EXAM 3: SEC 1/blood Flashcards
(58 cards)
1
Q
Blood
A
- made of formed elements (cells, cell fragments, plasma)
- plasma carries blood cells, proteins, nutrients, metabolic wastes, and other molecules being transported around the body
2
Q
Cardiovascular System Overview
A
- 2 loops: systemic and pulmonary
- closed system
3
Q
Systemic Loop
A
- carries blood from heart to the rest of the body
4
Q
Pulmonary Loop
A
- carries oxygen-poor blood to lungs and back to heart
5
Q
Parasympathetic Innervation
A
- releases acetylcholine through vagus nerve into atria
6
Q
Sympathetic Innervation
A
- releases norepi & epi through thoracic spinal nerves and bloodstream into atria and ventricles
7
Q
P wave
A
- atrial depolarization
8
Q
QRS complex
A
- atrial repolarization
- ventricular depolarization
9
Q
T wave
A
ventricular repolarization
10
Q
Normal open valve heart sound
A
- quiet and laminar flow
11
Q
Stenotic valve sound
A
- turbulent flow
- murmur
12
Q
Normal closed valve sound
A
- quiet, no flow
13
Q
Insufficient valve sound
A
- leaky valve
- turbulent backflow
- murmur
14
Q
Positive chronotropic factors
A
things that increase heart rate
15
Q
Negative chronotropic factors
A
things that decrease the heart rate
16
Q
Regulation of HR
A
- HR is controlled by the input from the nervous system: SNS increases HR, PSNS decreases HR
- AP created sooner via sympathetic stimulation increases HR creating more positive mem
- AP created later via parasympathetic decreases HR creating negative mem
17
Q
Frank-Starling Mechanism
A
- increase ventricular filling/preloading = increase in stroke volume = increase in cardiac output
- decrease preload = decrease stroke volume = decrease cardiac output
- norepi from sympathetic increases intracell calcium concentration increasing contractile force, increasing contractility, faster and stronger contractions and increasing HR with greater force development
18
Q
2 ways cardiac contractile force is regulated
A
- starling’s law (the effect of preload) and contractility (the effect of external neural, hormonal stimulation)
19
Q
Vascular System
A
- pressure in system falls as passes from one end to other
- pressure in pulmonary circulation is lower than in systemic
20
Q
upstream pressure systemic
A
aorta
21
Q
downstream pressure systemic
A
right atrium
22
Q
pulmonary circulation upstream
A
pulmonary artery
23
Q
pulmonary circulation downstream
A
left atria
24
Q
lowest pressure in heart
A
right atrium
25
Arteries
- compliance = change in vol / change in pressure
- the higher the compliance, the more easily can be stretched
- arteries are often called pressure reservoirs because of the elastic recoil - not as compliant as veins
- arteries stretch during systole and relax/squeeze down on blood during diastole
26
diastole pressure
- lowest pressure
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arterial pressure changes due to
age, stiffness, systolic pressure
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Active Hypermia
```
increase metabolic activity of organ
to
decrease O2, increase metabolites in organ interstitial fluid
to
arteriolar dilation in organ
to
increase blood flow to organ
```
29
Neural controls
- vasoconstrictors: sympathetic nerves that release norepi
| - vasodilators: neurons that release nitric acid
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Hormonal controls
- vasocontrictors: epinephrine, angiotensin II, vasopressin
| - vasodilators: epinephrine atrial natriuretic peptide
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Local controls
- vasocontrictors: internal blood pressure (myogenic response) Endothelin-1
- vasodilators: decrease in O2, K+, CO2, H+, osmolarity, adenosine, eicosanoids, bradykinin, substances released during injury, nitric oxide
32
All controls go to...
go into arteriolar smooth muscle, altering the arteriolar radius
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Capillaries
- the smallest blood vessels
- where gas and nutrient exchange happens by diffusion out of the blood into the tissues (or back into the blood)
- from interstitial fluid/space into capillaries = reabsorption
- movement fluid out of capillaries into interstitial space = filtration
34
Anatomy of capillary network
- arterioles carry O2 blood into
| - capillaries = primary site for microcirculatory exchange
35
Velocity of capillary blood flow
- velocity is slowest in capillary beds because they have a greater cross-sectional area
- slow velocity flow in capillaries
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Diffusion of capillary walls
- down gradient
- rate is fastest for small molecules (Co2 and O2)
- O2 and glucose diffuse down into tissue cells
- CO2 diffuses down and out of tissues into capillary
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Net filtration pressure
- fluid pressure in capillary is greater than fluid pressure in interstitial space outside
- fluid pressure gradient promotes filtration
- increase capillary pressure = increase filtration
- decrease capillary pressure = decrease filtration
- increase concentration of solute particles = increase osmotic pressure = decrease water concentration
- decrease solute concentration = decease osmotic pressure = increase water concentration
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Blood distribution
- pulmonary circulation = 12%
- heart = 9%
- arteries = 11%
- arterioles and capillaries = 7%
- veins = 61%
39
Short term regulation of arterial pressure and volume
- involves regulation of cardiac output and peripheral resistance
40
Arterial Baroreceptors
- stretch receptors sense arterial pressure
- impulses from baroreceptors are carried into CNS
- increase in pressure, causes baroreceptors to stretch, increases afferent impulses, decreasing sympathetic outflow to heart, arterioles, and veins, and increases parasympathetic outflow to heart
41
Long-term arterial pressure
- circulatory and renal system cooperates to adjust extracellular fluid volume and blood volume to maintain arterial pressure
- increase arterial pressure, increase renal output of solute and water, decrease extracellular fluid and blood volume
- increase blood volume has same affect as above
42
Hemorrhage and other causes hypotension
- decrease stroke volume
- increase heart rate
- decrease cardiac output
- decrease mean arterial pressure
- increase total peripheral resistance
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Upright posture and pressure
- pressure due to gravity = 80 mmHg
- causes blood to somewhat pool in lower limb arteries right after stand up
- reflexes quickly sustain normal
44
Exercise
- healthy stress on body
- blood flow goes to areas needed most
- decrease flow to brain, increase flow to muscle, same flow to heart, increase flow to skin, decrease flow to kidney and organs
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O2 consumption and training
- cardiac output increases in trained vs untrained allowing for more work rate
- heart rate is lower for work rate in trained vs untrained
- stroke volume increases O2 consumption in trained vs untrained
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Hypertension treatments
- diuretics
- beta-adrenergic receptors
- CA2+ channel blockers
- ACE inhibitors
- drugs
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Diuretics
- increase urine output and decrease extracellular volume decreasing pressure
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Beta-adrenergic receptors
- decrease in heart rate and decrease CO and pressure
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CA2+ channel blockers
- decrease smooth muscle contraction and lower peripheral resistance
50
ACE Inhibitors
- decrease overall activity of angiotensin system
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drugs
- reduce sympathetic mediated stimulation
52
Heart Failure
- the greater the degree of cardiac filling, the greater the stroke volume, and cardiac output
- the greater cardiac failure, the greater the expansion of extracellular fluid volume, the greater filling pressure end diastolic volume
- heart failure = stroke volume much less at rest
53
Coronary Artery Disease and heart attacks
- adequete blood flow to heart is essential
- if flow through vessels is down, O2 needs is not met, and may create heart attack
- atherosclerosis (plaque build up) largest risk factor
- treated via drugs, dilate arteries and veins, drugs that reduce sympathetic NS, drugs that decrease clotting, drugs that control cholesterol
- stents also used to treat if necessary
54
Eurythrocyte
- red blood cell
- bi-concave disk
- excess surface area
- allows for flexibility and traveling
- 100-120 lifespan days
55
RBC production
- iron absorbed via GI tract and enters plasma
- transfaren distributes iron around body and to bone marrow
- when blood cells leave, iron stays in spleen
- lack of iron = decrease RBC production = anemia
- circulates = 3 months
- regulation of eurythiopoetin = negative feedback
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Hemostasis
- preserve integrity of cardiovascular system and prevent blood loss
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Role of liver
- synthesizes bile salts, absorbs vit K, synthesizes clotting factors, allows clotting factors to enter blood
58
Anticlotting systems
- endothelial cells (thrombin and protein C) and plasminogen activators (plasmin and fibrin)
