Exam 2 Flashcards
(150 cards)
1
Q
what are the three layers of the heart what are they made of
A
Epicardium- visceral layer of the pericardium (outer)
Myocardium- thicker layer, cardiac muscle tissue
Endocardium- lining of the heart- inner – made up of endothelial cells (simple squamous epithelial cells)
2
Q
what are the 4 chambers of the heart and what do they do with blood
A
2 atria- receive blood from the body
2 ventricles- pumps blood out of the heart
3
Q
—– are blood vessels that carry blood towards the heart
A
veins
4
Q
—– are blood vessels that carry blood away from the heart
A
arteries
5
Q
What are the 3 veins that the right atrium receives blood from
A
Superior vena cava- blood from upper body
Inferior Vena Cava- blood from lower body
Coronary Sinus – drains blood from the myocardium
6
Q
The Left Atrium (LA) receives blood from
A
pulmonary veins. - blood from lungs
7
Q
The Right Ventricle (RV) pumps blood into the
A
pulmonary arteries -> lungs
8
Q
The Left Ventricle (LV) pumps blood into the
A
aorta-> all body tissues (except lungs)
9
Q
Name the pathway and its pump- blood vessels that carry blood to and from all body tissues and back to the heart (longest circuit)
A
Systemic circuit- left ventricle is pump
9
Q
Name the pathway and its pump- blood vessels toward the lungs and returns blood to the heart
A
Pulmonary circuit and the right ventricle is the pump
10
Q
Name the pathway and its pump- blood vessels that carry blood to and from the myocardium (shortest pump)
A
Coronary circuit and the left ventricle is the pump
11
Q
what is the longest circuit
A
systemic circuit
12
Q
what is the shortest pathway
A
coronary circuit
13
Q
Allow for one-way flow of blood through the heart (prevent backflow)
A
heart valves
14
Q
heart valves open and close due to
A
pressure differences
15
Q
what are the 4 heart valves and where are they located
A
2 Atrioventricular valves (AV valves)- Between the atria and ventricles
2 semilunar valves (SL valves)- Between the ventricles and the arteries carrying blood out of the heart
16
Q
what are the 2 AV valves and their location
A
Tricuspid valve – between RA and RV
Bicuspid valve (or mitral valve)- Between LA and LV
17
Q
what are the 2 SL valves and their location
A
Aortic SL valve – between LV and Aorta
Pulmonary SL valve- Between RV and pulmonary artery
18
Q
heard when both AV valves close
A
1st heart sound
19
Q
heard when both SL valves close
A
2nd heart sound
20
Q
—-are not heard when heart valves open
A
heart sounds
21
Q
—-cause valves to open and close
A
pressure differences
22
Q
when atrial pressure is higher than ventricular pressure is
A
lower due to venous return the AV valves open
23
Q
when ventricular pressure is higher (ventricles contract) than atrial pressure is
A
lower- the AV valves close and it is the 1st heart sound
24
what is the function of the papillary muscle and chordae tendineae
holds the AV valves in their closed position
25
when ventricular pressure is high (when ventricles are contracting) the pressure in aorta or pulmonary arteries is low
both SL valves open (no sound)
26
When pressure (high) in aorta or pulmonary arteries > ventricular pressure (low)
both SL valves close= 2nd heart sound
27
when both ventricles are relaxed the pressure
drops
28
blood flows ---- into the 2 atria
continuously due to no valves
29
Cardiac muscle cells / fibers are
Striated
Involuntary – cannot consciously control
Branched
Interconnected by intercalated discs
30
intercalated disc contains 2 kinds of cell junctions:
Desmosomes- anchoring junction
Gap junctions- communicating junctions
31
the heart acts as a function
syncytium (coordinated unit)
32
Can shorten
Have a stable membrane potential
Do not self-depolarize- cannot start action potentials
contractile fibers (99% of all cardiac muscle tissue)
33
Cannot shorten
Have an unstable membrane potential
Self-depolarizes- can start own action potentials
Autorhythmic fibers (1% of all cardiac muscle tissue)
34
cannot start action potentials (A.P.) because they have a stable membrane potential
contractile fibers
35
can initiate A.P because of their unstable membrane potential
Autorhythmic fibers
36
Made of autorhythmic fibers
That initiates and transmits electrical impulses (A.Ps) through the heart
That results in rhythmic contractions
The Cardiac Conduction System
37
order of cardiac conduction system
1. sinoatrial node (the pacemaker of the heart)
2. atrioventricular node
3. atrioventricular ventricle (the only electrical connection between atrium and ventricles )
4. left and right bundle branches
5. purkinje fibers (release AP)
38
the normal rhythm of heartbeat set by the SA node
sinus rhythm
39
start and conduct the A.Ps through the heart
autorhymic fibers
40
respond to the A.Ps of the autorhythmic fibers
contractile fibers
41
will then reach threshold and generate A.Ps
contractile fibers
42
phases of sinus rhythm and they ions they move
Depolarization- due to sodium ions (na+) entering the cell
Plateau- calcium (Ca2)ions enter the cell
Repolarization- Action potential ends due to K+ ions leaving the cell
43
A recording of the flow of electrical impulses (A.P.s) produced by the heart
electrocardiogram
44
three waves of EKG in one heart beat
P wave- atrial depolarization
QRS complex- ventricular depolarization
T wave- ventricle repolarization
45
time span between beginning of P wave and beginning of the QRS complex
P-Q interval
46
time span between the beginning of the QRS and the end of the T wave
Q-T
47
time span between the end of the QRS and the beginning of the T wave
Steady ventricular depolarization
S-T
48
all events associated with one heartbeat
cardiac cycle
49
systole is
contraction
50
diastole is
relaxation
51
depolarization causes
systole
52
repolarization causes
diastole
53
length of the cardiac cycle
.8 secons
54
length= .1 sec
atria= systole
ventricles= diastole
atrial systole
55
length= .3 sec
atria= diastole
ventricles= systole
ventricular systole
56
length= .4 sec
atria= diastole
ventricles= systole
relaxation period
57
Both atria contract shortly after P wave
AV valves remain open
SL valves remain closed
Ventricles fill with blood
atrial systole
58
Both ventricles contract shortly after QRS
AV valves close (1st heart sound)
Isovolumetric contraction period occurs in beginning- constant volume of blood in ventricles - all 4 chambers close
SL valves open
Blood pumped out of ventricles and into aorta and pulmonary arteries
ventricular systole
59
Ventricles relax shortly after T wave
SL vales close (2nd heart sound)
Isovolumetric relaxation period occurs in beginning
AV valves open in middle of period
Blood fills ventricles
relaxation period
60
constant volume of blood in ventricles; all 4 valves closed
isovolumetric
61
(brief period at beginning of Ventricular Systole) ventricles contract while valves closed
isovolumetric contraction
62
(brief period at beginning of Relaxation Period) – ventricles relax while valves closed
isovolumetric relaxation
63
amount of blood pumped out of each ventricle per minute
cardiac output
64
how is cardiac output measured
CO = HR (heart rate) x SV (stroke volume)
65
decreases HR to resting conditions
Decreases HR= decrease cardiac output
parasympathetic divison
66
increases HR and stimulates adrenal medulla to release epinephrine & norepinephrine
Increase HR= increase CO
sympathetic divison
67
amount of blood pumped out of each ventricle per heartbeat
stroke volume
68
factors affecting SV
preload, contractility, and afterload
69
The degree of stretch of heart wall
preload- Increase preload= increase SV= increase CO
70
increase in contractile force independent on stretch/ preload
contractility- Increase contractility= increase SV= increase CO
71
back pressure exerted on the SL valves due to arteriole pressure
afterload- Increase in afterload= decrease SV= decrease CO
Can lead to hypertension
72
the cardiovascular centers located in the
medulla oblongata
73
there are about ---- miles of blood vessels in the body
60000
74
blood vessels are made of
living cells
75
3 kind of blood vessels
Arteries- blood vessels that carry blood away from the heart
Veins- blood vessels that return blood to the heart
Capillaries- exchange vessels
76
walls of arteries and veins have 3 layers
tunica interna-
tunica media
tunica externa
77
innermost layer of blood vessel wall
Endothelial cells (simple squamous epithelial)
tunica interna
78
middle layer of blood vessel wall
Smooth muscle tissue
Causes vasoconstriction and vasodilation
tunica media
79
outermost layer of blood vessel wall
Mainly collagen fibers
tunica externa
80
capillaries walls have 1 layer
tunica interna
81
thin capillary walls allow for
rapid exchanges
82
high pressure system, thickest layer is tunica media, all layers have more elastic fibers
the arterial system
83
(largest diameter)- conducting arteries
Examples: aorta, pulmonary arteries
elastic arteries
84
distributing arteries
Examples: radial artery, brachial artery
muscular arteries
85
(smallest diameter)- resistance vessels (affect BP)
arterioles
86
The tunica media allows muscular arteries and arterioles to
constrict and dilate
87
----therefore can regulate blood flow into arterioles in specific organs
muscular arteries
88
---therefore can regulate blood flow into capillaries
arterioles
89
characteristics of capillaries
5-0 micrometers in diameter
Tunica interna only- thin walls
Tight junctions join cells together
Clefts- gaps between neighboring cells
90
continuous capillaries-
least permeable- most common- muscle tissue ad skin
91
fenestrated capillaries
has pores, very permeable- small intestine, filtration membrane of kidneys
92
sinusoids
large pores and clefts, extremely permeable- red bone marrow, spleen, liver
93
Movement of substances between plasma and interstitial fluid
capillary exchange
94
capillary exchange is aided by
diffusion, transcytosis, and bulk flow
95
passive process that moves particles from high to low concentrations
diffusion
96
using vesicles to shuttle substances across the cell
transcytosis
97
solutes and particles in a fluid move together due to pressure differences across the capillary wall
bulk flow
98
bulk flow outside of plasma and into interstitial fluid (positive NFP numbers cause)
filtration
99
bulk flow of interstitial fluid into the plasma (negative NFP numbers cause)
reabsorption
100
determine the direction of bulk flow
pressure differences
101
force exerted by a fluid against a wall
Acting at the capillary
hydrostatic pressure
102
force opposing hydrostatic pressure due to nondiffusing molecules
Nondiffusing molecules- proteins
acting at capillary
osmotic pressure
103
total pressure that promotes filtration
Net filtration pressure (NFP)
104
filtration occurs at the
beginning of capillary with NFP at +10 mm Hg
105
reabsorption occurs at the
end of capillary with NFP of - 9 mm Hg
106
Low pressure system
Has thinner walls and wider lumens than arteries (tunica externa is thickest layer)
Blood reservoirs of the vascular system
venous system
107
venous system consists of
Venules (smallest diameter)
Veins (large diameter) =Superior and inferior vena cava
- Valves present in veins to prevent backflow
Venous sinuses- specialized, broad veins supported by surrounding tissue; only has the tunica interna
Ex. Coronary sinus and dural sinus
108
branches of blood vessels providing alternate routes for blood to reach a particular region
anastomoses
109
---- drop along the vascular system
blood pressures
110
highest pressure (120-> 35 mm Hg)
arterial system
111
(35-> 16 mm Hg)
capillaries
112
lowest pressure (16 -> 0 mm Hg)
venous system
113
venous return of blood is aided by
Muscular pump-
Respiratory pump
Valves
114
amount of blood flowing through an organ in a given period of time (ml/min)
blood flow (F)
115
hydrostatic pressure of the blood
blood pressure (P)
116
opposition to blood flow
Resistance (R)
117
equation of blood flow
F= change in pressure/ R
increase in pressure = increase in flow
decrease in pressure, decrease in flow
resistance increases= decrease in flow
118
Constriction of the ventricles
increases blood pressure-> increases blood flow
119
what increases and decreases resistance
Greater blood viscosity increase resistance - polycythemia
Greater total blood vessel length increases resistance- obesity
Vasoconstriction increases resistance
Vasodilation decreases resistance
120
hydrostatic pressure exerted by blood- measures across the systemic circuit
blood pressure
121
maximum pressure in artery when ventricles contract (120)
systolic pressure
122
minimum pressure in artery during ventricular diastole (~80mm Hg)
diastolic pressure
123
systolic pressure minus diastolic pressure
pulse pressure
124
average pressure in artery
Mean Arterial Pressure (MAP)
125
neutral regulation of blood pressure is
short term
126
increase in BP:
Sympathetic increases HR and contractility
Sympathetic causes vasoconstriction
127
Decrease BP:
Parasympathetic decreases HR
Sympathetic causes vasodilation
128
Only the ------- of the Autonomic Nervous System can change the diameter of blood vessels Only the sympathetic division of the Autonomic Nervous System can change the diameter of blood vessels
sympathetic divison
129
hormonal regulation of BP is
short term
130
short-term regulation by:
Nervous system (parasympathetic and sympathetic)
hormones
131
long-term regulation by:
kidneys adjusting blood volume
132
normal BP is
about 120/80
133
high blood pressure (>140/90)
hypertension
134
low blood pressure (systolic pressure <100mm Hg)
hypotension
135
due to sudden change in position
orthostatic hypertension
136
long-term low blood pressure due to poor nutrition
chronic hypotension
137
sudden low blood pressure caused by circulatory shock
acute hypotension
138
condition when there is not enough blood in the blood vessels and blood cannot circulate normally
circulatory shock
139
shock due to loss of a large amount of blood
hypovolemic shock
140
shock due to extreme vasodilation- due to severe allergic reaction
vascular shock
141
shock when heart cannot pump adequately to circulate blood
cardiogenic shock
142
internal resistance of fluid to flow
blood viscosity
143
pathway through the pulmonary
Oxygen rich= Capitals
Oxygen poor= lower case
ra-> rv-> pulmonary arteries-> luNGS-> PULMONARY VEINS-> LA->LV->AORTA-> BODY tissues-> vena cava-> ra
144
pathway of systemic circuit
Oxygen rich= Capitals
Oxygen poor= lower case
la-> lv-> pulmonary arteries-> luNGS-> PULMONARY VEINS-> RA->RV->AORTA-> BODY tissues-> vena cava-> va
145
pathway of the coronary circuit
Oxygen rich= Capitals
Oxygen poor= lower case
AORTA-> CORONARY ARTERIES->MYOCArdium-> coronary veins-> coronary sinus-> ra
146
Angiotensin II- vasoconstriction
Epinephrine and norepinephrine- vasoconstriction- high HR
Antidiuretic hormone-vasoconstriction
hormones that raise BP
147
Atrial natriuretic peptide (ANP)-vasodilation
hormone that lowers the BP
148
renal regulation of BP is
long-term
149
Kidneys increase and decrease BP by
increasing and decreasing blood volume
