Cardiovascular system Flashcards
which part of the cardiovascular creates pressure to pump blood
heart
what carries blood away from the heart
arteries and arterioles
what exchanges O2, CO2, and nutrients with tissues
capillaries
what carries blood towards the heart
veins and venules
exercise cause increase of cardiac output due to increased in both ____ and ____
heart rate and stroke volume
at rest, a normal balance between sympathetic and parasympathetic cavity to the heart is maintained by what?
cardiovascular control center in the medulla oblongata
sympathetic uses this nerve to innervate both the SA node and the ventricles
Cardiac accelerator nerves
once the sympathetic nerve reaches the heart, what hormone does it release and what does this hormone do?
release norepinephrine upon stimulation, and act on beta receptors which causes an increase of heart rate and the force of myocardial contraction
give an example of sympathetic nerve stimulation
increase in right atrial pressure =increase in venous return; hence to prevent backup of blood in the systemic venous system, an increase in CO must occur.
CCC responds by increase sympathetic to the heart increase HR and CO = Increase in CO = decrease atrial pressure and decrease venous blood pressure
parasympathetic inverted by
vagus nerve
after making contact with SA node and AV node (parasympathetic), which hormone is released and what is the cause?
acetylcholine is released and cause a decrease in the activity of SA and AV due to hyper polarization
a decrease in parasympathetic tone to the heart may cause what? what happens if there an increase?
a decrease would cause elevate heart rate and increase would cause slowing of heart rate
give an example of sympathetic activity
EXAMPLE: Increase resting BP = Increase parasympathetic activity to the heart leading to a slow the HR and reduce CO. The result of Reduction in CO = decrease BP
cardiovascular system work with what system?
pulmonary
cardiovascular system works with the pulmonary system to? 3
- transport O2 and nutrients to tissues
- remove of CO2 wastes from tissues
- regulate body temperature
what is oncotic pressure?
oncotic pressure is the exchange of nutrients, wastes and gases that depends on capillary pressure, concentration gradient, and protein pressure
the exchange of nutrients, wastes and gases depends on? 3
- capillary pressure
- concentration gradient
- protein pressure
high number of proteins in the blood create movement into the?
capillary
high pressure in the capillary creates movement into the
tissues
brief description of pulmonary circuit
- right side of the heart
- pumps deoxygenated blood to the lungs via pulmonary arteries
- returns oxygenated blood to the left side of the heart via pulmonary veins
- low pressure system
brief description of systemic circuit
- left side of the heart
- pumps oxygenated blood to the whole body via arteries
- returns deoxygenated blood to the right side of the heart via veins
- high pressure system
the left ventricle (including the septum) accounts for how many percent of the total heart mass
75-80%
why is the LV thicker than the RV?
LV has a higher pressure systemic vasculature (pumps harder)
what is the purpose of heart valves?
prevent back flow of blood into the heart chambers
what is the chorda tendinae attached to and what does it prevent?
attached to the papillary muscles which prevent the AV valves from regurgitating when ventricles contract
layers of the heart
- epicardium (visceral pericardium)
- myocardium
- endocardium
Characteristics and function of the epicardium (visceral pericardium)
- serous membrane including blood capillaries, lymph, capillaries, and nerve fibers
- serves as lubricative outer covering
Characteristics and function of the myocardium
- cardiac muscle tissue separated by connective tissues and including blood capillaries, lymph capillaries, and nerve fibers
- provides muscular contractions that eject blood from the heart chambers
Characteristics and function of the endocardium
- endothelial tissue and a thick sub endothelial layer of elastic and collagenous fibers
- serves as protective inner lining of the chambers and valves
when the myocardium contracts, it squeezes the coronary vessel hard enough to ______ blood flow
reduce
the fibrous pericardium has a little to no give in it so any contusion to the heart increase the risk of a _____ _____.
compartment syndrome
the layers receives blood supply via ____
coronary arteries (high demand for oxygen and nutrients)
cardiac muscle - a syncytium
- latticework appearance
- striated
– intercalated discs - gap junctions
-uninucleated
cardiac muscle cell types
- cardiomyocytes
-excitatory muscle fibers - conductive muscle fibers
cardiac muscle cell characteristics (4)
- automaticity
- excitability
- conductivity
- contractility
define automaticity
refers to the ability to spontaneously depolarize
define excitability (irritability)
refers to the ability of a cell to reach its threshold potential - respond to a stimulus
define conductivity
refers to the ability of a cell to conduct an AP from one cell to the next
define contractility
refers to the ability of a cell to contract or shorten in response to a stimulus
true or false: excitatory and conductive muscle fibers possesses actin and myosin?
flase: possess almost no actin and myosin
excitatory and conductive muscle fibers are capable of
self excitation - automatic rhythmicity
excitation/contraction - unique differences (2)
- source of Ca2+ for contraction
- plateau of AP - longer contraction
heat and skeletal comparison - contractile proteins: myosin and actin
present
shape of muscle fibers - heart and skeletal muscle
H: shorter than skeletal muscle fibers and branching
S: elongated - no branching
nuclei - heart and skeletal muscle
H: single
S: multiple
Z discs - heart and skeletal muscle
H: present
S: present
striated - heart and skeletal muscle
yes to both
cellular junctions - heart and skeletal muscle
H: yes, intercalated discs; gap junctions
S: no junctional complexes
connective tissue - heart and skeletal muscle
H: endomysium
S: epimysium, perimysium. and endomysium
energy production - heart and skeletal muscle
H: aerobic (primary)
S: aerobic and anaerobic
calcium source (for contraction) - heart and skeletal muscle
H: sarcoplasmic reticulum and extracellular calcium
S: sarcoplasmic reticulum
neural control - heart and skeletal muscle
H: involuntary
S: voluntary
regeneration potential - heart and skeletal muscle
H: none - no satellite cells present
S: some possibilities via satellite cells
the cardiac cycle consist of
systole and diastole
what does the cardiac cycle refer to
repeating pattern of contraction and relaxation of the heart
the contraction phase is called
systole
the relaxation period is called
diastole
what prevents back flow into the atria
atrioventricular valves
systole
- contraction phase
- ejection of blood
- aprox. 2/3 blood is ejected form ventricles per beat
- time in systole is aprox. 1/3 of the total cardiac cycle
what happens at P wave?
Atrial depolarization
what happens at QRS wave?
ventricular depolarization
what happens at T wave?
ventricular repolarization
what’s consider a wave?
up and down line of the the graph
what is a segment?
what connects one wave to another
what is an interval?
one wave and one segment
what is the isometric line?
zero where the heart beat contracts
the importance of PR interval
causes a delay that occurs at the AV node. Allows filling of ventricles
what does RR interval interpret
calculate heart rate (heartbeat)
what makes up the heart rate variable?
R to R - the time delay to get from one R to another R
mean arterial blood pressure is determined by what two factors ?
Cardiac output and total vascular resistance
increase in cardiac output or vascular resistance results an increase in
MAP
which region serves as the pacemaker for the heart
Sinoatrrial node (SA node)
which node locates in the floor of the right atrium, connects the atria which the ventricles by a pair of conducive pathways called the right and left bundle branches?
Atrioventricular Node (AV node)
what does QT interval represent?
represents a whole systole contraction. Depolarization and repolarization of the ventricles
what does ST segment represent
ventricular contraction
where does AP originate?
Sinoatrial Node (the pacemaker)
action potentials are carried by the ____ ____ from the bundle branches to the ventricular walls
pukinje fibers
the myocardium is composed of three layers
- epicardium
- myocardium
- endocardium
the contraction phase of the cardiac cycle is called ____ and _____
systole and diastole
blood pressure can be increased by one or all of the following factors:
- increase in BV
- increase in HR
- increase in Blood viscosity
- increase in SV
- increase in peripheral resistance
a recording of the electrical activity of the heart during the cardiac cycle is called the
electrocardiogram (ECG or EKG)
what happens during diastole?
- pressure in ventricles is low
- filling with blood from atria
- AV valves open with ventricular P < atrial P
what happens during systole?
- pressure in ventricles rises
- blood ejected in pulmonary and systemic circulation
-semilunar valves open when ventricular P > aortic P
decrease of stroke volume could decrease ejection fraction that could lead to
heart failure
isovolumic contraciton
no change in volume
isovolumic relaxation
diastole part
systolic pressure is generated during
ventricular contraction
diastolic pressure in the arteries during
cardiac relaxation
____ ___ is the difference between systolic and diastolic
pulse pressure
increase in BP = decreased in
SNS activity
decrease in BP = increased in
SNS activity
TVR is based on
- diameter of the blood vessel
- viscosity of the blood
which organ regulate blood volume
kidney
BP =
CO x TPR
BP =
HR x SV x TPR
during isometric contraction, HR contraction would be stronger to deliver more blood oxygen through the body therefore what would happen?
increase of BP
a low HRV indicates?
an imbalance exists in autonomic regulations
physical inacvity promotes a decrease in
HRV
aerobic exercise result in increased of
HRV
End diastolic volume (EDV) is referred as
preload
Frank Starling demonstrated that
the strength of ventricular contraction increased with an enlargement of EDV
EDV results in a lengthening of
cardiac fibers that improves the force of contraction in a manner similar to that seen in skeletal muscle
