Exam 2: circulation Flashcards
1
Q
Main function of systemic circulation
A
Deliver oxygen, nutrients to tissues and remove CO2 and waste
2
Q
Systemic arteries carry blood under _____ out to tissue beds
A
High pressure
3
Q
Arterioles and pre capillary sphincters act as
A
Control valves to regulate local flow
4
Q
___ one cell layer thick
A
Capillaries
5
Q
Functional unit of circulatory system
A
Capillaries
6
Q
Capillaries exchange between
A
Tissues and blood
7
Q
Venues collect blood from
A
Capillaries
8
Q
Systemic veins return blood and act as
A
Dynamic storage
9
Q
Blood flow proportional to ____ EXCEPT in ___
A
Metabolic demand
Lungs
10
Q
Cardiac output controlled by
A
Local systemic tissue flow
11
Q
Arterial pressure control ____ of local flow or cardiac output
A
Independent
12
Q
Composition of aorta
A
Elastic tissue > fibrous tissue> smooth muscle
13
Q
Composition of typical artery
A
Smooth muscle > elastic tissue > fibrous tissue
14
Q
Composition of vein
A
Elastic tissue = smooth muscle = fibrous tissue
15
Q
Composition of capillary
A
Only endothelium
16
Q
At a given flow, greater drop in P in a segment =
A
Greater resistance to flow
17
Q
Greatest resistant to flow occurs in
A
Pre-capillary resistance vessels
18
Q
Systemic circulation is predominantly a
A
Parallel circuit
19
Q
Advantages of parallel circuit
A
- Independence of local flow control
- Minimize total peripheral resistance
- Oxygen rich blood supply to every tissue
20
Q
Total vascular resistance equal to
A
Sum of total pulmonic resistance + total peripheral resistance
21
Q
Viscosity of blood
A
3
22
Q
Viscosity of blood due to
A
RBCs
23
Q
Viscosity of plasma
A
1.5
24
Q
Viscosity of water
A
1
25
Velocity decrease =
Increase viscosity
26
___ increases flexibility of RBC’s and is 3rd most abundant protein in plasma
Fibrinogen
27
Cells line up in small vessels, which ____
Decreases viscosity
28
Normal range of hematocrit
38%-45%
29
Laminar flow
Streamline
Silent
Most efficient
Normal
30
Turbulent flow
Cross mixing
Vibrational noise
Least efficient
Associated with disease
31
A vessel may be occluded ____ before problems occur
75%
32
R < 2000, flow usually
Laminar
33
R > 3000, flow usually
Turbulent
34
Broad band associated with
Turbulent flow
35
Narrow band associated with
Laminar flow
36
RBCs moving forward transmitter compress sound waves and cause
Increase in frequency of returning waves
37
Distensibility
Ability of vessel to stretch
38
Compliance
Ability of vessel to stretch and hold volume
39
____ are more compliant and distensible
Veins
40
Systemic arteries, small change in volume associated with
Large change in pressure
41
Systemic veins, large change in volume associated with
Small change in pressure
42
Short term control of blood flow involves
Vasodilation
| Vasoconstriction
43
Long term control of blood flow involves
Changes in tissue vascularity
44
Release of PGI2
Inhibit platelet aggregation
Relax vascular smooth muscle
45
Release NO
Vasodilator
46
Release of endothelin
Constricts vascular smooth muscle
47
Bulk of exchange occurs where
Capillary
48
Vasomotion
Intermittent contraction of metarterioles and precapillary sphincters
49
Mechanisms of exchange
Diffusion
Ultrafiltration
Vesicular Transport
50
Oxygen uptake equal to
Product of flow X arterial-venous oxygen difference
51
Functional flow
Associated with increased oxygen uptake
52
Nonnutritive flow increase associated with
Shunting of blood through bed
53
Arterioles have what receptors
Alpha
54
Local vasodilator therory
Active tissue release local vasodilator which release vascular smooth muscle
55
Autoregulation
Ability to keep blood flow constant in face of changing arterial BP
56
Flow proportion to
Metabolic demand
57
SNS can either be angiogenic via ___ or cause vasoconstriction
NPY
58
Colloid osmotic pressure function of
Protein concentration
59
Primary plasma protein
Albumin
60
3 most abundant plasma proteins
1. Albumin
2. Globulins
3. Fibrinogen
61
Hydrostatic P gradient favors
Filtration
62
Colloid osmotic P favors
Reabsorption
63
Dominant colloid
Albumin
64
Donnan effect
Increases colloid osmotic effect
65
Leakiest capillary walls present in
Liver
66
Tightest capillary walls
BBB
67
Reflection coefficient reflects
How readily protein can cross capillary wall
68
RC = 0
All colloid proteins freely cross wall
None reflected
No colloid effect
69
RC = 1
All colloid proteins reflected
None cross capillary wall
Full colloid effect
70
Right lymph duct drains
Right side of head, neck, right arm, part of chest
71
____ drains lower body, L side head, L arm, part of chest
Thoracic duct
72
No true lymphatic vessels found in superficial skin, _____ and bones
Endomysium of muscle
73
True lymphatic vessels discovered in
CNS near dural venous sinuses
74
2/3 of all lymph from
Liver and intestines
75
Lymph nodes lined with
Macrophages
76
Greater than half of TPR is at
Systemic arterioles
77
Small horses
Ponies
78
How do palpate mare ovaries
Palpate through rectal canal
79
How low pressure falls is dependent on
Cycle length
| TPR
80
Increase CL will ___ DBP
Decrease
81
Increase TPR will ___ DBP
Increase
82
Receptor for NorEpi
Alpha
83
Gold and grey
Colors of Lou’s middle school
84
Increase in TPR causes decrease in
PR
85
Constriction of veins increases
Venous return
86
3 exceptions from SNS causing vasoconstriction
Brain
Lungs
Heart
87
1987
Last time Lou could beat students
88
Vascular tone is proportional to
CCP
89
SNS stimulates arterioles to
Increase critical closing pressure
90
If cardiac output is stopped, arterial pressure will
Fall and venous pressure will rise
91
MCFP is responsible for
Pressure gradient driving peripheral venous return
92
At a given MCFP, as central venous pressure rises,
Venous return falls
93
If MCPF = CVP..
Venous return goes to 0
94
As central venous pressure increases..
CO increases due to both intrinsic and extrinsic effects
95
Central venous pressure =
Right atrial pressure
96
Vasomotor center
Collection of neurons in MO and pons
97
Vasomotor center works through
SNS
98
4 major regions of vasomotor center
1. Pressure center
2. Depressor center
3. Sensory area
4. Cardioinhibitory area
99
Pressor center increases
BP via stimulation of SNS
100
Depressor center decreases
BP
101
Sensory area mediates
Baroreceptor reflex
102
Cardioinhibitory area stimulates
CNX
103
Pressor center aka
Vasoconstrictor center C1
104
Pressor center located
Anterolateral portions of upper MO
105
Effects of pressor center
Vasoconstriction
| Stimulate cardiac activity
106
Pressor center is ___active
Tonically
107
Depressor center aka
Vasodilator area A1
108
Effects of depressor center
Vasodilation
| Decreased cardiac activity
109
Sensory area A2 located
Posterolateral portion of pons and MO
In nucleus tractus solitarius
110
Depressor center located
Anterolateral lower MO
111
Sensory area A2 receive input from
CN 9 and 10
112
Sensory area A2 mediates
Baroreceptor reflex
Inhibits pressure center
Lowers BP
