Cardiovascular Flashcards
pulmonary circuit
heart to lungs
systemic circuit
heart pumping to the body tissues
Blood characteristics
flows slower than water
100.4 F
pH: 7.35-7.45
NaCl: .85-.9%
8% of body weight
4-6 L, less in females
layers in blood vessels
tunica intima: innermost
tunica media: middle
tunica externa: external
artery characteristics
elastic tissue, recoil
muscular
function to regulate blood flow to different body parts
smooth muscle fibers in the walls
arterioles characteristics
less elastic
more smooth muscle
site of blood flow resistance
pressure reduction valves: narrow lumen, thick muscle walls, regulate pressure in system
capillary characteristics
one cell wall thick
tight junction
internal respiration/gas exchange
tissue nutrition
venules/veins characteristics
walls thicker than capillaries
easily distensible
some smooth muscle for venoconstriction
one way valves in extremities to prevent backflow
more collagen in walls to expand
blood in veins is…
low pressure, slow flow
contains most of body’s blood in veins
flap valves
apex of the heart
pointed tip
pericardium
double walled sac around heart
two layers
parietal and visceral
protect/anchor heart
prevent overfilling of heart
reduce friction
epicardium
serous membrane = visceral pericardium
superfiical layer is the mesothelium
deeper layer contains mroe blood vessels and fat
myocardium
cardiac muscle
thickest part of the wall
deep to the epicardium
endocardium
connective tissue, squamous cells
folds form valves
line artia and ventricle cavities and structures projecting into the heart
three layers
skeleton of the heart
fibrous rings separate the atria from the ventricles
function of the heart valves
ensure unidirectional flow of blood through the heart
tricuspid valve
R AV valve
closes in ventricular contraction
pulmonary valve
semilunar valve
exits into the pulmonary arteries
mitral valve
L AV valve
2 cusps
closes in ventricular contraction
aortic valve
L ventricle to aorta
3 semilunar cusps
Branches of the left coronary artery
anterior interventricular
circumflex
branches of the right coronary artery
right marginal
posterior interventricular
coronary artery disease
occluding major coronary artery
inadequate circulation to an area of myocardium
cardiac conduction system
initiate and coordinate contraction
nodes and networks of specialized cardiac muscle cells
SA node
AV node
bundle of his
purkinje fibers
cardiac innervation
autonomic innervation
regulate heart rate, force of contraction, cardiac output
PNS and SNS
superficial and deep parts
superficial part of cardiac plexus
vagus nerve into cardiac branches
deep part of cardiac plexus
cardiac nerves from sympathetic trunk, recurrent laryngeal nerves, vagus nerves feed into plexus over trachea bifurcation
parasympathetic innervation of the heart function
decrease HR
reduced contractility
constrict coronary arteries
function of sympathetic innervation in the heart
increase HR and contractility
visceral afferents, position and function
through cardiac plexus returning to CNS
sense alterations in blood pressure and chemistry from vagal cardiac nerves
sense pain from cellular damage of the heart through sympathetic system
heart failure defintion
heart cannot keep up with workload to deliver oxygen to the rest of the body
ejection fraction
normal: 50-70% blood pumped out with each contraction
borderline: 41-49%
<40% is reduced EF
incidence of chronic heart failure
6 mil in US currently, increasing to 9 mil
high mortality
30$ bil each year
treatment for heart failure
exercise!
