Flashcards in Quiz 3 Deck (51):
1
Flow is governed by...
Pressure and resistance
2
Pressure
Moves fluid
3
Resistance
Opposes movement
4
By pulling back a syringe...
We increase the volume and decrease the pressure
The pressure outside the syringe is greater than the inside, so air moves in
5
By pushing on a syringe...
We decrease the volume and increase the pressure
The pressure outside the syringe is less than the inside, so air moves out
6
Heart Sounds
S1 and S2
7
S1
Closure of the AV valves
"Lub"
8
S2
Closure of the semilunar valves
"Dub"
9
Valvular Regurgitation
A condition in which blood leaks in the wrong direction because one or more heart valves closes improperly
Mitral valve prolapse is a common cause
10
Events of Ventricular Systole
Ventricular contraction
Atrial relaxation (filling)
11
Events of Ventricular Diastole
Ventricular relaxation (filling)
Atrial diastole continues throughout most of diastole
Atrial systole (ejection into ventricles) occurs near the end of diastole
12
End Diastolic Volume
Volume in each ventricle at the end of diastole (120-130mL)
13
End Systolic Volume
Volume remaining after systole (50-60mL)
14
Stroke Volume
Volume ejected per beat (EDV-ESV)
15
Ejection Fraction
Blood at beginning of systole ejected during systole
(EF=SV/EDV)
Lower EF indicated you are not pumping as much blood per beat, so therefore not as much blood to tissues
16
Ventricular Diastole (Passive Filling)
30mL
17
Atrial Systole
40mL
18
Stroke Volume
-70mL
19
EF
0.53mL
20
Necessity of Balanced Ventricular Output
1. Right ventricular output exceeds left ventricular output
2. Pressure backs up
3. Fluid accumulates in pulmonary tissues
1. Left ventricular output exceeds right ventricular output
2. Pressure backs up
3. Fluid accumulates in systemic tissue
21
Nerve Supply to the Heart
Autonomous: Intrinsic Rate
Receives additional input from the CNS
Sympathetic and parasympathetic input
22
Autonomic Regulation
Sympathetic stimulation to the heart originates in the lower cervical to upper thoracic spinal cord
Speeds up the heart and increases blood flow and ventricular output
23
Parasympathetic Stimulation
Originates in the nuclei of the vagus nerve in the medulla oblongata
Vagus nerve innervates SA and AV nodes
Slows the heart
24
Cardiac Output
Amount of blood pumped per beat per minute
Affected by stroke volume and heart rate (HR increases CO the most)
25
Cardiac Reserve
Difference between maximum output and output at rest
26
Three Factors that Affect Stroke Volume
Preload
Contractility
Afterload
27
Preload
Starling's Law of the Heart
Amount of tension on ventricular myocardium before it contracts
Increased Preload=Increased Contraction Strength
28
Starling's Law of the Heart
Ventricles eject as much blood as they receive
The more they are stretched, the harder they contract
29
Contractility
Contraction force for a given preload
Increased interaction affects stroke volume
30
Positive Inotropes
Increase contractility
31
Negative Inotropes
Decrease contractility
32
Afterload
The pressure that must be overcome before a semilunar valve can open
The force the ventricle is pumping against
Increased afterload increases contractility
Chronic increase in afterload results in hypertrophy
33
Stroke Volume vs. Preload
Increased SV=Increased Preload
Decreased SV=Decreased Preload
Increased SV=Increased Contractility
Decreased SV=Decreased Contractility
Increased SV=Decreased Afterload
Decreased SV=Increased Afterload
34
Sympathetic Stimulation
Increases HR, contractility, and stroke volume
Tachycardia
35
Parasympathetic Stimulation
Decreases HR
Bradycardia
Vagus nerve carries parasympathetic impulses to the heart
36
Coronary Artery Disease
Heart muscle receives insufficient blood supply due to the narrowing of vessels
37
Angina Pectoris
Heart pain from oxygen deprivation of cardiac muscle
38
Myocardial Infarction
Dead of area of heart muscle from lack of oxygen
Replaced by scar tissue
39
Circulatory Route
Heart--Aorta--Arteries--Arterioles--Capillaries--Venules--Veins--Vena Cava--Heart
40
Arteries
Carry blood from heart to capillaries in all tissues
41
Capillaries
Have thin walls to allow diffusion of oxygen, carbon dioxide, nutrients, and fluid
42
Veins
Bring blood from tissues back to heart
43
Arteries
Conducting arteries are the largest
Pulmonary, aorta, common carotid
All near the heart
"Main highway"
44
Medium Vessels
"Exit ramps"
Lots of smooth muscle
45
Distributing Arteries
Distribute blood to specific organs
46
Arterioles
Small arteries delivering blood to capillaries
Metarterioles form branches into capillary beds
47
Small Vessels
Resistance vessels
"Neighborhood"
48
Capillaries
Connect arterioles to venules
Sole source of exchange
Found near every cell in the body buy more extensive in highly active tissue (muscles, liver, kidneys, and brain)
49
Continuous Capillaries
Intercellular clefts are gaps between neighboring cells
Skeletal and smooth, connective tissue and lungs
4nm
Glucose, ions, amino acids
50
Fenestrated Capillaries
Plasma membranes have many holes
Kidneys, small intestine, choroid plexuses, ciliary process, and endocrine glands
20-100nm
H2O, retains proteins
51