Unit 15 - Vessels and Circulation Flashcards
1
Q
three classes of blood vessels
A
Arteries, Capillaries, Veins
2
Q
where the exchange of nutrients and gasses takes place between the tissue cells and the blood.
A
Capillaries
3
Q
The site where two or more arteries (or two or more veins) merge to supply the same body region is called an
A
“anastomosis”
4
Q
provide alternate blood supply routes to body tissues or organs.
A
Arterial anastomoses
5
Q
Veins form many more anastomoses than arteries.
A
True
6
Q
Some arteries do not form anastomoses; in these so-called ____, there is only one pathway through which blood can reach an organ (i.e. - renal artery of the kidney or splenic artery of the spleen).
A
“end arteries”
7
Q
Often, an artery will travel with a corresponding vein and these vessels are called
______ because they service the same body region and tend to lie next to
one another
A
“companion vessels”
8
Q
Both arteries and vein walls have three layers, called “____ (Latin for “coats”).
A
tunics”
9
Q
The tunics surround the “_____”, or inside space, of the blood vessel through which blood flows.
A
lumen
10
Q
The innermost layer of a blood vessel wall is the _____
A
tunica intima
11
Q
Tunica Intima is composed of _____ and a subendothelial layer made up of a thin layer of connective tissue
A
“endothelium”
12
Q
The tunica intima in veins has one-way valves. This is not seen in arteries.
A
True
13
Q
The _____ (Latin for “coat” and “middle”) is the middle layer of the vessel wall.
A
“tunica media
14
Q
Sympathetic innervation causes the smooth muscles to contract, resulting in
“vasoconstriction” (narrowing of the blood vessel lumen); when the fibers relax,
“vasodilation” (widening of the blood vessel lumen) results.
A
True
15
Q
The ______ (Latin for “coat” and “outside”) is the outermost layer of a blood vessel wall.
A
“tunica externa”
16
Q
In arteries, the thickest layer is the _____, while veins have a thicker _____.
A
tunica media, tunica externa
17
Q
The lumen in an artery is narrower than in a vein of the same size
A
True
18
Q
Arteries tend to have more elastic and collagen fibers in all their tunics, which means that artery walls remain open (patent) and can spring back to shape.
In contrast, vein walls tend to collapse if there is no blood in them
A
True
19
Q
Capillaries contain only the _____, but this layer consists of a basement membrane and endothelium only.
A
tunica intima
This allows for easy exchange of materials between the blood in the vessels and the fluid surrounding the tissue cells (interstitial fluid)
20
Q
In general, as an artery’s diameter decreases, there is a corresponding decrease in
the amount of elastic fibers and a relative increase in the amount of smooth
muscle.
A
True
21
Q
_____ are the largest arteries, with diameters ranging from 2.5 to 1 centimeter.
A
“Elastic arteries”
22
Q
There are several examples of elastic arteries.
- Aorta
- Pulmonary
- Brachiocephalic
- Common carotid
- Subclavian
- Common iliac arteries
A
True
23
Q
Elastic arteries branch into
A
muscular arteries.
24
Q
typically have diameters ranging from 1 centimeter to 3
millimeters
A
muscular arteries.
25
Muscular arteries have a proportionately thicker _____, with multiple layers of smooth muscle that give them better ability to vasoconstrict and vasodilate
tunica media
26
______ are the smallest arteries, with diameters ranging from 3 millimeters to 10 micrometers
Arterioles
27
Three basic types of arteries
Elastic arteries, muscular arteries, arterioles
28
In general, arterioles have less than ______ of smooth muscle in their tunica media
six layers
29
Larger arterioles have all three tunics, whereas the smallest arterioles have fewer.
True
30
By vasocontricting or vasodilating the arterioles can increase or decrease the arterial
blood pressure and also regulate blood flow through the capillaries.
True
31
the smallest blood vessels, connect arterioles to venules
capillaries
32
The average capillary diameter is ____ micrometers, just slightly larger than the diameter of a single erythrocyte (7 micrometers)
8-10
The narrow vessel diameter means erythrocytes must travel in single file through
each capillary
33
______” causes blockages and infarctions in body organs
“Sickle-cell disease
34
Sickle cell disease is caused by inheritance of a gene for abnormal hemoglobin (_______)
hemoglobin-S
35
Thus, capillaries are called the ____ of the cardiovascular system.
functional units
36
Three different structural types of capillaries
continuous capillaries, fenestrated capillaries, sinusoids
37
the most common type of capillaries, endothelial cells form a complete, continuous lining and are connected by tight junctions.
continuous capillaries
Materials can pass through the endothelia cells or the intercellular clefts to and from
the surrounding interstitial fluid.
38
have fenestrations within each endothelial cell and are
seen where a great deal of fluid transport occurs between the blood and interstitial
fluid of the tissues (i.e.-intestines, endocrine glands, and kidneys).
fenestrated capillaries
39
_____ tend to be wider, larger vessels with openings that allow for transport
of larger materials, such as proteins or cells (i.e. - blood cells).
“Sinusoids”
Sinusoids are found in the bone marrow, the spleen, the anterior pituitary, the liver, and at several other locations in the body
40
“Veins” drain capillaries and return blood to the heart
True
41
At rest, the body’s veins hold about ____ of the body’s blood.
(a) Thus, veins function as “blood reservoirs”
60%
42
_____” are the smallest veins, measuring from 8 to 100 micrometers in diameter.
Venules
43
A venule becomes a “vein” when its diameter is greater than _____
100 micrometers.
44
Smaller and medium-sized veins typically travel with muscular arteries, while the largest veins travel with (correspond to) elastic arteries
True
45
To prevent blood from pooling in the limbs and assist blood moving back to the heart, most veins contain numerous “one-way valves” formed primarily of tunica
intima and strengthened by elastic and collagen fibers.
True
46
Blood pressure in veins is too low to overcome the forces of gravity
True
47
dilated, tortuous (having many curves or twists) veins
Varicose Veins
48
Varicose veins are most common in the ____ of the lower limbs
superficial veins
49
Varicose veins in the anorectal region are called ____
hemorrhoids
50
In a procedure called___ an irritant is injected into small varicose veins to make them scar and seal off.
sclerotherapy
51
Moreover, nearby skeletal muscles squeeze veins when they shorten and contract.
This process is called the _______
“skeletal muscle pump”.
52
refers to a blood clot (thrombus) in a vein.
Deep vein thrombosis
53
The most common site for the thrombus is a vein in the ______ region.
calf (sural)
54
The most serious complication of DVT is a ____, in which a blood clot breaks free and travels to the lung, eventually blocking a branch of the pulmonary artery and potentially causing respiratory failure and death.
pulmonary embolus
55
Blood pressure is measured with a ________, an inflatable cuff with a pressure gauge that is wrapped around the upper arm to compress the brachial artery so no blood flows.
“sphygmomanometer”,
The pressure on the gauge at this moment (when sound is first heard) is the “systolic blood pressure” and corresponds to the highest pressure in the brachial artery caused by ventricular systole.
The pressure on the gauge at this moment is the “diastolic blood pressure” and corresponds to the lowest pressure in the brachial artery that occurs during ventricular diastole.
56
Blood pressure is expressed as a ratio, in which the upper number is the ____ pressure and the lower number is the _____ pressure.
systolic, diastolic
Normal blood pressure is approximately 120/80 mm/Hg
57
Is chronically elevated blood pressure, defined as a systolic pressure greater than 140 mm Hg and/or a diastolic pressure greater than 90 mm Hg
Hypertension
58
thicken the arteriole walls and reduce their luminal diameter, a condition called
arteriolosclerosis
59
is a chronically low blood pressure that results in symptoms such as fatigue, dizziness, and fainting.
hypotension
60
is a drop in blood pressure when an individual suddenly changes position, such as when a person stands up after lying down.
Orthostatic hypotension, or postural hypotension
61
The _____ emerge immediately from the wall of the ascending aorta (just superior to aortic semilunar valve) and
supply the heart.
“left coronary arteries” and “right coronary arteries”
62
The ascending aorta curves towards the left side of the body and becomes the _____
“aortic arch”
63
Components of aortic arch
Brachiocephalic Trunk, Left Common Carotid Artery, Left subclavian artery
64
the “brachiocephalic trunk”, which bifurcates into
right common carotid artery and “right subclavian artery”
65
Sudden decelerations (i.e.-car crashes) can damage the aortic arch or descending
thoracic aorta.
(a) Aortic transections are typically fatal (DRT).
(b) Aortic dissections are overall about 90% fatal and are very painful!
True
66
The _____ supply most of the blood to the head and neck.
“left” and “right common carotid arteries”
67
At the superior border of the thyroid cartilage, each artery divides into an “external carotid artery” that supplies structures external to the skull and an
“internal carotid artery” that supplies internal skull structures.
True
68
supplies structures external to the skull
“external carotid artery”
69
supplies internal skull structures.
internal carotid artery
70
Near this bifurcation is the _____” which contains pressure sensors (“baroreceptors”) which monitor blood pressure.
“carotid sinus
When stimulated, they cause slowing of the heart, vasodilation, and a fall in blood pressure.
71
The external carotid artery extends upward along the side of the neck and head and gives off several branches. One branch of particular interest is the ______ that pulsates vigorously when persons have a headache
“anterior temporal artery”
72
The internal carotid artery branches only after it enters the skull through the _____
carotid canal.
73
The _______ emerge from the subclavian arteries and travel through the transverse foramina of the cervical vertebrae before entering the skull through
the foramen magnum, where they merge to form the _______
“vertebral arteries”, “basilar artery”
74
The _____ (cerebral arterial circle) is an important anastomosis of arteries around the sella turcica.
“circle of Willis”
Blood flow to the circle of Willis is contributed by the inflow of blood from branches of the vertebral arteries and the carotid arteries
75
This arterial circle equalizes blood pressure in the brain and can provide collateral channels should one vessel become blocked.
“circle of Willis”
76
The aortic arch curves and projects inferiorly as the ______ that extends several branches to supply thoracic organs and the thoracic wall.
“descending thoracic aorta”
77
Connective tissue of the lungs is supplied by three or four small _______ that emerge as tiny branches from the anterior wall of the descending thoracic aorta
“bronchial arteries”
78
This is part of the systemic circulation that serves the lung tissues, except for the alveoli and alveolar capillaries, which are part of the pulmonary circulation.
“bronchial arteries”
79
Several small ______ emerge from the anterior wall of the
| descending thoracic aorta and supply the esophagus.
“esophageal arteries”
80
the ___ supplies arterial blood to the abdominal portion of the esophagus.
“left gastric artery”
81
What supplies diaphragm with blood
(a) The “superior phrenic (Greek for “diaphragm”) arteries” arise from the descending
thoracic aorta.
(b) The “musculophrenic arteries” that arise from branches of the subclavian arteries.
(c) The “inferior phrenic arteries” that emerge from the descending abdominal aorta.
82
When the descending thoracic aorta extends inferior to the diaphragm, it is renamed the ______ which extends branches to supply the abdominal
wall and organs
“descending abdominal aorta”
83
Three unpaired arteries emerge from the anterior wall of the descending abdominal aorta to supply the gastrointestinal tract.
“celiac trunk”
“superior mesenteric artery"
“inferior mesenteric artery”
84
located immediately inferior to the aortic
| opening through the diaphragm.
“celiac trunk”
85
This trunk is surrounded by the “celiac plexus”
| (solar plexus) which is the largest autonomic nerve plexus.
Celiac Trunk
86
Three branches emerge from the celiac trunk.
(a) The “left gastric artery” supplies the lesser curvature of the stomach and extends some branches to the esophagus.
(b) The “splenic artery” supplies the spleen, part of the stomach, and the pancreas.
(c) The “common hepatic artery” supplies the liver, part of the stomach, the duodenum, and the pancreas
87
is located immediately inferior to the celiac trunk.
“superior mesenteric artery"
88
It supplies the:
- Most of the small intestine (except for a portion of the duodenum)
- Pancreas
- Proximal portion of the large intestine
“superior mesenteric artery"
89
is the most inferior of the three unpaired arteries
| that arise from the descending abdominal aorta
“inferior mesenteric artery”
90
It emerges from the aorta at about the level of L3 and supplies:
- Part of the transverse colon
- Part of the descending colon
- Sigmoid colon
- Rectum
“inferior mesenteric artery”
91
Blood flow to the posterior abdominal organs, pelvis, and perineum - what other three unpaired arteries emerge from the sides of the descending abdominal aorta?
1) The “middle suprarenal arteries”, which supplies each adrenal gland.
2) The “renal arteries”, which supply each kidney.
3) The “gonadal arteries”, which supply each gonad (testes in males, ovaries in
females) .
92
The descending abdominal aorta then divides to form arteries that supply the pelvis, perineum, and lower limbs.
1) At the level of the fourth lumbar vertebrae, the descending abdominal aorta bifurcates into a ______.
(a) Each of these further divides into an ______
“left common iliac artery” and a “right common iliac artery”
“internal iliac artery” (to supply pelvic and perineal structures) and an “external iliac artery” (to supply the lower limb).
93
Both the upper and lower limbs are supplied by a main arterial vessel.
(a) The subclavian artery for the upper limb.
(b) The ______ for the lower limb.
This main arterial vessel bifurcates at the elbow or knee.
Arterial and venous arches are seen in both the hand and foot.
femoral artery
94
After the subclavian artery passes over the lateral border of the first rib, it is renamed the “__
axillary artery”.
The axillary artery extends branches to the shoulder and thoracic region.
95
When the axillary artery passes the inferior border of the teres major muscle, it is
renamed the _____
“brachial artery”.
96
In the cubital fossa, the brachial artery divides into an _____
“ulnar artery” (which
courses down the medial side of the forearm) and a “radial artery” (which courses
down the lateral side of the forearm).
97
Hospital workers often used the _____ in the lateral wrist for collecting arterial blood for blood gas analysis in hospitalized patients.
radial artery
98
Both the ulnar and radial arteries supply the muscles and structures of the forearm and wrist before they anastomose and form two arches in the palm.
(a) The “superficial palmar arch” (formed primarily from the ulnar artery).
(b) The “deep palmar arch” (formed primarily from the radial artery).
(c) “Digital arteries” emerge from the arches to supply the fingers.
True
99
The main arterial supply for the lower limb is the _____, which is a branch of the common iliac artery.
external iliac artery
100
The external iliac artery travels inferior to the inguinal ligament, where it is renamed the _____.
“femoral artery”
101
The femoral artery initially passes though an area called the ________ on the upper medial portion of the thigh.
- The femoral artery can be palpated here.
- It can be pressed to control bleeding (arterial pressure point)
- It can be penetrated to obtain blood samples for arterial blood gasses.
“femoral triangle”
102
The _______ emerges from the femoral artery to supply the hip joint and many of the thigh muscles.
“deep femoral artery”
103
The femoral artery passed into the region behind the knee where it is renamed the _______, which supplies the knee joint and muscles in this region.
“popliteal artery”
104
The popliteal artery divides into an ____ which supplies the anterior compartment of the leg, and a ______, which supplies the
posterior compartment of the leg.
“anterior tibial artery”, “posterior tibial artery”
105
The posterior tibial artery extends a branch called the _____, which supplies the lateral compartment of the leg
“fibular artery”
106
The posterior tibial artery continues on the plantar side of the foot, where it branches into the _____
‘medial plantar artery” and the “lateral plantar artery”
107
The anterior tibial artery crosses over the anterior side of the ankle, where it is renamed the “______
“dorsalis pedis artery”
108
(a) Clinically, palpation of the ______ can provide information about circulation of the foot.
(b) It also provides information about the circulation in general because the pulse taken
here is at the most distal portion of the circulatory system.
dorsalis pedis artery
109
The dorsalis pedis artery and a branch of the lateral plantar artery unite to form the _____ of the foot.
“plantar arch”
110
______ extend from the plantar arch and supply the toes.
“Digital arteries”
