Exam 3: Chapter 25: Circulation Flashcards
1
Q
blood supplies what to muscles?
A
oxygen
2
Q
muscle is dependent on what for activity
A
ATP supply
3
Q
during activity, muscles depend on what for their supply of ATP
A
oxygen
4
Q
Blood pressure is important for production of
A
urine
5
Q
Thermoregulation or vascular heat exchangers are important for
A
warm or cool weather
6
Q
Circulation within the body moves…
A
blood, O2, CO2, nutrients, organic waster, hormones, immune system products, and heat
7
Q
What is muscle tissue of the heart made of?
A
cardiac tissue known as myocardium
8
Q
What are the 2 parts of the left side of the human heart?
A
a weakly muscular atrium and a strongly muscled ventricle
9
Q
oxygenated blood is received from the _____ and sent to the _______.
A
received from the lungs and then sent to the body
10
Q
Blood arrives to the left atrium via the _______.
A
pulmonary veins
11
Q
Blood leaves the left ventricle via the ______.
A
systemic aorta
12
Q
Blood returns to the heart via the ________.
A
venae cavae
13
Q
where does blood enter the heart?
A
right atrium
14
Q
Role of the right side of the heart:
A
pump deoxygenated blood to the lungs
15
Q
After leaving the right ventricle, blood enters the ______.
A
pulmonary trunk, then to the pulmonary arteries and the lungs
16
Q
During the beating of the heart there is contraction a (_______) and a relaxation (________).
A
systole; diastole
17
Q
isometric contraction
A
the volume of blood in the ventricle is constant
18
Q
When pressure of blood in the heart is high enough:
A
the aortic valve opens, and the blood is pushed from the ventricle
19
Q
After blood enters the aorta, ventricular pressure drops and….
A
you have isovolumetric relaxation; next you have ventricular filling
20
Q
What is the hearts most important feature?
A
cardiac output; the volume of blood it pumps per unit time; output of the left ventricle
21
Q
cardiac output
A
HR x stroke volume
22
Q
circulation must deliver…
A
oxygen to the myocardium
23
Q
The ventricular myocardium is second only to the brain in its’ need for
A
aerobic catabolism and O2 demand
24
Q
The heart muscle gets blood and O2 from
A
the coronary arteries
25
Blood goes to the ______ in the heart muscles and then enters the ________.
capillaries; coronary viens
26
Blockage of the coronary artery can cause a:
heart attack; O2 can't get to the heart muscle, so the muscle quickly breaks down
27
The electrical impulses for heart contraction may originate in....
muscle cells or neurons
28
Depolarization of the muscle cell membranes causes
the contraction
29
myogenic vs. neurogenic
myogenic: electrical impulse to contract is in the muscle cells
neurogenic: impulse comes from nerve cells
30
vertebrate have what types of hearts
myogenic hearts
31
Muscle cells are electrically coupled by
gap junctions; occurs at intercalated discs
32
The pacemaker in mammals
sinoatrial node (SA), located above the right atrium
33
SA cells are specialized:
have a high frequency of depolarization, first cells to depolarize
34
Conduction:
the process whereby depolarization spreads through heart muscle cells
35
Conducting system pathway:
atrioventricular node (A-V node), A-V bundle, bundle branches, Purkinje cell fibers
36
a heart produces an electrical signature:
the electrocardiogram
37
voltage differences of the heart are recorded by
EKGs
38
P wave of EKG
made by heart muscle depolarization of the 2 atria (atrial contraction)
39
The QRS
comes from the depolarization of the 2 ventricles (ventricular contraction)
40
T wave
repolarization of the ventricles
41
Heart action is modulated by:
hormonal, nervous, and intrinsic controls
42
with fear our heart races, and these hormones are produces
epinephrine and norepinephrine; produced by the adrenal medullary glands
43
Connects from heart to CNS
some are sympathetic (excitatory) and parasympathetic (inhibitory) parts of the autonomic nervous system
44
with exercise, ________ stimulation is greater
sympathetic
45
intrinsic controls are things like:
the stretching of the heart muscle during contraction; increases force and allows the heart to match in input with the output
46
Frank-Starling mechanism:
present in vertebrates; allows the cardiac output to be synchronized with the venous return, arterial blood supply and humoral length, without depending upon external regulation to make alteration
47
perfusion in the vascular system:
the forced flow of blood through the blood vessels
48
Blood pressure:
the force moving the blood; measure in mm of mercury (mmHg)
49
The greatest pressure during cardiac contraction:
the systolic pressure
50
The lowest pressure:
the diastolic pressure during relaxation
51
In resting young adults the systolic to diastolic pressure is:
120/75
52
hydrostatic pressure:
present in vessels, increases with height; pressure in the leg arteries is greatest, much lower in the head and neck
53
Factors that go into affecting blood flow; make up total fluid energy of the blood
potential energy of the beating heart, kinetic energy of the blood in motion, and potential energy of the blood as a result of the earth's gravity
54
Blood always moves from ___ to _____ total fluid energy
high to low
55
The rate of blood flow depends on:
differences in blood pressure and on vascular resistance
56
What regulates the rate of blood flow?
when muscles of the walls of a blood vessel changes the radius of the vessel by contracting or relaxing
57
blood flow rate
∆P/R, where ∆P is the entry and exit BP and R is vascular resistance
58
resistance relationship to vessel radius
resistance is inversely proportional to the vessel radius
59
The dissipation of energy:
pressure and flow turn to heat during circulation of the blood
60
laminar flow
the fluid in the center moves without resistance, whereas the fluid at the walls doesn't move at all
61
slipperiness
the viscosity of the fluid, contributes to flow
62
high viscosity means:
greater friction, loss of kinetic energy, and heat production
63
pressure is converted to
heat
64
a drop in blood pressure from one point to another is a measure of
the energy cost of blood flow
65
in arterioles and capillaries, BP:
drops a lot with blood flow
66
Energy cost change in arterioles and capillaries
greater
67
circulation has the lungs in series with
the systemic tissues; O2 delivery can be maximized to the systemic tissues
68
mammals have a ______ circulatory system
closed
69
each part of the systemic vascular system has distinctive
anatomical and functional features
70
all vessels have a layer of _______ on the inside
vascular endothelium
71
vascular endothelium may secrete:
nitric oxide or prostacyclin into the blood, or secrete hormones, degrade hormones, or have an immune role
72
nitric oxide or prostacyclin functions
affect contraction and relaxation of smooth muscle and also may play a role in clotting
73
thick walls of arteries function to:
handle high blood pressures and stretch
74
Artery walls are thick with:
lots of smooth muscle and connective tissue
75
Elasticity of arteries allows for
BP to be more stable
76
arterioles and capillaries wall size
thinner; deal with lesser BP
77
microcirculatory beds consist of 3 types of vessels:
arterioles, capillaries, and venules
78
arterioles
smaller versions of arteries; have smooth muscle and connective tissue but are not as thick
79
the smooth muscle in arterioles has a role in:
the vasomotor regulation of where blood is sent; vasoconstriction and dilation apply here
80
arteriolar muscles are regulated by:
the sympathetic part of the autonomic nervous system
81
circulation hormones and chemicals like NO (a vasodilator) are generated from the:
vascular endothelium
82
precapillary sphincters
have a role in blood flow
83
change of blood flow to skeletal muscle during exercise:
can increase by a factor of ten or more
84
vasodilation and constriction allow for what time of blood flow regulation
sensitive temporal and spatial regulation
85
capillaries:
once cell layer thick, just vascular endothelium, walls are fenestrated (have openings); aquaporins are present
86
capillaries are the main location for:
the exchange of O2 and water, as well as other substances from the blood to the cells
87
capillary density
important with high levels in skeletal muscle, brain, and heart muscle
88
angiogenesis of capillaries
making new capillaries and is regulated by activators and inhibitors like paracrine chemicals
89
venules carry
deoxygenated blood
90
veins have
low BP and thin walls
91
passive one-way valves help with
blood flow
92
skeletal muscle contractions
help move blood
93
veins are elastic:
can expand to hold blood
94
mammals and birds have what type of circuit
high-pressure systemic circuit
95
greater blood flow is needed for
increased demands of O2 transport
96
BP and rate of flow decreases in the
arterioles and capillaries
97
a closed circulatory system is:
energetically expansive
98
blood plasma osmotic pressure
greater osmotic pressure than extracellular liquid; water tends to move into the blood from the extracellular tissues
99
blood plasma proteins
a lot don't cross membranes, makes plasma richer than liquid in tissues
100
hydrostatic pressure of the blood
greater than tissues liquid; efflux occurs in the capillaries
101
excess fluid goes to the
lymphatic system
102
as blood enters the venules; pressure
decreases
103
pulmonary system differences
low pressure system to keep the lungs "dry"; shorter, has less resistance, and is a low-pressure system
104
if water left the blood i the lungs, it would result in
pulmonary edema
105
during exercise, blood flow is increased by:
orchestrated changes in cardiac output and vascular resistance
106
rate of O2 delivery =
cardiac output x (arterial O2 concentration - venous O2 concentration)
107
during exercise in humans, venous blood is more _______ than at rest
more deoxygenated
108
trained althetes changes
cardiac output is 6-7x resting, and resistance is reduced during exercise; BP is prevented from being too high
109
what helps reduced resistance
vasodilation; more muscle capillaries are open and carrying blood
110
endurance training increases capillaries where?
muscles
111
How much cardiac output do human skeletal muscles recieve?
20% of cardiac output at rest and 80% with hard whole-body exercise; blood flow to internal organs is reduced by vasoconstriction
112
smaller animals heart rate
higher to keep up with their demand for O2
113
Giraffes BP
higher BP of 220 mmHg to get blood to their brains with a 1.6m neck
114
vascular countercurrent exchangers
blood flowing from the body core to the periphery (like the legs & feet) carries heat that can be readily lost through the skin; example is to keep the testis cool in males
