Physiology of the Cardiovascular System Flashcards
What are three purposes of the cardiovascular system?
- Move blood around of body
- Oxygen and nutrient dispersement
- Get rid of waste products
Describe the arterial system.
- Oxygen and nutrient containing blood
- High pressure transport
Describe the venous system.
- Blood returned here
- Low pressure return
What side of the heart is low pressure?
Right side.
What side of the heart is high pressure?
Left side.
How many chambers are in the heart?
Four motherfucker.
Which ventricle is larger and why?
Left ventricle is larger because it has to pump blood to the entire body, while the right ventricle only pumps blood to the lungs.
How does blood flow in the heart?
Through unidirectional valves from atrium to ventricle
What is a heart murmur?
Turbulence caused by a leak in valve causing bidirectional flow.
When the atrium is empty, the valve is ______. When the atrium is full, the valve is ______.
Atrium empty = valve closed
Atrium full = valve open
When the ventricle is full, the valve is _____.
Closed.
What are cardiac muscles called?
Cardiomyocytes.
How does cardiac muscle differ from skeletal muscle?
- Cardiac muscle has its own internal electical system
- Cardiac muscles have gap junctions
What are gap junctions, and why are there so many of them in cardiac muscle?
Tunnels that allow for movement between adjacent cells. So many allow for consistent pumping.
90% of cardiac cells are ____ cells. 10% of cardiac cells are ____ cells.
90% - contractile
10% - pacemaker (autorhythmic)
What do pacemaker cells do, and what are the three sets?
- Sets baseline rate of contraction independent of rest of body
- Sinoatrial node, atrialventricular node and Purkinje fibers
What are the individual functions of the sinoatrial nodes, atrialventricular nodes and Purkinje fibers?
- Sinoatrial node - causes contact and push into ventricle (sets pace for rest)
- Atrialventricular node - responsible for contraction of ventricle
- Purkinje fibers - Responsible for contraction of ventricle
Do autorythmic cells have no resting potential?
Yes, the do not have resting potentials.
How does the autonomic nervous system modify heart rate?
Parasympathetic slows it.
Sympathetic speeds it up.
T or F: Smooth muscle is thicker on the artery side.
Fucking true.
Why are capillaries so thin?
For efficient nutrient and gas exchange during rapid blood flow.
What does hydrostatic pressure do between tissue and blood?
Drives nutrients out of blood and into interstitial fluid.
What does osmotic pressure do between tissue and blood?
Drives waste products into blood.
Why do runner’s experience a high, or flow-mediated dilation?
Blood flow creates shear stress in veins. Vessel membranes tugged, acting on pressure sensors. eNOS flows into smooth muscle, causing muscle to relax and increasing body’s capacity to make blood.
