Midterm 2 Flashcards
What is the starling equation?
Quantifies the movement of fluids in/out of a capillary as a result of the filtration process that is based on hydrostatic pressure and oncotic pressure.
Hydrostatic pressure is the pressure of fluids (i.e. blood) in the capillaries.
The oncotic pressure is the number of proteins in the blood that absorb fluids. (Net driving force to keeps fluids in the vessel)
If there is too much fluid such that hydrostatic > oncotic then fluid there won’t be a sufficient amount of proteins in the blood to soak up the fluids and will likely leak out into the lungs
If the vessel wall becomes abnormally permeable such as infection or inflammation then blood protein can move out of the capillary into interstitial space
Define the determinants of cardiac output and state the factors that influence each.
Cardio output = HR * SV
- Heart rate is the initial driver of cardiac output until HR is maxed, then Stroke volume takes over to increase CO.
- Greater preload, afterload, and heart contractility can change SV and increase CO.
- Total peripheral resistance influences the afterload of the heart
How can left ventricular failure cause pleural effusion?
Systemic pressure can back up into pulmonary circulation to push fluid out of the capillaries into the pleural space
Distinguish between systole and diastole and how they relate to cardiac function.
Systole occurs when the cardiac muscle contracts and the pumps blood to enter the systemic circulation
- Diastole is when the cardiac muscle relaxes and the right atrium refills with more blood before another contraction.
End-Diastolic volume (EDV) is the main determinant of preload, which is the volume of blood loaded into the ventricles before a contraction occurs.
Define the factors that determine blood pressure.
Cardio output, total peripheral resistance (vessel wall diameter), blood viscosity (thickness), vessel wall elasticity.
What is preload?
Preload is the amount of blood in the ventricles right before contractions occur, this is dependent on how much blood enters the heart
- Venous return can be assisted by respiratory, skeletal muscle pump
What are the branches of the heart?
-Left Branch
Circumflex, left descending anterior artery (front and bottom on LV)
- Right Branch (right side of the heart)
- Marginal branch, right coronary branch
what type of receptors control the SA node and ventricles?
Beta Receptors in the sympathetic NS control the SA node and ventricles?
what sensory components can affect the cardiovascular control center of the brain?
Sensory nerves from muscles > because they are the biggest consumer of O2.
Hypothalamus > temp control, therefore, the temperature is a stimulant.
Baroreceptors for BP
Chemoreceptors for PCO2, PO2, pH, etc.
what factor increase and decreased contractility of the heart?
Increase: circulating catecholamines, sympathetic stimulation, digitalis (made from flowers), Digoxin.
Decrease: Beta-blockers, PNS stimulation,
