Cardiovascular * Flashcards
what are the three types of vesseles ?
arteries , veins and capillaries
where does blood travel in arteries ?
blood traveling away from heart
where does blood travel in capillaries ?
between arteries and veins
where does blood travel in veins ?
blood travelling towards the heart
describe pressure of arteries:
high pressure = thick walls
describe pressure of veins:
low pressure = thin walls
what do larger arteries mean ?
election (important for conduction and propulsion)
what do smaller arteries mean ?
muscular (vascular tone)
how big are capillaries ?
single cell thick
in which vessel does diffusion happen ?
capillaries
what do valves contain when below the heart ?
valves
what is an arteriole ?
small artery that regulates blood flow to capillary networks
which vessel contains sphincters - “resistance vessel” ?
arterioles
what do sphincters in arterioles do ?
vasoconstriction and vasodilation
what do venues do ?
- drain capillary blood but smallest ones are also a site of diffusion
- highly distensible - “capacitance vessels”
which vessels are known as “capacitance vessels” ?
venules
what are venous sinus ?
drains venous blood back t the heart or other veins + exist in 2 locations
- dural venous sinus in the brain formed by the dura mater
- coronary sinus in the heart
what are the two locations of the venous sinus ?
dural venous sinus in the brain and the coronary sinus in the heart
what are anastomoses ?
- union of 2 or more arterial branches supplying the same are
- collateral blod supply to preserve blood supply to important areas
what is the order of the closed loops of vessels ?
- arteries
- arterioles
- capillaries
- venules
- veins
what type of blood comes to the heart ?
deoxygenated
what type of blood exits the heart ?
oxygenated
what are varicose veins ?
twisted & enlarged veins
when do varicose veins develop ?
when valves are unable to close properly = retrograde flow
where do we typically find varicose veins ?
- typically in superficial veins (limbs)
- within anal canal (hemorrhoids)
- bleeding esophageal varices = life treating liver disease
when valves promote unidirectional flow back towards the heart, what does this cause ?
varicose veins
what causes varicose veins ?
congenital (born with valves that wont close properly), mechanical (pregnancy or prolonged standing )
what prevents veins from building out ?
elastic stockings
what is the main function of arteries ?
conduction + propulsion of blood
what is the main function of arterioles ?
resistance vessels
what is the main function of capillaries ?
gas exchange and diffusion
what is the main function of venules ?
capacitance vessels
wha is the main function of veins ?
return blood to heart
what is the main function of anastomoses ?
provide collateral blood supply
what “drains venous blood from the surface of the brain” ?
sinus
“high pressure vessel with elastic or muscular walls”
arteries
“single cell thick, exist in networks”
capillaries
what are anastosomes ?
two vessels supplying the same area
what are the two arches of anastomosis in supination ?
deep palmer arch and superficial palmar arch
what does the right side of the body brachiocephalic lead into ?
subclavian artery
in regards to arterial support, where will blood start off ?
abdominal aorta
in regards to deep veins, when do deep veins return blood ?
during exercise
in regards to deep veins, when do superficial veins return blood ?
at rest
what does sinus mean ?
similar to vein (cardiac sinus and dural sinus)
what does anastamsis ?
2 arteries providing collateral supply
how many valves of the heart are there ?
2 (left and right)
which valve of the wall is thick/thin ?
right = thinner walls
left = thicker walls
how many chambers of the heart are there ?
4 (2 atria and 2 ventricles)
how many valves of the heart are there ?
4
what does the heart communicate with ?
the lungs (pulmonary) and the body (systemic)
which side of the heart is deoxygenated vs oxygenated ?
right side = deoxygenated
left side = oxygenated
describe the cardiac muscle:
- striated
- involuntary
what are cardiomyocytes ?
contractible excitable heart cell
what do cardiomyocytes contain the same contractile filaments as ?
skeletal muscle (sarcomere)
cells are joined end to end and are connected via __________
intercalated discs
what are intercalated discs ?
gap junctions that link cardiac muscles so that electrical impulses can travel between cells and cause to contract almost simultaneously
where are nuclei located ?
centrally located
what are the two types of cardiomyocytes ?
- pacemaker
- non-pacemaker cells
what is “pacemaker” ?
- auto-rhythmic cells “automaticity”
- spontaneously contract
- SA node, some fibers in AV node, bundle of His and Purkinje fibers
what are “non-pacemaker cells” ?
- bulk of the heart
-basic contractile myocytes - depolarization is induced by adjacent cells depolarizing
what is syncytium ?
network of cardiomyocytes connected via intercalated discs
what are the two syncytial of the heart ?
the atrial syncytium and ventricular syncytium
what do the two syncytia of the heart allow ?
this will allow for the atria to contract prior to ventricular contraction
what are two types of action potential ?
neuronal and cardiomyocytes
what are neuronal action potentials ?
rapid depolarization (1ms)
what are cardimyocyte action potentials ?
(200-400ms) little slower than neural action potentials
describe the difference between pacemaker cells and myocytes ?
pacemarker cells = slow response
myocytes = faster response
what is depolarization in cardiomyocytes caused by?
sodium and calcium
what is the refractory period ?
period of time in which the cardiac cell is unable to initiate another action potential for some duration of time after an action potential as initiated
describe the Na and K gradient in regards to cells:
cells are like salty bananas, salt on the outside and potassium on the inside, then potassium channels open
what is the SA node also known as ?
the pacemaker
describe the SA node :
- origin of cardiac impulse
- rate of depolarization is greatest here (it drives everything else)
where is depolarization the greatest in the heart ?
SA node
describe the AV node:
- locate at the center of the heart, between the atria and ventricles
- electrically connects atria and ventricles via bundle of His
- slows the SA node
how does the AV node electrically connect the atria and ventricles ?
thought the bundle of his
what slows down the signals from the SA node ?
AV node
what does the AV node do after slowing the signal of the SA node ?
allows for atrial blood to empty into ventricles
what is an ECG machine ?
records the hearts electrical activity
how do ECG’s work ?
as cardimyocytes depolarize/repolarize, electrical currents pass across the body
what is the clinical test that we use to measure changes in electrical signal across cardiomyocytes ?
ECG (electrocardiogram)
what happens when we use different configurations during an ECG ?
it leads to more characteristic patterns
what is an ECG recording ?
summed recording of all the electrical events that are happening in the heart
what are the “waves” detected during and ECG recording ?
- P-wave
- QRS-wave
- T- wave
what is happening during the P-wave ?
atrial depolarization
what is happening during the QRS wave ?
ventricular depolarization
what is happening during the T-wave ?
ventricular repolarization
what is the cardiac cycle ?
sequence of events that occur and repeat with heart beat
what are the two things happening in the cardiac cycle ?
systole and diastole
what does systole mean ?
ventricular contraction
what does diastole mean ?
ventricular relaxation
how many phases are there in the cardiac cycle ?
7
what are the 6 recordings of the cardiac cycle ?
- aortic pressure
- left ventricular pressure
- left arterial pressure
- left ventricular volume
- ECG
- heart sounds
what are the three basic principals of the heart ?
- conduction to contraction to flow
- blood flows from higher to lower pressure
- valves open/close based on pressure gradient
what are heart sounds caused by ?
closing valves
what are the two closing valves of the heart ?
S1 = mitral alve (left AV valve)
S2 = semilunar valv (aortic)
what does the contraction of a heart do to pressure ?
increases it
what does the relaxation of a heart do to pressure ?
decrease it
what happens in atrial systole ?
- atria contract
- ventricles relax
-pushes last bit of blood into ventricles
what happens in isovolumetric contraction ?
- atria relax
- ventricles contract
- no blood is ejected = isovolumetric
what happens in rapid ejection of the cardiac cycle ?
- aortic and pulmonary valves open
- blood rushes into aorta and pulmonary trunk
- volume falls in ventricles rapidly
- pressure in ventricles continues to increase
what happens in reduced ejection of the cardiac cycle ?
- pressure begins to decrease in aorta as the last bit of blood leaves the ventricles
- pressure in atria continues to rise as atria passively fill with blood
- T-wave = ventricular repolarization
what happens in isovolumetric diastole (relaxation) ?
- semilunar valves closes (heart sound 2)
- ventricles enter diastole
- AV vales are still closed thus volume of blood in ventricles doesn’t change = is-volumetric relaxation
what happens in rapid filling of the cardia cycle ?
- pressure in atria exceed pressure in ventricles and AV valves open
-blood dumps into ventricles from atria “rapidly filling” then; atrial volume + pressure drops and ventricular volume + pressure rises
what happens in reduced filling of the cardiac cycle ?
- blood passively flows into heart from vena cava + pulmonary arteries
(AV valves are open, so it flows directly into ventricles) - P-wave starts = atrial contraction triggered
how many ribs are there in the thoracic cage ?
12 ribs
what are the three bones of the sternum ?
- manubrium
- body
- xyphoid process
what is the thoracic cage composed of ?
- 12 ribs
- sternum
- costal cartilage
- thoracic vertebrae
what is the designed goal of the thoracic cage ?
protect vital organs
what are the 5 compartments of the thoracic compartment ?
- superior mediastinum
- middel mediastinum
- anterior mediastinum
- posterior mediastinum
- L + R pleural cavities
what is the mediastinum ?
a space within your chest that contains your heart and other structures
what is the thoracic inlet ?
located at the crossroads between imaging of the neck and chest
what is the length of the thoracic inlet ?
manubrium to 1st rib to T1
what is the length of the superior mediastinum located ?
sternal angle to T4 base
what is the length of the diaphragm ?
central tendon continuous with fibrous pericardium
what are the contents of the superior mediastinum ?
- sup vena cava
- brachiocephalic veins
- arch of aorta + branches
- trachea
- esophagus
what are the contents of the middle mediastinum ?
- heart
- pericardium
- great vessel roots
what are the contents of the posterior mediastinum ?
- descending thoracic aorata
- esophagus
- vagus nerve
- sympathetic trunk
what are the contents of the anterior mediastinum ?
- connective tissue
- tymus gland
what are the contents of the lungs ?
- lungs
- pleura
- hilum ( pulmonary arteries/veins and primary bronchi)
in which thoracic compartment is the esophagus located ?
posterior mediadtinum
in which thoracic compartment is the heart located ?
middle mediastinum
in which thoracic compartment is the arch of the aorta ?
superior mediastinum
in which thoracic compartment is the lungs ?
pleural cavities
in which thoracic compartment is the pericardium ?
middle mediastinum
what happens in the right atria ?
entrance for superior + inferior vena cava + coronary sinus + anterior cardiac veins
what happens in the left atria ?
entrance for pulmonary veins
what is the first part of the heart to contract, pushing blood into ventricles via atrioventricular valves ?
atria
what are the key landmarks of the atria ?
fossa ovale and auricle
what muscle is important for contraction in the atria ?
pectinate
what is the texture of the posterior wall of the atria ?
smooth (derived from embryonic vasculature)
what is the second part of heart to contract ?
ventricles
which ventricle sends blood to lungs via pulmonary trunk ?
right ventricle
which ventricle sends blood to the body via the aorta ?
left ventricle
which ventricle is responsible for pulmonary circulation ?
right ventricle
which ventricle is responsible for systemic circulation ?
left ventricle
which ventricle has the pulmonary semilunar valve ?
right ventricle
which ventricle has the aortic semilunar valve ?
left ventricle
what are the key landmarks of the ventricles ?
interventricular septum and ligaments arteriosum
what is the importance of the interventricular septum ?
important for coordinated contraction
which muscle is very important for contraction of the ventricle ?
trabeculae
which muscles are anchor points for cord tendonae of AV valves ?
papillary muscles
how many valves are there in the heart ?
4
how many atrioventricular valves are there in the heart ?
2
how many semilunar valves are there in the heart ?
2
where is the atrioventricular valve located ?
atrium to ventricle
which AV valve is on the right side of the heart ?
tricuspid
which AV valve is on the left side of the heart ?
bicupsid/mitral
what prevents back flow in the 2 AV valves ?
chord tendineae
where is the semilunar valves located ?
ventricle to aorta/pulmonary trunk
what “holds blood, prevent back flow” ?
cusp shape
how would you describe the AV valves letter wise ?
like an M
how would you describe semilunar valves letter wise ?
like a W
what are the great vessels of the systemic circulation ?
- aorta (from left ventricle)
- superior vena cava
- inferior vena cava
where does the superior + inferior vena cava drain into ?
the right atrium
what are the three arches of the aorta (systemic circulation) ?
- brachicephalic trunk
- L common carotid
- L sunclavian
what type of arteries are ascending in the aorta (left ventricle) ?
coronary arteries
what are the great vessels of the pulmonary circulation ?
arteries and veins
is it arteries or veins that have the pulmonary trunk ?
arteries
is it arteries or veins that have left and right pulmonary arteries and contains deoxygenated blood going to lungs ?
arteries
what does it mean to have heart failure ?
heart muscle doesn’t pump as well as it should (decreased oxygen and nutrient delivery)
what are some symptoms of heart failure ?
shortness of breath, fatigue and coughing
what happens if theres left sided heart failure ?
systemic circulation impaired (muscles too weak and ventricle doesn’t refill)
what happens if theres right side heart failure ?
typically caused by left side impairement (fluid backs up through lungs, and eventually venous system)
describe the 5 steps of fetal circulation ?
- oxygenated fetal blood from he placenta passes to the fetus via the umbilical vein
- blood bypasses the liver (via the ducts venous) and enters the inferior vena cava
- blood entering the right atrium from the IVC bypasses right ventricle (lungs not yet functional) to enter the left atrium via the oval foramen
- blood from the SBC enters right atrium, passes to the right ventricle, and moves into the pulmonary trunk where it enters the aorta via the ducts arteriosus
- partially oxygenated blood in the aorta returns to the placenta via the paired umbilical arteries that arise from the internal iliac arteries
how many layers are there of the pericardium ?
3
what is the pericardium ?
3-layered sac in which the heart resides
what are the three layers of pericardium ?
- fibrous pericardium
- parietal
- visceral
which layer of the pericardium is the outer and toughest layer ?
fibrous pericardium
which layer of the pericardium is the outer layer ?
parietal
which layer of the pericardium I the inner layer ?
visceral (epicardium)
what is the first branch of the aorta ?
coronary arteries
when is the coronary artery valve opens ?
blood flow during ventricular systole
when is the coronary arteries valve closed ?
black flow of blood closes valve and causes filling of coronary arteries
what are the two coronary circulations ?
right and left coronary artery
describe the right coronary artery ?
- right marginal
- posterior interventricular
- branches to SA and AV nodes (hard to see)
describe the left coronary artery ?
- anterior interventicular/left anterior descending
- circumflex (left marginal)
coronary circulation veins =
coronary sinus
what are the 6 coronary sinus veins ?
- great cardiac vein
- left posterior ventricular vein
- left marginal vein
- middle cardiac vein
- small cardiac vein
- anterior cardiac veins
what is a heart attack/myocardial infarction ?
disruption to coronary blood floe
what is a common cause of a heart attack ?
commonly caused by atherosclerosis, a narrowing of the lumen due to plaque deposits on the vessel
what are some risk factors of heart attacks ?
- smoking
- increased blood pressure
- increased chloesterol
- obesity, diabetes
- decrease exercise
- stress
- age, family, medical history, herritage
is a heart attack and cardiac arrest the same thing ?
no
what does angina mean ?
temporary disruption
what does location and extent of damage depend on ?
location of damaged vessel
what are the 6 cavities that the thorax can be divided into ?
superior, middle, anterior & posterior mediastinum and pleura
what are two remnant fetal structures, once responsible for bypassing the lungs ?
foramen ovale and ligamentum arteriosum
what is circulation to the heart termed ?
corony circulation
