Ch. 8: Vascular System

Question 1

Anatomy of Vascular Structures

• ____ carry blood ____ from the heart
• ____ carry blood to the____ and back from the ____
• Arteries divide into progressively smaller____, the smallest of which are the ____
• Arterioles lead into the ____, which are minute vessels that branch and form a network in which materials are exchanged between ____ and tissue fluid
• After the blood passes through the ____, it is collected in the small veins or ____
• Venules unite to form larger vessels that eventually return the blood to the heart for ____

Answer 1

Anatomy of Vascular Structures

• Arteries carry blood away from the heart
• Veins carry blood to the heart and back from the tissues
• Arteries divide into progressively smaller branches, the smallest of which are the arterioles
• Arterioles lead into the capillaries, which are minute vessels that branch and form a network in which materials are exchanged between blood and tissue fluid
• After the blood passes through the capillaries, it is collected in the small veins or venules
• Venules unite to form larger vessels that eventually return the blood to the heart for recirculation

Question 2

An Artery Has ____ Layers:

(1) Tunica ____ (inner layer), which itself has three layers

• A layer of ____ cells lining the arterial passage (lumen)
• A layer of delicate ____ tissue
• An elastic layer made up of a network of ____ fibers

(2) Tunica media (middle layer)

• Smooth muscle fibers with ____ and ____ tissue

(3) Tunica adventitia (external layer)

• ____ ____ tissue with bundles of smooth muscle fibers and elastic tissue
  
  • The vasa ____ makes up the tiny arteries and veins that supply the ____ of blood vessels

Answer 2

An Artery Has Three Layers:

(1) Tunica intima (inner layer), which itself has three layers

• A layer of endothelial cells lining the arterial passage (lumen)
• A layer of delicate connective tissue
• An elastic layer made up of a network of elastic fibers

(2) Tunica media (middle layer)

• Smooth muscle fibers with elastic and collagenous tissue

(3) Tunica adventitia (external layer)

• Loose connective tissue with bundles of smooth muscle fibers and elastic tissue
  
  • The vasa vasorum makes up the tiny arteries and veins that supply the walls of blood vessels

Question 3

Arteries

• Hollow elastic tubes that carry blood ____ from the heart
• Enclosed within a ____ that includes a ____ and ____
• Smaller arteries contain ____ ____ tissue and more ____ muscles than the ____ arteries
• Elasticity of the larger arteries is important for maintaining ____ blood flow
• The pulsatile abdominal aorta will ____ ____ in diameter with changes in ____

Answer 3

Arteries

• Hollow elastic tubes that carry blood away from the heart
• Enclosed within a sheath that includes a vein and nerve
• Smaller arteries contain less elastic tissue and more smooth muscles than the larger arteries
• Elasticity of the larger arteries is important for maintaining steady blood flow
• The pulsatile abdominal aorta will not change in diameter with changes in respiration

Question 4

Veins

• Hollow ____ tubes with diminished tunica ____ that carry blood ____ the heart
• Appear ____ (little elastic tissue or muscle within their walls)
• Have a larger total diameter than the arteries
  
  • Move blood more ____
• Contain special ____ that prevent ____ and permit blood to flow only in ____ direction—toward the heart
• IVC should ____ slightly with ____ ____

Answer 4

Veins

• Hollow collapsible tubes with diminished tunica media that carry blood toward the heart
• Appear collapsed (little elastic tissue or muscle within their walls)
• Have a larger total diameter than the arteries
  
  • Move blood more slowly
• Contain special valves that prevent backflow and permit blood to flow only in one direction—toward the heart
• IVC should dilate slightly with suspended respiration

Question 5

Aorta

• ____ principal ____ in the body
• Divided into ____ sections:
  
  • Root of the aorta
  • Ascending aorta and arch
  • Descending aorta
  • Abdominal aorta and abdominal aortic branches
  • Bifurcation of the aorta into iliac arteries

Answer 5

Aorta

• Largest principal artery in the body
• Divided into five sections:
  
  • Root of the aorta
  • Ascending aorta and arch
  • Descending aorta
  • Abdominal aorta and abdominal aortic branches
  • Bifurcation of the aorta into iliac arteries

Question 6

An Artery Has ____ Layers:
(1) Tunica ____ (____ layer), which itself has three layers

• A layer of ____ cells lining the ____ passage (lumen)
• A layer of delicate ____ tissue
• An elastic layer made up of a network of ____ fibers

(2) Tunica media (____layer)

• Smooth muscle fibers with ____ and ____ tissue

(3) Tunica adventitia (____layer)

• ____ ____ tissue with bundles of ____ ____ fibers and elastic tissue
  
  • The vasa ____ makes up the tiny arteries and veins that supply the walls of blood vessels

Answer 6

An Artery Has Three Layers:
(1) Tunica intima (inner layer), which itself has three layers

• A layer of endothelial cells lining the arterial passage (lumen)
• A layer of delicate connective tissue
• An elastic layer made up of a network of elastic fibers

(2) Tunica media (middle layer)

• Smooth muscle fibers with elastic and collagenous tissue

(3) Tunica adventitia (external layer)

• Loose connective tissue with bundles of smooth muscle fibers and elastic tissue
  
  • The vasa vasorum makes up the tiny arteries and veins that supply the walls of blood vessels

Question 7

Arteries

• ____ elastic tubes that carry blood ____ from the heart
• Enclosed within a sheath that includes a ____ and ____
• Smaller arteries contain less ____ tissue and more ____ muscles than the larger arteries
• Elasticity of the larger arteries is important for maintaining steady ____ ____
• The ____ ____ aorta will ____ ____ in ____ with changes in respiration

Answer 7

Arteries

• Hollow elastic tubes that carry blood away from the heart
• Enclosed within a sheath that includes a vein and nerve
• Smaller arteries contain less elastic tissue and more smooth muscles than the larger arteries
• Elasticity of the larger arteries is important for maintaining steady blood flow
• The pulsatile abdominal aorta will not change in diameter with changes in respiration

Question 8

Veins

• tubes with diminished tunica that carry blood the heart
• Appear collapsed (little tissue or within their walls)
• Have a larger total than the
  
  • Move blood more
• Contain special that prevent and permit blood to flow only in direction—toward the
• IVC should slightly with suspended

Answer 8

Veins

• Hollow collapsible tubes with diminished tunica media that carry blood toward the heart
• Appear collapsed (little elastic tissue or muscle within their walls)
• Have a larger total diameter than the arteries
  
  • Move blood more slowly
• Contain special valves that prevent backflow and permit blood to flow only in one direction—toward the heart
• IVC should dilate slightly with suspended respiration

Question 9

Aorta

• ____ principal ____ in the body
• Divided into five sections:
  
  • ____ of the aorta
  • Ascending aorta and ____
  • Descending aorta
  • Abdominal aorta and abdominal aortic ____
  • Bifurcation of the aorta into ____ arteries

Answer 9

Aorta

• Largest principal artery in the body
• Divided into five sections:
  
  • Root of the aorta
  • Ascending aorta and arch
  • Descending aorta
  • Abdominal aorta and abdominal aortic branches
  • Bifurcation of the aorta into iliac arteries

Question 10

Size of Abdominal Aorta & Iliac Branches

Men

• Diameter +/-SD (mm): ____ +/-____
  Women
• Diameter +/-SD (mm): ____ +/-____

Answer 10

Size of Abdominal Aorta & Iliac Branches

Men

• Diameter +/-SD (mm): 20.2 +/- 2.5
  Women
• Diameter +/-SD (mm): 17.0 +/- 1.5

Question 11

Anterior Branches of the Abdominal Aorta

Answer 11

• Celiac trunk (CT)
• Common hepatic artery (CHA)
• Gastroduodenal artery (GDA)
• Right and left gastric artery (RGA/LGA)
• Splenic artery (SA)

Question 12

Abdominal Aortic Branches

• ____ arteries arise from the lateral walls of the aorta to supply the undersurface of the diaphragm
• ____ trunk is the first anterior branch of the aorta, arising 1 to 2 cm inferior to the ____
• ____ ____ artery is the second anterior branch, arising approximately 2 cm from the ____ trunk
• ____ arteries are lateral branches arising just inferior to the superior mesenteric artery
• The small ____ mesenteric artery arises anteriorly near the ____
• The distribution of these branch arteries is to the visceral organs and the mesentery

Answer 12

**Abdominal Aortic Branches

• Phrenic arteries arise from the lateral walls of the aorta to supply the undersurface of the diaphragm
• Celiac trunk is the first anterior branch of the aorta, arising 1 to 2 cm inferior to the diaphragm
• Superior mesenteric artery is the second anterior branch, arising approximately 2 cm from the celiac trunk
• Renal arteries are lateral branches arising just inferior to the superior mesenteric artery
• The small inferior mesenteric artery arises anteriorly near the bifurcation
• The distribution of these branch arteries is to the visceral organs and the mesentery**

Question 13

Five main branches supply the small bowel:

Answer 13

1. Inferior pancreatic artery
2. Duodenal artery
3. Colic artery
4. Ileocolic artery
5. Intestinal artery

Question 14

Three main branches of the inferior mesenteric artery

Answer 14

• Left colic
• Sigmoid
• Superior rectal arteries

Question 15

Lateral Branches of the Abdominal Aorta

Answer 15

• Phrenic arteries
• Renal arteries
• Gonadal artery

Question 16

Common Iliac Arteries

• Arise at the bifurcation of the abdominal aorta at the ____ lumbar vertebra (near the superior ____)
• Divide into the ____ and ____ iliac arteries

Answer 16

Common Iliac Arteries

• Arise at the bifurcation of the abdominal aorta at the fourth lumbar vertebra (near the superior sacrum)
• Divide into the internal and external iliac arteries

Question 17

Sonography of the Aorta

• Abdominal aorta is relatively easy to image with ultrasound because of significant changes in acoustic impedance between its elastic walls and the blood-filled lumen
• Assess ____, calcification, ____, or dissection
• Multiple ____ windows may be used
• Longitudinal, transverse, and ____
• Arterial system may be affected by ____, ____, ____ tissue disorder, rupture, thrombosis, or infections

Answer 17

Sonography of the Aorta

• Abdominal aorta is relatively easy to image with ultrasound because of significant changes in acoustic impedance between its elastic walls and the blood-filled lumen.
• Assess diameter, calcification, thrombus, or dissection
• Multiple acoustic windows may be used.
• Longitudinal, transverse, and decubitus
• Arterial system may be affected by atheroma, aneurysm, connective tissue disorder, rupture, thrombosis, or infections

Question 18

Clinical reasons for sonographic evaluation:

• Pulsatile ____ mass
• Abdominal pain ____ to the back
• Abdominal ____
• ____ compromise in the lower legs

Answer 18

Clinical reasons for sonographic evaluation:

• Pulsatile abdominal mass
• Abdominal pain radiating to the back
• Abdominal bruit
• Hemodynamic compromise in the lower legs

Question 19

• Triple A – ____ ____ ____
• Triple A’s are ordered to rule out an ____

Answer 19

• Triple A –Abdominal aortic aneurysm
• Triple A’s are ordered to rule out an aneurysm

Question 20

Abdominal Aortic Aneurysm

• An aneurysm is defined as a ____ localized ____ of an ____, with an increase in ____ of greater than ____ times its normal diameter.
  
  • Descriptive terms: ____, ____, and dumbbell
• Diagnosed at ____ cm or greater (AP measurement)
• Most are true aneurysms and involve all ____ layers.
• ____% are infrarenal.
  
  • Below the ____ artery
• Anteroposterior (AP) diameter is measured on ____ views
• Mural ____ is common with a larger aneurysm
• ____ (with tortuosity, folding) is present
• Aortic ____ is the result of trauma
• ____ aneurysm is the result of infection
• Surgery is considered when an aneurysm is >____ cm
  
  • Unless they are not in condition for surgery

Answer 20

Abdominal Aortic Aneurysm

• An aneurysm is defined as a permanent localized dilation of an artery, with an increase in diameter of greater than 1.5 times its normal diameter.
  
  • Descriptive terms: bulbous, saccular, and dumbbell
• Diagnosed at 3 cm or greater (AP measurement)
• Most are true aneurysms and involve all three layers.
• Ninety-five percent (95%) are infrarenal.
  
  • Below the renal artery
• Anteroposterior (AP) diameter is measured on sagittal views
• Mural thrombus is common with a larger aneurysm
• Atherosclerosis (with tortuosity, folding) is present
• Aortic pseudoaneurysm is the result of trauma
• Mycotic aneurysm is the result of infection
• Surgery is considered when an aneurysm is >5 cm
  
  • Unless they are are in condition for surgery

Question 21

Fusiform Aneurysm and Saccular Aneurysm
- Fusiform are ____ developing, they develop over ____ (More ____)
- Saccular form ____

Answer 21

Fusiform Aneurysm and Saccular Aneurysm
- Fusiform are slow developing, they develop over time (More uniform)
- Saccular form suddenly

Question 22

Risk Factors of Abdominal Aortic Aneurysms:

• Tobacco
• ____ (high blood pressure)
• ____ disease
• Chronic ____ ____ disease (COPD)
• Family history for ____ ____ ____

Answer 22

Risk Factors of Abdominal Aortic Aneurysms:
- Tobacco
- Hypertension (high blood pressure)
- Vascular disease
- Chronic obstructive pulmonary disease (COPD)
- Family history for abdominal aortic aneurysm

Question 23

Symptoms of Abdominal Aortic Aneurysms:

Answer 23

• Palpable abdominal mass (Something the doctor can feel)
• Back pain
• Drop in hematocrit (rupture)
  
  • Percentage of RBC
• May be asymptomatic

Question 24

Size and Treatment Options:

• Aneurysms <____ cm in diameter are followed every ____ months with intervention if the patient becomes____
• For aneurysms ____ to ____ cm in diameter, ____ intervention may be suggested if the patient is in ____ health
• Aneurysms >____ to ____ cm may benefit from ____ repair, especially if patient has other factors for rupture (e.g., hypertension, smoking, COPD)
• Highest risk patients: Aneurysms >____ to ____ cm in diameter pose the ____ risk; risk increases with age and other medical problems

Answer 24

Size and Treatment Options:

• Aneurysms <4 cm in diameter are followed every 6 months with intervention if the patient becomes symptomatic.
• For aneurysms 4 to 5 cm in diameter, surgical intervention may be suggested if the patient is in good health.
• Aneurysms >5 to 6 cm may benefit from surgical repair, especially if patient has other factors for rupture (e.g., hypertension, smoking, COPD).
• Highest risk patients: Aneurysms >6 to 7 cm in diameter pose the greatest risk; risk increases with age and other medical problems

Question 25

**Treatment of Abdominal Aortic Aneurysms** **Surgical intervention** - Is suggested with associated ____ and ____ involvement - Length of the ____ aortic neck is important to help determine the surgical approach - ____ stent grafts for treatment are a less invasive approach to the repair of an aneurysm - Treatment: To place a ____ (plastic instrument to keep walls open and strong) - A form of repair

Answer 25

**Treatment of Abdominal Aortic Aneurysms** **Surgical intervention** - Is suggested with associated renal and iliac involvement - Length of the infrarenal aortic neck is important to help determine the surgical approach - Endovascular stent grafts for treatment are a less invasive approach to the repair of an aneurysm - Treatment: To place a stent (plastic instrument to keep walls open and strong) - A form of repair

Question 26

**Inferior Vena Cava** - Formed by the union of the ____ ____ veins ____ to the ____ common iliac artery at the level of the ____ lumbar vertebra - Ascends ____ through the ____ space on the ____ side of the aorta, ____ to the liver and piercing the central tendon of the diaphragm at the level of the ____ thoracic vertebra to enter the ____ atrium of the heart - Its entrance into the lesser sac separates it from the ____ vein - Caudal to the ____ vein entrance, the inferior vena cava (IVC) shows posterior “____” through the bare area of the liver

Answer 26

**Inferior Vena Cava** - Formed by the union of the common iliac veins posterior to the right common iliac artery at the level of the fifth lumbar vertebra - Ascends vertically through the retroperitoneal space on the right side of the aorta, posterior to the liver and piercing the central tendon of the diaphragm at the level of the eighth thoracic vertebra to enter the right atrium of the heart - Its entrance into the lesser sac separates it from the portal vein - Caudal to the renal vein entrance, the inferior vena cava (IVC) shows posterior “hammocking” through the bare area of the liver

Question 27

**Tributaries of the IVC** - Three anterior hepatic veins: ____ hepatic vein drains the ____ lobe of the liver, the ____ hepatic vein drains the ____ lobe, and the ____ hepatic vein drains the ____ lobe of the liver **Three lateral tributaries** - Right ____ vein (the left suprarenal vein drains into the left renal vein) - ____ veins - Right ____ or ____ vein - Five lateral abdominal wall tributaries: the ____ ____ vein and the four ____ veins - Three veins of origin: the two common iliac veins, and the median sacral vein

Answer 27

**Tributaries of the IVC** - Three anterior hepatic veins: right hepatic vein drains the right lobe of the liver, the middle hepatic vein drains the caudate lobe, and the left hepatic vein drains the left lobe of the liver - Three lateral tributaries - Right suprarenal vein (the left suprarenal vein drains into the left renal vein) - Renal veins - Right testicular or ovarian vein - Five lateral abdominal wall tributaries: the inferior phrenic vein and the four lumbar veins - Three veins of origin: the two common iliac veins, and the median sacral vein

Question 28

**Anterior Tributaries to IVC** - The **____ veins ** are the ____ visceral tributaries of the inferior vena cava - They originate between the **____** of the liver and **drain ____** into the inferior vena cava at the level of the ____ - The hepatic veins return **____** blood from the liver - The veins collect blood from the three minor tributaries within the liver: the **____ hepatic vein drains** the **____ lobe** of the liver, the **____ hepatic vein** drains the **____ lobe**, and the **____ hepatic vein** drains the **____ lobe of the liver** - The ____ and ____ hepatic veins may fuse before emptying into the inferior vena cava - The hepatic veins are divided into three components: right, middle, and left. They all drain into the IVC at the level of the ____

Answer 28

**Anterior Tributaries to IVC - The hepatic veins (HV) are the largest visceral tributaries of the inferior vena cava - They originate between the segments of the liver and drain posteriorly into the inferior vena cava at the level of the diaphragm - The hepatic veins return unoxygenated blood from the liver - The veins collect blood from the three minor tributaries within the liver: the right hepatic vein drains the right lobe of the liver, the middle hepatic vein drains the caudate lobe, and the left hepatic vein drains the left lobe of the liver - The middle and left hepatic veins may fuse before emptying into the inferior vena cava - The hepatic veins are divided into three components: right, middle, and left. They all drain into the IVC at the level of the diaphragm**

Question 29

**Lateral Tributaries to the IVC**

Answer 29

- Right and left renal veins - Gonadal veins - Suprarenal veins

Question 30

**Renal Veins** Left Renal Vein: - Arises ____ to exit from the ____ of the kidney - Flows from the ____ kidney ____ to the ____ mesenteric artery and ____ to the aorta to enter the ____ wall of the inferior vena cava Right Renal Vein: - Flows directly from the hilum of the ____ kidney into the ____ aspect of the inferior vena cava - It seldom accepts tributaries; the right ____ and right ____ veins enter the inferior vena cava directly

Answer 30

Left Renal Vein: - Arises medially to exit from the hilus of the kidney - Flows from the left kidney posterior to the superior mesenteric artery and anterior to the aorta to enter the lateral wall of the inferior vena cava Right Renal Vein: - Flows directly from the hilum of the right kidney into the posterolateral aspect of the inferior vena cava - It seldom accepts tributaries; the right adrenal and right gonadal veins enter the inferior vena cava directly

Question 31

**Abnormalities/Pathology Inferior Vena Cava**

Answer 31

- Congenital abnormalities: - Double IVC - Infrahepatic interruption of the IVC - IVC dilation - IVC tumor - IVC thrombosis

Question 32

**IVC Tumors and Thrombus** **Hepatic Portion of Inferior Vena Cava** - **Masses posterior** to the hepatic portion of the inferior vena cava are the right ____, neurogenic, and hepatic - With enlargement of the liver, the cava is **____** rather than displaced - A localized liver mass would produce ____, lateral, or medial displacement of the inferior vena cava, whereas a mass in the posterior caudate lobe and right lobe may ____ the cava **Small Bowel (Lower) Segment** - ____ spine abnormalities or lymph nodes would ____ the inferior vena cava

Answer 32

**Hepatic Portion of Inferior Vena Cava - Masses posterior to the hepatic portion of the inferior vena cava are the right adrenal, neurogenic, and hepatic - With enlargement of the liver, the cava is compressed rather than displaced - A localized liver mass would produce posterior, lateral, or medial displacement of the inferior vena cava, whereas a mass in the posterior caudate lobe and right lobe may elevate the cava Small Bowel (Lower) Segment - Lumbar spine abnormalities or lymph nodes would elevate the inferior vena cava**

Question 33

**Portal Vein** - Formed **____** to the **____** by the **union** of the **____ mesenteric vein** and **____ veins** - Trunk is 5 to____ cm in length. - **Carries blood** from the **____ tract** to the liver by means of its two main branches: the **____** and **___ ____ veins** - **Drains blood** from the **____ tract**; from the ____ end of the esophagus to the upper end of the ____ canal; and from the **____**, **____**, bile ducts, and **spleen** - The diameter is less than ____ mm

Answer 33

**Portal Vein - Formed posterior to the pancreas by the union of the superior mesenteric vein and splenic veins - Trunk is 5 to 7 cm in length. - Carries blood from the intestinal tract to the liver by means of its two main branches: the right and left portal veins - Drains blood from the gastrointestinal tract; from the lower end of the esophagus to the upper end of the anal canal; and from the pancreas, gallbladder, bile ducts, and spleen - The diameter is less than 14 mm**

Question 34

**Portal Triad** - Contains a branch of the ____ vein, ____ artery, and ____ ____ within a ____ tissue sheath - This gives the portal vein an ____ wall. - AKA: ____ ____ - “____ ____”

Answer 34

**Portal Triad** - Contains a branch of the portal vein, hepatic artery, and bile duct within a connective tissue sheath - This gives the portal vein an echogenic wall. - Porta hepatis - “Mickey mouse”

Question 35

**Splenic Vein** - A tributary of the ____ circulation - Begins at the hilum of the ____, where it is formed by the union of ____ veins - Joined by the ____ gastric and left ____ veins - Runs along the ____ border of the ____

Answer 35

**Splenic Vein** - A tributary of the portal circulation - Begins at the hilum of the spleen, where it is formed by the union of several veins - Joined by the short gastric and left gastroepiploic veins - Runs along the posteromedial border of the pancreas

Question 36

**Superior Mesenteric Vein** - Passes **____** to the **____ part of the duodenum** and **____ to the neck of the pancreas** where it joins the **____ vein** to form the **____ ____ vein** - Receives ____ that correspond to the branches of the superior mesenteric artery where it is joined by the inferior ____ vein to the right ____ vein from the right aspect of the ____ curvature of the stomach - Drains blood from several smaller veins: the middle ____ vein (transverse colon), right ____ vein (ascending colon), and ____ duodenal vein

Answer 36

**Superior Mesenteric Vein** **- Passes anterior to the third part of the duodenum and posterior to the neck of the pancreas where it joins the splenic vein to form the main portal vein - Receives tributaries that correspond to the branches of the superior mesenteric artery where it is joined by the inferior pancreaticoduodenal vein to the right gastroepiploic vein from the right aspect of the greater curvature of the stomach - Drains blood from several smaller veins: the middle colic vein (transverse colon), right colic vein (ascending colon), and pancreatic duodenal vein**

Question 37

**Inferior Mesenteric Vein** - Drains the left ____ of colon and upper colon and ascends ____ along the left ____ muscle - Begins ____ down the anal canal as the superior ____ vein - Receives many tributaries along its way, including the left ____ vein - Drains several tributaries: the left ____ vein (descending colon), ____ vein (sigmoid colon), and superior ____ vein (upper rectum)

Answer 37

**Inferior Mesenteric Vein** - Drains the left third of colon and upper colon and ascends retroperitoneally along the left psoas muscle - Begins midway down the anal canal as the superior rectal vein - Receives many tributaries along its way, including the left colic vein - Drains several tributaries: the left colic vein (descending colon), sigmoid vein (sigmoid colon), and superior rectal vein (upper rectum)

Question 38

**Portal Venous Hypertension** - Caused by the obstruction of the ____ vein, ____ vein, IVC, or prolonged congestive ____ failure - Doppler determines whether portal flow is **____** (toward) or **____** (away) - Portal blood is diverted in a ____ direction via various collateral venous pathways, with the formation of multiple ____ anastomoses - Portal vein shows low ____ - Patent ____ vein is the definitive diagnosis - Typical portal ____ venous flow varies - Condition is most frequently caused by ____ and obstruction of portal venous radicles by fibrosis and regenerating nodules - Is less frequently caused by portal venous thrombosis or other obstruction - Respiratory variation of vessels is usually lost in portal hypertension; no collapse of veins exists

Answer 38

**Portal Venous Hypertension** - Caused by the obstruction of the portal vein, hepatic vein, IVC, or prolonged congestive heart failure - Doppler determines whether portal flow is **hepatopetal** (toward) or **hepatofugal** (away) - Portal blood is diverted in a hepatofugal direction via various collateral venous pathways, with the formation of multiple portosystemic anastomoses - Portal vein shows low velocity - Patent paraumbilical vein is the definitive diagnosis - Typical portal hypertensive venous flow varies - Condition is most frequently caused by cirrhosis and obstruction of portal venous radicles by fibrosis and regenerating nodules - Is less frequently caused by portal venous thrombosis or other obstruction - Respiratory variation of vessels is usually lost in portal hypertension; no collapse of veins exists

Question 39

**Sonographic Findings**

Answer 39

- Dilated portal, splenic, superior mesenteric vein - Patent paraumbilical vein - Varices - Splenomegaly with dilated splenic radicles - Diminished response to respiration in portal system - Dilated hepatic and splenic arteries - Ascites - Small liver with irregular surface or large liver with abnormal texture