Vascular System Pt 2 Flashcards
_____ cells produce vasoactive substances that can
induce contraction and relaxation of the smooth muscle
vascular wall
Endothelial
Endothelial cells produce vasoactive substances that can
induce contraction and relaxation of the ____
smooth muscle
vascular wall
Examples of vasoactive substances produced by endothelial cells:
Nitric Oxide (NO) and Prostacyclin
Effects of Nitric Oxide (NO) and Prostacyclin
Relaxation of smooth
muscle
______ also prevents platelet adhesion and clumping
leading to blood clotting
Prostacyclin
Prostacyclin also prevents _____
leading to blood clotting
platelet adhesion and clumping
Endothelin 1 is a very potent ____ peptide
vasoconstrictor
T/F: The permeability of capillary endothelial cells is tissue-
specific
True
topographic permeability: the endothelial
cells at the ___ end are more permeable than those at
the ____ end.
venous end; arterial end
____ venules have the greatest
permeability to leukocytes
Postcapillary
Postcapillary venules have the greatest
permeability to ____
leukocytes
Endothelial cells also play a role in the process of ____ and inflammation.
cell
homing
____ cells also play a role in the process of cell
homing and inflammation.
Endothelial
Endothelium can adapt to changes in their
environment. Become activated and ___
change
function
Endothelium are activated by ____
cytokines
Endothelium: Activated by cytokines & develop specializations
for ____ lymphoid cells
emigration of
Activated Endothlium: Become cuboidal and express ___ (usually after some
tissue damage).
cell adhesion
molecules for neutrophils
Become cuboidal and express cell adhesion
molecules for ____ (usually after some
tissue damage). Facilitates migration of
_____ into local tissue.
neutrophils
Storage granules found in endothelium of A, V &
endocardium (not lymphatics)
Weibel-Palade Bodies
Weibel-Palade Bodies contain Von Willebrand Factor and ____
P-selectin
essential for blood coagulation, binds with
factor VIII & leads to platelet adhesion
Von Willebrand Factor
Von Willebrand Factor binds with Factor __?
VIII (8)
____ increases the permeability of endothelium &
facilitates leukocytes leaving the bloodstream
P-selectin
facilitates leukocytes leaving the bloodstream
P-selectin
Endothelium normally locally impermeable to
substances in the blood. Some vasoactive factors
(____) cause cells to lose attachment to one
another & retract
histamine
Endothelium normally locally impermeable to
substances in the blood. Some vasoactive factors
(histamine) cause cells to lose attachment to one
another & ___
retract
T/F: Similar to arteries, veins consist
of tunics.
True
(Venous System) T/F: the distinction of TM
from a TA is often not clear
true
(Venous System) T/F: A distinct internal elastic lamina
is often not seen
True
(Venous System) The muscular tunica media is
____ than in arteries, and
smooth muscle cells have an
irregular orientation,
approximately ___
thinner; circular
A typical characteristic of veins
is the presence of _____
valves (to
prevent reflux of blood)
___ are capacitance
(reservoir) vessels
Veins
The venous system starts
at the end of the capillary
bed with a _____ that structurally
resembles continuous
capillaries but with a
wider lumen & more
pericytes
postcapillary
venule
_____
(~10-50 m in diameter)
are the preferred site of
migration of blood cells
into tissues (diapedesis)
Postcapillary venules
migration of blood cells
into tissues
(diapedesis)
Postcapillary venules converge to form _____
muscular
venules
Postcapillary venules converge to form muscular
venules, which converge & lead to a series of
veins of progressively ____ diameter
larger
Veins have a relatively ___ wall in comparison
with arteries of the same size
thin
The high capacitance of veins is attributable to
the distensibility of their wall (compliance
vessels) and, therefore, the content of blood is
____ relative to the volume of the veins
large
The high capacitance of veins is attributable to
the ____ of their wall (compliance
vessels) and, therefore, the content of blood is
large relative to the volume of the veins
distensibility
Large & medium sized Vv
called ____
muscular Veins
Small muscular Vv may or
may not contain ___
internal
elastic lamina
Medium muscular Vv
contain ____ only (elastic lamina)
internal elastic
lamina
T/F: Large muscular Vv contain
internal & external elastic
laminae
true
Smooth Mm in ____
controls luminal diameter of
muscular Vv & venules
tunica media
Vasoactive
substances (e.g.,
histamine,
serotonin) act on
____
venules
Enlarge
intercellular
spaces =>
___permeability of
vessel (increase or decreason)
↑ increase permeability
Why is indicated when you get varicose veins?
You get varicose veins when the valves in your veins don’t close properly.
—direct connections between
arterial & venous system; bypass capillary bed
AV shunts
AV shunts—direct connections between
arterial & venous system. Allow bypass of what structure?
bypass capillary bed
AV shunts: Type of anastomosis; common in skin,
function in ___
thermoregulation
—V or A directly connecting two
capillary beds
Portal vessels
Examples of portal vessels:
(e.g., hepatic portal V, a venous portal system)
___ is an
inflammation of your
blood vessels
Vasculitis
Vasculitis: Causes changes in the
___ of blood vessels,
including thickening,
weakening, narrowing and
scarring.
walls
What do the changes caused by vasculitis result in?
Changes restrict blood
flow, resulting in organ and
tissue damage
Atherosclerosis: The thickening and hardening of the walls of arteries caused by
atherosclerotic plaques of lipids, cells, and connective tissue
deposited in the ___
tunica intima
Atherosclerosis is frequently seen in arteries sustaining ____, it does not affect veins and is the cause of myocardial
infarction, stroke, and ischemic gangrene
high blood
pressure
T/F: Atherosclerosis can also affect veins
False
T/F: Atherosclerosis is now recognized as a chronic inflammatory
disease, characterized by features of inflammation at all stages of
its development
True
Atherosclerosis correlates with the serum levels of ___ or ___
cholesterol or
low-density lipoprotein (LDL).
A genetic defect in _____ (familial hypercholesterolemia) is associated with
atherosclerosis and myocardial infarction before patients reach 20
years of age.
lipoprotein
metabolism
A genetic defect in lipoprotein
metabolism (____) is associated with
atherosclerosis and myocardial infarction before patients reach 20
years of age.
familial hypercholesterolemia
Atherosclerosis: When endothelium of vessel
damaged, ____ adheres to
exposed proteins
cholesterol
Atherosclerosis: Once ____ heals,
cholesterol patch reabsorbed
endothelium
(Atherosclerosis) Phagocytosis by Mφ, later by
endothelial & subintimal cells =>
foam cells
(Atherosclerosis) If inflammatory response
becomes chronic =>
atherosclerosis & plaque
formation
T/F: Atherosclerosis is only local
False: can be generalized or local
Atherosclerosis is later, accompanied by
_____ & formation of fibrous,
connective tissue capsule
proliferation of smooth Mm
cells
Atherosclerosis is later, accompanied by
proliferation of smooth Mm
cells & formation of ____
fibrous,
connective tissue capsule
(Atherosclerosis) As cells within plaque die => ____ results
necrosis & secondary
calcification (aka “hardening
of Aa”)
(Atherosclerosis) Often associated with
____—due to ↓ in
diameter of vessel lumen &
↑ systolic bp
hypertension
(Atherosclerosis) Initiates clotting cascade =>
thrombus formation
If piece of thrombus breaks
off =>
embolus; aka
thromboembolic disease
embolus; aka
_____ disease
thromboembolic
Sudden occlusion by
____ => acute ischemic
event
embolus
↓ O2 (anoxia) to heart Mm
=>
chest pain (angina)
Most common cause of
ischemic heart disease is
atherosclerosis
atherosclerosis: ____ of
coronary Aa may ↓ by 90%
lumen
Gradual narrowing of vessel:
stenosis
Gradual narrowing
(stenosis) by plaque =>
thrombosis (occlusion) of
vessel
(Thrombo-embolic disease) As plaque enlarges, or if
endothelium damaged,
exposes underlying ___
collagen
If Thrombo-embolic disease untreated & portion of
Mm dies => ____ (death by
ischemia)
myocardial
infarction
Since cardiac Mm cells in Go
phase (terminally
differentiated), unable to
regenerate; all healing
occurs via ____
fibrosis
–Since cardiac Mm cells in Go
phase (terminally
differentiated), unable to
regenerate; all healing
occurs via fibrosis
–But connective tissue less
contractile than Mm => (how does this affect function)
↓
function or partial loss of
function
___ is similar to MI,
except affects brain instead
of heart
Stroke
Like cardiac cells, ____ in brain also terminally
differentiated
Neurons
Stroke can result in _______,
with similar cell death &
loss of function
cerebral infarct
(Stroke) ____ determines
symptoms & severity
Location of clot
Conduct immune cells and lymph to lymph
nodes,
lymphatic vessels
Remove excess fluid accumulated in
interstitial spaces
lymphatic vessels
(lymphatic vessels) Transport chylomicrons, lipid-containing
particles, through lacteal lymphatic vessels
inside the _____
intestinal villi
(Lymph vascular system) Structurally similar to
Vv, but endothelial
cells ____, with
greater permeability
thinner
Lymph endothelial
cells highly active in
___
phagocytosis
Lymph vascular system: Very thin tunica ___
tunica media
Lymph vascular system: ____ present;
basement membrane
& pericytes may be
present or absent
Valves
Begin as dilated tubes with closed ends in proximity to
blood capillaries & collect tissue fluid (lymph)
Lymphatic Capillaries
(Lymphatic Capillaries) Wall is an endothelium lacking a ____
complete basal lamina
T/F: Lymphatic capillaries can be found in most tissues
True! Exceptions are cartilage, bone, epithelia, CNS & placenta.
(Lymph vascular system) Drain excess fluid
(lymph) from ECS &
return it to
___
bloodstream
Lymph formed as
result of ____
in arterioles
high
hydrostatic pressure
Lymph formed as
result of high
hydrostatic pressure
in arterioles; exceeds
_____ exerted by
plasma proteins =>
leakage of water,
electrolytes, & plasma
proteins from
capillaries into ECS
colloidal oncotic
pressure
_____ are interspersed along lymphatic vessels
Lymph nodes
Lymph Nodes contain ____ for
antigenic sampling &
recognition, activation of
immune cells & production of
Ab
lymphoid tissue
_____ lymph drainage
important in tumor metastasis
Asymmetrical
Easiest way to identify lymph
vessels in section—
Thin walled, lack ____,
contain smooth, eosinophilic,
proteinaceous fluid (lymph),
occasional WBC’s
Basement membrane
rudimentary or absent +/-
pericytes
blood
___ drained by series of
interconnected, blind-ending
tubules (lymphatics
ECS
Lymphatics Converge on _____—largest
lymph vessels in body
thoracic duct (&
R lymphatic duct)
Lymphatics contain tunica ___
tunica media
(lymph vascular system) No central pumping
mechanism—movement of
lymph accomplished via
___
skeletal Mm contraction, body
movement
Lymph returns to bloodstream
at junction of ____
L internal jugular
V & L subclavian V
Immobility may lead to
____, swollen
feet
peripheral edema
Lymphatic Drainage occurs in 2 ways
intrinsic contraction, extrinsic contraction
When vessels become expanded by lymph, the smooth
muscle of the wall contracts. Each segment of the lymphatic
vessel between successive valves, called lymphangions,
behaves like an automatic pump.
intrinsic contraction
External factors such as contraction of the surrounding
muscles during exercise, arterial pulsations, and
compression of tissues by forces outside the body compress
the lymph vessel and cause pumping
extrinsic contraction
When lymph drainage is impaired, excess fluid accumulates
in the tissue spaces, this is called ____
edema
is caused by a defect in the transport
of lymph because of abnormal vessel development
or damaged lymphatic vessels
Lymphedema
is a parasitic infection of
lymphatic vessels by Wuchereria bancrofti or Brugia
malayi worms, transmitted by mosquito bites.
Filariasis (elephantiasis)
–This
condition causes damage to the lymphatic vessels
with chronic lymphedema of legs and genitals.
–occurs in tropical countries
Filariasis (elephantiasis)
are caused by the
accumulation of high fat containing fluid, or chyle, in
the abdomen or thorax as a result of trauma,
obstruction, or abnormal development of lymphatic
vessels.
Chylous ascites and chylothorax
t/f: cardiac cells and neurons are both terminally differentiated
true
