Hemodynamics and the Circulatory System Flashcards
1
Q
What are the three functions of blood?
A
Transportation, regulation, protection
2
Q
What does blood regulate?
A
- PH
- Water in plasma has heat absorbing and coolant properties which help maintain and adjust body temperature
3
Q
What does blood protect against?
A
- Clotting of blood protects against excessive blood loss
- WBCs protect against disease through phagocytosis and production of antibodies
4
Q
What does blood transport?
A
- Transports O2 from lungs to cell
- Carries CO2 from body cells to lungs
- Transports nutrients from GI tract to body cells
- Carries heat and waste products away from cells
- Transports hormones from endocrine glands to other body cells
5
Q
What are five characteristics of blood?
A
- Blood is more dense and more viscous than water and flows more slowly
- Temperature of blood is 38oC (100.4oF)
- Blood has slightly alkaline PH
- Blood makes up about 8% of body weight
- Blood volume is 4-5 liters (1.2 gal) in an average adult female and 5-6 (1.5 gal) in an average adult male
6
Q
Whole blood is composed of what two components?
A
- Blood plasma
- Formed elements
7
Q
- ____ is a watery liquid that contains dissolved substances
- ____ is usually about 55% plasma
A
Blood plasma
8
Q
- ____ are cells and cell fragments
- ____ are usually about 45% blood
- ____ are usually more than 99% RBCs of total blood volume
- ____ are usually less than 1% WBCs of total blood volume
A
Formed Elements
9
Q
When formed elements are removed from blood, the remaining straw-colored liquid is called ____
A
Blood plasma
10
Q
____ is about 91.5% water and 8.5% solutes
A
Plasma
11
Q
What are the three types and percentages of plasma proteins that make up the 7% of solutes that are synthesized by the liver?
A
12
Q
What is included in the remaining 1.5% of solutes in plasma?
A
- Electrolytes
- Nutrients
- Regulatory substances such as enzymes and hormones
- Gases and waste products such as urea, Uris acid, creatinine, ammonia and bilirubin
13
Q
The three components of formed elements of blood include?
A
14
Q
____ contain oxygen carrying protein called hemoglobin and do not contain a nucleus
A
RBCs (erythrocytes)
15
Q
The percentage of total blood volume occupied by RBCs is called the ____?
A
Hematocrit
16
Q
____ are nucleated and do not contain hemoglobin
A
WBCs (leukocytes)
17
Q
____ leukocytes include eosinophils, basophils and neutrophils
A
Granular
18
Q
____ leukocytes include lymphocytes and monocytes
A
Agranular
19
Q
____ function to protect the body against foreign substances, accumulation of damaged cells, and infectious organisms
A
WBCs
20
Q
____ are actually cell fragments with pieces of cell membrane that originate from large cells called megakaryocytes that splinter into 2000-3000 fragments
A
Platelets (thrombocytes)
21
Q
____ are disc shaped and are not nucleated; help stop blood loss from damaged vessels by forming a platelet plug; release chemicals that promote blood clotting
A
Platelets
22
Q
____ form a closed system that carries blood away from the heart to the body tissues and then returns blood from the tissues to the heart
A
Blood vessels
23
Q
- Large elastic arteries leave the heart and divide into medium sized muscular arteries that branch to various regions of the body
- Medium sized arteries branch into smaller vessels called ____
A
Arterioles
24
Q
When Arterioles enter tissues, they branch into microscopic vessels called ____
A
Capillaries
25
* Substances are exchanged between blood and body tissue through the thin capillary walls
* Before leaving tissues, capillaries unite to form very **small veins** called \_\_\_\_
Venules
26
* Venules merge to form veins
* Veins carry blood from tissues back to the heart
* **Large vessels** are nourished from their own blood vessel supply called the \_\_\_\_
Vasa Vasorum
27
What are the three **tunics or coats** that Arterial walls have?
1. Tunica interna (intima)
2. Middle tunica (tunica media)
3. Outer coat (tunica externa)
28
Intima is composed of a thin lining of simple squamous epithelium called \_\_\_\_, a basement membrane and a layer of elastic tissue called the internal elastic lamina
Endothelium
29
\_\_\_\_ is a continuous layer of cells that lines the entire cardiovascular system
Endothelium
30
\_\_\_\_ is the thickest tunic layer
Tunic media
31
\_\_\_\_ Consists of **elastic and smooth muscle fibers** arranged in rings around the lumen
Tunica media
32
\_\_\_\_ consists of mostly **elastic and collagen fibers**
Outer coat (tunica externa)
33
An **increase** in sympathetic stimulation causes muscle **contraction** that
**reduces** the size of the vessel lumen (**vasoconstriction**)
34
An **decrease** in sympathetic stimulation causes muscle **relaxation** that
**widens** the size of the vessel lumen (**vasodilation**)
35
If an artery is damaged muscles will ____ producing a ____ that limits blood flow and ____ blood loss
contract; vascular spasm; reduces
36
Largest diameter **arteries** are called
elastic arteries
37
Elastic arteries help propel blood while ventricles are \_\_\_\_
Relaxed
(during diastole)
38
When ventricles of the heart \_\_\_\_, blood is ejected into elastic arteries and Arterioles walls stretch.
Contract
39
The stretched arterial walls store mechanical energy and function as \_\_\_\_
Pressure Reservoir
40
When the ventricles are relaxed the vessel walls recoil and transfer ____ energy in the walls to \_\_\_\_energy in the blood
mechanical; kinetic
41
The aorta, brachialcephalic, common carotid, subclavian, vertebral, pulmonary and common iliac arteries are ____ arteries
elastic
42
Muscular arteries (such as brachial artery in the arm and radial artery in the forearm) are called ____ arteries
distributing
43
**Walls** of ____ arteries are relatively thick in proportion to **diameter** of lumen
muscular arteries
44
\_\_\_\_ are **small arteries** that are important in regulating blood flow from arteries to capillaries
Arteriols
45
A change in ____ of Arterioles can significantly change \_\_\_\_
46
\_\_\_\_ are microscopic vessels that usually connect arterioles and venules
capillaries
47
Flow in these vessels is called
microcirculation
48
\_\_\_\_ represent the **greatest cross-section** area of the circulatory system
capillaries
49
Blood flows the slowest in \_\_\_\_
capillaries
50
When several capillaries unite, **small veins** are formed called \_\_\_\_
venules
51
Venules collect blood from capillaries and drain into \_\_\_\_
Viens
52
\_\_\_\_ frequently appear collapsed or flattened when sectioned and contain numerous valves
viens
53
1. ____ are thin folds of tunica interna that form flap like cusps that project into the vessel lumen
2. ____ project one way toward the heart
3. ____ aid in returning venous blood by preventing back flow of blood
Valves
54
\_\_\_\_ is a vein with a thin endothelial wall and contains no smooth muscle to alter diameter
vascular (venous sinus)
55
The union of the branches of two or more arteries feeding the same region is called \_\_\_\_
Anastomoses
56
\_\_\_\_ provide an alternate route for blood to reach a tissue or organ
Anastomoses
57
The alternate route of blood flow to a tissue or organ (in the presence of disease, injury, etc.) through an anastomosis is called \_\_\_\_
collateral circulation
58
Arteries that do not anastamose are known as \_\_\_\_
end arteries
59
The largest portion of blood volume **at rest** (60%) is found in
systemic veins and venules
60
Systemic capillaries hold about ____ of blood volume; Arteries and arterioles hold about \_\_\_\_
5%; 15%
61
Because they hold a large volume of blood, veins and venules function as \_\_\_\_
blood reservoirs
62
The volume of blood that flows through any tissue at a given period of time is called ____ and is measured in ml/min
blood flow
63
The ____ of blood flow is inversely related to total cross-sectional area
velocity
64
As arteries branch, cross-sectional area ____ and velocity of blood flow \_\_\_\_
increases; decreases
65
When branches combine, cross-sectional area ____ and velocity of flow increases
decreases; increases
66
\_\_\_\_ is the time it takes for blood to pass from the RA, through the pulmonary circulation to the LA, through the systemic circulation down to the foot and back to the RA; is usually one minute when resting
Circulation time
67
\_\_\_\_ is the volume of blood that is ejected into the systemic (or pulmonary) system each minute (at rest is about 5.25 l/min)
Cardiac output (CO)
68
SV (Stroke volume) x HR (heart rate) =
(CO) Cardiac output
69
end diastolic volume – end systolic volume of the LV =
(SV) Stroke volume
70
At rest SV is about ____ ml
70ml
71
Due to friction between blood and vessel walls, what two other factors affect cardiac output
blood pressure and resistance
72
Blood flows from regions of ____ pressure to ____ pressure
higher; lower
73
The greater the **pressure difference**, the ____ the flow; higher resistance ____ blood flow
greater; lowers
74
Blood pressure is the ____ exerted on vessel walls by the blood
hydrostatic pressure
75
\_\_\_\_ is generated by contraction of the ventricles and is highest in the aorta and large systemic arteries
BP (Blood Pressure)
76
Resting BP in an adult rises to about 120 mm/hg during ____ and falls to about 80 mm/hg during \_\_\_\_
systole; diastole
77
Diastolic BP + 1/3 (Systolic BP – Diastolic BP) =
MABP (Mean arterial BP)
78
MABP / R (resistance) =
CO
79
BP ____ progressively as the distance of blood from the LV \_\_\_\_
decreases; increases
80
If ____ decreases an amount greater than 10% of total blood volume then BP drops
blood volume
81
Normal volume of blood in an adult is about ____ liters
5 liters
82
An increase in blood volume (such as water retention) will ____ BP
increase
83
\_\_\_\_ refers to the apposition of blood flow as a result of friction between the blood and vessel walls
Resistance
84
**Resistance** depends upon the average \_\_\_\_, \_\_\_\_, and \_\_\_\_\_
1. blood vessel radius
2. blood viscosity
3. total vessel length
85
The **smaller** the **radius** of the vessel the ____ the resistance it offers to blood flow (inversely proportional)
greater
86
Blood thickness (viscosity) depends mostly on the ratio of RBCs to \_\_\_\_. The thicker the blood the higher the resistance (directly proportional) anemia or hemorrhage will deplete RBCs and proteins and cause a decrease in resistance and BP
plasma volume
87
\_\_\_\_ refers to all the vascular resistances offered by the systemic vessels, Arterioles function to control SVR
Systemic vascular resistance (SVR)
88
Blood return to the heart from systemic veins depends upon the pressure difference between ____ (16mmHg) and the ____ (5mmHg)
venules; RA
89
Although this pressure difference is small, ____ is adequate because resistance in veins is very low
venous return
90
If pressure increases in the \_\_\_\_, then venous flow will back up (may be seen in the case of a regurgitant tricuspid valve)
RA
91
The skeletal muscle pump propels venous blood by contraction and relaxation of muscles
