Exam 2 - Week 7 (Cardiovascular) Flashcards
3 layers of the heart
Endocardium, myocardium, epicardium
Where is the hart located?
Media Stinum between the lungs and enclosed in a double walled pericardial sac
Visceral pericardium
= epicardium = serous membrane with small amounts of lubricating fluid within the pericardial cavity between the membranes to facilitate heart movement
AV Valves; names, and what do they do?
Right - tricuspid
Left - bicuspid
They separate the atria from ventricles
Semilunar valves; names, and what do they do?
They separate left and right side of heart and regulate flow of the artery they belong to
Aortic valve
Pulmonary valve
Baroreceptors - location, function
Location: aortic arch and carotid sinus
Function: sensitive to stretch or pressure within the arterial system
-Relay information to basal motor center in the brainstem and alerts autonomic nervous system to act accordingly
Chemoreceptors - location, function
Location: aortic and carotid bodies
Function: capable of initiating changes in HR and arterial pressure in response to increased arterial CO2 pressure
-When stimulated, they subsequently stimulate the basal motor sensor to increase cardiac activity
How does the parasympathetic nervous system regulate the cardiovascular system?
- Mediated by vagus nerve
- Decreases HR by slowing SA node rate which reduces conduction through the AV node
How does the sympathetic nervous system regulate the cardiovascular system?
Fight or flight response
-Increases HR, increases speed of impulses and conduction through AV node, increases force of atrial and ventricular contractions
S1 indicates
“Lubb” - closure of the AV valves
S2 indicates
“Dubb” - closure of the semilunar valves
What are murmurs caused by?
- Incompetent valves
- Unusual turbulence in bloodflow
- Hole in the heart septum
Pulse
indicates heart rate
Pulse deficit
difference in the rate between apical and radial pulse
Automaticity
Ability to discharge and electrical impulse spontaneously
Rhythmicity
Ability to generate an electrical impulse at regular intervals
Conductivity
Ability to send an electrical impulse from one area to the next along an electrical pathway
Cardiac Output
= HR x SV
The amount of blood pumped out by each ventricle in 1 min
HR
the number of contractions of the ventricles each minute
SV
The amount of blood ejected from each ventricle with each contraction
Where is the cardiac control center located?
In the medulla oblongata
Cardiac reserve
ability of the heart to increase output in response to increased demand
Preload
The work imposed on the heart before contraction begins = end diastolic pressure when ventricles have filled
When does preload increase?
Hypovolemia, regurgitation of valves
Afterload
The force required to eject blood from the ventricle = resistance that the Left ventricle must overcome to circulate blood
When does after load increase?
HTN, vasoconstriction
Ventilation Perfusion Ratio = VQ Ratio
measurement used to measure/assess efficiency and adequacy of the matching of air that reaches alveoli to blood that reaches alveoli
V = air that reaches alveoli Q = blood that reaches alveoli
Hypercoagulability
abnormality of blood coagulation that increases risk of thrombosis
Blood coagulation
process by which blood changes from liquid to gel
