1What is cardiac output the measure of?
Cardiac performance
2Formula for cardiac output?
CO = Heart Rate x Stroke Volume
3What is stroke volume?
Volume of blood before contraction minus volume of blood after contraction.
4Equation for stroke volume?
SV = EDV - ESV
5What determines heart rate?
Sinoatrial node
6What innervates heart rate?
Autonomic Nervous System (ANS)
7Location of cardiovascular control center
Brain stem
8Pathway altered by cardiovascular control center
cAMP pathway
9Venous return
Blood returning to the heart from the veins
10What regulates extrinsic stroke volume? What does extrinsic regulation increase?
Sympathetic stimulation and epinephrine. Cytosolic Ca²⁺ and contraction strength
11Flow rate
Volume of blood per minute
12Pressure gradient
Change in pressure between two areas of a vessel; blood flows from an area of higher to lower pressure.
13Where is the pressure gradient derived from?
The heart
14Where is the highest blood pressure location in the circulatory system?
Aorta
15What does the vascular tree consists of?
Arteries, arterioles, capillaries, venules, veins
16Special function of arteries
Pressure reservoir
17Special functions of arterioles
Regulate distribution of blood flow and blood pressure, they are major resistance vessels due to small radii
18Makeup of arteries
Thick layers of vascular smooth muscle, elastic, and fibrous connective tissue (allows arteries to expand).
19Makeup of arterioles
Less elastic, more muscular
20Capillaries
site of exchange
21Function of venules
Receive blood from capillaries; connect to veins
22Makeup of venules
Thin exchange epithelium (allows diffusion)
23Function of veins
Return blood to the heart and act as volume reservoirs
24Makeup of veins
Thin smooth muscle walls; contain one-way valves to prevent backflow
25What do elastic fibers in arteries do?
Expand when large volumes of blood are received during ventricular systole
26Arteries passively ______ during diastole
Recoil
27Recoil
Fibers of the vessels snapping back passively
28Contraction
An active inward pull
29What do arteries maintain?
High blood pressure
30Blood Pressure
The force exerted by blood against a vessel wall
31Maximum pressure during ventricular systole
Systolic Pressure
32Minimum pressure when blood is draining out
Diastolic Pressure
33Mean Arterial Pressure (MAP) Equation
Diastolic + 1/3(Pulse Pressure)
34What is the main driving force for blood flow?
Mean Arterial Pressure
35What does Mean Arterial Pressure represent?
Average pressure responsible for driving blood forward
36What feature allows arterioles to change resistance?
Their radii can change
37Structural makeup of arterioles
Thick smooth muscle and little elastic tissue
38What type of innervation do arterioles receive?
Sympathetic innervation
39What two factors regulate vascular tone?
Myogenic activity of smooth muscle and sympathetic nervous system
40What are the controlling factors of vascular tone?
Intrinsic (local) and extrinsic (systemic) factors
41What do intrinsic factors control in arterioles? (vascular tone)
distribution of cardiac output
42What do extrinsic factors control in arterioles? (vascular tone)
blood pressure
43What chemical signals indicate increased metabolic demand?
Low O2, High CO2, High Acidity, Increased K+ ions
44Endothelial-derived relaxing factor (EDRF)
Causes vasodilation by inhibiting Ca++
45What are the 2 types of extrinsic control of arterioles?
Neuronal and Hormonal
46Neuronal extrinsic control
Sympathetic nervous system