Cardiovascular Flashcards
(230 cards)
1
Q
what is the definition of an artery?
A
blood vessel that carries blood away from the heart
2
Q
what is the definition of a vein?
A
blood vessel that carries blood to the heart
3
Q
what are the exceptions to the O2 concentration trends in arteries and veins?
A
pulmonary arteries/veins, umbilical arteries/veins in fetus
4
Q
what is the first functional system to develop in vertebrate embryos?
A
the vascular system
5
Q
what 2 processes does development of blood vessels occur via?
A
vasculogenesis and angiogenesis
6
Q
which is first vasculogenesis or angiogenesis?
A
vasculogenesis
7
Q
what is vasculogenesis?
A
de novo making of primitive blood vessels
8
Q
what is angiogenesis?
A
remodelling of primary capillary networks, formation of arteries and veins
9
Q
what do blood and vessels develop from in intraembryonic vasculogenesis?
A
lateral plate mesoderm
10
Q
what do blood and vessels develop from in extraembryonic vasculogenesis?
A
extrembryonic mesoderm associated with yolk sac (endoderm derived)
11
Q
what does intraembryonic vasculogenesis form?
A
dorsal aorta and posterior cardinal vein, capillary networks in mesoderm of each organ
12
Q
what do de novo blood vessels develop from?
A
blood islands
13
Q
what are blood islands?
A
small cell clusters where the peripheral cells give rise to the endothelial cells and the central cells become blood cells
14
Q
what are hemangioblasts?
A
central cells of blood islands which develop into blood cells
15
Q
what does extraembryonic vasculogenesis form?
A
the capillary network draining into the veins that brings nutrients and gases to the embryo
16
Q
what causes endothelial cells to migrate in angiogenesis?
A
secreted factors (e.g. VEGF) and hypoxia
17
Q
are arteries and veins made from the same endothelial precursor cells?
A
yes
18
Q
where do veins and arteries sort from each other?
A
in the capillary plexus
19
Q
where do angioblasts coalesce to form the aortal and cardinal vein beneath it?
A
the midline of the embryo
20
Q
what ensures that arteries and veins only fuse with their blood vessel type?
A
different cell surface receptors
21
Q
what induces vein formation?
A
arteries
22
Q
what can nerves secrete to induce artery formation?
A
angiogenic factors (e.g. VEGF)
23
Q
why do arteries and peripheral nerves grow alongside each other?
A
they induce each others’ formation
23
Q
when does vasculo- and angiogenesis take place in the adult body?
A
new blood vessels after injury, in muscle after exercise, new vessels to bypass blocked vessels
23
what is the tunica interna made of?
endothelial cells and basement membrane
23
what is it called when new vessels are formed to bypass blocked vessels?
collateral circulation
23
what can arteries secrete to induce nerve formation?
nerve growth factors
23
what are the components of the arterial wall?
tunica interna, tunica media, tunica externa
24
what is the tunica media made of?
smooth muscle cells and elastic net, autonomic innervation
24
what is the function of tunica intima?
exchange with tissues
24
what is the arterial wall layer that varies the most in size?
tunica media
25
what is tunica externa made of?
loose connective tissue, vegetative nerves, vasa nervosum, vasa vasorum
26
what anchors blood vessels to the surrounding tissue?
tunica externa
27
what is the vasa vasorum?
vessels of the vasculature, nutrient supply to larger arteries
28
where are the conducting arteries located?
close to the heart
29
where are the distributing muscular arteries located?
further from the heart
30
what do arterioles have to regulate flow?
sphincters
31
what is the average capillary diameter?
5-15micrometers
32
what layers make up the capillary wall?
endothelium and outer basement membrane
33
what layers make up vein walls?
tunica intima, media and externa
34
what acts as a blood reservoir in liver and spleen?
the venous system- venous sinuses
35
what stops backward flow in veins?
valves formed by tunica interna
36
what promotes venous return?
contraction of adjacent skeletal muscle and pulsation of adjacent arteries
37
what type of large blood vessels are found superficially?
veins
38
what is the name of regions where collateral arteries join with other arteries?
anastomoses
39
what is the Latin name of the network of blood vessels reaching a given tissue or organ?
rete arteriosum
40
what is the name of arteries which don't anastomose with other arteries?
terminal or end arteries
41
what happens when terminal arteries are blocked?
tissue dies
42
where are terminal arteries found?
heart, brain, central artery of retina, kidneys
43
what are arteriovenous anastomoses?
connections between arterioles and venules bypassing a capillary bed
44
what structures are able to interrupt flow to/from a capillary bed?
barrier arteries and sphincter veins
45
what is a rete mirabile?
exuberant parallel branching from a blood vessels that reunites in a single vessel
46
where are rete mirabile found?
in brain, in renal glomeruli of kidney
47
what is a portal venous system?
when blood from a capillary bed pools into another capillary bed through veins before going to the heart
48
what is the function of portal venous systems?
to transport products directly from 1 region to another, avoiding spreading to the rest of the body
49
where does the hepatic portal system take blood from?
capillary beds of GI tract, spleen, pancreas
50
where does the hepatic portal vein take blood to?
capillary beds in sinusoids of the liver
51
what is the function of the hepatic portal system?
absorption and detoxification of metabolites before they reach systemic circulation
52
what drains venous blood from the liver into the caudal vena cava?
hepatic veins
53
where do hepatic veins drain blood from and to?
from liver into caudal vena cava
54
what are 3 examples of portal systems?
hypophyseal portal system, renal portal system, hepatic portal system
55
how many main chambers do fish have in their hearts?
2 - atrium and ventricle
56
what do fish breathe through?
their gills
57
where does blood pass from ventral aorta in fish?
through gills where its oxygenated, then via dorsal aorta to supply head and body
58
what structure in the fish developed into lungs in mammals?
swimbladder
59
what does the swim bladder do?
fills with air so the fish can float
60
what divides the heart into its 4 chambers?
septum
61
in what group did the 4 chambered heart evolve independently?
archosaurs
62
which gill arch artery became the aorta in mammals?
gill arch 4 artery
63
which gill arch section became the common carotid in mammals?
section between arches 3 and 4
64
which blood supply in fish became the external and internal carotid in mammals?
blood supply to head
65
what contains the ventricles of the heart, base or apex?
apex
66
where are atria in the heart?
craniodorsal
67
which ventricle is long and pointy?
left
68
which ventricle is crescent shaped and cranial?
right
69
which ventricle has a thicker muscular wall?
left
70
what sort of action does the cardiac muscle have?
wringing
71
in which species is the aorta contractile?
rabbit
72
which veins does the right atrium receive?
cranial and caudal vena cava, azygos vein, coronary sinus
73
what is the azygos vein?
a single vein which drains the dorsal thorax
74
what is the coronary sinus?
a venous tube that drains almost all of the heart
75
what is the function of the intervenous crest?
directs blood ventrally instead of blood colliding
76
what are auricles?
side pouches of atria
77
why are auricles darker tissue than rest of atria?
different embryological origin from atria
78
what is the function of auricles?
increase the volume of atria
79
where are auricles located relative to their respective atrium?
cranially and to the left
80
what is the foramen ovalis?
connection between left and right atrium in fetus
81
what is the name of the connection between the left and right atrium in the fetus?
foramen ovalis
82
what is the fossa ovalis?
dent in heart between left and right atrium left by foramen ovalis
83
what is the name of the dent in adult hearts left by the foramen ovalis?
fossa ovalis
84
what is the right atrioventricular valve called?
tricuspid valve
85
why is the right atrioventricular valve called tricuspid?
3 flaps anchored to ventricle
86
what anchor the RAV to the ventricle?
chorda tendinae
87
what is the RAV anchored to?
the papillary muscles
88
what are the trabeculae carneae?
fine ridges on internal surface of ventricle
89
what is the function of the trabeculae carnae?
create rolling cylinders of blood between them, bulk blood flow can occur above them
90
what path does blood take from the right ventricle?
spirals around cranial side of heart to the left side, pulmonary artery emerge on the left hand side
91
why does the left ventricle often look very small in dissection?
thick muscle makes it collapse post mortem
92
what carries the coronary vessels?
coronary groove between muscles of atrium and ventricle
93
where do the pulmonary veins enter the heart?
roof of left atrium
94
how many pulmonary veins are there?
6/7
95
what is the left atrioventricular valve called?
bicuspid/mitral valve
96
what are the moderator bands?
strands from the septum to the wall of the ventricle
97
what is the latin name for moderator bands?
trabecula septomarginalis
98
what direction does blood pump out of left ventricle?
craniodorsally through aorta
99
what are the ossa cordis?
bones of the heart formed in big and old cows, horses, deer
100
what does the great coronary vein disgorge into?
right atrium
101
where does the right coronary artery come out of the heart?
cranially
102
what path does the right coronary artery take?
rolls around right side of heart as circumflex
103
what path does the left coronary artery take?
rolls around left side of heart as circumflex
104
what is the origin of the right descending branch in dogs and ruminants?
from left coronary artery
105
what is the origin of the right descending branch in horses and pigs?
from right coronary artery
106
what is the origin of the right descending branch in cats?
either right or left coronary artery
107
what does the blood in coronary vein run in the same direction as?
blood in left circumflex coronary artery
108
what % of cardiac output is coronary?
15%
109
why do major vessels lie outside the myocardium?
they would be occluded by pressure inside heart
110
in which species does the azygos come from the left side of the heart?
pigs, some ruminants
111
what does the azygos drain into in species with L. azygos?
coronary sinus
112
what supplies parasympathetic innervation to heart?
vagus nerves with branches to SAN and AVN
113
what is the effect of cardiovagal stimulation?
reduces heart rate
114
what supplies sympathetic innervation to heart?
fibres from stellate and middle cervical ganglia to all myocardium and vessels
115
what is the effect of cardiosympathetic stimulation to heart?
increase rate and force of contraction
116
what is the audible/palpatable (and visible at ICS6 in dogs + horses) beat of the heart?
apex beat
117
what produces the 'lub' sound of the heart?
T and M valves closing
118
what produces the 'dup' sound of the heart?
A and P valves closing
119
what are the functions of the lymphatic system? (4)
drains + filters interstitial fluid, drains FAs + 2-monoglycerides from intestine via lacteals, transports and houses immune cells, lymph nodes and MALT
120
what are the 2 forces in the blood capillaries?
osmotic and hydrostatic pressure
121
what does osmotic pressure drive in the capillaries?
water from interstitium into capillaries
122
what direction does hydrostatic pressure drive water in in the capillaries?
out of the capillaries (all directions except backwards)
123
what is the symbol for osmotic pressure?
Π
124
what is the symbol for hydrostatic pressure?
P
125
is hydrostatic pressure or osmotic pressure greater at arterial end of capillaries?
hydrostatic pressure
126
is hydrostatic pressure or osmotic pressure greater at venous end of capillaries?
osmotic pressure
127
is the difference between hydrostatic and osmotic pressure greater at the arterial or venous end of capillaries?
arterial
128
what percentage of efflux drains into the lymphatic system?
about 15%
129
what are lymph capillaries?
blind-ending, endothelium lined, permeable collecting chambers
130
which are more permeable, lymph capillaries or blood capillaries?
lymph capillaries
131
what does lymph contain as well as water?
rbcs, wbcs, proteins (antibodies, hepatic proteins), microbes
132
where are lymphatic vessels not present?
CNS, bone marrow, cartilage, epidermis, alveoli, placenta
133
how do lymphatic vessels move lymph fluid? (3)
skeletal muscle pump, nearby arterial pulsing, intrinsic smooth muscle contractility
134
what causes intrinsic smooth muscle in lymphatic vessels to contract?
sympathetic nerves if BP lowers
135
where does most lymph drain into blood?
at venous angle, into left external jugular vein
136
what drains into the left external jugular vein?
most lymph vessels
137
what drains via the right lymphatic duct to the right jugular vein?
right head, neck, forelimb and thorax
138
what is the only lymph chamber in domestic mammals?
the cisterna
139
where is the cisterna?
between CdVC, aorta and spine
140
what are lymphaticovenous anastomoses?
dormant connections between lymphatic system and venous system
141
how many sacs does the lymphatic system develop from?
6
142
what do the chambers of the early lymphatic system grow out of?
veins
143
what grows out of the chambers of the early lymphatic system?
ducts
144
how many of the sacs regress in lymphatic development?
5
145
which sac doesn't regress in lymphatic development?
the cisterna chyli
146
what might inadequate lymph drainage lead to in tissues?
oedema
147
what might inadequate lymph drainage lead to in cavities?
effusions
148
do large animals tend to get more oedema or effusions?
oedema
149
do small animals tend to get more oedema or effusions?
effusions
150
what might rupture of the thoracic duct lead to?
chylothorax
151
what is chylothorax?
chyle filling up the thoracic cavity
152
what is a lymphocentre?
a lymph node/cluster of lymph nodes
153
in which species are lymphocentres a single lymph node?
carnivores
154
in which species are lymphocentres a cluster of lymph nodes?
ungulates
155
what does lymph drain into lymph nodes via?
afferent lymphatics at the periphery
156
what forms the internal network of lymph nodes?
capsules (elastic and smooth muscle)
157
what are the capsules in lymph nodes made of?
elastic and smooth muscle
158
what divides the lymph fluid into compartments in lymph nodes?
trabeculae given off by capsules
159
what is the first thing lymph encounters in the lymph nodes?
the germinal centres
160
what are the germinal centres?
B-lymphocytes surrounded by T cells
161
what is the final part of the lymph nodes lymph drains through before leaving?
medullary sinuses- series of inflated tubes lined by antibody secreting mature B-cells
162
where does lymph exit the lymph node?
efferent lymphatics at the stalk
163
in which species is the lymph node reversed?
pigs
164
what is inflammation of the lymph node called?
lymphadenitis
165
what does MALT stand for?
mucosa-associated lymphoid tissue
166
which ducts does MALT not have?
afferent ducts
167
where is MALT found (8)?
pharynx (tonsils), nose, intestine, prepuce, vagina, mammary glands, larynx, 3rd eyelid
168
where are ungulate tonsils usually situated?
under mucosa
169
how does the spleen develop?
as mesodermal swelling in greater omentum
170
what is the shape of the dog spleen described as?
England-shaped
171
how many splenic arteries does the visceral surface of the spleen receive?
around 25
172
what is the red pulp of the spleen?
complex reticuloendothelial mesh and blood-filled sinusoids, many monocytes
173
what is the function of the red pulp of the spleen?
breaks down rbcs, stores rbs, makes rbcs in fetus
174
what percentage of the blood in the resting horse is stored in the spleen?
30%
175
what is the white pulp of the spleen made of?
lymphoid B-cell nodules or cylinders, surrounded by T-cells
176
what innervation does the spleen receive?
sympathetic, a few vagal fibres, some myelinated sensory fibres
177
what is the spleen a common site of in dogs?
tumours
178
what is the thymus?
a primary lymphoid organ
179
where is the thymus?
ventral to trachea, dorsal to sternum, cranial to heart
180
what is the function of the thymus?
formation and maturation of T lymphocytes
181
where do immature T-lymphocytes infiltrate the thymus from?
the internal thoracic artery
182
what happens to thymocytes in the thymus cortex?
weakly binding thymocytes are eliminated
183
what are Hassall's corpuscles?
epithelial whorls of endo-, meso- and potentially ectoderm
184
what is the first functional organ in the embryo?
the heart
185
what does the circulatory system develop from?
mesoderm, primarily lateral plate
186
where is the mesoderm that the heart develops from located?
lateral to the cranial part of the neural plate
187
what is the endocardial tube?
tube of fused cardiac precursors that will form the inner layer of the heart
188
what does the myocardium secrete?
cardiac jelly
189
what does the cardiac jelly separate?
the myocardium and endocardium
190
what lie between the primitive atrium and ventricle?
sulci (atrioventricular and bulboventricular)
191
what acts as the pacemaker in the heart tube?
sinus venosus
192
what help in preventing back flow in the heart tube?
the cardiac jelly and sulci
193
what is the first change in looping of the heart tube?
a leftward and ventral movement of the ventricle
194
what is dextrocardia?
folding of the heart tube in the wrong direction
195
what is dextrocardia often accompanied by?
situs invertus
196
what does the inversus viscerum mutation lead to?
randomised left-right orientation of the heart
197
what gene is normally only transcribed in cells on the left side of the primitive streak?
nodal
198
where is the nodal gene found to be transcribed in inv/inv mutants?
on the right side of the primitive streak
199
where is the nodal gene found to be transcribed in iv/iv mutants?
randomly on right or left side
200
what will the caudal part of the bulbus cordis give rise to?
the right ventricle
201
what does the primitive atrium remain as in the heart?
the auricles
202
what do the atria arise from?
sinus horn and pulmonary veins
203
what fuse to form the septum intermedium?
the cranial and caudal cushions
204
what is the first septum to form in the atria?
septum primum
205
what is the ostium primum?
the gradually diminishing hole between the atria in cardiac development
206
what creates the ostium secundum?
apoptosis in some of the cells near the cranial edge between the atria
207
what is the second septum to form?
septum secundum
208
where does septum secundum grow from?
the roof of the atria to the right of the septum primum
209
what is the name for the remaining gap between the septum secundum and septum intermedium?
the foramen ovale
210
what causes the foramen ovale to close at birth?
the change in pressure in the atria
211
where does the muscular ventricular septum grow from?
the caudal edge of the original bulboventricular sulcus
212
what is the final step in septation?
formation of the spiral septum
213
what do the ridges that form the spiral septum develop from?
neural crest cells
214
where does fusion of the paired ridges in spiral septum formation begin?
at the caudal edge of the truncus arteriosus
215
why does fusion of the paired ridges in spiral septum formation spread rostrally and caudally?
ensures that the ventricles don't become separated before outflow is partitioned
216
what does the spiral septum link with caudally?
the muscular ventricular septum and septum intermedium
217
what are the two shunts that allows the lung to be bypassed in foetal circulation?
foramen ovale, ductus arteriosus
218
what causes the foramen ovale to close after first breath?
reduced pressure in right atrium means septum primum is flattened against septum secundum
219
what can be used to keep the ductus arteriosus patent?
injection of prostaglandins
220
what can induce the ductus arteriosus to constrict if it remains patent?
prostaglandin inhibitors
221
what is the most commonly diagnosed congenital heart defect in dogs?
patent ductus arteriosus
222
what may be seen as part of the tetralogy of fallot?
ventricular septal defects
223
what is the lymphoid role of bone marrow?
formation and maturation of B lymphocytes
