Cardiac Flashcards
three objectives of a multicellular organism
- deliver glucose
- deliver O2
- remove waste
three primary roles of the human circulatory system
- transportations
- respiratory, nutritive, excretory
- regulation
- hormones, regulatory molecules
- protection
- immunity, clotting
SVC
superior vena cava
RV
right ventricle
RA
right atria
PA
pulmonary artery
IVC
inferior vena cava
LV
left ventricle
LA
left atria
tricuspid
RA/RV valve
- opens when ventricle is relaxing
pulmonary semilunar
RV/PA
- open when ventricle is contracting
mitral
LA/LV
- open when ventricle is relaxing
aortic semilunar
LV/AO
- open when ventricle is contracting
stroke volume
volume of blood dispelled from heart every beat
cardiac output equation
cardiac output = (stroke volume)(cardiac rate)
what are the tendons holding valves to muscles called?
chordae tendineae
what are the muscles that open and close valves called?
papillary muscles
valves provide two main things
- one way blood flow
- regulated/controlled blood flow
what are the two holes in a fetal heart?
- foramen ovale
- ductus arteriosus
foramen ovale
between two atrium, but has also been observed between two ventria
ductus arteriosus
connection between the PA and aortic arches
- with the first breath, the increase of O2 stimulates the aortic arch to contract, pulling away from the PA and seals shut
cyanosis
septum defect between chambers
- right to left shunt
- deO2 move to O2
distribution of blood flow
veins: 67%
arteries: 11%
capillaries: 5%
heart: 5%
pulmonary circulation: 12%
blood movement through the heart
- enters from the SCV/IVC
- enters into the RA
- moves from the RA into the RV
- goes into the PA
- goes into the lungs for gas exchange
- moves into the PV
- enters the LA
- enters the LV
- moves to the aortic arch into the body
two types of nerves innervate the heart
- parasympathetic: vegas, conserves the energy of the body system, slows bpm
- sympathetic: sympathetic ganglion, prepares body for an emergency, flight/fight response, accelerates bpm
signal movement in the heart
- sympathetic/parasympathetic nerves send signals to the sinoatrial node
- sinoatrial node sends signals to the atrioventricular node via accelerator nerves
- the atrioventricular node sends signals through the bundles of His to, purkinje fibers to the rest of the heart
systole
orderly contraction of the heart
diastole
relaxation phase of the heart cycle
maintenance of the action potentials is drive by _____.
Ca2+, calcium
what does calcium do to an action potential?
- extends the top plateau
- extends the absolute refractory period
fast response AP
- atria, ventricles, purkinje fibers
- steep upsweep and large amplitude
- L type Ca2+ channels, long lasting
- cannot spontaneously depolarize
slow response AP
- SA and VA nodes
- T type Ca2+ channels, transient, responsible for upsweep
- resting action potential is not stable
- spontaneous depolarization
ACTIVATED FIRST
S1 heart sound
- in line with 3 on graph of heartbeat
- closure of tricuspid and mitral valves
S2 heart sound
- in line with 5 on the graph of heartbeat
- closure of pulmonary semilunar and aortic semilunar
where can you listen to the S1 heart sound?
- 5th intercostal space, left of sternum
- left 5th intercostal space, at heart apex
S3 heart sound
- ventricle is vibrating in child
- heart disease in adults
S4 heart sound
normal, atria contraction
P wave
atria depolarizing
Q, R, S, waves
two events
- ventricular depolarization
- repolarization of atria
T wave
repolarization of ventricles
what is a heart murmmur?
blood regurgitates back through valves
- defective heart valves
- rheumatic fever endocarditis
- mitral stenosis aka calcification of bicuspids
bradycardia
less than 60 bpm
tachycardia
greater than 100 bpm
ectopic pacemakers
cells outside the SA node assume pacemaker activity
ventricular tachycardia
ectopic pacemaker activity explicitly in the ventricles causing them to beat separately from the atria
flutter
200-300 bpm
- regular rhythm but generally leads to fibrillation
atrial fibrillation
the pumping action of the atria stops, but the ventricles still pump 80% of the blood
- can live for years without knowing
- reestablishment can be done via drug therapy
ventricular fibrillation
the pumping action of the ventricles stop, only 20% of blood is pumping
- only live minutes
- must be shocked and hope the proper rhythm restores
- 10-15% recover, need a pacemaker
a normal P-R rhythm takes…
0.12 to 0.2 seconds
atrioventricular block (AV)
changes in the P-R period
1st degree AV block
greater than 0.20 seconds between P and R, too long
2nd degree AV block
AV node becomes damaged and only 2/3 of the action potentials make it to the ventricle
- multiple P waves without an associated QRS spectra
3rd degree AV block
no action potentials reach the ventricles from the atria, so the atria are beating by the SA node and the ventricles are beating via ectopic pacemaker activity (irregular)
- only answer is an artificial pacemaker
myocardial infraction
heart attack
- suppressed/irregular QRS accompanied by reduced O2
ischemia
low O2 environment
- ST depression
formation of plaque is driven by…
cholesterol
HDL
high density lipoprotein
- carries to the liver or degrade it
GOOD
LDL
low density lipoprotein
- carries cholesterol to all cells
BAD
chances of coronary heart disease is inversely related to…
the concentration of HDL
when does HDL increase?
in pregnancy and breastfeeding, estrogen, exercise
when does HDL decrease?
smoking (nicotine)
thrombosis
accumulation of a lipid plaque
embolism
moving thrombosis
embolisms clogging a coronary vessel in the heart cause…
myocardial infarction
embolisms clogging vessels in the brain can cause…
cerebral thrombosis/embolism
- cerebral vascular accident or stroke
treatments for a thrombosis/embolism
- bypass
- angioplasty
- scape out plaque (don’t do this lol)
- blood thinners
- intravessel cementation
- stints
angioplasty
using a balloon to compact plaque to allow blood flow to be restored
