Blood vessels Flashcards
(98 cards)
1
Q
Which of the following describe structure of BV
A
Tunica interna is a layer the lines the blood vessel and is exposed to blood.
E all the above
2
Q
Describe endothelium
A
barrier to platelets and erythrocytes, allow substrates to pass, produce chemicals that control artery tone
3
Q
Describe layers of tunica and structure
A
Provide structure and rigidity to blood vessel.
4
Q
Describe major blood vessels
A
Arteries are sometimes called resistance vessels. Expand during systole and recoil during diastole.
5
Q
Which describe medium sized arteries
A
Provide blood to major organs. 3/4 smooth muscle
6
Q
Describe small aterioles
A
Control blood flow to major organs/tissues. Have thicker tunica media and little tunica externa
7
Q
Aneurysm is a process by which the arterial wall thins forming a bluging sac that can burst with each heartbeat
A
TRUE
8
Q
Which describes the pathology of aneurysm
A
blood accumulates between tunica layers separates them. tend to form in adomal aorta, renal arteries, ruptures cause hemorrage, caused by syphallis
9
Q
Common cause of aneuysm
A
atherosclerosis & Hypertesion
10
Q
What is true of arteries?
A
Arterial receptors transmit outputs to the brainstem to regulate heart rate, vasomotion and respirtation. Carotids contain baroreceptors.
11
Q
Which following describes cartid bodies and aortic bodies
A
chemoreceptors monitor O CO2 ph . small round bodies near arties.
12
Q
Capillaries is where nearly all fluids, nutrients wastes are exchanged.
A
True.
13
Q
Capillaries are composed by
A
Basal lamina, endothelial cells
14
Q
What are capillary structures?
A
Fenestrated, sinusoids, continuous
15
Q
Describe continuous capillaries.
A
Lined with pericytes that can contract to regulate blood flow, endothelial cells forming a tube with intercellular clefts, allow passage of substrates like glucose
16
Q
Fenestrated capillaries
A
Endothelial cells riddled with holes or filtration pores. locted where filtration is necessary or maximum
17
Q
Synusoids
A
includes bone marrow, liver and spleen. Allow proteins to cross capillary bed, allow for secretion of new cells into bblood stream. irregular blood filled tissues.
18
Q
True regarding capillaries.
A
3/4 capillaries shut down to blood flow. Metarterioles supply blood to capilary beds. Meta arterioles surpass closed caps and directly supply blood to venules
19
Q
What opens an closes capillary sphincters
A
Muscle at rest closes capillary sphincters. fulls tomach opens capillary sphincters
20
Q
Veins
A
decreased capacity for blood containment than arteries. merge to form larger veins.
21
Q
Post capillary venules
A
. No muscle fibers with some fibroblasts and tunica interna.
22
Q
Muscular venules
A
up to 1mM in diameter. Have one or 2 layers of smooth muscle in tunica media. have thin tunica externa
23
Q
Medium veins
A
failure of venous valves results in vericose veins. up to 10mM in dia. skeletal muscle pump propels blood
24
Q
Describe structure of blood vessel.
A
Walls of arteries and veins, composed of 3 layers called TUNICS. Tunica interna, tunica media, tunica externa.
25
Describe different types of arteries.
Arteries: Efferent vessels of cardo system. Carry blood AWAY from heart. Resistance vessels. resists high blood pressure. More muscular than veins.
1) Conducting (large/elastic): biggest arteries. Internal elastic lamina, border bwtn interna and media. Media 40-70 elastic sheets perforated like swiss cheese. External elastic lamina. Stiffen by athersclerosis can't expand or recoil as freely.
2) Distributing (muscular/medium): distribute blood to specific organs. Internal and external elastic laminae, thick and conspicuous.
3) Resistance (small): Thicker tunica media in proportion to lumen. Smallest arteries called arterioles. very little tunica externa.
26
Describe different types of Capillaries.
1) Continuous capillaries: Occur in most tissues, skeletal muscle. Basal lamina surrounds epithelium. Endothelial cell separated by intercellular clefts (small solutes can pass, but big molecules, proteins, etc. are held back). Some have cells called pericytes.
2) Fenestrated: endothelial cells with holes. Allow for rapid passage of small molecules. Kidneys, endocrine glands, small intestine, choroid plexus of the brain.
3) Sinusoids: Irregular blood-filled spaces in the liver, bone marrow, spleen and other organs. Separated by wide gaps, no basal lamina, large fenestrations.
27
Describe different types of Veins.
Thin walled and flaccid, expand easily to accommodate an increase volume of blood.
1) Postcaillary venules: smallest of veins. More porous than capillaries. Venules exchange fluid with surrounding tissues.
2) Muscular venules: Receive blood from postcapillary venules. Have a tunica media of one or two layers of smooth muscle, and a thin tunica externa.
3) Medium veins: Most veins with individual names are in this category. Most form venous valves directed toward heart. Varicose veins result with failure of valves.
4) Venous sinuses: very thin walls, large lumens, and no smooth muscle. Coronary sinus of heart, and dural sinuses of brain. Not capable of vasomotion.
5) Large veins: diameters greater 10mm. Smooth muscle in all 3 tunics. Thin media, moderate amount of smooth muscle. externa thickest, longitudinal bundles of SM. Venae cavae, pulmonary veins, internal jugular veins, renal veins.
28
Trace the general route usually taken by the blood from the heart and back again.
Heart -> arteries -> capillaries -> veins -> heart.
Portal system: Blood flows through two consecutive capillary networks before returning to heart. Occur in kidneys, connecting hypothalamus and anterior pituitary, intestines to liver.
29
Anastomisis
Point where two blood vessels merge.
30
Arteriovenous anastomosis (shunt)
Blood flows from an artery directly into a vein and bypass the capillaries. Occur in fingers, palms, toes, and ears, reduce heat loss in cold weather by allowing warm blood to bypass these exposed surfaces.
31
Venous anastomoses
one vein empties directly into another. Provide several alternative routes of drainage from an organ, so blockage of a vein is rarely as life-threatening as blockage of an artery.
32
Arterial Anastomosis
Two arteries merge provide alternative routes of blood supply to a tissue.
33
Describe 3 layers of tunics
1) Tunica Interna: Lines inside of vessel and is exposed to blood. Simple squamous epithelium called endothelium. Secretes chemicals that stimulate dilation or constriction. Repels blood cells and platelets so they don't stick. If damaged, form blood clot.
2) Tunica media: middle layer and usually the thickest. Consists of smooth muslce, collagen, and sometimes elastic tissue. Strengthens vessels and prevents blood pressure from rupturing them. Provides vasomotion.
3) Tunica externa: Outermost layer. Consists of loose connective tissue that merges with neighboring blood vessels, nerves, other organs. Vasa vasorum small vessels that supply blood to outer half of wall or larger vessel.
34
How is the Tunica Media different in a conducting artery, arteriole and venule.
Conducting artery: Consists of 40-70 layers of elastic sheets, perforated like swiss, alternating with thin layers of smooth muscles, collagen, and elastic fibers. Dominated by elastic tissue. Media is LARGER than externa.
Arterioles: Thicker tunica media, very little tunica externa.
Venule: Muscular have tunica media of 1 or 2 layers of smooth muslce, and thin tunica externa.
35
What is the difference between a medium vein and a medium (muscular) artery? What is the functional reasons for these differences?
Medium veins: Tunica media is thinner than in medium arteries. Exhibits bundles of smooth muscles, but no continuous smooth muscle layer. Thick tunica externa. Thin internal elastic lamina.
Medium (muscular) artery: Have up to 40 layers of smooth muscle that takes up 3/4 of wall thickness. Both internal and external elastic lamina are thick and conspicuous. Distribute blood to specific organs.
35
Anastomosis/portal system -vs- typical pathway for blood flow
Anastomosis/portal systems have to flow through 2 or more capillary beds before going through to the heart. Portals systems goes through 2 capillary beds. Anastomosis blood flows from an artery directy into vein bypassing capillary bed (poss. frostbite) venous most common. arterial two arteries merge routes of blood supply to tissue.
Typical pathway heart ->arteries->capillaries -> veins -> Heart
36
Anastomosis/portal system -vs- typical pathway for blood flow
Anastomosis
36
Anastomosis/portal system -vs- typical pathway for blood flow
Anastomosis/portal systems have to flow through 2 or more capillary beds before going through to the heart. Portals systems goes through 2 capillary beds. Anastomosis blood flows from an artery directy into vein bypassing capillary bed (poss. frostbite) venous most common. arterial two arteries merge routes of blood supply to tissue.
37
What is the relationship between blood pressure, resistance and flow.
My impression is that arterial blood pressure when within normal levels, flows without difficulties into the blood stream. When this normal level raises to a higher one, there is a narrowing in the blood vessels, making the blood circulation more slow and consequently overcharge the heart work, causing fatigue to that person and easing the formation of atheromas. Conclusively a normal blood pressure makes the blood circulation becomes more efficient, thus nourishing cells better.
38
How is blood pressure expressed?
Two pressures are recorded: Systole (contracted) Diastole (relax). Difference between the two is pulse pressure.
39
Describe 3 factors that determine resistance to blood flow.
Blood viscosity: the thickness of the blood either speeds up blood flow or slows it down.
Vessel length: the farther a liquid travels the more friction it encounters, flow declines.
Vessel radius: Vasomotion, adjusting the radius of blood vessels.
40
Describe some local influences on vasomotion.
Autoregulation: tissues to regulate their own blood supply.
Vasoactive chemicals: Substances that stimulate vasomotion.
Reactive hyperemia: and increase above the normal level of flow. (when skin flushes after cold)
Angiogenesis: growth of new blood vessels (uterine lining after period)
41
Describe some hormonal influences on vasomotion.
Angiotensin II: Potent vasoconstrictor raises BP
Aldosterone: "salt-retaining hormone"
Atrial natriuretic peptide: secreted by heart, antagonizes aldosterone.
ADH: promotes water retention.
Ephinepherine/norepinepherine: stimulate muscle to contract.
42
Why is arterial blood flow pulsatile and venous flow is not?
Since venous return to the heart, the passage through body has slowed down and evened out the blood pressure.
43
Describe 3 factors that determine resistance to blood flow.
Blood viscosity: the thickness of the blood either speeds up blood flow or slows it down.
Vessel length: Vessel Radius
44
Describe some hormonal influences on vasomotion.
Angiotensin II: Potent vasoconstrictor raises BP
Aldosterone: "salt-retaining hormone"
Atrial natriuretic peptide: secreted by heart, antagonizes aldosterone.
ADH: promotes water retention.
Ephinepherine/norepinepherine: stimulate muscle to contract.
45
Why is arterial blood flow pulsatile and venous flow is not?
Since venous return to the heart, the passage through body has slowed down and evened out the blood pressure.
46
How does the baroflex serve as an example of homeostasis and negative feedback?
When BP rises, input INHIBITS sympathetic cardiac and vasomotor neurons and reduces sympathetic tone, and it excites vagal fibers to heart. This reduces heart rate and cardiac output, dialates arteries and veins, and reduces BP. IF BP drops below normal, the opposite occurs.
47
How does the body can shift the flow from one organ system to another?
Through vasomotion, through central or local control. E.g.CENTRAL during exercise, sympathetic nervous system can selectively reduce blood flow to kidneys and digestive tract yet increase perfusion to skeletal muscles. . LOCAL: Exercise, arteries in lungs, coronary circulation and muscles dialate. To increase circulation, vasoconstriction occurs elsewhere such as kidneys/digestive tract.Reduces perfusion for the time being.
48
How does the baroflex serve as an example of homeostasis and negative feedback?
When BP rises, input INHIBITS sympathetic cardiac and vasomotor neurons and reduces sympathetic tone, and it excites vagal fibers to heart. This reduces heart rate and cardiac output, dialates arteries and veins, and reduces BP. IF BP drops below normal, the opposite occurs.
49
How does the body can shift the flow from one organ system to another?
Through vasomotion, through central or local control. E.g.CENTRAL during exercise, sympathetic nervous system can selectively reduce blood flow to kidneys and digestive tract yet increase perfusion to skeletal muscles. . LOCAL: Exercise, arteries in lungs, coronary circulation and muscles dialate. To increase circulation, vasoconstriction occurs elsewhere such as kidneys/digestive tract.Reduces perfusion for the time being.
52
How do materials get from the blood to the surrounding tissues?
They are moved through the capillary exchange--a two way movement of fluid. Can occur through diffusion, Transcytosis, and filtration/reabsorption
53
Describe the cause and effects of edema.
Causes of edema: increased capillary filtration. Kidney failure for example, failure of left ventricle causes pressure to back up in lungs causing pulmonary edema.
Reduced capillary reabsorption: Hypoproteinemia severe burns due to loss of protein from body surface, kidney diseases that allow protein to escape urine.
Obstructed lymphatic drainage: interfere with fluid drainage and lead to accumulation of tissue fluid.
Effects of edema: can't breathe and waste disposal is affected, pulmonary edema suffocation as fluid replaces air. Headaches, nausea, delirium, coma. severe edema body could go into shock.
54
How is the blood in veins returned to the heart?
The flowback to the heart called the venous return achieved by: 1) Pressure gradient-pressure generated by heart to come back(weak) 2) Gravity: blood from head and neck flow down to heart. no force needed. 3) Skeletal muscle pump: Muscles pump and squeeze blood out of vein, making sure they go in one direction. 4) Thoracic (respiratory) pump: flow of blood from abdominal to thoracic cavity. expands when respiration/expiration 5) Cardiac suction: systole, tendinous cords pull AV valves cusps downward.
55
What is the importance of physical activity in venous return?
Heart beats faster and harder, increasing cardiac output and BP. Increase in respiratory rate and depth enhances the action of thoracic pump. Increased venous return increases cardiac output, imp. in perfusion of muslces when they need it.
56
What are the several causes of circulatory shock?
Circulatory shock is where any state in which cardiac output is insuficient to meet bodys metabolic needs. 1) Cardiogenic shock -inadequate pumping by heart 2) Low venous return shock - cardiac output is low bc too little blood is returning to heart.
1) hypovolemic shock- most common--loss of blood volume, by hemmorage, bleeding ulcers . . .
2) Obstructed VRS: growing tumor or aneurysm
3) Venous pooling: long periods of standing or sitting from widespread vasodialation.
57
Name and describe stages of shock.
Compensated shock: several homeostatic mechanisms act to bring about spontaneous recovery.
Decompensated shock: lifethreatening positive feedback loops occur.
58
How does respiration aid venous return?
When you inhale, your thoracic cavity expands and internal pressure drops while downward movement of the diaphragm raises pressure in abdominal cavity. Blood flows faster when you inhale.
59
How does the brain maintain stable perfusion?
It regulates its own blood flow in respsonse to changes in BP and chemistry.
60
What are the cause and effects of strokes and transient ischemic attacks?
Ischemia: insufficient blood flow to the brain to meet metabolic demand. TIA may result from spasms of diseased cerebral arteries. Could be a warning sign of an impending stroke. Characterized by temporary dizziness, loss of vision and loss of vision.
Strokes CVA: sudden death of brain tissue caused by ischemia. Produced by athersclerosis, thombosis, or ruptured aneurysm. Could be unnoticeable to fatal. Blindness, paralysis, loss of sensation/or speech.
61
Explain mechanisms that increase muscular perfusion during exercise.
During exercise, the arterioles dilate in response to epinepherine and norepinepherine from the adrenal medulla and sympathetic nerves. Blood has to be diverted from other organs to meet the needs of working muscles. Muscular contraction compresses blood vessels and impedes flow.
62
Blood pressure: Pulmonary circuit -vs- systemic circuit
Arterial blood contains less oxygen than the venous blood. thin walls, less elastic tissue than systemic arteries. Has lower BP. 1) Slow has more time for gas exchange. 2) capllaries engaged entirely in absorption. Prevents fluid accumulation in alveolar walls and leumens. Oncotic pressure overrides hydrostatic pressure.
Systemic arteries dilate in response to hypoxia and improve tissue perfusion. Pulmonary arteries constrict, lungs not ventilated well.
63
What is the route of blood through the pulmonary circuit?
1) pulmonary trunk 2) right and left PULMONARY arteries 3) Superior lobar artery 4) Middle lobar 5) inferior arteries 6) arteries split into basketlike capillary beds that surround pulmonary alveoli. Blood unloads here . pick up on PV7)Pulmonary veins, exit lung at hilum, return to heart
64
What are the principal systemic arteries of the axial region?
From top to bottom: Superficial temporal, facial, eternal carotid, internal carotid, common carotid, vertebral, subclavian, brachiocephalic, aortic arch, internal thoracic, subscapular, deep brachial, radial collateral, brachial, superior ulnar collateral, radial, ulnar, interosseous, palmar arches.
After diaphragm: common hepatic, splenic, renal, superior mensenteric, gonadal, inerferior messenteric, common iliac, internal iliac, external iliac,
In legs: Deep femoral, femoral, popliteal, anterior tibial, posterior tibial, fibular, arcuate.
65
What are the principal systemic VEINS of axial region?
External jugular, internal jugular, brachiocephalic, subclavian, superior vena cava, hapatic, inferior vena cava, renal, gonadal, common iliac, internal iliac, external iliac.
66
What are the principal veins of the Upper LIMBS
Subclavian, axillary, cephalic, basilic, brachial, median cubital, median antebrachial, radial, ulnar, cephalic, basilic, deep venous palmar arch, superficial venous palmar arch, dorsal venous network
67
What are the principal arteries of the UPPER LIMBS
Common carotid, subclavian, axillary, circumflex humeral, bachiocephalic trunk, brachial, deep brachial, superior ulnar collateral, radial collateral, Inerosseous: common posterior anterior, radial, ulnar, deep palmar arch, superficial palmar arch.
68
What are the principal arteries of the LOWER LIMBS
Common iliac, internal iliac, external iliac, femoral, deep femoral, adductor hiatus, popliteal, anterior tiibal, posterior tibial, fibular, doral pedal, medial tarsal, lateral tarsal, arcuate, lateral plantar, medial plantar, deep plantar arch.
69
What are the veins of the LOWER LIMBS
Inferior vena cava, common iliac, external iliac, internal iliac, femoral, deep femoral, circumflex femoral, great saphenous, small saphenous, anterior tibial, fibular, posterior tibial, dorsal venous arch, medial plantar, deep plantar venous arch, lateral plantar
70
Blood normally flows into a capillary bed from
Metarteriole
71
Plasma solutes enter the tissue fluid most easily from
fenestrated capillaries
72
A blood vessel adapted to withstand a high pulse pressure would be
elastic tunica media
73
The substance most likely to cause a rapid drop in blood pressure
histamine
74
A person with a systolic blood pressure of 130mm hg and a diastolic pressure of 85mm hg would have a mean arterial pressure of
100mm Hg
75
The velocity of blood flow decreases if
viscosity increases
76
Blood flows faster in venule than in a capillary because venules
have larger diameters
77
In a case where interstitial hydrostatic pressure is negative the only force causing capillaries to reabsorb fluid is
colloid osmotic pressure of the blood
78
Intestinal blood flows to the liver by way of
the hepatic portal system
79
The brain receives blood from all of the following arteries except the _______ artery or vein
internal jugular
80
The capillaries of skeletal muscles of the structural type called
continuous capillaries
81
_________ shock occurs as a result of exposure to an antigen to which one is hypersensitive
Anaphalactic
82
The role of venous return is called the
thoracic pump
83
The differnece between the colloid osmotic pressure of blood and that of the tissue fluid is called
oncotic pressure
84
Movement across the capillary endothelium by the uptake and release of fluid droplets is called
transcytosis
85
All efferent fibers of the vasomotor center belong to the _______ division of the autonomic nervous system
sympathetic
86
The pressure sensors in the major arteries near the head are called
baroreceptors
87
Most of the blood supply to the brain comes from a ring of arterial anastomoes called
artrial circle
88
The major superficial veins of the arm are the ________ on the medial side, and ________ on the lateral side.
Basilic; Cephalic
89
In some circulatory pathways, blood can get from an artery to a vein without going through capillaries
TRUE
90
In some cases, a blood cell may pass through two capilary beds ina single trip from left ventricle to right atrium.
TRUE
91
The bodys longest blood vessel is the great saphenous vein.
TRUE
92
Arteries have a series of valves that ensure a one way flow of blood.
VEINS not arteries
93
If the radius of a blood vessel doubles and all other factors remain the same, blood flow through that vessel also doubles.
False
94
The femoral triangle is borded by the inguinal ligament, sartorius muslce and adductor longus muscle.
TRUE
95
The lungs recieve both pulmonary and systemic blood
TRUE
96
Blood capillaries must reabsorb all the fluid they emit or else edema will occur.
False. Capillaries reabsorb 85% of the fluid they filter, the rest is absorbed by the lymphatic system.
97
An aneurysm is a ruptured blood vessel.
False. An aneurysm is a weak, bulging vessel that MAY ruputre.
98
In the baroflex, a drop in arteral blood pressure triggers a corrective vasodialation of hte system blood vessels.
False. The response to falling BP is a corrective vasoconstriction.
