arterial supply, venous and lymphatic drainage of the VC Flashcards
(156 cards)
1
Q
Bone receives up to what?
A
10% of cardiac output, allowing it to have a high level of remodelling and repair
2
Q
Hence disruption of blood supply can impede what?
A
repair and growth
3
Q
Vertebral column is one of what?
A
the largest stores of bone marrow in the body
4
Q
2 types of bone marrow?
A
Red marrow and Yellow marrow
5
Q
The vertebral column receives its blood supply segmentally from where?
A
segmental arteries, Vessels lying adjacent to the vertebral column give branches
6
Q
red marrow is what?
A
Red marrow → primary site of haematopoiesis, hence needs rich vasculature
7
Q
The cervical vertebrae are supplied by what?
A
the vertebral and ascending cervical arteries
8
Q
Vertebral artery, along with vertebral veins and sympathetic nerves, travel where? what is the exception?
A
through the transverse foramen of C1-6, Exception of C7 where the artery passes around the vertebra and not through the transverse foramen
9
Q
can variations occur in the arterial supply?
A
yes, Study found 20% of specimens had anatomical variation of vertebral artery (Accessory vessels, lateral loops)
Also in 20% the vertebral artery entered through the transverse foramen of a vertebra other than C6
10
Q
Vertebral artery gives spinal branches which enter where?
A
the vertebral canal through the intervertebral foramen
11
Q
Ascending cervical artery runs along where?
A
the anterior tubercles of the transverse processes at the level of C4
12
Q
Ascending cervical artery
Also gives spinous branches which enter where?
A
the vertebral canal through the intervertebral foramen
13
Q
Ascending cervical artery Has been shown to only give spinal branches to where?
A
to the C4-5 and C3-4 foramen (occasionally C2-3)
14
Q
There is evidence that C5-6 and C6-7 are supplied by what?
A
branches from the deep cervical artery and the cost cervical trunk
15
Q
The thoracic vertebrae are supplied by what?
A
the posterior intercostal and subcostal arteries
16
Q
First 2 pairs of post. Intercostal arteries are branches of what?
A
the superior intercostal artery from costo-cervical trunk of the subclavian
17
Q
Pairs 3-11 arise from what?
A
the posterior wall of the thoracic aorta
18
Q
variances of arterial supply of thoracic region?
A
In most individuals these pared vessels arise symmetrically.
However, in a cadaveric study found that these vessels were asymmetrically distributed in 16% of specimens
One vessel may also supply 2 vertebrae
19
Q
The 12th pair of arterial supply thoracic region are termed what?
A
the subcostal arteries as they arise below the ribs
20
Q
Spinal branches enter where?
A
through the intervertebral foramen
21
Q
L1-4 are supplied by what?
A
the lumbar arteries
22
Q
how many paired lumbar arteries are there?
A
4
23
Q
where do the lumbar arteries arise?
A
arise from posterior wall of abdominal aorta
Pass laterally along the vertebra until they reach the intervertebral foramen
24
Q
Lumbar arteries usually arise ?
A
symmetrically
25
L5 is supplied by what?
lumbar branches from the middle sacral and iliolumbar arteries
26
Branches from the middle sacral artery are much..?
smaller than the lumbar segments
27
Branches from the middle sacral artery are Reinforced by?
posteriorly by iliolumbar branches and a communicating artery from L4
28
The sacrum and coccyx are supplied by what?
the lateral sacral arteries which also show a wide range of variation
29
arterial blood supply of cervical vertebrae?
Vertebral and ascending cervical
30
cervical arterial supply arising from?
Subclavian and inferior thyroid
31
arterial blood supply of thoracic vertebrae?
Posterior intercostal and subcostal
32
thoracic arterial supply arising from?
Subclavian and thoracic aorta
33
arterial blood supply of lumbar 1-4 vertebrae?
lumbar
34
lumbar 1-4 arterial supply arising from?
abdominal aorta
35
arterial blood supply of lumbar 5 vertebrae?
Middle sacral and iliolumbar
36
lumbar 5 arterial supply arising from?
Abdominal aorta and internal iliac
37
sacrum and coccyx arterial supply arising from?
lateral sacral
38
sacrum and coccyx arterial supply arising from?
internal iliac (post. division)
39
The main segmental arteries supplying each region give what?
10-20 periosteal branches
40
main segmental arteries supply what?
Supply the periosteum of vertebrae
41
Periosteal branches of adjacent segmental arteries anastomose where? and are More prominent between?
on anterolateral and posterior surfaces,More prominent between L4-5
42
Metaphyseal anastomosis
| Surrounds where?
the anterior and lateral surfaces
43
Beyond the spinal branch, segmental artery branches into what?
an anterior and posterior artery
44
Anterior part → ?
to other surrounding tissues
45
Posterior part →?
supplies the posterior parts of the vertebra
46
Spinal branch branches into what?
Anterior vertebral canal artery
Segmental medullary artery
Posterior vertebral canal artery
47
Anterior vertebral canal artery → ?
to vertebral body
48
Segmental medullary artery → ?
to spinal cord (covered later)
49
Posterior vertebral canal artery → ?
to vertebral arch
50
The anterior canal branches send nutrient arteries via what?
the nutrient foramen into the body to supply the red marrow
51
Segmental arteries → ?
Periosteal and Equatorial branches
52
Segmental arteries →? → ? → ?
Spinal branch, Anterior and posterior canal branches, (from ant. Canal) Nutrient arteries
53
There are 3 types of intra-osseous arteries?
peripheral, equatorial, metaphyseal
54
Peripheral →?
supply the outer circumference
55
Equatorial → ?
supply the central core of the body (along with the nutrient arteries)
56
Metaphyseal →?
supply an annular zone between
57
This distribution results in what?
zoning of the blood supply to the vertebral body
58
Mature intervertebral discs are what? apart from what?
largely avascular structures, Apart from periphery which receives supply from adjacent vessels
59
what to IV discs rely on in terms of blood supply?
Rely on diffusion from the trabecular bone of adjacent vertebrae for nutrients
60
Hence any disruption of flow to the vertebral bodies will cause what?
will heavily impact the IVDs
61
Branches of metaphyseal and nutrient arteries form what?
a capillary plexus in the endplate
62
Cells within the IV disc require what?
require nutrition in order to maintain their integrity, hence a good blood supply is essentia
63
Because blood supply is from vertebral bodies, supply of the IVD is what?
zoned
64
As aging occurs, arteries begin to do what?
gradually narrow and deteriorate
65
what are the first arteries to be affected in disc degeneration?
Metaphyseal and nutrient arteries first affected
66
what happens to the peripheral arteries in disc degeneration?
peripheral arteries increase in number, IV disc also gains greater peripheral supply
67
what is linked to disc degeneration ?
Decreased blood supply
68
It has been shown that disc degeneration first appears where?
at the centre of the disc
69
can periphery can be capable of repair long after centre has degenerated
yes
70
what else can also be contributed to by smoking and other pathologies ?
Reduction in blood supply can also be contributed to by smoking and other pathologies
Pathologies such as scoliosis can cause the cartilaginous end plate to calcify, limiting blood flow and causing degeneration of the disc
71
what is Schmorl's nodes?
herniation of nucleus pulposus through bony and cartilaginous end plate into the adjacent vertebral body
72
where does Schmorl's nodes occur?
Occur frequently in humans and are usually asymptomatic but can be associated with back pain
73
where is Schmorl's nodes usually observed?
Commonly observed on radiographs and at autopsy (studies have found that ~73% of the population present with small herniations)
74
does Schmorl's nodes occur more frequently in men or women?
men 76% of cases
75
where does Schmorl's nodes occur?
Tends to occur at the thoracolumbar transition region (T7-L1)
76
what has Schmorl's nodes been correlated with?
disc degeneration in some studies
77
The spinal cord is supplied by how mant longitudinal arteries arising from where
3 longitudinal arteries arising from the vertebral artery
78
anterior spinal artery runs where?
in the anterior median sulcus
79
anterior spinal artery branches into what?
sulcal arteries
80
what are the 3 longitudinal arteries supply the spinal cord?
anterior spinal artery
| 2x posterior spinal arteries
81
where do the posterior spinal arteries run?
down the posterolateral sulcus
82
what do the posterior spinal arteries divide into?
2 collateral arteries that branch to form the pia plexus?
83
where do the 2 posterior spinal arteries supply?
1/3 of spinal cord
84
largest anterior segmental medullary artery (artery of Adamkiewicz) arises where?and supplies where?
around T12 or L1 → supplies inf. 2/3 of spinal cord
85
where is there less supply in the spinal cord?
Less supply in mid thoracic region compared to cervical and thoracolumbar regions
86
where do the radicular arteries supply?
they supply spinal nerve roots, but segmental medullary arteries are also referred to as radicular feeder arteries.
87
radicular arteries end where before reaching where?
end in the nerve root before reaching the ant. Or post. Spinal arteries, but segmental medullary go on to feed into the spinal arteries.
88
where do the anterior and posterior segmental medullary arteries enter?
through nerve roots
89
what is spinal cord infarction?
death of nervous tissue as a result of interrupted blood supply
90
how common or rare is spinal cord infarction?
Relatively rare, accounts for 0.3-1% of strokes
91
If the blood supply is damaged or interrupted (e.g. during surgery) depending if it’s anterior or posterior what can occur?
different areas of the spinal cord will be damaged, resulting in specific, different neurological consequences
92
damage to anterior in relation to spinal cord infarction results in?
loss of motor functions
93
damage to posterior in relation to spinal cord infarction results in?
loss of sensory functions
94
which spinal cord infarction is more common?
95% of spinal cord infractions occur anteriorly
95
where is spinal cord infarction most common and why?
thoracic region due to reduced blood supply
96
what would a patient present with, with spinal cord infarction?
present with sudden onset of symptoms with rapid progression.
However, due to it’s rarity the exact course isn’t well documented and symptoms and progression can vary
97
what are the causes of spinal cord infarction?
Vertebral fractures
Dislocations
Vasculitis
external compression (e.g. abdominal tumours)
98
current treatments of spinal cord infarction?
Currently treatment is aimed at any detectable causes
99
what is the venous drainage of spinal cord?
6 longitudinal veins that run down the length of the spinal cord including :
3 anterior and 3 posterior spinal veins
100
anteromedian vein is located where?
located deep - In the lumbar region
101
anteromedian vein is accompanied by what?
2 anterolateral veins
102
what is the dominant vessel in the lumbar area?
A midline posteromedian vein
103
spinal cord receives blood from where?
neural tissue via sulcal veins
104
sulcal veins drain where?
into the radicular veins then drain to the internal vertebrae venous plexus
105
blood from the external vertebrae plexus drains where?
drains into the systemic veins including:
Mainly innominate veins at cervical level
Azygos vein at thoracic level
Ascending lumbar vein at the lumbar level
106
the venous plexus in relation to thhe VC is formed by what?
spinal veins, both inside and outside the vertebral canal
107
the plexuses includes what?
internal (or epidural) and external vertebral venous plexus
108
what does the venous plexuses lack?
valves
109
the internal vertebral venous plexus is located where?
Located beneath the bony elements of the vertebral foramina
110
the internal vertebral venous plexus is embedded where?
Embedded in loose areolar tissue layer known as epidural adipose tissue
111
the internal vertebral venous plexus is divided into what?
Divided into the anterior and posterior vertebral plexus
112
what is involved in the internal vertebral venous plexus?
4 longitudinal channels, two along posterior aspect of vertebral canal, two along the anterior aspect of canal
113
does the internal vertebral venous plexus have valves?
no
114
The anterior and posterior plexuses (IVVP) communicate freely with what?
one another through a series of venous rings, there is one opposite each vertebra.
115
At the foramen magnum the anterior and posterior pleaxuses (IVVP) form what?
an intricate net-work which opens into the vertebral vein
116
Radicular veins and the basivertebral veins all join what?
the internal vertebral venous plexuses and drain the vertebral column
117
The vertebral vein is formed from what?
The vertebral vein is formed from small tributaries springing from this plexus
118
where is the anterior and posterior pleaxuses (IVVP) found?
anterior- Found on the posterior surfaces of the vertebral bodies
posterior- Found in front of the vertebral arches
119
The two anterior channels lie where?
either side of the posterior ligament
120
The posterior channels lie where?
Lie on the inner surfaces of the laminae and ligament flava
121
where does the anterior internal venous plexus anastomose?
Anastomosing across the midline
122
where does the posterior internal venous plexus anastomose?
Anastomose across the midline with some vessels emerging to join the posterior external plexus by passing between the free medial edges of the ligament flava
123
the anterior internal venous plexus recieves what?
Receiving the basivertebral vein, anterior to the ligament
124
what is the External Vertebral Venous Plexus?
Network of veins surrounding the external aspect of the vertebral column
125
what is the External Vertebral Venous Plexus divided up into?
Divided into an anterior plexus surrounding the vertebral bodies and a posterior plexus associated with the neural arches
126
what does the External Vertebral Venous Plexus communicate with?
Communicates with the internal venous plexuses through the intervertebral foramina
127
what drains into the external vertebral plexus?
The internal plexus drains into the external plexus, which in turn drains into the vertebral veins of the neck and segmental (intercostal, lumbar, and sacral) veins of the trunk
128
the anterior external venous plexus surrounds what?
vertebral body
129
anterior external venous plexus communicated with what?
Communicates with the basivertebral veins and intervertbral veins
130
where is the posterior external venous plexus found?
Found along the posterior surfaces of the vertebral arches and the spinous process of the vertebrae.
131
the posterior external venous plexus best developed where?
cervical region
132
The intervertebral veins go where?
through the intervertebral foramina with the spinal nerves
133
The intervertebral veins drain what?
The intervertebral veins drain the internal and external vertebral plexus
134
Basivertebral veins come from where?
come from the foramina on the posterior surfaces of the vertebral bodies
135
Basivertebral veins run through where?
the vertebral body, communicate posteriorly with the internal vertebral plexus and anteriorly with the external vertebral venous plexus
136
do the intervertebral veins and basivertebral veins have valves?
unknown
137
what could this unknown fact about the veins explain?
This could be an explanation as to why pelvic neoplasms can metastasize in vertebral bodies
e.g. prostate carcinoma
138
what follows the arteries?
Deep lymphatic vessels commonly
139
At each level, lymph drains to their associated nodes?
Cervical vertebral column → Deep cervical nodes
Thoracic → Posterior intercostal nodes
Lumbar column → Lateral aortic and retro-aortic nodes
Pelvis → Lateral sacral and internal iliac nodes
140
The lymphatic system can frequently act what?
act as a pathway for the spread of disease, such as cancer metastasis and various inflammatory disorders
141
Breast cancer is frequently associated with what?
bone cancer due to the fact breast tissues drain to the axillary lymph nodes – proving a pathway for the spread of disease
142
how many breast cancer patients develop bone cancer?
Up to 70% of terminal breast cancer patients also develop bone cancer (primarily in the vertebral column) due to the extensive lymphatic network around the vertebral column
143
The spread of cancer from one part of the body to another is named ?
METASTASIS
144
A metastatic tumour is a what?
tumour that is formed by cells that have spread
145
Cells can break off the tumour and what happens?
therefore travel to other parts of the body through the bloodstream or lymphatic system. This can result in them settling in a different area and ending up in any organ or tissue
146
The most common site of metastasis is where?
the vertebral column
147
Spinal column metastases is commonly what?
secondary to malignant neoplasm of the breast, lung and prostate
148
In 90% of patients, what is the initial symptom?
pain
149
what can occur in metastatic spread
Fracturing or collapsing of the vertebral body, pressure on the periosteum from within the vertebra, or nerve root and spinal cord compression
150
how many terminally ill patients will have metastases and where?
30-90% of terminally ill patients with cancer have metastases somewhere spinal column segment
151
The principal process of spinal metastasis is through
| what?
the Batson venous plexus
152
who first described metastasis and when?
Anatomist Oscar Vivian Batson, who first described it in 1940
153
Network of valve-less veins connecting what?
the deep pelvic veins and thoracic veins to the internal vertebral venous plexuses
154
metastasis believed to what?
Believed to provide a route for spread of pelvic cancer metastases/ infections to the spine due to reversed blood flow
155
Provide a route for what?
Provide a route for breast cancer metastases to vertebrae, skull, pelvic bones
156
In 1940, Batson injected contrast into the vein of the penis in males and veins of the breast in women
Results showed what?
that tumor cells spreading in blood into the spinal veins.
