short sections of the pancreas neck and uncinate process separated by the anechoic, longitudinal section of the superior mesenteric vein. Note how the uncinate process sits directly anterior to or in front of the inferior vena cava. The level where the pancreas neck is anterior to the superior mesenteric vein and the uncinate process is slightly inferior to the portal splenic confluence or portal vein, as 16 clearly demonstrated in this image. Short sections of the pancreas - NECK and UNCINATE PROCESS 17  Short sections of the pancreas - BODY Sagittal scanning plane image of the abdomen just to the left of the midline, showing a short section of the body of the pancreas, superior to the anechoic, long section of the celiac axis/splenic artery, immediately anterior to the anechoic short section of the splenic vein, anterior to the anechoic long sections of the superior mesenteric artery and aorta, and posterior to portions of the liver and stomach. 18 Short sections of the pancreas - BODY 19  7 4 6 Name the 1 8 numbered 5 2 5 structures: 3 1. ___________ 2. ____________ 3. ___________ 4. ___________ 5. ___________ 6. ____________ 7. ___________ 8. ___________ URINARY SYSTEM ANATOMY AND FUNCTION URINARY SYSTEM COMPONENTS 1. KIDNEYS – the main organs in the urinary system filtering blood and producing urine 2. URETERS – transport the urine from the kidneys to the bladder 3. URINARY BLADDER – stores urine until it is expelled from the body 4. URETHRA – a small tube that extends from the urinary bladder to an external opening. In males, the urethra also LABfunctions as a VALUES TO reproductive ASSESS tract.FUNCTION: FOR RENAL Blood Urea Nitrogen (BUN) Creatinine (Cr) Elevation may indicate renal disease.  5 The paired kidneys and ureters are retroperitoneal Lying anterior to the deep muscles of the back and psoas major muscle PARARENAL SPACES 1. Splenorenal space (recess) 2. Hepatorenal recess, Morrison’s pouch (posterior to the liver, anterior to the right kidney)  LIVER NEY T KID R LE M USC AS PSO SPINE longitudi RUQ coronal plane view: Name the structures nal Name orientation of the kidney Name the image directions KIDNEY PROTECTIVE LAYERS 1. RENAL CAPSULE - innermost connective tissue 2. ADIPOSE LAYER – perirenal fat 3. GEROTA’S CAPSULE OUTERMOST PROTECTIVE LAYER – fibrous sheath The kidney is divided into two regions: the renal sinus - collecting system the parenchyma - functional part of the kidney, including the renal cortex and renal medulla The renal parenchyma is measured from the margin of the renal sinus to the border of the kidney. RENAL CORTEX AND MEDULLA RENAL SINUS The average adult kidney size is up to 11.5 cm in length, 6 cm in width, and 3.5 cm in thickness. In children, renal size varies with age.  HILUM The opening along the medial aspect of the kidney is termed – renal hilum. Renal hilum is where blood vessels, nerves, lymphatic vessels, and the ureter enter or exit the renal sinus  LEFT RENAL VEIN Left renal vein is longer than right Left renal vein runs between Aorta and SMA Left renal vein accepts left Gonadal vein and left Suprarenal vein Right renal vein is shorter than left and may receive right suprarenal vein Answer the following questions: What is the pathway of the right renal artery? What is a prominent vascular landmark that helps visualize  Congenital Variants of Column of Bertin Renal Form LOCATION – seen in medulla APPEARS AS – indentation of renal sinus by renal cortex, prominent cortex in between medullary pyramids; continuous with cortical tissue MIMICS – renal mass, mass-like area Dromedary hump LOCATION – bulging out along the lateral border of the kidney, usually seen on the left kidney APPEARS AS – continuous with cortex Dromedary hump MIMICS – renal mass, mass-like area  Congenital Variants of Renal Form Junctional parenchymal defect LOCATION –upper pole of renal parenchyma, cortex APPERANCE – an echogenic triangular area in the upper pole of the kidney; best seen in longitudinal MIMICS – solid echogenic mass Fetal lobulation LOCATION – the surface of the kidney, an outline of the kidney APPERANCE – indentations between calyces; best seen on sagittal images MIMICS – mass Congenital Variants of Kidney by Location Ectopic kidney LOCATION – one or both kidneys located outside of the renal fossa Most common ectopia is pelvic kidney – simple ectopia TYPES – simple ectopia or crossed ectopia; ureters have normal insertion Horseshoe kidney LOCATION - Horseshoe kidney, also called renal fusion, is when two kidneys are fused or joined together. They form a shape like a horseshoe APPEARANCE ON IMAGING – isthmus should be imaged with ultrasound to confirm the diagnosis; isthmus is seen  Ureters - thin muscular tubes Ureters that are 25–30 cm long, 4-7 mm in diameter Ureters originate at the 1 ureteropelvic junction (renal pelvis, proximal ureter) They course through the retroperitoneum until the ureterovesical junction Bladder trigone 2 At this level, they pass obliquely 3 through the muscular bladder JUNCTIONS OR SITES OF CONNECTION IN wall, creating a valve THE UPPER AND LOWER URINARY TRACTS mechanism that prevents urine 1. UPJ – ureteropelvic junction 2. UVJ – ureterovesical junction reflux 3. VUJ –vesicourethral junction Ureteral Peristalsis  Bladder, Urethra Bladder - large muscular bag; pyramidal in shape when empty; distends superiorly when fuller Apex – an anterior extension of the bladder, suspended by a median umbilical ligament that ends at the umbilicus Base – triangular in shape posteroinferior side of the bladder, aka trigone; has two ureteral openings and inferior urethral opening Bladder function is urine collection; Bladder contracts to expel urine through the Urethra - Membranous Hollow Canal,urethra measureto4-6mm the outside The urethra begins at the trigone of the urinary bladder and ends at the urethral orifice. The male urethra is longer than the female urethra. The urethra may be noted during sonographic examination of the female and male genital tract. A portion of the male urethra is surrounded by the prostate gland SPLEEN  SPLEEN is a largest lymphatic organ Located between the eighth and eleventh ribs Spleen resides in the intraperitoneal cavity Lies in the left hypochondrium or left upper quadrant (LUQ) Inferior to left hemidiaphragm Posterior to stomach  Inferior pole SPLEEN SPLEEN SAG TRV Normal measurements for the average adult should be 8 to 13 Dimensions Measurement cm in length, 7 cm in width, and Spleen long axis, length 8-13 cm 3 to 4 cm in thickness. The spleen decreases slightly in size Spleen AP diameter 7-8 cm width with aging. Spleen thickness 3-4 cm The size also varies in accordance with the nutritional status or the presence 36  Accessory Spleen The most common congenital anomaly is the accessory spleen. Splenic tissue separated from the spleen is usually found near the splenic hilum or adjacent to the tail of the pancreas. Accessory spleens are typically small and round and have the same echogenicity as the spleen.  Microanatomy Periarterial space is the area of white pulp (T- cells, B-cells, macrophages) Lymphoid tissue, consists of about 25% of all parenchyma White pulp has a triple layer of tissue that is responsible for: 1. Fighting infections, viruses 2. Initiating immune response – WBC production 3. Smallest Producingarteries have no solid walls, allowing antibodies blood (RBCs) to flow freely into the red pulp of parenchyma Red pulp consists of CORDS and VENOUS SINUSES Cords-clusters of macrophages (secondary filter for infections) Venous sinuses have no solid walls and let RBCs through special slots Only healthy RBCs can pass through into the sinuses and into the central veins Red pulp main function – filtering, removing, and ADRENAL GLAND Adrenal Cortex 3 Hormones 2 1 The adrenal cortex, which produces steroid hormones, is subdivided into three zones listed from outer to inner: (1)the zona glomerulosa, which produces mineralocorticoids (for the regulation of aldosterone to regulate electrolyte metabolism (sodium), therefore blood pressure ); (2)the zona fasciculata, which produces glucocorticoids (for the regulation of cortisol, which is an antistress and anti-inflammatory hormone); and (3) the zona reticularis, which produces gonadocorticoids (for regulating the secretion of androgens and estrogens, which are the sex hormones of an individual).  4 Adrenal Medulla The adrenal medulla produces epinephrine (adrenalin) and norepinephrine. These hormones have a wide range of effects. Epinephrine dilates the coronary vessels and constricts the skin and kidney vessels. It increases coronary output, raises oxygen consumption, and causes hyperglycemia. Norepinephrine constricts all arterial vessels except the coronary arteries (which dilate). It is the essential regulator of blood pressure. Epinephrine, in particular, is responsible for the fight-or-flight reaction. It stimulates the metabolic rate, allowing more available energy. Peptides – growth hormones GI TRACT  GI Tract Anatomy Digestive System Parts 1. Digestive Tract – above the diaphragm 2. Gastrointestinal Tract – below the Digestive Tract consists of diaphragm Mouth Esophagus Salivary gland (assisting with digestion) Gastrointestinal Tract or alimentary canal consists of Stomach Small intestine Large intestine Liver and Pancreas (assisting with digestion organs) GI tract is about 8 meters in length. 43  5 Layers – Gut Signature Layers of Bowel 1. Mucosa: directly contacts the intraluminal contents; lined with epithelial folds; echogenic 2. Muscularis Mucosa - hypoechoic 3. Submucosa – echogenic 4. Muscularis Propria - contains circular and longitudinal bands of fiber; hypoechoic 5. Serosa: a thin, loose layer of connective tissue; echogenic Regardless of its caliber, the bowel shows a stratified morphology consisting of five concentric rings of alternating echogenicity referred to as the gut signature. The normal bowel from the stomach to the colon has an average mural thickness of 3–5 mm, depending on the degree of distention. 44  Sono-Anatomy / Gastroesophageal junction T 45 3 Anatomy / Appendix Ascending colon Appendix – rudimental intestinal blind-ended extension (vermiform Ileocecal process) junction Attached to the proximal ascending colon - CECUM Appendix varies from 2 to Terminal Ilium Appendi 20 cm in length, averaging x 9 cm External Iliac Outer diameter should be artery and vein 46  Sonographic evaluation of the gastrointestinal tract Appendix Appendix is located under the abdominal wall at McBurney’s point McBurney’s point is located by drawing a line from the right anterosuperior iliac spine to the umbilicus At approximately the midpoint of this line lies the root of the appendix Position of the appendix varies; among the known configurations – retrocecal variant – challenging to visualize 47  2 1 Appendix. Sonographic Appearance 1. Normal appearing appendix imaged in cine- loop, small appendicolith seen in the proximal portion 2. Image 2, 3 shows a normal-appearing appendix rising from the cecum and draping 3 over iliac vessels 3. In image 4, note the impressive length of 48 Appendix. Sonographic Appearance 49  CONGENITAL CONDITION OF MECKEL’S DIVERTICULUM MECKEL’S DIVERTICULUM - Ileal outpouching due to persistence of vitelline duct (remnant of umbilical cord structure) 90% of pediatric cases show GI bleeding Rule of 2s Seen in ∼ 2% of population Located within 2 feet of ileocecal valve Length of 2 inches (on average) Symptomatic usually before age 2 2 main complications in adults: Diverticulitis (20%) and intestinal https://radiologykey.com/meckel- obstruction (40%) diverticulum-2/ 50  GI Tract Organs Blood Supply Stomach is supplied by 1. Right and Left Gastric arteries 2. Gastroepiploic artery (HA) 3. Vasa Brevia (SA) Small intestines are supplied by 1. SMA 2. GDA 3. Superior Pancreaticoduodenal artery Large intestines are supplied by 1. SMA 2. IMA 3. CA The venous system parallels the arterial system and empties into the portal venous system. 51  SMA and IMA Blood Distribution Transverse colon Splenic flexure Descending colon SMA supplies – small intestines, ascending and Sigmoid colon and colon proximal and mid portions of the transverse colon IMA supplies - distal 1/3 of the transverse colon, splenic flexure, descending colon, sigmoid colon, and rectum ABDOMINAL CAVITY COMPARTMENTS INTRAPERITONEAL, RETROPERITONEAL AND SUBPERITONEAL ORGANS INTRAPERITONEAL ORGANS: Liver Gallbladder Spleen Stomach Jejunum, ileum Cecum Transverse and sigmoid colon RETROPERITONEAL ORGANS: Kidneys and adrenal glands Pancreas Duodenum (2-4) Ascending and descending colon IVC and Aorta  Abdominal wall Muscles and Aponeurosis RECTUS ABDOMINUS RECTUS ABDOMINUS RIGHT LINEA ALBA LEFT LINEA SEMILUNARIS OBLIQUE MUSCLES TRANSVERSUS MUSCLE PERITONEAL LINING INTRAPEROTONEAL CAVITY  CRURA OF THE DIAPHRAGM diaphragmatic crura - right and left fibromuscular bundles that attach the diaphragm to the lumbar vertebra left crus can be visualized anterior to the aorta above the level of the celiac artery (2) right crus is visualized posterior to the caudate lobe and IVC (cr)  Major clusters of the lymph nodes seen on ultrasound: para-aortic, groin areas, cervical regions, peri-portal, axillary Sonographic Appearance of Normal Nodes Lymph nodes typically have Hypoechoic cortex Hyperechoic fatty hilum Lymphoma Oval in shape or wider than taller