Page 1
CONDENSED Exam 3 Patho Study Guide.
The systemic circulatory system is a closed system
Anything that affects one part of this close system, it will affect the rest of the close system
(makes sense).
L= Lung and R= Rest of Body
● Right Heart: Pulmonary circulation and pumps blood through the lungs- no 02
● Left Heart: Systemic circulation and pumps blood through the body
○ Flow of fluid and blood depends on
■ Pressure differences between the ends of a vessel
● Blood pressure keeps the vessels open-too high causes problems
(ex. hypertension-heart failure)
■ Vessel resistance to fluid flow
● Small vessels have more resistance
○ Arterioles have more smooth muscle > vasoconstriction
● Longer vessels have more resistance
● More viscous fluids have greater resistance
○ Polycythemia: thicker blood - increased hematocrit
increases resistance
, Page 2
● Arteries have higher resistance
■ Adequate volume to fill the blood vessel
○ Total Peripheral Resistance: pressure the blood must overcome to keep moving
● Heart’s job is to pump blood, oxygen, hormones, etc. through the
body
○ Heart is main source of hydrostatic pressure (pushing) - when ventricles contract
it takes a lot of pressure to move the blood forward
○ Heart is unique because it can generate its own action potentials
■ SA Node (primary pacemaker) > AV Node > Purkinje Fibers
Cardiac cycle
LUV-DUB sounds when ventricles contracts and the shutting of cardiac valves (tricuspid,
pulmonary, mitral, and aortic (semilunar)
○ Systole: Ventricles Contracts (squeezes)-blood pushes against AV valves and the
valves shut after letting blood through to be distributed to the rest of the body
■ Afterload (if really high, heart works harder to overcome the systemic
vascular resistance (aorta and the rest of the systemic circulation), and if this
continues, the heart will eventually fail-result in left Heart failure): resistance
from the aorta and the vascular system the Left heart must overcome to push
blood from the left ventricle into the aorta, and to the rest of the body.
What cause afterload to increase: hypertension, medications that causes
vasoconstriction, etc.
○ Diastole: Ventricle Relaxes (blood fills in)-after blood flows out through AV valves,
the semilunar valves closed to let blood fill back up
■ Preload: Venous return-Filling pressure of the heart at the end of
diastole- Preload is venous return to the heart to fill during diastole.
○ Pulse pressure: Difference between the systolic and diastolic blood pressures
○ Mean arterial pressure: average pressure during ventricular contraction and relaxation
■ Good indicator of perfusion - goal of 60mm/Hg at a minimum (Under 60 is bad)
■ Diastolic BP + Pulse Pressure / 3
○ Blood pressure: pressure of blood upon blood vessels walls
■ BP = CO x Total peripheral resistance
Cardiac output
Volume of blood ejected from heart /minute - ~4-8L/min
● CO = Heart Rate x Stroke Volume - THINK LEFT VENTRICLE
CONDENSED Exam 3 Patho Study Guide.
The systemic circulatory system is a closed system
Anything that affects one part of this close system, it will affect the rest of the close system
(makes sense).
L= Lung and R= Rest of Body
● Right Heart: Pulmonary circulation and pumps blood through the lungs- no 02
● Left Heart: Systemic circulation and pumps blood through the body
○ Flow of fluid and blood depends on
■ Pressure differences between the ends of a vessel
● Blood pressure keeps the vessels open-too high causes problems
(ex. hypertension-heart failure)
■ Vessel resistance to fluid flow
● Small vessels have more resistance
○ Arterioles have more smooth muscle > vasoconstriction
● Longer vessels have more resistance
● More viscous fluids have greater resistance
○ Polycythemia: thicker blood - increased hematocrit
increases resistance
, Page 2
● Arteries have higher resistance
■ Adequate volume to fill the blood vessel
○ Total Peripheral Resistance: pressure the blood must overcome to keep moving
● Heart’s job is to pump blood, oxygen, hormones, etc. through the
body
○ Heart is main source of hydrostatic pressure (pushing) - when ventricles contract
it takes a lot of pressure to move the blood forward
○ Heart is unique because it can generate its own action potentials
■ SA Node (primary pacemaker) > AV Node > Purkinje Fibers
Cardiac cycle
LUV-DUB sounds when ventricles contracts and the shutting of cardiac valves (tricuspid,
pulmonary, mitral, and aortic (semilunar)
○ Systole: Ventricles Contracts (squeezes)-blood pushes against AV valves and the
valves shut after letting blood through to be distributed to the rest of the body
■ Afterload (if really high, heart works harder to overcome the systemic
vascular resistance (aorta and the rest of the systemic circulation), and if this
continues, the heart will eventually fail-result in left Heart failure): resistance
from the aorta and the vascular system the Left heart must overcome to push
blood from the left ventricle into the aorta, and to the rest of the body.
What cause afterload to increase: hypertension, medications that causes
vasoconstriction, etc.
○ Diastole: Ventricle Relaxes (blood fills in)-after blood flows out through AV valves,
the semilunar valves closed to let blood fill back up
■ Preload: Venous return-Filling pressure of the heart at the end of
diastole- Preload is venous return to the heart to fill during diastole.
○ Pulse pressure: Difference between the systolic and diastolic blood pressures
○ Mean arterial pressure: average pressure during ventricular contraction and relaxation
■ Good indicator of perfusion - goal of 60mm/Hg at a minimum (Under 60 is bad)
■ Diastolic BP + Pulse Pressure / 3
○ Blood pressure: pressure of blood upon blood vessels walls
■ BP = CO x Total peripheral resistance
Cardiac output
Volume of blood ejected from heart /minute - ~4-8L/min
● CO = Heart Rate x Stroke Volume - THINK LEFT VENTRICLE
