the cardiovascular system and its control Flashcards
what are the 3 major circulatory elements of the cardiovascular system
- a pump (heart)
- channels or tubes (blood vessels)
-a fluid medium (blood)
what are the major functions of blood
- delivers 02 nutrients
-removes CO2, other waste - transports hormones, other molecules
- temperature balance and fluid regulation
what are the 4 chambers of the heart and where are they located?
right and left atria (RA,LA): top receiving chambers
right and left ventricles (RV, LV): bottom, pumping chambers
what circulation does the right heart do ?
pulmonary circulation
what circulation does the left heart do?
systematic circulation
the right heart pumps ___ blood from ___ to ___
deoxygenated, body, lungs
the left heart pumps _____ blood from ____ to ___
oxygenated, lungs, body
what is the order of blood from the right heart?
Superior, inferior vena cavae ->RA -> tricuspid valve ->RV -> pulmonary valve -> pulmonary arteries -> lungs
what is the order of blood from the left heart ?
Lungs -> pulmonary veins -> LA ->mitral valve -> LV -> aortic valve -> aorta
myocardium itself needs ___
blood
what side of the heart does the right coronary artery supply?
right side of heart
what side of the heart does the left (main) coronary artery supply ?
the left side
what is myocardium?
cardiac muscle
what are the left ventricle characteristics?
-pumps blood to entire body
-thickest walls (hypertrophy)
-LV hypertrophies with exercise and with disease
- exercise and disease adaptations are different
skeletal muscle cells characteristics?
- large, long, unbranched, multinucleated
-intermittent, voluntary contractions
-Ca2+ released from SR
what are the myocardial cells characteristics ?
-small, short, branched, one nucleus
-continuous, involuntary rhythmic contractions
- calcium- induced calcium release
what type and the characterisics of myocardial cell fiber?
-only one fiber type
-high number of mitochondria
-striated
Cardiac muscle fibers connected by regions called ____
intercalated discs
what are desmosomes ?
hold cells together
what are gap junctions?
rapidly conduct action potentials
what are the steps to the calcium induced release ?
1.AP spreads along sarcolemma down T-tubules
2.DHP receptors (a special Ca2+ channel) in T-tubule are stimulated and open
3.Ca2+ to enter cell, but insufficient to cause contraction
4.Instead, triggers ryanodine receptors (another special Ca2+ channel) on SR to release Ca2+
what causes the heart to beat ?
-Contraction is caused by electrical stimulation of the heart tissue.
-Electrical impulse:
Right atrium -> throughout the entire heart.
-Starting point : Sinoatrial node (SA node)
What are the components involved in the intrinsic control of heart activity and responsible for generating and spreading electrical signals?
Sinoatrial (SA) node
Atrioventricular (AV) node
AV bundle (bundle of His)
Purkinje fibers
How does the electrical signal spread in the intrinsic control of heart activity, and what is the intrinsic heart rate observed in certain patients?
The electrical signal spreads via gap junctions.
The intrinsic heart rate (HR) is observed to be 100 beats/min.
This phenomenon is observed in heart transplant patients due to the absence of neural innervation.
how does the SA node initiate contraction signal for the cardiac conduction system?
-Pacemaker cells in upper posterior RA wall
-Signal spreads from SA node via RA/LA to AV node
-Stimulates RA, LA contraction
how does the AV node delays, relays signals to ventricles?
-In RA wall near center of heart
-Delay allows RA, LA to contract before RV, LV
-Relays signal to AV bundle after delay
What are the functions and characteristics of the AV bundle within the cardiac conduction system?
-The AV bundle relays signals to the right ventricle (RV) and left ventricle (LV).
-It travels along the interventricular septum.
-The AV bundle divides into right and left bundle branches.
-It sends signals toward the apex of the heart.
What are the characteristics and functions of Purkinje fibers in the cardiac conduction system?
-Purkinje fibers send signals into the right ventricle (RV) and left ventricle (LV).
-They are terminal branches of the right and left bundle branches.
-Purkinje fibers spread throughout the entire ventricle wall.
-Their main function is to stimulate the contraction of the RV and LV.
what is the order of the cardiac conduction system?
SA node, AV node, AV bundle/bundle of his, bundle branches, purkinje fibers
what are the parasympathetic control functions and characteristics when it comes to the extrinsic control of heart activity ?
-Decreases force of contraction
-Decreases HR below intrinsic HR
-Intrinsic HR: 100 beats/min
-Normal resting HR (RHR): 60 to 100 beats/min
-Elite endurance athlete: 35 beats/min
what is the function of the sympathetic nervous system and charcterisics whenit comes to the extrinsic control of heart activity?
-Increases force of contraction
-Increases HR above intrinsic HR
-Determines HR during physical, emotional stress
-Maximum possible HR: 250 beats/min
how does ecg record the hearts electrical activity ?
-10 electrodes, 12 leads
-Different electrical views
-Diagnostic tool for coronary artery disease
what are the 3 basic phases of the ecg?
-P wave: atrial depolarization
-QRS complex: ventricular depolarization
-T wave: ventricular repolarization
what are some examples of cardiac arrythmias?
(B,T,P,A,Vt,Vf
Bradycardia (pathological vs. exercise induced)
Tachycardia (pathological vs. exercise induced)
Premature ventricular contraction
Atrial flutter, fibrillation
Ventricular tachycardia
Ventricular fibrillation
what are the terminology of cardiac function?(H,Cc,Ef,Co)
-Heart rate (bpm)
-Cardiac cycle
-Stroke volume (ml/beat)
-Ejection fraction
-Cardiac output (Q* L/min)
CO-what is the formula for total volume of blood pumped per minute?
CO (Q) = HR X SV
what is the cardiac output at rest ?
-HR ~70 beats/min
-SV ~70 mL/beat
-70 beats/min x 70 mL/beat = 4,900 mL/min
-Use L/min (4.9 L/min)
resting cardiac output is 4.2 to 5.6 L/min what is the average total blood volume and how many times does the tbv circulate in a min?
5L and once every min