Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Physiology > Exam #2 (Ch 4 & 5) > Flashcards

Exam #2 (Ch 4 & 5) Flashcards

(98 cards)

Start Studying
1
Q

Pulmonary circulation is a low/high pressure system

A

Low Pressure System

Right heart, pulmonary arteries, veins & capillaries & pulmonary system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Systemic circulation is a low/high pressure system

A

High Pressure System

Left heart, and rest of body arterial circulation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

In order to create a flow one needs

A

A pressure gradient

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Deliver blood and nutrients to tissues
Takes waste away from tissue
Assist in regulating blood pressure

A

Blood Vessels

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Blood Vessels

A

Deliver blood and nutrients to tissues
Takes waste away from tissue
Assist in regulating blood pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Where do arteries conduct blood?

A

Arteries conduct blood away from the heart

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Are arteries high or low pressure?

A

High pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is the largest artery?

A

Aorta

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are characteristic of the walls of the arteries?

A

Elastic tissue
Smooth muscle
Connective tissue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is stressed volume?

A

The blood that is in the arteries is under high pressure so it is called stressed volume

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

The blood that is in the arteries is under high pressure so it is called

A

Stressed Volume

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

The smallest branches of the arteries

A

Arterioles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

The site of highest resistance to blood flow

A

Arterioles. Their walls are made up of smooth muscle.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

The smooth muscle of the arterioles are tonically active or inactive?

A

Tonically active (always contracted)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

The sympathetic fibers that innervate the smooth muscles of the arterioles

A

Alpha 1: found on the arterioles near skin & splanchnic organs. Cause contraction or vasoconstriction
Beta 2: Less common & cause relaxation or vasodilation when activated. Found in skeletal muscle cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

These sympathetic fibers of the smooth muscles of the arterioles are found near skin & splanchnic organs. Cause contraction or vasoconstriction.

A

Alpha 1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

These sympathetic fibers of the smooth muscles of the arterioles are found in skeletal muscle cells. They are less common. Cause relaxation or vasodilation when activated

A

Beta 2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Capillaries

A

Thin-walled allowing for effective diffusion

Lined w/ a single layer of endothelial cells again allowing for exchange of nutrients, water, and gases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

The Selective Perfusion of Capillaries is determined by

A

The degree of dilation or constriction of the arterioles & precapillary sphincters. The degree of dilation or constriction controlled by sympathetic innervation of vascular smooth muscles & by vasoactive metabolites produced in the tissues

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Veins

A

Thin-walled
Modest amount of elastic tissue
Very large capacitance. Contains the largest proportion of blood in the cardiovascular system (most blood volume is found in veins)
Considered unstressed volume
Have valves to prevent retrograde or back flow
Innervated by sympathetic fibers. An increase in sympathetic activity = constriction = reduces their capacitance & therefore reduces the unstressed volume

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

The blood in the veins is also called

A

Unstressed volume

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Purpose of valves in veins

A

Prevent retrograde or back flow

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Increase in sympathetic activity on veins

A

Increase in sympathetic activity = constriction = reduces their capacitance & therefore reduces the unstressed volume

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Formed from merged capillaries (low pressure)

A

Venules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Velocity of blood flow
``` V = Q/A Rate of displacement of blood per unit time V = Velocity of blood flow (cm/sec) Q = Flow (mL/sec) A = Cross-sectional area (cm^2) ```
26
Variables Impacting Blood Flow Velocity
It is directly proportional to blood flow & inversely proportional to cross-sectional area
27
Where is blood flow high & where is it low?
Blood flow is higher in the aorta (small cross sectional area) than the sum of all the capillaries (large cross sectional area)
28
How do we want blood flow velocity to be in areas of exchange?
Lower velocity allows for optimal exchange
29
Blood Flow is determined by
Pressure gradient | Resistance
30
Equation for Blood Flow
Q = ∆P/R ``` Q = Flow (mL/min) ∆P = Pressure difference (mmHg) R = Resistance (mmHg/mL/min) ```
31
Blood flow is directly proportional to ____ & inversely proportional to _____
Magnitude of blood flow is directly proportional to pressure gradient and inversely proportional to resistance
32
The major mechanism for changing blood flow in the cardiovascular system is by
Changing the resistance of blood vessels. Occurs primarily at the level of the arterioles due to smooth muscle contraction.
33
Total Peripheral Resistance (TPR)
Resistance of the entire systemic vasculature. Aka Systemic Vascular Resistance (SVR) R = ∆P/Q
34
Resistance to Blood Flow is dependent on
Vessel diameter/radius & blood viscosity. Also based on parallel or series arrangement of blood vessels
35
Poiseuille Equation
R = 8µl / πr^4 ``` R = Resistance µ = viscosity of blood l = length of blood vessel r = radius ```
36
According to the poiseuille equation resistance is proportional to
Directly proportional to viscosity, length, and inversely proportional to the radius raised to the 4th power (r^4)
37
Series Resistance of Blood Flow
Within a given organ Within the organ or blood flows from the major artery to smaller arteries, to arterioles, to capillaries, to venules, to veins As resistors are added, total resistance increases Total resistance of a system arranged in series is equal to the sum of the individual resistances
38
Parallel Resistance of Blood Flow
Found among the various major arteries branching off the aorta As resistors are added, total resistance decreases Total resistance in a parallel arrangement is less than any of the individual resistances 1/Rtot = 1/R1 + 1/R2 This arrangement ensures pressure is not loss through the system
39
What is the purpose of parallel resistance of blood flow?
It ensures pressure is not loss through the system
40
Laminar blood flow
Straight. Ideally, blood flow in the cardiovascular system is laminar. Shows a parabolic profile of velocity within a blood vessel. Velocity of flow at the vessel wall is zero, and maximal at the center
41
Turbulent blood flow
Disrupted flow. Stream mixes radially & axially. Found at the valves or at the site of a blood clot, or in vessels of high velocity. More energy (pressure) is required to drive turbulent blood flow than laminar blood flow. Often accompanied by audible vibrations called heart sounds or murmurs
42
This type of blood flow is often accompanied by audible vibrations called heart sounds or murmurs
Turbulent flow
43
What is Reynold's number?
It predicts whether flow will be laminar or turbulent
44
An increase is Reynold's number means
Greater tendency for turbulence
45
If Reynold's number is less than 2000 then
Blood flow is likely laminar
46
If Reynold's number is greater than 2000 then
Blood flow is likely turbulent
47
If Reynold's number is greater than 3000 then
Blood flow is always turbulent
48
What factors increase Reynold's number?
A decrease in blood viscosity (ex: decrease in hematocrit, anemia), also increase cardio output An increase in blood velocity (ex: narrowing of blood vessel; thrombi)
49
What is compliance or capacitance?
Describes the distensibility of blood vessels | Inversely related to elastance
50
Formula for compliance
C = V / P ``` C = compliance V = volume (mL) P = pressure (mmHg) ```
51
What happens to the amount of pressure in the systemic circuit as blood flows through it?
Pressure decreases progressively through the systemic circulation due to increased resistance
52
Blood pressure is highest in
The Aorta
53
Blood pressure is lowest in
The Vena Cava
54
The largest vein in the body?
IVC
55
Diastolic Pressure
Pressure in the artery during ventricular diastole/relaxation It is the lowest arterial pressure measured during a cardiac cycle
56
Systolic Pressure
Arterial pressure measured during ventricular systole/contraction Highest arterial pressure measured during a cardiac cycle
57
Pulse Pressure
Difference between systolic and diastolic pressure. Co-relates to stroke volume
58
Mean Arterial Pressure (MAP)
Average pressure in a complete cardiac cycle. MAP = diastolic pressure + 1/3 pulse pressure
59
This type of pressure fluctuates during the cycle and is pulsatile
Arterial Pressure
60
This type of pressure is very low due to high compliance
Venous Pressure
61
Atrial Pressure
lower than venous pressure
62
Dicrotic notch or incisura
The "blip" in the arterial pressure curve. Produced when the aortic valve closes
63
What produces the "blip" in the arterial pressure curve?
When the aortic valve closes. It is called the Dicrotic notch or incisura
64
Arteriosclerosis
Is a pathology that will alter the arterial pressure curve. It is due to plaque deposits in the arterial walls which decreases diameter/radius. It stiffens walls making them more rigid & less compliant
65
Impact of Arteriosclerosis on Arterial Pressure Curve
Systolic pressure, pulse pressure, & mean pressure will be increased
66
Impact of Aortic Stenosis on Arterial Pressure Curve
Occurs when the aortic valve is stenosed (hardened) due to calcification Stroke volume is decreased b/c less blood enters the aorta on each beat. Systolic, pulse, & mean pressure will be decreased
67
Aortic regurgitation
Due to incompetent valve causing retrograde flow
68
The pacemaker of the heart
SA (Sinoatrial) Node. the AP originates from SA node
69
Why is the SA node the pacemaker of the heart?
B/c it has the highest intrinsic firing rate in the heart
70
Normal heart rate
60-100 bmp
71
Sequence of myocardium activation
SA node -> AV node -> Bundle of His (common bundle) -> Right/Left Bundle Branches -> Purkinje Fibers
72
Latent Pacemakers take over when
SA node firing rate decreases SA node stops completely or is removed If the intrinsic rate of firing of a latent pacemakers should become faster than that of the SA node, then it assumes the pacemaker role Blocked conduction from SA node to conducting pathways
73
Excitability
The ability of cardiac cells to initiate an action potential in response to an inward, depolarizing current. Reflects the recovery of channels that carry the inward current for the upstroke of the action potential
74
Refractory Period
The time during which another action potential cannot be elicited
75
Absolute Refractory Period
Period during which another action potential can be initiated, regardless of how much inward current is supplied. Begins with upstroke of the AP and ends after the plateau. Cell has repolarized to about -50 mV
76
Effective Refractory Period
Period during which a generated action potential cannot be conducted Slightly longer than the Absolute Refractory Period The Na+ channels begin to recover whereby they become available to carry inward current Inward current is not enough to conduct to the next site
77
Relative Refractory Period
Period during which an action potential can be elicited, but more than usual current is required. Immediately after the ARP when repolarization is almost complete
78
Chronotropic Effects
Effects of the ANS on heart rate (HR) via SA node
79
Positive Chronotropic vs Negative Chronotropic Effects
Positive increases HR, Negative decreases HR
80
Chronotropic Effectors determine the heart rate by controlling
The rate of phase 4. The smaller the phase 4, the faster the heart rate. Mechanism of Action for both, you change the flux of sodium. To increase HR you increase the influx of sodium. To decrease HR you decrease the influx of sodium
81
Positive chronotropic effects sympathetic nervous system via
Beta 1
82
Negative chronotropic effects parasympathetic nervous system via
M2
83
Dromotropic Effects
Effects of the ANS on conduction velocity via AV node
84
Positive vs Negative dromotropic effects
Positive leads to an increase in conduction velocity via AV node. Negative leads to a decrease in conduction velocity via AV node
85
Sympathetic receptor for positive dromotropic effects
B1
86
Parasympathetic receptor for negative dromotropic effects
M2
87
What is a heart block?
AP not being conducted from atria to ventricle
88
A measurement of tiny potential differences on the surface of the body that reflect the electrical activity of the heart
Electrocardiogram (ECG or EKG)
89
P Wave
Represents depolarization of the atria. Duration of the wave correlates with conduction time through the atria. Atrial repolarization is not seen on a normal ECG, b/c it is "buried" in the QRS complex
90
PR interval
From beginning of P wave to the beginning of Q wave (initial depolarization of the ventricle). Correlates w/ conduction time through the AV node. It represents ventricular filling
91
QRS complex
Represent depolarization of the ventricles | Conduction thru the ventricle is similar to the atria b/c of high conduction velocity of the His-purkinje system
92
T wave
Represents repolarization of the ventricles. Ventricular relaxation or diastole
93
QT interval
Interval from beginning of Q wave to end of the T wave. Represents the entire period of depolarization & repolarization of the ventricles. Contraction & relaxation
94
ST segment
From end of S wave to the beginning of the T wave. Represents ventricular repolarization
95
Gap junctions allow are heart muscle to behave as
A syncytium or a unit
96
Inotropism
The intrinsic ability of myocardial cells to develop force at a given muscle cell length
97
The amount of calcium released by the sarcoplasmic reticulum is dependent on
1. The size of the inward calcium current | 2. The amount of calcium that was previously stored in the SR
98
Positive Ionotropic Effects
Increase in contractility Use Beta 1 as receptors Increase Rate of Relaxation

Physiology (13 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions