Vascular Strucures Flashcards
What is the cardiac cycle? 5
- Arteries transport oxygenated blood from LV to muscles and organs in the body
- Veins return unoxygenated blood from the muscles and organs to the RA
- Unoxygenated blood travels from the RA to the RV where it is forced into the pulmonary arteries
- Blood is carried to the lungs and an exchange of gas occurs
- Oxygenated blood returns to the heart via pulmonary veins to the LA
What are the 3 principle layers of the vessels?
- Tunica Intima
- Tunica media
- Tunica Adventitia
What is the tunica Intima composed of?
Endothelial lining and elastic tissue
What is the tunica media composed of?
Elastic fibres and smooth muscle
What is the tunica Adventitia made of?
Elastic and collagen fibres
Which are thicker arterial walls or veins?
Arterial walls
Venous calibre varies with what?
Respiration
Veins contain what to assist in the transport of blood?
Valves
Arterial blood flow is influenced by what?
The heart
Venous blood flow is influenced by what? 3
- Pressure gradient
- Breathing
- Muscle contraction
Between veins and arteries which has larger diameters?
Veins
Blood flow is slower in arteries or veins?
Veins
Where is the aorta located? 2
- Retroperitoneal
- Anterior to spine/left of midline
Where does the aorta enter?
The abdomen through the diaphragm at the level of T12
What happens as we move caudally on the aorta?
More anterior and tapers distally
What structures are anterior to the aorta? 10
- Crura
- Celiac axis
- Lesser sac
- SMA
- LRV
- Pancreatic body
- IMA
- SV
- SA
- LLL
What are the aortic branches? 6
- Celiac artery (truck or axis)
- Super mesenteric artery (SMA)
- Right and left renal arteries
- Right and left gonadal arteries
- Inferior mesenteric arteries (IMA)
- Common iliac arteries (CIA)
Where is the Celiac axis located on the aorta?
Within the first 2 cm of the abdominal aorta
What does the celiac axis divide into? 3
- Left gastric artery
- Common hepatic artery
- Splenic artery
What is the smallest branch of the celiac axis?
Left gastric
What is the path of the common hepatic artery?
Horizontal path to the right
Where is the common hepatic artery located? 2 (in relation to the pancreas and main portal vein)
- Superior to the pancreatic head
- Anterior to the main portal vein
Where does the common hepatic artery enter?
Porta hepatis
What are the hepatic artery branches? 3
- Gastroduodenal artery
- Right gastric artery
- Cystic artery
What does the cystic artery arise from?
Arises form right hepatic artery
What does the cystic artery supply? 3
- GB
- CBD
- HD
What is the largest of the 3 branches of the Celiac axis? What does it supply?
- Splenic artery
- Supplies blood to the pancreas, spleen, and stomach
Where is the splenic artery located? (In relation to the spleen and the Pancreas) 2
- Left towards the spleen
- Posterior and superior to the pancreas body and tail
Where is the SMA located in relation to the pancreatic body and the uncinate process ? 2
- Posterior to pancreatic body
- Anterior to uncinate process
What does the SMA supply?
Small and large bowel
Where is the renal arteries branch located on the aorta?
Inferior to the SMA
Where is the Right renal arteries located in relation to the IVC?
Posterior
Which is longer the Right renal artery or the left renal artery?
Right renal artery because the aorta is located on the left side of the body
Are the gonadal arteries often seen on ultrasound?
Not typically
What is the IMA?
Last major branch of the aorta
What does the IMA supply typically? 3
- Left transverse, descending colon
- Sigmoid colon
- Upper rectum
Is the IMA seen typically on U/S
no
Where does the Aorta bifurcate at?
L4
The Common iliac arteries course where?
Inferiorly and posteriorly
What does the Common iliac arteries divide into?
External and internal iliac arteries
How do we measure the aortic wall?
Outer wall to the outer wall
What are common iliac measurement?
Males: 1.4- 1.5 cm
Females: 1.2 cm
What is the patient prep for aortic scans?
Overnight fast, this decreases gas in abdomen
What is the most common settings for aortic scans? (What kind of probe we use, What frequency the probe is) 3
- 2-6 MHz
- Curvilinear probe
- Presets depends on body habitus
For aortic scans how does the patient position themselves?
Supine however coronal plane is an option
What is the largest vessel that returns blood to the heart?
IVC
What is the IVC formed by? (where is it formed by, and by what)
The union of the Common iliac veins at the L5
The IVC is located in what plane?
Retroperitoneal and right of midline
The IVC courses how?
Cranially and enters the RA of the heart
What is the size of the IVC?
Variable: Dilated if >2.5 cm
The renal veins enter what aspect of the IVC?
Lateral
How are the renal veins located in relation to the renal arteries?
They are anterior to the arteries
Which is shorter the RRV or the LRV?
RRV
Where is the LRV located in relation to the aorta and SMA
- Anterior to aorta
- Posterior to SMA
What do the gonadal veins drain?
Testicular or ovarian
What does the Right gonadal vein empty into?
IVC
Where does the Left gonadal vein drain into?
LRV
Where are the lumbar veins located?
- Lateral to spine
- Posterior to Psoas
How many hepatic veins are there?
Three
1. Left
2. Middle
3. Right
What does the hepatic veins do?
Drain blood form the liver
What does the hepatic veins drain into?
Into the IVC just inferior to the diaphragm
Does the hepatic veins have valves?
No
What happens to the hepatic veins close to the diaphragm and IVC?
Increase in size
What are the sonographic appearance of the IVC?
- anechoic right of ML
- Does not taper
- Walls not as echogenic as aorta
- Oval shaped, anechoic
- Respiratory changes
Does the IVC respond to respiratory change?
Yes
In what plane is the Hepatic vein best seen?
Transverse plane
What does the portal venous system drain? 4
- Bowel
- Spleen
- Pancreas
- GB and Bile ducts
What happens in the portal venous system in relation to the liver, IVC, and hepatic veins?
Blood traverses liver and drains in to IVC via Hepatic veins
The Porta venous system does not do what? And does not contain what?
- connect directly into the IVC
- Contain valves
What is the Porta venous system formed by? 3
Union of the
1. SV
2. SMV
3. IMV
The Splenic veins starts where?
Splenic hilum and courses medially
Where is the splenic vein located in relation to the pancreas and SMA?
- Posterior and inferior to body and tail of pancreas
- Anterior to aorta and SMA
What kind of path does the splenic vein have?
Tortuous
What is the portal confluence?
Where the Splenic vein and the SMV join
What is the start/ origin of the main portal vein?
Portal confluence
Where does the SMV run in relation to the SMA?
Parallel and to the right of the SMA
Where is the SMV located in relation to the uncinate process of the pancreas?
Anterior to the uncinate process of the pancreas
Where does the SMV originate?
Root of the mesentery
What is the Main portal vein formed by?
Union of the Splenic vein and the SMV
Where is the confluence located in relation to the pancreas? Which part of the pancreas?
Posterior to the pancreatic neck
How big is the main portal vein?
<13 mm in diameter
How does the Main portal vein travel? 3
To the
1. Right
2. Superior
3. Oblique
from the confluence
Where does the Main portal vein enter? What does it divide into?
Enters the liver at the porta hepatis and divides into the right and left portal veins
The main portal vein supplies how much oxygen to the liver?
50-60%
The Left portal vein moves along which surface?
Anterior surface of caudate then turns anterior
The Left portal vein divides into which branches? 2
Medial and lateral branches
Between the right and left portal vein, which is shorter and fatter?
The right portal vein
How does the right portal vein travel?
Posterior and caudal
The right portal veins divides into which branches?
Anterior and posterior branches
The transverse plane of the right portal displays what axis for the liver?
long axis
What is the sonographic appearance of the portal veins? 3 (wall apperance, collapsibility, size in relation to porta hepatis)
- Echogenic walls
- Do not collapse
- Decrease in size moving away from the porta hepatis
What is the normal spectral waveforms for the IVC?
- Phasic
- Bidirectional/ Pulsatile (chaotic)
What is the normal spectral waveforms for the hepatic veins? 2
- Phasic, pulsatile
- Flow away from the liver Because it is draining blood away
What is the normal spectral waveforms for the renal artery?
Low resistance
What is the normal spectral waveforms for the renal vein?
phasic flow variations
What is the normal spectral waveforms for the portal veins?
- Phasic, continuous, hepatorenal
- Some pathological conditions can reverse the flow of blood (hepatofugal).
What does hepatopedal mean?
Towards the liver
What does hepatofugal mean?
Away from the liver
What is the normal spectral waveform for the aorta?
- Moderate resistance above the renals
- High resistance below the renals