ANPH - Cardiovascular CH 22 Flashcards
1
Q
Hemodynamics
A
collection of mechanisms that influence the dynamic (active and changing) circulation of blood
2
Q
Circulation of different volumes of blood per minute is essential for healthy survival T/F
A
True
3
Q
Circulation control mechanisms must accomplish, which two functions?
A
Maintain circulation
Vary volume and distribution of the blood circulated
4
Q
Conduction system of the heart is
Composed of, which four major structures?
A
Sinoatrial node (SA) node Atrioventricular (AV) node AV bundle (bundle of His) Subendocardial branches (Purkinje fibers)
5
Q
Conduction system structures are more highly specialized than ordinary cardiac muscle tissue and permit slow conduction of an action potential through the heart. T/F
A
False - Conduction system structures are more highly specialized than ordinary cardiac muscle tissue and permit RAPID conduction of an action potential through the heart
6
Q
Initiates each heartbeat and sets its pace
Specialized pacemaker cells in the node possess an intrinsic rhythm
A
SA node (pacemaker)
7
Q
Sequence of cardiac stimulation Starting from SA node (pacemaker) to AV Node
A
After being generated by the SA node, each impulse travels throughout the muscle fibers of both atria and the atria begin to contract
As the action potential enters the AV node from the right atrium, its conduction slows to allow complete contraction of both atrial chambers before the impulse reaches the ventricles
8
Q
Sequence of cardiac stimulation Starting After AV Node to Purkinje fibers
A
After the AV node, conduction velocity increases as the impulse is relayed through the AV bundle into the ventricles
Right and left branches of the bundle fibers and subendocardial branches (Purkinje fibers) conduct the impulses throughout the muscles of both ventricles, stimulating them to contract almost simultaneously
9
Q
Graphic record of the heart’s electrical activity, its conduction of impulses; a record of the electrical events that precede the contractions of the heart
A
Electrocardiogram (ECG or EKG)
10
Q
Production of an ECG
A
Electrodes are attached to the subject
Voltage changes that represent the heart’s electrical activity are sensed by electrodes and recorded on paper
11
Q
Composition (ECG waves) of normal ECG recording is composed of?
A
P wave—represents depolarization of the atria
QRS complex—represents depolarization of the ventricles and repolarization of the atria
T wave—represents repolarization of the ventricles
12
Q
represents depolarization of the atria
A
P wave
13
Q
represents depolarization of the ventricles and repolarization of the atria
A
QRS complex
14
Q
represents repolarization of the ventricles
A
T wave
15
Q
ECG intervals between P, QRS, and T waves can provide information about….?
A
rate of conduction of an action potential through the heart
16
Q
U wave
A
tiny “hump” at end of T wave—represents repolarization of the papillary muscle (or a two-part T wave) and may appear on ECG as well
17
Q
Absent or small U waves usually considered normal T/F
A
True
18
Q
U waves are never a sign of hypokalemia or too much digoxin T/F
A
False - U waves MAY BE a sign of hypokalemia or too much digoxin
19
Q
Cardiac cycle
A
a complete heartbeat
20
Q
Cardiac cycle consists of…..?
A
Consists of contraction (systole) and relaxation (diastole) of both atria and both ventricles
21
Q
Cycle is often divided into depth intervals T/F
A
False - Cycle is often divided into TIME intervals
22
Q
This cycle begins with the P wave of the ECG, which triggers atrial contraction
Contraction of atria creates a pressure gradient that pushes blood out of the atria into the relaxed ventricles
Due to pressure gradients, AV valves are open; SL valves are closed
Ventricles are relaxed and filling with blood from atria.
What Part of the Cardiac Cycle is this referred to as?
A
Atrial systole
23
Q
Onset of ventricular systole coincides with the R wave of the ECG and the appearance of the first heart sound
Occurs between the start of ventricular systole and the opening of the SL valves
Ventricular volume remains constant as the pressure increases rapidly
Which part of the Cardiac cycle is this referred to as?
A
Isovolumetric ventricular contraction
24
Q
Why does the SL valves not open when AV valves do?
A
Intraventricular pressure rises enough to close AV valves, producing the first heart sound
Intraventricular pressure is not yet high enough to open the SL valves
25
When do the SL valves open? How?
SL valves open and blood is ejected from the ventricles when the intraventricular pressure exceeds the pressure in the pulmonary artery and aorta
26
What are the Two types of Ejection?
Rapid ejection
| Reduced ejection
27
Rapid ejection
initial short phase characterized by a marked increase in ventricular and aortic pressure and in aortic blood flow
28
Reduced ejection
characterized by a less abrupt decrease in ventricular volume; coincides with the T wave of the ECG
29
Ventricular diastole begins with this phase
Occurs between closure of the SL valves and opening of the AV valves
A dramatic fall in intraventricular pressure but not enough to open the AV valves, thus no change in volume
Second heart sound is heard during this period
Which part of the cardiac cycle is this?
Isovolumetric ventricular relaxation
30
Continued ventricular relaxation reduces intraventricular pressure and returning venous blood increases intraatrial pressure, producing enough of a pressure gradient to push open the AV valves
Blood rushes into the relaxing ventricles; influx lasts approximately 0.1 second and results in a dramatic increase in ventricular volume
Which part of the cardiac cycle is this?
Passive ventricular filling
31
first sound, believed to be caused primarily by contraction of the ventricles and by vibrations of the closing AV valves
This sound is called?
Systolic sound
32
Name 2 basic types of heart sounds
Systolic sound
| Diastolic sound
33
short, sharp sound; thought to be caused by vibrations of the closing of SL valves
This sound is called?
Diastolic sound
34
Heart sounds have clinical significance because they provide information about the functioning of the valves of the heart
T/F
True
35
what factor allows blood to flow?
| Also known as part of the Primary Principle of Circulation
Blood flows because a pressure gradient exists between different parts of its volume; this is based on Newton’s first and second laws of motion
36
blood circulates from the left ventricle to the right atrium of the heart because a blood pressure gradient exists between these two structures; likewise, a blood pressure gradient drives blood flow from the right ventricle to the left atrium
T/F
True
37
Perfusion pressure
the pressure gradient needed to maintain blood flow through a local tissue
38
P1–P2 is the symbol used to represent
a pressure gradient, with P1 representing the higher pressure and P2 the lower pressure
39
Primary determinant of arterial blood pressure is
the volume of blood in the arteries; a direct relationship exists between arterial blood pressure and arterial blood volume
40
Cardiac output (CO)
volume of blood pumped out of the heart per unit of time (ml/min or L/min)
41
Cardiac output (CO)—determined by
stroke volume and heart rate
42
Stroke volume (SV)
volume pumped per heartbeat
43
SV (volume/beat) HR (beats/min)=?
CO (volume/min) = SV (volume/beat) HR (beats/min)
44
In practice, CO is computed by a formula called?
Fick’s formula
45
Heart rate and stroke volume determine CO, but does not tend to change CO, arterial blood volume, and blood pressure in the same direction
T/F
False - Heart rate and stroke volume determine CO, so ANYTHING that changes either ALSO tends to change CO, arterial blood volume, and blood pressure in the same direction
46
Starling’s law of the heart
Within limits, the longer, or more stretched, the heart fibers at the beginning of contraction, the stronger the contraction
47
The amount of blood in the heart at the end of _______determines the amount of stretch placed on the heart fibers
diastole
48
The myocardium contracts with enough strength to match its pumping load (within certain limits) with each stroke—unlike........?
mechanical pumps
49
Can contractility(strength of contraction) can also be influenced by chemical factors?
Yes
50
Two Contractility Chemicals? Type?
Neural—norepinephrine
| endocrine—epinephrine
51
Neural—norepinephrine; endocrine—epinephrine
| These are Triggered by?
stress, exercise
52
the ratio of stroke volume (SV) to end-diastolic volume (EDV) is known as?
Ejection fraction (EF)
53
Ejection fraction (EF)—Usually expressed as a
percentage: EF = 55%
54
Healthy adults have EFs of at least 65%
| T/F
False - Healthy adults have EFs of at least 55%
55
EF goes down as the myocardium improves
| T/F
False - EF goes down as the myocardium FAILS
56
Are there more Factors that affect heart rate than the SA Nose?
Yes - SA node normally initiates each heartbeat; however, various factors can and do change the rate of the heartbeat
57
Two Cardiac pressoreflexes
Aortic baroreceptors and carotid baroreceptors
58
Where Are the Aortic baroreceptors and carotid baroreceptors
located in the aorta and carotid sinus
59
Why are Aortic baroreceptors and carotid baroreceptors (Cardiac pressoreflexes) so important?
Extremely important because they affect the autonomic cardiac control center, and therefore parasympathetic and sympathetic outflow, to aid in control of blood pressure
60
Where is the Carotid sinus reflex?
Located at the beginning of the internal carotid artery
61
Sensory fibers from carotid sinus baroreceptors run through the carotid sinus nerve and the glossopharyngeal nerve to the cardiac control center
Parasympathetic impulses leave the cardiac control center, travel through the vagus nerve to reach the SA node
T/F
True
62
Other reflexes that influence heart rate
| Full list
Anxiety, fear, and anger often increase heart rate
Grief tends to decrease heart rate
Emotions produce changes in heart rate through the influence of impulses from the cerebrum by way of the hypothalamus
Exercise normally increases heart rate
Increased blood temperature or stimulation of skin heat receptors increases heart rate
Decreased blood temperature or stimulation of skin cold receptors decreases heart rate
63
Peripheral resistance
resistance to blood flow imposed by the force of friction between blood and the walls of its vessels
64
the thickness of blood as a fluid is called?
Blood viscosity
65
Factors that affect blood viscosity?
High plasma protein concentration can slightly increase blood viscosity
High hematocrit (% RBC) can increase blood viscosity
Anemia, hemorrhage, or other abnormal conditions may also affect blood viscosity
66
muscles in walls of arteriole may constrict vessel (vasoconstriction) or dilate vessel (vasodilation), thus changing diameter of arteriole- name this mechanism
Vasomotor mechanism
67
Small changes in blood vessel diameter cause small changes in resistance, making the vasomotor mechanism ideal for regulating blood pressure and blood flow
T/F
False - Small changes in blood vessel diameter cause LARGE changes in resistance, making the vasomotor mechanism ideal for regulating blood pressure and blood flow
68
How resistance influences blood pressure
Arterial blood pressure tends to vary directly with peripheral resistance
Friction caused by viscosity and small diameter of arterioles and capillaries
Muscular coat of arterioles allows them to constrict or dilate and change the amount of resistance to blood flow
69
_______ helps determine arterial pressure by controlling the amount of blood that runs from the arteries to the arterioles
Peripheral resistance
70
Increased resistance and decreased arteriole runoff lead to
to higher arterial pressure
71
Does Peripheral resistance occur locally (in one organ), or does the total peripheral resistance (TPR) increase, thus generally raising systemic arterial pressure?
Either -
Can occur locally (in one organ), or the total peripheral resistance (TPR) may increase, thus generally raising systemic arterial pressure
72
Vasomotor control mechanism—controls changes in the....?
diameter of arterioles; plays role in maintenance of the general blood pressure and in distribution of blood to areas of special need
73
Sudden increase in arterial blood pressure stimulates...?
aortic and carotid baroreceptors; results in arterioles and venules of the blood reservoirs dilating
74
Decrease in arterial blood pressure results in stimulation of...?
vasoconstrictor centers, causing vascular smooth muscle to constrict
75
Medullary ischemic reflex acts during?
acts during emergency situation when there is decreased blood flow to the medulla; causes marked arteriole and venous constriction
76
Are Vasomotors controlled by higher brain centers?
Yes -
impulses from centers in cerebral cortex and hypothalamus are transmitted to vasomotor centers in medulla to help control vasoconstriction and dilation
77
Vasomotor chemoreflexes —chemoreceptors located in aortic and carotid bodies are sensitive to ?
hypercapnia, hypoxia, and decreased arterial blood pH
78
Local control of arterioles—several local mechanisms produce vasodilation in localized areas; referred to as
reactive hyperemia
79
Venous pumps
blood-pumping action of respirations and skeletal muscle contractions facilitate venous return by increasing pressure gradient between peripheral veins and venae cavae
80
Respirations—inspiration increases the pressure gradient between peripheral and central veins by decreasing central venous pressure and also by increasing peripheral venous pressure T/F
True
81
Skeletal muscle contractions—promote arteriole return by squeezing veins through a contracting muscle and milking the blood toward the heart T/F
False - Skeletal muscle contractions—promote VENOUS return by squeezing veins through a contracting muscle and milking the blood toward the heart
82
One-way ______ in veins prevent backflow
Valves
83
Changes in total blood volume change the amount of blood returned to the heart T/F
True
84
Capillary exchange—governed by ______of the capillaries
Starling’s law
85
At arterial end of capillary, outward hydrostatic pressure is the strongest or weakest force?
Strongest - moves fluid out of plasma and into IF
86
At venous end of capillary, inward osmotic pressure is strongest force; moves fluid into plasma from IF. What % of fluid is lost by plasma at arterial end is recovered
90%
87
Lymphatic system recovers fluid not recovered by capillary and returns it to the ________ before it is returned to the _________
venous blood
| heart
88
mechanisms that change total blood volume most quickly are
those that cause water to quickly move into or out of the plasma
89
decreases the amount of water lost by the body by increasing the amount of water that kidneys resorb from urine before the urine is excreted from the body; triggered by input from baroreceptors and osmoreceptors
ADH mechanism
90
Renin-angiotensin-aldosterone system (RAAS) ________water loss
decreases
91
Renin
released when blood pressure in kidney is low; leads to increased secretion of aldosterone, which stimulates retention of sodium, causing increased retention of water and an increase in blood volume
92
Angiotensin II
intermediate compound that causes vasoconstriction, which complements the volume-increasing effects of renin and promotes an increase in overall blood flow
93
ANH mechanism
adjusts venous return from an abnormally high level by promoting the loss of water from plasma, causing a decrease in blood volume; increases urine sodium loss, which causes water to follow osmotically
94
A variety of __________restore normal blood pressure after a sudden change in pressure
feedback responses
95
Arterial blood pressure is Measured with the aid of
a sphygmomanometer and stethoscope
96
as the pressure in the sphygmomanometer cuff is gradually decreased what is the name of the sound you are listening for?
Korotkoff sounds
97
force of the blood pushing against the artery walls while ventricles are contracting
Systolic blood pressure
98
force of the blood pushing against the artery walls when ventricles are relaxe
Diastolic blood pressure
99
difference between systolic and diastolic blood pressure
Pulse pressure
100
Describe Arterial bleeding and why it bleeds in that way
blood escapes from artery in spurts because of alternating increase and decrease of arterial blood pressure
101
Describe Venous bleeding and why it bleeds in that way
blood flows slowly and steadily because of low, practically constant pressure
102
How is Minute volume determined?
determined by the magnitude of the blood pressure gradient and peripheral resistance
103
Poiseuille’s law
Minute volume = Pressure gradient / Resistance
104
The velocity of Blood Flow is governed by what physical principle?
by the physical principle that when a liquid flows from an area of one cross-sectional size to an area of larger size, its velocity decreases in the area with the larger cross section
105
Why does Blood flows more slowly through arterioles than arteries?
because total cross-sectional area of arterioles is greater than that of arteries, and capillary blood flow is slower than arteriole blood flow
106
Venule cross-sectional area is smaller than capillary cross-sectional area, causing blood velocity to _____ in venules and then veins with a still smaller cross-sectional area
increase
107
alternate expansion and recoil of an artery
Pulse
108
Clinical significance of Pulse
reveals important information regarding the cardiovascular system, blood vessels, and circulation
109
Physiological significance of Pulse
expansion stores energy released during recoil, conserving energy generated by the heart and maintaining relatively constant blood flow
110
Existence of pulse is due to two factors
Alternating increase and decrease of pressure in the vessel
Elasticity of arterial walls allows walls to expand with increased pressure and recoil with decreased pressure
111
Pulse wave
Each pulse starts with ventricular contraction and proceeds as a wave of expansion throughout the arteries
Gradually dissipates as it travels, disappearing in the capillaries
112
Where the pulse can be felt - Summary for all
wherever an artery lies near the surface and over a bone or other firm background
113
Venous pulse
detectable pulse exists only in large veins; most prominent near the heart; not of clinical importance
114
Blood flow shifts materials from place to place and redistributes heat and WBC's
T/F
False - Blood flow shifts materials from place to place and redistributes heat and PRESSURE
115
Blood Flow Is Vital to maintaining homeostasis of internal environment
T/F
TRUE!!!
116
Location of the heart
Lies in the mediastinum, behind the body of the sternum between the points of attachment of ribs two through six
117
Approximately two thirds of the hearts mass is to the right of the midline of the body, and one third is to the left
T/F
False - approximately two thirds of its mass is to the LEFT of the midline of the body, and one third is to the RIGHT
118
Posteriorly the heart rests on the bodies of thoracic vertebrae ______________
five through eight
119
lies on the diaphragm, pointing to the left
Apex of the heart
120
lies just below the second rib
Base of the heart
121
Boundaries of the heart are clinically important as an aid in diagnosing heart disorders
T/F
True
122
What age is the heart transverse and appears large in proportion to the diameter of the chest cavity?
At birth
123
When does the heart attains its adult shape and weight?
Between puberty and 25 years of age
124
In adults, the shape of the heart tends to resemble that of the...?
chest
125
3 Structures of the heart coverings
| Pericardium
Fibrous pericardium
Serous pericardium
Pericardial space
126
Fibrous pericardium
tough, loose-fitting inextensible sac
127
Serous pericardium
parietal layer lies inside the fibrous pericardium, and visceral layer (epicardium) adheres to the outside of the heart
128
Pericardial space
lies between visceral and parietal layers and contains 10 to 15 ml of pericardial fluid
129
Function of the heart coverings
provides protection against friction
130
Wall of the heart is made up of which three distinct layers ?
Epicardium
Myocardium
Endocardium
131
delicate inner layer of endothelial tissue
Endocardium
132
thick, contractile middle layer of heart wall; compresses the heart cavities, and the blood within them, with great force
Myocardium
133
outer layer of heart wall
Epicardium
134
four cavities with the right and left chambers separated by
the septum
135
Two superior chambers known as “receiving chambers” because they receive blood from veins
Atria
136
earlike flap protruding from each atrium
Auricle
137
Why is the Myocardial wall of each atrium is not very thick?
because little pressure is needed to move blood such a small distance
138
Two lower chambers known as “pumping chambers” because they push blood into the large network of vessels
Ventricles
139
Why is the Ventricular myocardium is thicker than the myocardium of the atria?
because great force must be generated to pump the blood a large distance
140
mechanical devices that permit the flow of blood in one direction only
Valves of the heart
141
prevent blood from flowing back into the atria from the ventricles when the ventricles contract
Atrioventricular (AV) valve
142
2 Atrioventricular (AV) valves
```
Tricuspid valve (right AV valve)
Bicuspid, or mitral, valve (left AV valve)
```
143
Bicuspid, or mitral, valve (left AV valve)
similar in structure to tricuspid valve except has only two flaps
144
Tricuspid valve (right AV valve)
guards the right atrioventricular orifice; free edges of three flaps of endocardium are attached to papillary muscles by chordae tendineae
145
half-moon–shaped flaps growing out from the lining of the pulmonary trunk and aorta; prevent blood from flowing back into the ventricles from the aorta and pulmonary trunk
Semilunar (SL) valves
146
2 Semilunar (SL) valves
Pulmonary valve—at entrance of the pulmonary trunk
| Aortic valve—at entrance of the aorta
147
Set of connected rings that serve as a semirigid support for the heart valves and for the attachment of cardiac muscle of the myocardium
Skeleton of the heart
148
what Serves as an electrical barrier between the myocardium of the atria and that of the ventricles?
Skeleton of the heart
149
blood supply of heart tissue
Coronary circulation
150
First branches to come off the aorta
Coronary arteries—myocardial cells receive blood from the right and left coronary arteries
151
Ventricles receive blood from
branches of both right and left coronary arteries
152
Most abundant blood supply from the Coronary arteries goes?
goes to the myocardium of the left ventricle
153
Right coronary artery is dominant in approximately _____ of all hearts and the left in about _____; in approximately ______ , neither coronary artery is dominant
50%
20%
30%
154
Few anastomoses exist between the larger branches of the coronary arteries
T/F
True
155
After going through cardiac veins, blood enters the coronary sinus to drain into
the right atrium
| Several veins drain directly into the right atrium
156
made up of modified cardiac muscle, it generates and distributes the heart’s own rhythmic contractions; can be regulated by afferent nerves
Conduction system of the heart
157
located near the arch of the aorta, made up of the combination of sympathetic and parasympathetic fibers
Cardiac plexuses
158
Fibers from the cardiac plexus accompany the _________ to enter the heart
right and left coronary arteries
159
Most fibers end in the _____, but some end in the _______ and in the atrial myocardium; the SA node acts as the heart’s pacemaker
SA node
| AV node
160
Sympathetic nerves
accelerator nerves
161
Vagus fibers
inhibitory, or depressor, nerves
162
formation of new blood vessels
Angiogenesis
163
Arteries
Carry blood away from heart—all arteries except pulmonary artery carry oxygenated blood
164
arteries—largest type in body
Elastic (conducting) arteries
| Examples: aorta and its major branches
165
Able to stretch without injury
| Accommodate surge of blood when heart contracts and able to recoil when ventricles relax
Elastic (conducting) arteries—largest in body
Examples: aorta and its major branches
Able to stretch without injury
Accommodate surge of blood when heart contracts and able to recoil when ventricles relax
166
Smaller in diameter than elastic arteries
| Examples: brachial, gastric, superior mesenteric
Muscular (distributing) arteries
167
Muscular layer is thin
| T/F
False - THICK
168
Smallest arteries
| Important in regulating blood flow to end organs
Arteries
169
Short connecting vessel between true arteriole and 20 to 100 capill
Metarterioles
170
Metarterioles are Encircled by
precapillary sphincters
171
what part of the metarterioles is free of precapillary sphincters?
Distal end called thoroughfare channel, which is free of precapillary sphincters
172
primary exchange vessels
Capillaries = Microscopic vessels
173
Carry blood from arterioles to venules
Capillaries
174
together, arterioles, capillaries, and venules constitute the....?
microcirculation
175
Capillaries are Not evenly distributed—highest numbers in tissues with high metabolic rate; may be absent in some “avascular” tissues, such as cartilage
T/F
True
176
4 Types of capillaries
True capillaries
Continuous capillaries
Fenestrated capillaries
Sinusoids
177
True capillaries
receive blood flowing from metarteriole with input regulated by precapillary sphincters
178
Continuous capillaries
Continuous lining of endothelial cells
| Openings called intercellular clefts exist between adjacent endothelial cells
179
Fenestrated capillaries
Have both intercellular clefts and “holes,” or fenestrations, through plasma membrane to facilitate exchange functions
180
Sinusoids
Large lumen and tortuous course
Absent or incomplete basement membrane
Very porous—permit migration of cells into or out of vessel lumen
181
Carry blood toward the heart
Veins
182
Act as collectors and as reservoir vessels; called capacitance vessels
Veins
183
Structure of blood vessels
| Components or “building blocks” commonly present
Lining endothelial tissue
Collagen fibers
Elastic fibers
Smooth muscle tissue
184
Lining endothelial tissue
one layer of squamous endothelial cells
185
Collagen fibers
Exhibit woven appearance
Formed from protein molecules that aggregate into fibers
Visible with light microscope
Have only a limited ability to stretch (2% to 3%) under physiological conditions
Function to strengthen and keep lumen of vessel open
186
Elastic fibers
Composed of insoluble protein called elastin
Form highly elastic networks
Wavy fibers can stretch more than 100% under physiological conditions
Play important role in creating passive tension to help regulate blood pressure throughout the cardiac cycle
187
Only lining found in capillary
| Lines entire vascular tree
Lining endothelial tissue
188
Lining endothelial tissue
Provides a smooth luminal surface—protects against intravascular coagulation
Intercellular clefts, cytoplasmic pores, and fenestrations in cells allow exchange to occur between blood and tissue fluid
Capable of secreting a number of substances
Capable of reproduction
T/F
True
189
Smooth muscle tissue
Present in all segments of vascular system except capillaries
Most abundant in elastic and muscular arteries
Exerts active tension in vessels when contracting
190
Structure of blood vessels
| 3 Layers
Tunica externa
Tunica media
Tunica intima
191
Tunica externa
found in arteries and veins (tunica adventitia)
192
Tunica media
found in arteries and veins
193
Tunica intima
found in all blood vessels; only layer present in capillaries
194
blood flows from the left ventricle of the heart through blood vessels to all parts of the body (except gas exchange tissues of lungs) and back to the right atrium
Systemic circulation
195
venous blood moves from right atrium to right ventricle to pulmonary artery to lung arterioles and capillaries, where gases are exchanged; oxygenated blood returns to left atrium by way of pulmonary veins; from left atrium, blood enters the left ventricle
Pulmonary circulation
196
End-arteries
arteries that eventually diverge into capillaries
197
Name of Main arteries that give off branches, which continue to rebranch, forming arterioles and then capillaries
Systemic arteries
198
Arterial anastomosis
arteries that open into other branches of the same or other arteries; incidence of arterial anastomoses increases as distance from the heart increases
199
Arteriovenous anastomoses or shunts occur when blood flows from an viein directly into a artery.
T/F
False - Arteriovenous anastomoses or shunts occur when blood flows from an ARTERY directly into a VEIN
200
_______are the ultimate extensions of capillaries; unite into vessels of increasing size to form venules and then veins
Systemic veins
201
Large veins of the cranial cavity are called
dural sinuses
202
Veins anastomose the same as arteries
| T/F
True
203
Venous blood from the head, neck, upper extremities, and thoracic cavity (except lungs) drains into ......?
superior vena cava
204
Venous blood from thoracic organs drains directly into ....?
superior vena cava or azygos vein
205
Veins from the spleen, stomach, pancreas, gallbladder, and intestines send their blood to the liver by way of the ....?
hepatic portal vein
206
In the liver the venous blood mingles with arterial blood in the sinusoids and is eventually drained from the liver by hepatic veins that join the inferior vena cava . This type of Circulation is called?
Hepatic portal circulation
207
Venous blood from the lower extremities and abdomen drains into the inferior vena cava
T/F
True
208
Basic plan of fetal circulation
additional vessels needed to allow fetal blood to secure oxygen and nutrients from maternal blood at the placenta
209
Two umbilical arteries
extensions of the internal iliac arteries; carry fetal blood to the placenta
210
Placenta
where exchange of oxygen and other substances between the separated maternal and fetal blood occurs
211
Where is Placenta
attached to uterine wall
212
returns oxygenated blood from the placenta to the fetus; enters body through the umbilicus and goes to the undersurface of the liver where it gives off two or three branches and then continues as the ductus venosus
Umbilical vein
213
continuation of the umbilical vein and drains into inferior vena cava
Ductus venosus
214
opening in septum between the right and left atria
Foramen ovale
215
small vessel connecting the pulmonary trunk with the aortic arch
Ductus arteriosus
216
Umbilical vein within the baby’s body becomes
the round ligament of the liver
217
When umbilical cord is cut, the two umbilical arteries, the placenta and umbilical vein, no longer function
T/F
True
218
Changes in circulation at birth -
| Ductus venosus becomes the...?
the ligamentum venosum of the liver
219
Changes in circulation at birth -
| Foramen ovale...?
functionally closed shortly after a newborn’s first breath and pulmonary circulation is established; structural closure takes approximately 9 months
220
Changes in circulation at birth -
| Ductus arteriosus...?
contracts with establishment of respiration, becomes ligamentum arteriosum
221
Birth—change from placenta to ________?
-dependent system
222
Heart and blood vessels maintain basic structure and function from Childhood through.....?
childhood through adulthood
223
Only apparent normal changes occur as a result of exercise
Exercise thickens myocardium
| Exercise increases the supply of blood vessels in skeletal muscle tissue
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Adulthood through later adulthood—degenerative changes
Atherosclerosis—blockage or weakening of critical arteries
Heart valves and myocardial tissue degenerate—reduces pumping efficiency
