Unit 2 - Chapter 15 - Circulation of Blood Flashcards
1
Q
oxygen rich blood is pumped through a series of what
A
arteries
2
Q
what is the largest artery in the body
A
aorta
3
Q
what do arteries subdivide into
A
arterioles
4
Q
what do arterioles do
A
control the flow into microscopic exchange vessels called capillaries
5
Q
capillaries are grouped together in something called…..
A
capillary beds
6
Q
what do capillary beds do
A
- supply most of the tissues in the body
- permit the exchange of nutrients and gases between the blood and tissue fluid around the cells
7
Q
what happens with blood as it exits the capillary beds
A
it moves into small venules which merge with other venules to form the larger veins
8
Q
what is the largest vein in the body
A
superior vena cava and inferior vena cava
9
Q
give a brief synopsis of the blood vessels and the movement of blood
A
- arteries carry blood away from the heart and toward capillaries
- veins carry blood toward the heart and away from capillaries
- capillaries carry blood from the tiny arterioles into tiny venules
- aorta carries blood out of the left ventricle of the heart
- vena cavae returns blood to the right atrium after the blood has circulated the body
10
Q
all vessels are made up of a vessel wall that surrounds a space called a…..
A
lumen
11
Q
what are the 3 layers that make up the walls of arteries and veins
A
- tunica externa (outer layer)
- tunica media (middle layer)
- tunica intima (inner layer)
12
Q
what is the outer later “tunica externa” composed of
A
- made of connective tissue fibers
13
Q
what do the connective tissue fibers of the tunica externa do
A
- help resist stretching and to prevent it from bursting under pressure
- connect to the extracellular matrix to support the vessel and hold it in place
14
Q
what is the middle later “tunica media” composed of
A
- a layer of smooth muscle and a layer of elastic connective tissue
15
Q
what does the smooth muscle is the tunica media do
A
- permits changes in blood vessel diameter
- contract or relax to regulate how much blood will flow into a nearby capillary bed
16
Q
what does the inner layer “tunica intima” consist of
A
epithelial cells
17
Q
what is so special about the epithelial cell layer in the tunica intima
A
it is the only layer
- it’s a single layer of squamous epithelial cells called endothelium
18
Q
what does the epithelial cell layer in the tunica intima do
A
- minimizes the accidental formation of blood clots
19
Q
explain the skeletal muscle pump
A
- when skeletal muscles surrounding veins contract, the contraction squeezes the walls of the veins which then pushes blood through the venous valves and towards the heart
20
Q
explain the respiratory pump
A
- involved pressure changes in the thoracic and abdominal cavities during breathing
21
Q
when a surgeon cuts into a body, what can they see and what can’t they see
A
- can see arteries, arterioles, veins, venules
- can’t see capillaries
22
Q
what are capillaries known as and why
A
- known as exchange vessels
- because substances such as glucose, oxygen, carbon dioxide, hormones and wastes can quickly pass through the thin endothelial lining
23
Q
what is the function of arteries and arterioles
A
- distribute blood from the heart to capillaries
- constricting/dilating
- help maintain adequate arterial blood pressure
24
Q
what is osmosis
A
the passive movement of water molecules from an area of lower solute concentration to an area of higher solute concentration throught a membrance that is permeable to water but not to solute
25
what is filtration
the passive movement of fluid and its dissolved solutes resulting from a hydrostatic pressure gradient where the pressure on one side of the membrane is greater than the pressure on the other side
26
what is the function of veins and venules
- collect blood from capillaries and return it to the heart
- venules collect blood from the capillaries and then merge with one another to form the veins
- the larger veins serve as blood resevoirs
27
what is arteriosclerosis (hardening of the arteries)
a common type of vascular disease that blocks arteries and weakens arterial walls
28
what is arteriosclerosis characterized by
- initial thickening of arterial walls that progresses to hardening as calcium deposits form; this reduces blood flow
- this reduced blood flow leads to ischemia (decreased blood supply to a tissue)
- this eventually leads to necrosis (cell and tissue death)
- necrosis that progresses to decay is called gangerene
29
what does ischemia mean
decreased blood supply to a tissue
30
what is necrosis
cell and tissue death
31
what is gangerene
necrosis that has escalated to cell/tissue decay
32
what is arteriosclerosis associated with
high blood levels of triglycerides and cholesterol
33
how can arteriosclerosis be managed
- vasodilators
- angioplasty
34
what does a vasodilator do
triggers the relaxation of the smooth muscles of the arterial walls, causing the arteris to widen/dilate
35
what occurs in an angioplasty
- defalted balloon attached to a long tube called a catheter is inserted into a partially blocked artery and then inflated
- as the balloon inflates, the plaque is pushed outward along with the arterial wall; widening the artery to improve blood flow
36
what can cause an aneursym
- damage to arterial walls caused by arteriosclerosis
37
what is an aneursym
- a section of an artery that has become unusally widened because of weaking of the arterial wall
38
why are aneursym's dangerous
they promote the formation of thrombi (atypical clots)
- if a thrombus breaks off forming an embolus that can travel and become lodges in the small blood vessels supplying the heart, brain or some other organ
39
what can a ruputures brain aneurysm or an embolus lead to
cva
- cerebrovascular accident
40
what are varicose veins
dilated, swollen, buldging veins in which blood tends to pool rather than continue on toward the heart
41
where do varicosities/varices usually occur
in superficial veins near the surface of the body
42
what are hemorrhoids
varicose veins in the rectum/anus
43
what can cause hemorrhoids
excessive straining during defecation which creates pressure
- or preganancy
44
how are varicose veins be treated
- support stocking/socks
- surgical removal
-
45
how can hemorrhoids be treated
- rubber band ligation where an elastic band is places aroudn the base of the hemorrhoid until the tissue dies
- laser, infrared, surgical remover, cyrotherapy are also used
- for milder cases, consuming more dietary fiber
46
what is phlebitis and what is a common cause
vein inflammation
- irritation from an iv catheter is a common cause
47
what is thrombophlebitis
- acute phlebitis caused by clot formation - if this clot gets free and then lodged in another vessel a pulmonary embolism occurs
- more common in veins than arteries
- characterized by pain and discoloration of tissue
48
what is a pulmonary embolism
when an embolusm lodges in the circulation of the lung
49
what does hepatic portal circulation refer to
the route of blood flow from digestive organs to theliver
50
what happens with the veins from the spleen, stomach, pancreas, gallbladder and intestines
they don't empty into the inferior vena cava , instead they merge to form the hepatic portal vein
51
what is the basic flow of blood
arteries to arterioles to capillaries to venules to veins and back to the heart
52
how does blood flow in the hepatic portal circulation
from the capillary beds in the digestive organs to capillary beds in the liver where the liver processes that blood before it returns blood to the usual pathway
53
expand on the blood glucose level of blood entering and leavingf the hepatic portal vein
the blood leaving has a lower blood glucose level than the blood entering
54
how is circulation in the body before birth different from circulation after birth
because the fetus obtains nutrients and oxygen from uterine blood rather than from it's own lungs and digestive organs
55
give a brief synopsis of how nutrients and oxygen from from mom to baby in utero
- blood vessels carry fetal blood to the placenta where the exchange occurs and then return it to the fetus
- 3 vessels accomplish this (2 small umbilical arteries and 2 larger umbilical vein)
56
what type of blood do the umbilical arteries and the umbilical vein carry
- umbilical arteries carry oxyen-poor blood
- umbilical vein carries oxygen-rich blood
57
what is the ductus venosus
its a continuation of the umbilical vein
- it serves as a shunt that allows most of the blood returning from the placenta to bypass the immature fetal liver and empty directly into the inferior vena cava
58
what does the foramen ovale do
shunts blood from the right atrium directly into the left atrium
59
what does the ductus arteriosus do
connects the pulmonary artery to the aorta
60
what does hemodynamics refer to
the set of processes that influence the flow of blood
61
what does blood pressure mean
its simply the pressure or push of blood as it flows through the cardiovascular system
62
expand on blood pressure in the arteries and veins
- its highest in the arteries and lowest in the veins
63
what is the blood pressure gradient all about
- the one for the entire systemic circulation is the difference between the average or mean blood pressure in the aorta and the blood pressure at the termination of the venae cava where the join at the right atrium of the heart
64
what happens when you have low blood pressure
blood will not perfuse/flow to the organs of the body
65
what are some factors that influence blood pressure
- blood volume
- the strength of heart contraction
- heart rate
- blood thickness
- resistance to blood flow
66
what is the direct cause of blood pressure
the volume of blood in the vessels and the strength of the heartbeat
67
explain the coorelation with heart rate and blood pressure
- increased heart rate increased blood pressure
- decreased heart rate decreased blood pressure
68
how does blood viscosity affect blood pressure
the thicker the blood, the more resistance to flow-and the higher the blood pressure will rise
- the less viscous the blood the lower the blood pressure
69
what happens to the blood viscosity in the condition polycythemia
the number of ref blood cells increase beyond typical numbers and thus increases blood viscosity and thus increased blood pressure
70
what is peropheral resistance
a force that resists the flow of blood in a blood vessel
71
does blood presure fluctuate in a healthy person
yes
72
what are the 5 mechanisms thar promote the movement of venous blood through the cardiovascular system and back to the right atrium
1) continues beating of the heart, which pumps blood through the entire cardiovascular system
2) adewuate blood pressure in the arteries, to push blood to and through the veins
3) properly functioning venous valves that ensure continued blood flow in one direction - toward the heart
4) contraction and relaxation of skeletal muscles, which squeezes blood through segments of veins
5) changing pressures in the chest cavity during breathing that produce a kind of pumping action in the veins in the thorax
73
what actually occurs when you have a pulse
- its an artery alternately expanding and then recoiling
- the recoil occurs from the changing arterial blood pressure that occur during the cardiac cycle
74
what does a pulse tell you
- info about the rate, strength, and rhythmicity of the heartbeat
- and about blood pressure
75
what are the 3 places you can feel a pulse on the side of your head/neck
- superficial temporal artery in front of the ear
- common carotid artery in the neck along the front edge of the sternocleidomastoid muscle
- facial artery at the lower margin of the mandible at a point below the corner of the mouth
76
what are the 3 points you can detect your pulse in the upper limb
- axillary artery in the armpit
- brachial artery at the bend of the elbow along the inner or medial margin of the biceps / brachii muscle
- radial artery at the wrist
77
what is a radial pulse
the most frequently monitores and easily accessible pulse to find in the body
78
what are the 4 points that you can detect your pulse in the lower extremitys
- femoral artery
- popliteal artery behind and just proximal to the knee
- posterier tibial artery just behind the medial malleolus (inner bump of the ankle)
- dorsalis pedis artery on the front surface of the foot, just below the bend of the ankle joint
79
what does primary, essential or idiopathic mean in relation to hypertension (high blood pressure)
- means they have no known cause
80
what does secoundary hypertension mean
means it has an identifiable cause
81
what are the risk factors to developing hypertension
- family history of hypertension
- males are more susceptible
- age
- high stress levels
- obesity
- calcium deficiences
- high intakes of alcohol/caffeine
- smoking
- lack of exercise
82
what are symptoms of hypertension
headaches
dizziness
fainting
83
what does circulatory shock mean
failure of the circulatory system to adeequately deliver oxygen to the tissues, resulting in imapirment of cell function throught the body
84
what is cardiogenic shock
circulatory shock that results from any type of heart failure including severe myocardial infraction, heart infections, etc.
85
what is hypovolemic shock
circulatory shock that results from a decrease in blood volume in the blood vessels
- causes low blood pressure and reduces blood flow to the tissues
- caused by loss of interstitial fluids
86
what is neurogenic shock
circulatory shock that results from widespreas dilation of blood vessels caused by an imbalance in autonomic stimulation of smooth muscles in vessel walls
87
what is anaphylactic shock
circulatory shock that results from an acute allergic reaction called anaphylaxis
- causes systemic blood vessel dilation which leads to a rapid drop in blood pressure
88
what is septic shock
circulatory shock tgat results from complications of septicemia, which is a condition in which infectious agents release toxins into the blood which dilate the blood vessels causing shock
