lect 10- cardiovascular system Flashcards
what layer of the heart wall is composed of endothelial cells, connective tissue, and smooth muscle cells, as well as purkinje fibers
endocardium
what heart wall layer is the principle layer of the heart, composed of cardiac tissue.
myocardium
compare the myocardium in the atria to the ventriucles
atria is thinner than ventricles
what is another name for the visceral layer of serous pericardium
epicardium
what layer of the heart wall is adhered to the outer surface of the heart, and contains the blood vessels and nerves that supply the heart
epicardium
what is the base of the fibrous pericardium attached to
central tendon of diaphragm
what is the anterior part of the fibrous pericardium attached to
sternopericardial ligaments
what is the fibrous pericardium innervated by
phrenic nerve
what vessels mainly supply the fibrous pericardium
Right and left pericardiophrenic vessels
what does the parietal pericardium line
the inner surface of the pericardial cavity
what is the pericardial cavity lined by
mesothelial cells
how much serous fluid is contained in the pericardial cavity
15-50mL
what cells produce the lubricating fluid contained in the pericardial cavity
mesothelial cells
what type of epithelium do the mesothelial cells have
squamous-like epithelium
what is the pacemaker of the heart
SA node
what is the only element of the heart that can carry impulses across the fibrous skeleton
AV bundle
what is the course of the heart’s electric system
SA node to AV node to bundle of his to purkinje fibers
what artery is then alpha 1 contained in
pulmonary artery
what action does alpha one cause
constriction
what is beta 2 very important for
relaxations
what does sympathetic influence of the heart arise from
spinal cord levels of T1-T4/6
where do the sympathetics synapse and terminate for the heart
synapse in celiac ganglia and terminate in SA and AV nodes
what hormone causes increase in heart rate
norepinephrine
what is parasympathetic influence of cardiac innervation provided by
vagus nerve
where do postsynaptic fibers of the cardiac innervation terminate
at SA and AV nodes
what hormone do the parasympathetic influence fibers secrete
acetylcholine
what does acetylcholine do to the heart rate
decrease it (bradycardia)
what secretes epinephrine and norepinephrine
adrenal medulla
what does activation of beta1 receptors cause an increase force of
contraction (inotropic effect) and rate (chronotropic effect)
what are the high pressure receptors located in the carotid sinuses and aortic arches
baroreceptors
what are the low pressure receptors located in the walls of atria, provide information of cardiac distension
volume receptors
what are aortic and carotid bodies located at the bifurcation of the common carotid artery and aortic arch that monitor oxygen, CO2, and pH
chemoreceptors
what does ADH do
increases pressure because it is an anti-diuretic (eventually increases pressure because more water is retained)
what is the loose connective tissue layer on the atrial side of the valve, loosely arranged collagen and elastic fibers. it is involved in diminishing vibrations with valve closure
spongiosa
what is the core of the heart valve, extensions of skeletal rings
fibrosa
what is the part of the heart valve that is covered with endothelium, contains many layers of dense connective tissue and elastic fibers. it lines surface adjacent to the ventricle.
ventricularis
what is the ventricular continuous with in the AV valves
chord tendinae
describe the tunica intimate of vascular walls
layer of squamous epithelial cells, basal lamina and sub endothelial layer
what is the main component of the tunica intima
endothelium
describe the tunica media of vasculature walls
middle layer composed mainly of rings of smooth muscle but also a varying amount of elastin
describe the tunica adventitia of vascular walls
outermost layer, mostly collagenous tissue thin in arteries, thick in veins.
what is transcellular migration
migration through cells
what is paracellular migration
migration between cells
how do Endothelial cells maintain nonthrombogenic barrier
by producing anticoagulants and antithrombogenic substances
what does damage to endothelial cells cause the release of
prothrombogenic substances (von willebrand factor)
what does sheer stress cause the ECs to do
produce NO, which causes vasodilation, which drops BP
what does metabolic stress cause ECs to do
release prostacyclin which causes vasodilation
what does the endothelin family cause
influx of calcium and muscular contraction causing vasoconstriction and raises BP
what is the only hormone that can break down clots once coagulation has occurred
plasmin
what happens when lipoproteins have been oxidized by free radicals and macrophages endocytose them
macrophages become foam cells that are characteristic of atheromatous plaques
what disease may be present if foam cells occur
atheromatous plaques
what are some examples of elastic arteries
aorta, brachiocephalic trunk, iliac arteries, left common carotid, left subclavian, pulmonary artery
what are the flow regulators to capillaries beds
arterioles
what layer of the artery is ill-defined in arterioles
tunica adventitia
what layers are capillaries missing
tunica media and adventitia
describe the endothelial cells in capillaries
single layer of endothelial cells
why must RBCs found themselves to get through capillaries
because capillaries are smaller than erythrocytes
where are continuous capillaries typically found
muscle, CNS, lungs
what may surround continuous capillaries
pericytes
what do pericytes respond to
NO
what do pericytes provide
vascular supper and promote stability of capillary through physical and chemical signaling with the endothelial cells
where are fenestrated capillaries typically found
endocrine glands and site of fluid and metabolite absorption
where are discontinuous capillaries typically found
spleen, liver and bone marrow
what is another name for discontinuous capillaries
sinusoidal capillaries
what is the principle site of histamine and serotonin secretion
post capillary venue (PCVs)
describe the shape of PCVs
cuboidal in shape with ovoid nucleus
what do histamine and serotonin promote
vasoactive substances that promote extravasation of fluid and emigration of WBCs from vessels during inflammation and allergic reactions
describe the relationship of small veins to PCVs
they are distal to PCVs
compare tunica media of arteries to veins
thicker in arteries than veins
compare tunica adventitia of arteries to veins
thinner in arteries than veins
describe the tunica adventitia muscle of large veins
longitudinally oriented smooth muscle
what are some examples of large veins
IVC, portal vein, subclavian and SVC
what are broad spaces in the dura mater of the cranial cavity that are lined with endothelial cells but void of smooth muscle
venous sinuses
how do lymphatic capillaries typically start
as ended tubes in the capillary beds
what do lymphatic vessels unite to form
the right lymphatic trunk and the thoracic duct
where do the lesions involved in atherosclerosis develop (what layer)
tunica intimate of arteries
what is hypertension usually caused by
atherosclerosis
what blood pressure do you have to be above to be considered hypertensive
140/90 mm Hg
what is a sudden loss of perfusion to an area of the heart wall
myocardial infarction
what is the most likely location for myocardial infarction
left anterior descending artery
what is the second most likely location for myocardial infarction
right coronary artery
what is the third most likely location for myocardial infarction
left circumflex artery
