Blood Vascular System Flashcards
(188 cards)
1
Q
The blood and lymphatic vascular systems are classified as what type of tissue?
A
specialized connective tissue
2
Q
The cardiovascular system consists of which three components?
A
Heart, Pulmonary circulation, Systemic circulation
3
Q
Two main groups of arteries are ____ and _____
A
Conducting (elastic arteries) and Distributing (muscular) arteries
4
Q
Which arteries are large arteries closest to the heart and have very high blood pressure and flow?
A
Conducting (Elastic) Arteries
5
Q
Blood flow in aorta is _____
A
320mm/sec
6
Q
Two examples of conducting (elastic arteries)
A
Aorta, Renal artery
7
Q
Which arteries are smaller in diameter with slower blood flow?
A
Distributing (Muscular) Arteries
8
Q
What do muscular arteries lead to?
A
Arterioles which lead to capillaries
9
Q
Exchange of metabolites and transport through the vessel wall is only possible in ____
A
Capillaries
10
Q
Why is exchange only possible in capillaries?
A
Because only here the blood flow is sufficiently reduced and the vessel wall sufficiently thin
11
Q
What is the speed of blood flow in the capillaries?
A
about 0.3mm/sec
12
Q
In systemic circulation, arterial blood is ______ while venous blood is ______.
A
richly oxygenated; poorly oxygenated
13
Q
In pulmonary circulation, arterial blood is ______ while venous blood is ______.
A
poorly oxygenated; richly oxygenated
14
Q
Endothelial cells are derived from what embryonic origin?
A
Embryonic mesenchyme
15
Q
Are endothelial cells considered epithelial or connective tissue cells?
A
Connective tissue cells
16
Q
Endothelial cells line the lumina of _____
A
All the vessels of the blood vascular and lymphatic vascular systems
17
Q
Describe the appearance of endothelial cells lining blood vessels.
A
Very flattened, elongated cells with elongated nuclei that protrude into the lumina
18
Q
What is the estimated total number of endothelial cells in the human body, surface area and weight?
A
6x10²³ cells; 700-1000 m²; 1.5 kg
19
Q
What important local factor is produced by endothelial cells?
A
Nitric oxide
20
Q
The diameter of blood capillaries varies according to _____
A
Functional status of the tissue or organ
21
Q
What happens to capillary diameter when functional demands rise?
A
It enlarges to allow increased exchange of oxygen and metabolites
22
Q
The differences between the 3 types of capillaries are visible at the _____ and not by ____
A
Ultrastructural level (not by light microscopy)
23
Q
What are the three types of capillaries?
A
Continuous, Fenestrated, Sinusoids
24
Q
Continuous endothelial cells in continuous capillaries are loacted on a _____
A
Continuous basal lamina
25
In cross-section, continuous capillaries consist of how many endothelial cells connected by _____
2-3 endothelial cells connected by tight junctions
26
An area where the edge of one cell protrudes into the lumen in the region of the contact between the ends of two endothelial cells of continuous capillaries is termed _____
Marginal fold
27
Which capillary is common in most endocrine glands?
Fenestrated capillaries
28
Small invaginations of the cell surface in continuous capillaries are termed ____
Caveolae
29
How do materials cross continuous capillaries?
Micropinocytotic vesicles via transcellular transport
30
Where are continuous capillaries commonly found?
Organs with strict control on access of substances from the blood (e.g. CNS, thymus)
31
Which type of capillaries have pores or fenestrae in their endothelial cells?
Fenestrated capillaries
32
What is the typical diameter of fenestrae in fenestrated capillaries?
80-100 nm
33
Fenestrated capillaries lie on ______
Continuous basal lamina
34
Where are fenestrated capillaries commonly found?
Endocrine glands and renal glomeruli
35
Which type of capillary has irregular vessels with large diameters?
Sinusoids
36
Diameter of sinusoids is _____
30-40 nm
37
3 organs where sinusoids are commonly found?
Liver, endocrine glands, hematopoietic organs (bone marrow & spleen)
38
Sinusoids cannot be fenestrated T or F
False; Sinusoids are fenestrated in many cases
39
3 organs where sinusoids can be fenestrated
Hypophysis, suprarenal cortex, pancreas
40
What cells are commonly associated with the walls of sinusoids?
Phagocytes
41
What are the two major pathways for exchange of materials through capillary walls?
Transcellular and intercellular
42
Transcellular transport through capillary walls occurs via what structures?
Micropinocytotic vesicles in the endothelium (in continuous capillaries) and Fenestrations (in fenestrated endothelium or sinusoids)
43
Intercellular transport through capillary walls occurs via what structures?
Gap junctions and Spaces between endothelial cells (sinusoids of spleen, liver)
44
_____ cells are inconspicuous, elongated, mesenchyme-like cells associated with capillaries
Pericytes (Perivascular cells)
45
What roles do pericytes play after vascular injury?
Repair of blood vessels and connective tissue
46
What 3 structures can pericytes develop into?
Fibroblasts, smooth muscle cells, and possibly phagocytes
47
What are the three main layers of a muscular artery wall?
Tunica intima, Tunica media, Adventitia
48
What are the components of the tunica intima?
Endothelium, Sub-endothelial layer, Inner elastic limiting membrane (elastic lamina)
49
What are the components of the tunica media?
Circular (or spiral) smooth muscle and Concentric elastic lamina
50
What are the components of the adventitia?
Connective tissue, Outer elastic limiting membrane, Vasa vasorum
51
____ are small blood vessels that supply oxygen and nutrients to the walls of arteries
Vasa vasorum
52
Why do arteries need vasa vasorum?
Because the blood flow in the arterial lumen is too fast for nutrient exchange
53
Tunica media of elastic arteries contains ____ well-developed elastic lamina
50–75
54
The elastic lamina in elastic arteries are interspersed between ____
Thick smooth muscle bands
55
What is the function of the elastic lamina in elastic arteries?
Prevent excessive expansion of vessel diameter and provide shock absorption
56
During diastole, how do elastic arteries help maintain blood flow?
They recoil and impel the blood forward
57
Elastic arteries act as _____ when the heart is inactive or when no forward pressure is exerted by the heart?
Act as an auxiliary pump
58
How does vascular smooth muscle maintain blood pressure?
By maintaining vessel diameter during blood flow
59
What controls the tonus of smooth muscle cells in arteries and arterioles?
Autonomic nervous system and endocrine secretions
60
____ is a vascular condition is associated with increased smooth muscle tonus
Hypertension
61
What is the diameter of blood capillaries?
about 7-9 μm
62
What is the diameter of typical lymph capillaries?
10-50μm
63
What is the diameter of arterioles?
0.5 mm or less
64
Diameter of venules?
20-50μm
65
What layers are present in arterioles?
Tunica intima (with endothelium only and very thin inner elastic limiting membrane), Tunica media (with 4–5 smooth muscle layers), Tunica adventitia (fairly thin)
66
____ are small vessels that are on the border between arterioles and the capillary bed
Metarterioles
67
Role of metarterioles
They act as sphincters and cut off the flow of blood into the capillary bed
68
Direct connection between an arteriole and a venule is ____
Arteriovenous anastomosis
69
Where are arteriovenous anastomoses especially common?
Dermis of the skin
70
Vessels whose terminal branches do not anastomose are _____
Anatomical end arteries
71
What is the result of blockage in anatomical end arteries?
Infarction of the supplied tissue
72
Examples of anatomical end arteries include arteries of which organs?
Heart (coronary arteries), kidneys, brain
73
Arteries that have anastomoses and hence alternative routes for blood and oxygen in case of blockage are termed
Functional end arteries
74
List 4 common arterial disorders
Atherosclerosis, Arteriosclerosis, Hypertension, Aneurysms
75
Arterial disorder: fatty deposits and occlusion
Atherosclerosis
76
Arterial disorder: hardening of the arteries
Arteriosclerosis
77
Arterial disorder: ballooning of the vessel
Aneurysms
78
Occlusion of the lumen of arteries result in ____ and _____
Cardiac and Cerebral infarct
79
The return of blood to the heart from the capillary beds follows what sequence?
Small venules → small veins → large veins
80
The route of veins is in ____ to arteries
Parallel
81
State two reasons why veins are more likely to appear collapsed in histological preparations.
Thinner walls and less elastic or distensible than arteries
82
Veins are ___ numerous than arteries, have ____ (size) diameter of vessels
More numerous, larger diameter than arteries
83
Greater relative number of vasa vasorum in veins is because?
Veins have much less oxygenated blood
84
Valves are found in which type of vessels?
Veins
85
How are veins classified based on size?
Large, medium, or small veins
86
Compared to arteries, the borders between the layers of veins are?
Much less distinct
87
In veins, smooth muscle in the tunica media are ___ and in tunica adventitia are ____
All circular (grouped in bundles) in media; longitudinal in adventitia
88
Most muscles in veins are present in which layer? and their orientation?
Adventitia; Longitudinal
89
What role do muscles in veins play?
Tonus
90
Where are valves especially present in veins?
In veins that transport blood against gravity (e.g. legs)
91
What forms the structure of venous valves?
Folds of the tunica intima (endothelium + connective tissue)
92
What condition can result from weakness in vein walls and valve incompetence?
Varicose veins and improper closure of valves
93
In total mesentery preparations, why are erythrocytes visible in venules but not arterioles?
Venule walls are thinner
94
_____ in lymphatic organs have high or cuboidal endothelium
Post-capillary venules
95
What is the role of specialized post-capillary venules in lymph nodes?
Permit recirculation of lymphocytes (especially T-lymphocytes) from blood to lymph
96
The umbilical blood vessels are described as what?
Atypical
97
What is unusual about the single umbilical vein?
It is very muscular
98
The tunica intima of umbilical arteries is composed of ____
Endothelium only
99
What are the two muscle layers of the tunica media in umbilical arteries?
Inner longitudinal, outer circular layers
100
What type of fibers are present throughout the media of umbilical arteries?
Elastic fibers
101
In a typical blood vessel configuration, what kind of vessel enters the capillary bed and what type of vessel exits the capillary bed?
Artery or arteriole enters; Venule or vein leaves
102
In ___ system, blood vessel leaving the capillary bed is the same type as the one entering
Portal system
103
2 places with examples of venous portal system
Hepatic portal system in liver, In Hypothalamus-hypophysis
104
Where is an arterial portal system found?
Renal cortex
105
In the renal cortex, afferent arterioles break into _____
Capillary bed of glomerular tufts (renal corpuscle)
106
Veins are more numerous than arteries and have more vasa vasorum T or F
True
107
Functions of the lymph vascular system include the return of what substances to the blood from connective tissue spaces?
water, electrolytes, and plasma proteins
108
What role does the lymph vascular system play in extracellular fluid?
Homeostasis of the volume of extracellular fluid
109
Which immune cells and immune proteins are returned from lymph nodes to the blood by the lymph vascular system?
lymphocytes and immunoglobulins (antibodies)
110
What is the nature of lymph fluid?
Fairly clear, transparent fluid
111
What kind of flow occurs in small lymph capillaries and lymph vessels?
Passive flow
112
Where are lymph capillaries typically found?
In most organs close to blood capillaries except CNS
113
Which major body system is an exception to lymph capillary presence?
Central Nervous System (CNS)
114
The wall of a lymph capillary is composed of a single layer of endothelium about ____ thick
0.3μm
115
Why are lymph vessels hard to detect in histological preparations?
Because the lumen tends to collapse
116
Unlike blood vessels, lymph capillaries lack what structural feature?
Basal lamina
117
Do lymph capillaries contain pericytes or adventitial cells?
No
118
Marginal folds are present in which vessels?
Blood capillaries (not lymph capillaries)
119
Compared to blood capillaries, the lumen of lymph capillaries is usually free of _____
Cells (e.g., erythrocytes and other blood cells)
120
Valves constructed from _____ prevents backflow of lymph in lymph vessels
endothelial cells
121
Lymph capillaries drain into what kind of vessels?
Larger lymph vessels with large lumina and thin walls
122
Where do large lymph vessels ultimately drain?
Two large lymphatic ducts at the base of the neck
123
Name the two large lymphatic ducts.
Thoracic duct and right lymphatic duct
124
The thoracic duct and right lymphatic duct return lymph to the ________.
Blood
125
How many afferent vessels and efferent vessels does a lymph node typically have?
Several afferent vessels; Only one single efferent vessel
126
What happens to lymph as it passes through a lymph node?
It is filtered
127
What are the three tunics of a typical blood vessel wall?
Tunica intima, tunica media, tunica adventitia.
128
The innermost layer of a blood vessel wall is the ____.
Tunica intima.
129
Tunica intima is delimited from tunica media by the ____.
Internal elastic lamina.
130
The tunica media consists primarily of circumferential __________ and variable amounts of ______.
Smooth muscle; Small amounts of connective tissue
131
The tunica media is separated from the tunica adventitia by the ____.
External elastic lamina.
132
Which tunic blends with the surrounding connective tissue and lacks a clearly defined outer border?
Tunica adventitia.
133
Which tunic delimits vessel wall towards the lumen of the vessel?
Tunica intima
134
Endothelial lining (simple, squamous) and connective tissue make up ____
Tunica intima
135
The tunic that consists mainly of connective tissue fibres is
Tunica adventitia
136
True or False: All three tunics are present in all types of blood vessels.
False. They vary depending on the size and type of vessel.
137
The sum of diameters of all capillaries is ______ than that of the aorta.
Significantly larger.
138
Which effect does the total cross-sectional area of capillaries have on blood flow and pressure?
It decreases blood pressure and flow rate.
139
Continuous capillaries have continuous ______ and ______.
Endothelial cells and basal lamina
140
_____ and ____ in continuous capillaries function as selective filters.
Endothelial cells and basal lamina
141
T or F Continous capillaries do not form openings that would allow substances pass capillary wall wwithout passing endothelial cell and basal lamina
True
142
Fenestrated capillaries contain small openings called ____ derived from ____ which facilitate exchange between blood and interstitial fluid.
Fenestrations (derived from pinocytotic vesicles).
143
Which capillaries have endothelial cell body with small pores and a complete basal lamina?
Fenestrated capillaries.
144
Which type of capillaries allows even cells to pass due to their incomplete endothelial and basal lamina layers?
Sinusoidal capillaries.
145
Which capillaries are formed by fenestrated endothelial cells, which may not form a complete layer of cells.
Sinusoidal capillaries
146
Where would you typically find sinusoidal capillaries?
In organs where free exchange of substances or cells is advantageous (e.g., liver, bone marrow).
147
Sinusoidal capillaries form large, irregularly shaped vessels called ____.
Sinusoids.
148
Basal lamina is incomplete in which capillary type?
Sinusoidal capillaries
149
_____ control flow of blood from one chamber to another by preventing backflow
valves
150
Blood supply to the heart is provided by the ___ ___ and ___ system
Coronary artery and vein
151
Right and left coronary arteries branch off of the
Aorta
152
Cardiac veins deliver blood to ___ and back to the ___
coronary sinus; right atrium
153
Coronary artery disease usually results from ___
plaques in arterial walls
154
___ is chest pain due to inadequate oxygen delivery to the body
Angina pectoris
155
___ occurs when blood supply to the heart is completely blocked, leading to muscle death
Myocardial infarction
156
Heart contracts as a unit due to ___ that help conduct electrical signals through the heart
atrial and ventricular syncytia
157
S-A node is continuous with the ___ syncytium
atrial
158
Cells of the _____ can initiate impulses on their own; activity is ___
S-A node; rhythmic
159
Arterial pressure is too high in ___
Hypertension
160
List 7 risk factors for hypertension
Sedentary lifestyle, smoking, obesity, diet, stress, arteriosclerosis, genetics
161
In hypertension, the ___ ventricle enlarges due to increased workload
left
162
Consequences of hypertension include: ___, ___, and ___
heart disease; damage to blood vessels; heart failure
163
___ and ___ carry blood away from the heart
Arteries; arterioles
164
___ are the site of exchange in the blood vascular system
Capillaries
165
___ and ___ return blood to the heart
Venules; veins
166
___ prevents platelet aggregation in blood vessels
Endothelium
167
_____ secretes substances controlling vessel diameter
Endothelium
168
Tunica media contains ___ and ____, innervated by ___ nerves
smooth muscle and connective muscle; sympathetic
169
Which tunic is missing in the smallest arteries
Tunica media
170
___ tunic is connective tissue and is vascularized
Tunica externa
171
In capillaries, oxygen and nutrients move out by ___ and CO₂ moves in
diffusion
172
In capillaries, blood pressure moves molecules out by ___
filtration
173
______ maintain osmotic pressure of blood
Plasma proteins
174
Veins have ___ walls and ___ muscle; hold ___ blood than arteries
thinner; less; more
175
Many veins in limbs have ___ to prevent backflow
valves
176
Varicose veins arise when ___ is prolonged
pressure on valves
177
The heart is a ___, delivering blood to the lungs and the body
double pump
178
Blood leaves the heart through ___ and returns via ___
arteries; veins
179
The heart rate is regulated by a ___ system
conducting
180
Heart beats about _____ times per day
100000
181
The cardiac cycle is regulated by the _____ in the _____
cardiac center in the medulla oblongata
182
Cardiac center in the medullar oblongata regulates cardiac cycle and ____
sympathetic and parasympathetic input
183
Heart rate is affected by ___, ___, and ___
exercise; temperature; ion balance
184
Long-term control of cardiac rate involves ___, ___, ___, and ___
ADH; angiotensin; EPO Erythropoietin; ANP Atrial Natriuretic Peptide
185
Arterial blood pressure is influenced by _____, ____, ___ and ___
heart action, blood volume, peripheral resistance; blood viscosity
186
Failure to regulate blood pressure can lead to ___
disease
187
Structural features of arteries and veins suit their roles in ___ and ___ of blood
delivery; return
188
The circulatory system adjusts to functions like ___ and ___
exercise; digestion
