the cardiovascular system and its control Flashcards
(97 cards)
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.