Lecture 19 - Abdominal Veins and Visceral Innervation Flashcards
(72 cards)
1
Q
What are the two systems of venous drainage?
A
- Portal system
- Caval system
2
Q
What is the portal system?
A
- Blood from some abdominal viscera drains into the portal vein
- Filtered by the liver
3
Q
What are the abdominal viscera that drains into the portal vein?
A
- Spleen
- Pancreas
- Gallbladder
- GIT
4
Q
What neurovasculature connects the portal system to the inferior vena cava?
A
Via hepatic veins
5
Q
Where do the hepatic veins drain into the IVC?
A
Below diaphragm before passing through the caval hiatus
6
Q
What form the capillaries in the portal system?
A
Two veins
7
Q
What is the caval system?
A
Blood from the rest of the lower body drains into the inferior vena cava
8
Q
Where does the caval system pass?
A
Through the central tendon of the diaphragm at T8 (through caval hiatus)
9
Q
How is blood carried back to the inferior vena cava?
A
Via paired veins
10
Q
Where is the IVC located in relation to the midline?
A
To the right of the midline
11
Q
What does the location of the IVC cause left veins to do?
A
- Left veins can be substantially longer
- Left veins drain into the renal vein
12
Q
What left veins are substantially longer?
A
Renal vein
13
Q
What left veins drain into the renal vein?
A
- Suprarenal vein
- Gonadal veins
14
Q
What do the right veins drain into?
A
The inferior vena cava
15
Q
What are the structures of the caval system?
A
- Inferior phrenic vein
- Hepatic veins
- Suprarenal vein
- Renal veins
- Gonadal veins
- Common iliac vein
16
Q
What is left renal vein entrapment syndrome?
A
- AKA nutcracker syndrome
- Compression of the left renal vein
- Passes between abdominal aorta and superior mesenteric artery
- Leads to blockage of venous return
17
Q
What is the consequence of nutcracker syndrome?
A
- Problems with venous drainage from left kidney and left gonad
- Symptoms: Referred pain, blood in urine, and varices
18
Q
What 3 major vessels drain into the portal vein?
A
- Splenic vein
- Inferior mesenteric vein
- Superior mesenteric vein
19
Q
Where does the splenic vein drain blood from?
A
- Spleen
- Foregut (large portion: esophagus, stomach, pancreas)
20
Q
Where does the inferior mesenteric vein drain blood from?
A
Hindgut
21
Q
Where does the inferior mesenteric vein drain?
A
Splenic vein
22
Q
Where does the superior mesenteric vein drain blood from?
A
Midgut
23
Q
The joining of which neurovasculature creates the portal vein?
A
- Splenic vein
- Inferior mesenteric artery
- Superior mesenteric vein
24
Q
Where does blood enter in the portal system?
A
- Proper hepatic artery
- Portal vein
25
What does blood in the portal vein contain?
Venous blood contains nutrients and toxins
26
What does the proper hepatic artery supply?
Regular arterial blood supply to the liver
27
What is the function of the portal system?
1. Blood filtration
2. Nutrient metabolism
28
What is the portal triad?
1. Portal vein
2. Proper hepatic artery
3. Bile duct
29
What are portosystemic anastomoses?
- Occurs in individuals with elevated pressure in the portal vein
- Blood that normally drains via the portal system enters systemic circulation
- Occurs at these sites
30
What can portosystemic anastomoses lead to?
Enlargement of veins in these regions (exp: varices/caput medusae)
31
Where are the 3 portosystemic anastomoses?
1. Gastroesophageal junction
2. Anterior abdominal wall around umbilicus
3. Anorectal junction
32
What type of innervation does the lumbar plexus provide?
Somatic innervation
33
What are the nerves of the lumbar plexus?
1. Iliohypogastric
2. Ilioinguinal
3. Genitofemoral
4. Lateral cutaneous nerve of the thigh
5. Femoral
6. Obturator
34
What are the two types of viscera motor innervation?
Sympathetic and parasympahtetic
35
What effects can sympathetic innervation have on the body?
- Increase epinephrine release
- Decrease urine production
- Decrease GI motility
36
What effects can parasympathetic innervation have on the body?
- Relaxation of sphincters
- Increase digestive enzyme production
- Increase GI motility
- Increase urine production
37
What are prevertebral ganglia?
Where preganglionic sympathetic neurons of sympathetic splanchnics synapse
38
What are the 4 prevertebral ganglia?
1. Celiac ganglia
2. Superior mesenteric ganglion
3. Aorticorenal ganglion
4. Inferior mesenteric ganglion
39
What neurons synapse in the celiac ganglia?
Greater splanchnic nerve
40
What neurons synapse in the superior mesenteric ganglion?
1. Lesser splanchnic nerve
2. Least splanchnic nerve
41
What neurons synapse in the aorticorenal ganglion?
Lesser splanchnic nerve
42
What neurons synapse in the inferior mesenteric ganglion?
Lumbar splanchnic nerve
43
What are the 4 plexes of visceral sympathetic innervation?
1. Celiac and renal plexes
2. Superior mesenteric plexus
3. Inferior mesenteric plexus
4. Superior hypogastric plexus
44
What makes up the celiac and renal plexes?
Thoracic splanchnic n. + vagal trunk branches
45
Where does the celiac and renal plexes innervate?
Foregut and kidneys
46
What makes up the superior mesenteric plexus?
Lesser and least splanchnic n. + vagal trunk branches
47
Where does the superior mesenteric plexus innervate?
Midgut
48
What makes up the inferior mesenteric plexus?
Lumbar splanchnic n. + vagal trunk branches
49
Where does the inferior mesenteric plexus innervate?
Hindgut
50
Where does superior hypogastric plexus innervate?
Pelvic viscera
51
What passes through these plexes but do not synapse in prevertebral ganglia?
Parasympathetic neurons + visceral sensory neurons
52
What do visceral plexes follow to reach their destinations?
Follow vessels/major arteries
53
What is an example of the plexus following a major artery?
Superior mesenteric plexus:
Follows superior mesenteric artery + major branches to midgut
54
Where does most of the parasympathetic innervation of the abdomen originate from?
Vagus nerve
55
Where is parasympathetic innervation carried?
- Through the diaphragm (along the esophagus)
- Via anterior and posterior vagal trunks
56
What does the parasympathetic innervation innervate?
Foregut and midgut
57
Where does parasympathetic innervation of the hindgut and pelvis come from?
S2-S4 sacral outflow
58
What does the parasympathetic innervation from S2-S4 arise as?
Pelvic splanchnic nerves
59
Where do the pelvic splanchnic nerves run?
- Enters inferior hypogastric plexus
- Axons ascend toward inferior mesenteric region
60
Where does visceral sensation from organs return?
To spinal cord
61
How does visceral sensation return to the spinal cord?
Via plexes and splanchnic nerves
62
What are spinal levels associated with?
Referred pain patterns to the corresponding dermatomes (ipsilaterally)
63
What are the associated spinal levels for the liver?
T6-T9
64
What are the associated spinal levels for the stomach?
T6-T9
65
What are the associated spinal levels for the spleen?
T6-T8
66
What are the associated spinal levels for the kidneys?
T10-L1
67
What are the associated spinal levels for the small intestine ?
T8-T10
68
What are the associated spinal levels for the ascending colon?
T10
69
What are the associated spinal levels for the transverse colon?
T11
70
What are the associated spinal levels for the descending colon?
T12-L3
71
What are the associated spinal levels for the sigmoid colon?
S2
72
What are the associated spinal levels for the rectum?
S4
