Cardiovascular Flashcards
plasma
liquid component of blood, blood is suspended in plasma
cellular elements of blood
red blood cells, white blood cells, platelets
red blood cells, white blood cells and platelets
red: contains of hemoglobin that transport oxygen
white: defend body from infection and disease
platelets: aid in the formation of clots
open circulatory system vs closed circulatory system
open: have a heart to pump hemolymph (their version of blood), but limited piping (blood diffuses through tissue)
closed: have a heart and vessels (pipes) to control the flow of blood
vertebrate circulatory system
series of pipes (blood vessels) that direct blood to various places in the body, driven by the heart, has pulmonary and systemic cirulation
pulmonary circulation vs systemic circulation
pulmonary: to and from the respiratory organs
systemic: sends blood to the rest of the body
blood vessels
system of tubes that transports blood throughout the body
conservation of mass
blood is not removed from or added to the blood vessels (volume of blood is constant)
pressure
force applied over an area
Fluid in pipes equations
As the pipe gets narrower fluid velocity increases, A1v1=A2v2
F/A1<F/A2 (A2 smaller area), as the pipe gets narrower, fluid pressure increases
Blood pressure (hydrostatic)
measured force being exerted to move blood through the system
3 layers (walls of blood vessels) that surround lumen
tunica intima, tunica media, tunica adventitia
vasa vasorum
the smaller vessels that supply blood to large blood vessels
what type of muscle is in the walls of arteries and veins?
smooth muscle
vasoconstriction and vasodilation
vasoconstriction: when the smooth muscle contract
vasodilation: smooth muscles relax and vessels open
Arteries
move away from the heart
large arteries have lots of elastic fibers and less smooth muscle
tunica media is almost entirely elastic fibers
blood comes out with most energy and will have the highest velocity
Arterial function and disease (what is arterial disease)
walls of arteries expand when high pressure blood is pumped from the heart (pulse)
elastic fibers cause recoil that pushes blood further
Arterial disease is when elastic fibers harden (recoil doesn’t occur, so high pressure blood enters fragile vessels)
Arterioles
loose much of the elastic fibers and smooth muscles, direct blood to local tissues
capillaries
small tubes that connect the arteries to the veins, organized into capillary beds, where gas/nutrient exchange occurs, lack tunica media and tunica adventitia, tube made entirely of tunica intima (thin layer)
describe the diameter, area, blood pressure and velocity of arteries, veins, and capillaries
capillaries have small diameters, the largest area, the lowest velocity of blood flow
veins have the lowest blood pressure and largest diameter
arteries have highest blood pressure and velocity
diffusion
process that gases, nutrients, ions, and heat are exchanged across a membrane
occurs in capillary beds
slower the blood flow the more time for diffusion
microcirculation
capillary beds along with the arterioles and venules
flow through the beds controlled by smooth muscle (precapillary sphincters)
shunts allow for blood to completely bypass the bed
ischemia
side cramps due to a lack of sufficient blood to the stomach for digestion
exercising after a meal the skeletal muscles are given preference for bood over digestive system
hypotensive shock
after severe or traumatic injury, microcirculation may fail to regulate properly, too many vessels open leading to a drop in pressure and failure of circulation
veins
collecting tubes that return blood to the heart, 70% of blood is in the veins, very low pressure
tuncia media in veins
primary composed of smooth muscles with very little elastic fiber
solutes
dissolves particles within the fluid
osmotic pressure
force that arises from the imbalance of solutes to move across a membrane (everything wants to even out)
leaked fluids in capillaries
hydrostatic pressure causes fluid to leak out at start of capillary bed
osmotic pressure causes fluid to seep back in at the end of the capillary bed
the lymphatic system collects this excess fluid and returns it to the veins
lymph fluid
carried by the lymphatic system (mostly water, dissolves proteins, and electrolytes)
lymphatic hearts
help move fluid via muscle action
lymph nodes and lymphodema
masses of lymphatic tissues filled with white blood cells (clean lymph before it enters circulatory system)
lymphedema is swelling if fluid is built up in connective tissue
describe anterior primitive condition of heart
blood leaves heart via ventral aorta, aorta divides into external carotids and aortic arches, arches pass through gills gaining oxygen, arches reconnect into dorsal aorta, dorsal aortae travel back to the rest of the body, internal carotids feed the head and brain split, blood returning from the anterior comes through the anterior cardinal vein
describe posterior primitive condition of heart
dorsal aorta runs all the way to the tail (called caudal artery), braches feed blood to different organs (subclavian, renal, iliac), blood from posterior drained by posterior cardinal vein and lateral abdominal vein
portal systems
where blood runs from one set of capillaries to another without going through the heart (for reason other than distributing oxygen)
hepatic system
runs from the digestive system to the liver, delivering nutrients
renal system
brings blood from the tail/ rear limbs straight to the kidneys
afferent arteries
braches come off the ventral aorta to deliver to the capillary beds in the gills
efferent artery
connects to the dorsal aorta, the collecting loop empties into the efferent artery
aortic arch in sharks
First arch reduced into spiracle in sharks and the aortic arch is lost
enlarged gills slits result in extra branches for collecting loops
aortic arches in teleost fish
loses both arch 1 and 2
front of the animal gets oxygenated via the external carotid that loops down from the dorsal aorta
aortic arches in lungfish
have gills and lungs (have arch 2)
efferent branch of 6 arch turns into pulmonary artery feeding blood to lungs (beginnings of 2nd circuit)
oxygenated blood flows into heart via pulmonary vein for recirculation
lost gills associated with arches 3 and 4
where is oxygenated and deoxygenated blood in lungfish directed?
deoxygenated blood returning from the body is directed into arches 5 and 6 through gills
arch 6 is pulmonary arch and redirects blood to the lungs when air is gulped oxygenated blood from lungs is directed into systemic arches (3 and 4) as it leaves the heart
aortic arches of salamanders
caroid duct (link between 3 and 4) disappears
common carotid artery now feed both carotid arteries in the head
arches 3,4, and 5 feed the rest of body while 6 still has pulmonary arched branching off
aortic arches in frogs
1,2,and 5 are gone
arch 3 is carotid arch
arch 4 is sole systemic arch feeding the rest of the body
arch 6 is completely separated from dorsal aorta creating closed pulmonary loop
aortic arches in reptiles
ventral aorta split into 3 as it comes out from heart creating 3 circuits:
pulmonary trunk
right and left systemic arches
right systemic arch is dominant
pulmonary trunk
feeds directly into the lungs creating closed pulmonary loop
left and right systemic arch
split from the heart and rejoin again after the heart in the dorsal aorta
aortic arch in birds
left systemic arch never develops
right systemic arch feeds the entire body
connection between the left and right and the carotids is called the brachiocephalic artery
aortic arches in mammals
systemic arch arises from left systemic arch
subclavian arches both arise from systemic arch and feed the limbs
carotid arch
feeds blood to the head
systemic arch
feeds blood to the rest of the body
pulmonary arch
create pulmonary circuit, arch 6
4 chambers of the fish heart
sinus venosus, atrium, ventricle, and conus arteiosus
4 chambers of human heart
atrium and ventricles (in left and right chambers)
sinoatrial node
pulmonary trunk and aortic trunk
valves in heart
sinoatrial, atrioventricular, and conal
sinoatrial valve
between sinus venosus and atrium
atrioventricular valve
between atrium and ventricle
conal valve
valves within the conus and arteriosus
what separates the atria from the ventricles?
left and right atrioventricular valves
role of pulmonary
controls blood flow into the pulmonary artery from the right ventricle
role of aortic valve
controls flow from the left ventricle into the aorta
heart cavity
heart resides in the pericardial cavity that is lined by pericardium
in mammals pericardium is filled with pericardial fluid
aspiration effect
heart is in semi rigid cavity
ventricle contracts to squeeze blood out, reducing it in volume
creates negative pressure that causes the venous sinus and atrium to expand
steps of pumping of blood
1 blood enters right atrium
2 moves into right ventricle
3 blood pumped from ventricle to lungs by pulmonary artery
4 blood returns to left atrium from lungs
5 enters left ventricle
6 left ventricle pumps blood to the rest of the body by the aorta
SA node (pacemaker)
initaites contraction wave
AV node (atrioventricular)
creates a delay and sends signal to apex
contraction of pumping blood
muscles around atria contract to squeeze blood to ventricle
muscles around ventricle relax allowing them to refill
muscles around ventricle contract causing blood to be squeezed out of heart
muscles around atria are relaxes allowing blood to go from veins to heart
steps of signaling
1 pacemaker generated wave of signals to contract atria
2 signal is delayed at AV node (completely empties atria)
3 signal passes to the apex of the heart
4 signal spreads across ventricles (contract upward to push blood up)
systole and diastole
systole is contraction phase
diastole is the relaxation phase
systolic and diastolic (blood pressure)
systolic is peak ventricular systole (highest pressure at ventricle)
diastolic is right before ventricular contraction (body relaxing)
fish heart
S shaped that allows sequential contraction of atrium and ventricle and aspiration effect
conus arteriosus is changes to bulbus arteriosus (lacks caridac muscles, contains elastic fibers, helps dampen blood flow directly into gills)
lungfish hearts
has incomplete separation within chambers atrium separated by interatrial spetum and ventricle separated by interventricular septum
atrioventricular plug creates 2 channel for blood flow
(oxygenated from pulmonary vein, deoxygenated from systemic vein)
atrioventricular plug
raised tissue that acts like a valve between chambers
fish heart double circuit
deoxygenated blood returning from the body is kept in right side, pulmonary arch redirect blood to the lung when it is gulped, oxygenated blood from lungs moves along left channel, blood is direct in systemic arch as it leaves heart
frog heart
atrium is separated and recieves bood from. pulmonary and systemic veins
ventricle is not separated and has trabecular along edge
the difference in O2 causes blood to separate as it passes the chamber (prevents mixing)
turtle heart
atrium is fully separated into 2 chambers
the ventricle is considered a single chamber but is composed of 3 interconnected chambers that keep blood separate
crocodile heart
ventricle is fully divided
left systemic arch appears to be fed by right ventricle
foramen of panizza connect right and left systemic arches
foramen of panizza
connect right and left systemic arches, allows for greater control in different environments
shunts blood away from lungs during diving so energy is not wasted when lungs lack air
crocodiles breathing air
ventricle contracts and oxygenated blood from left ventricle fills right systemic arch
high pressure in ventricle causes blood to move across foramen panizza into left systemic arch
closes lunar valve and blocks deoxygenated blood from right ventricle
blood from right ventricle can only enter pulmonary arch
crocodiles diving
vasoconstriction occurs in pulmonary system prevent easy flow from right ventricle
increases pressure in right ventricle
deoxygenated blood flows through left systemic arch and into body bypassing lungs
diving in mammals
heart rate drops (bradycardia) reducing flow to lungs
anaerobic metabolism increases generating chemical energy without oxygen
microcirculation directs blood to necessary organs
can’t alter blood flow through heart (no shunting effect)
coronary artery disease
blocked blood vessels feeding the heart
arryhythmia
abnormal heart rhythm
congenital heart defects
heart problems a person is born with (septal defects)
cardiomyopathy
abnormaility in the heart muscles
pacemaker
regulates heartbeat, small device placed in body to help control rhythms, uses low energy electrical pulses to prompt heart beats
ventricular assist device (VAD)
mechanical pump that supports heart function and blood flow, heart is not relaced just assisted
creates pump for blood to go into aorta, does job of right ventricle
total atrificial heart (TAH)
completely replaces both ventricles, end stage heart failure, temporary replacement while awaiting a heart transplant
mechanical devices that aide the heart
pacemaker, VAD, and TAH
why would you get a pacemaker?
arrhythmia (abnormal heart rate)- tachycardia (too fast) and bradycardia (too slow)that prevents heart from pumping sufficient blood
heart block: electrical signal is disrupted as it moves across the heart
types of pacemakers
single chamber: wire goes to the right ventricle alone
dual chambers: wires go to both right ventricle and atrium
biventricular: wire goes to the right atrium, and both ventricles
types of progamming of pacemakers
demand pacemaker is when it monitors heartbeat and sends signal if something goes wrong (waits for something to go wrong)
rate responsive speeds up or slows down rate based on activity level
types of VAD
LVAD: blood enter pump from left ventricle and pumped directly into aorta
RVAD: blood enters pump from right atrium and pumped directly into pulmonary artery
BiVAD: combination of LVAD and RVAD
History of artificial heart
1983 is when first artificial heart successfully transported into dog
1949 is when precursor of TAH is built at Yale
1952 is when first mechanical heart is used to keep human alive during surgery
1964 wants to devoplot TAh by end of decade
1969 first surgical use of TAH (survived 64 hrs)
1982 first attempt to permanently implant TAH
1985 successfully used as bridge to tranplantation
1990 FDA revoked approval (manufacturing issues)
Jarvil TAH pateints
in 1982 first patient lasted 112 days but died to circulatory collaspe
second patient lasted 620 days did due to blood clots and strokes (circulation not working properly)
artifical hearts currently under development
BiVACOR (has pulse) soft artificial heart
