Module 7 Circulation Flashcards
1
Q
Body Water Distribution
A
- 40% intracellular
- 15% interstitial
- 5% plasma
2
Q
Lymphatic System
A
- Passive drainage
- Returning excess extravascular fluid to vascular system
3
Q
Hemostasis
A
- Blood clotting
- Prevent excessive bleeding
- After blood vessel damage
3
Q
Disrupted Fluid Balance
A
- Pathological conditions that alter endothelial function
- Increase vascular hydrostatic pressure
- Decrease plasma protein content
3
Q
Inadequate Hemostasis
A
- Hemorrhage
- Compromise regional tissue perfusion
- Hypotension, shock, death
4
Q
Derangements in Blood Supply/Fluid Balance
A
- Edema
- Thrombosis
- Embolism
- Ischemia & infraction
- Altered perfusion (hemorrhage/shock)
5
Q
Edema
A
- Accumulation of fluid
- Interstitial/intercellular tissue
- Leads to swelling of subcutaneous tissues
6
Q
Local Edema Factors
A
- Lymphatic obstruction
- Vascular permeability
7
Q
Systemic Edema Factors
A
- Cardiovascular function
- Overall fluid balance
- Salt retention
8
Q
Sterling Forces (Move Fluid Out)
A
- Hydrostatic pressure
- Interstitial fluid osmotic pressure
9
Q
Sterling Forces (Draw Fluid In)
A
- Plasma osmotic pressure (colloid)
- Tissue (interstitial) fluid pressure
10
Q
Edema Occurrence Conditions
A
- Increase in intravascular hydrostatic pressure
- Fall in colloid osmotic pressure/oncotic pressure of plasma
- Lymphatic obstruction
- Sodium retention
11
Q
Localized Edema
A
- Increased hydrostatic pressure due to local vascular obstruction
- Lymphatic obstruction compression by tumour/inflammation
12
Q
Generalized Edema
A
- Reflects a global disorder of fluid/electrolyte metabolism
- Increased hydrostatic pressure
- Decreased colloid osmotic pressure
- Sodium retention
13
Q
Decreased Colloid Osmotic Pressure
A
- Loss of serum albumin proteins in renal failure
- Decreased synthesis of albumin
- Loss of serum proteins (malnutrition)
14
Q
Hydrostatic Edema
A
- Hydrostatic pressure at venous end elevated
- Decreases reabsorption
- If lymphatic capacity exceed edema fluid accumulates
15
Q
Oncotic Edema
A
- Decrease in osmotic pressure
- Loss of albumin
- Decreases reabsorption
- Edematous fluid accumulates
16
Q
Inflammatory/Traumatic Edema
A
- Vascular bed ‘leaky’ following injury to endothelium
- Local or systemic
17
Q
Lymphedema
A
- Lymphatic obstruction
- Accumulation of interstitial fluid
- Insufficient reabsorption
- Deficient removal of proteins
- Increasing osmotic pressure in interstitial space
18
Q
Thrombosis
A
- Formation of a mass (clotted blood)
- Within heart or blood vessels
19
Q
Thrombus Components
A
- Platelets
- Fibrin
- Red & white blood cells
20
Q
Thrombosis Causes
A
- Endothelial injury
- Stasis/turbulent blood flow
- Hypercoagulability of blood
21
Q
Endothelial Injury Causes
A
- Physical injury
- Inflammation
- Infectious agents
- Abnormal blood flow
- Metabolic abnormalities
22
Q
Blood Flow Change Causes
A
- Turbulence
- Stasis (slow circulation)
- Decreased cardiac output
- Increased blood viscosity
23
Blood Composition Change Causes
- Increase in platelets
23
Hypercoagulability
- High blood clotting tendency
- Alterations in coagulation factors
- Genetic/acquired
24
Thrombus Prognosis
- Dissolve/lyzed by fibrinolytic activity
- Increase in size & obstruct vessels
- Breakdown & form emboli
- Organized & may recanalize
25
Commonly Affected Vessels
- Coronary artery (heart attack)
- Cerebral artery (stroke)
- Mesenteric arteries (intestinal infarction)
- Renal arteries (kidney infarct)
- Arteries of the leg (gangrene)
26
Embolism
- Occlusion of blood vessel by mass (embolus)
- Travels through circulation
- Becomes lodged in blood stream
27
Thromboembolus
- Most common type of emboli
- Formed from a thrombus
- Thromboemboli arise from thrombi
- Size range
- Occur in arteries or veins
28
Pulmonary Emboli
- Arise from deep veins of the legs
- Small
- Clinically silent
- Undergo organization over time
- Incorporated into the vascular wall
29
Arterial Emboli
- Heart
- Thrombi on heart walls/diseased valves
- May lodge in brain (stroke/infraction)
30
Cause of Ischemia
- Due to inadequate blood supply to an area to tissue
31
Causes of Blood Vessel Obstruction
- Thrombus
- Embolus
- Pressure
- Damage (vessel wall inflammation)
32
Ischemia Effects
- Infarction (severe & complete)
- No effects (collateral blood supply)
33
Infarction
- Tissue death
- Results in necrosis
- After occlusion of an end artery
33
Infarcts
- Coagulative necrosis
- Inflammatory response develops along margins
- Well defined in 1-2 days
- Majority replaced by scar in repair phase
34
White (Pale) Infarct
- Organs with single blood supply (heart, kidney, spleen)
- Arterial occlusion/insufficiency
35
Red (Hemorrhagic) Infract
- Organs with dual blood supply (liver, lung, intestine)
- Venous occlusion/insufficiency
35
Hemorrhage
- Escape of blood from vessels
- Into surrounding tissue/exterior of body/body cavity
35
Hematoma
- Accumulation of blood in soft tissues
35
Hemorrhage Causes
- Trauma to large blood vessels (surgical/fracture)
- Weakened artery
- Infections
- Invasive tumours
- Hypertension
- Hemorrhagic diatheses
36
Petechia
- Pinpoint hemorrhage (1-2mm)
- In the skin
- Rupture of capillaries/arterioles
- Involves mucous membranes & serosal surfaces
36
Purpura
- Superficial hemorrhages in skin (3-5mm)
37
Ecchymosis
- Large superficial hemorrhage
- Bruise/skin discoloration
- Heme degradation from hemoglobin in RBCs
37
Hemothorax
- Collection of blood in pleural cavities
- Trauma/rupture of aorta
37
Hemarthrosis
- Collection of blood in joint
38
Shock
- Diminished cardiac output/reduced circulating blood volume
- Impairs tissue perfusion
- Cellular hypoxia
- Failure of circulatory system to supply blood
39
Shock Causes
- Decreased blood volume
- Decreased cardiac output
- Redistribution of blood
39
Hypovolemic Shock
- Hemorrhage
- Fluid loss
- Inadequate blood/plasma volume
40
Cardiogenic Shock
- Failure of myocardial pump
- Intrinsic myocardial damage
- Extrinsic pressure
- Obstruction of outflow
41
Neurogenic Shock
- Injury of spinal cord
- Loss of function of sympathetic NS
41
Consequences of Shock
- Decreased tissue perfusion
- Hypoxia/anoxic cell injury
- Decline in cardiac output
41
Septic Shock
- Overwhelming microbial infections
- Outpouring of inflammatory mediators
- Innate & adaptive immune cells
- Arterial vasodilation
- Vascular leakage
- Venous blood pooling
42
Anaphylactic Shock
- Allergy condition
- Systemic vasodilation & increased permeability
- Triggered by IgE hypersensitivity (type 1)
43
Atria
- Collect blood returned from body/lung
- Prep ventricles
44
Coronary Arteries
- 2 connect to aorta
- Supply heart with nutrients & blood
45
Pump Function
- Motor (muscle)
- Fuel supply from coronary arteries (blood/oxygen)
- Valves
- Wiring/control (cardiac conduction)
46
Pulmonary Circulation
- Right ventricle pumps venous blood
- To lungs for oxygenation
- Low pressure
47
Systemic Circulation
- Left ventricle pumps oxygenated blood
- Out to organs
- High pressure
47
Left Ventricle Wall
- Thicker than right wall
- Pump blood to body
- Under high pressure
- More pathology occurs
48
Atherosclerosis
- Chronic disease
- Medium & large arteries
- Initiated on endothelial lining surface
- Illness results in damage of organ systems
49
Atherosclerosis Pathogenesis
1. Chronic endothelial injury
2. Endothelial dysfunction
3. Smooth muscle emigration (macrophage activation)
4. Macrophages & smooth muscle cells engulf lipids
5. Smooth muscle proliferation, collagen & ECM deposition
6. Fatty plaque develops over years
50
Chronic Endothelial Injury Examples
- Hypertension
- Smoking
- Toxins
- Virus
- Immune reactions
- Homocysteine
- Hyperlipidemia
51
Endothelial Dysfunction
- Increased permeability
- Leukocyte adhesion
- Monocyte adhesion
- Emigration
51
Atherosclerosis Non-Modifable Risk Factors
- Old age
- Family history (early onset heart disease)
52
Atherosclerosis Modifiable Risk Factors
- Smoking
- Hypercholesterolemia
- Diabetes mellitus
- Chronic hypertension
53
Coronary Artery Plaques
- Causes stenosis (narrowing)
- Results in ischemia of supplied organ
54
Ischemic Necrosis
- Severe plaque
- Tissue death of organ
- Insufficient blood supply
- Causes an infarct (dead tissue)
- Infarction process initiated
55
Endothelial Dysfunction Steps
1. Foam cells
2. Fatty streak
3. Intermediate lesion
4. Fibrous plaque
5. Complicated lesion/rupture
56
Endothelial Dysfunction Characteristics
- Slow progression
- Long silent phase
- Prevention is key
57
Heart Complications of Endothelial Dysfunction
- Angina pectoris
- Myocardial infarction (dead tissue)
58
Brain Complications of Endothelial Dysfunction
- Transient ischemic attack
- Stroke
58
Leg Complications of Endothelial Dysfunction
- Intermittent claudication
- Gangrene
58
Plaque Treatment
- Medications (pain relief)
- Coronary angioplasty & stent
- Bypass surgery
59
Acute Coronary Thrombosis
- Blood clot occurs within hours to minutes
- Emergency (short time period)
- Tissue damage/death without immediate treatment
59
Thrombolytics
- Medication
- Dissolve clots (thrombus) in vessel walls
- Restore blood flow
- Prevent/limit infarction
- Does not remove plaques
60
Percutaneous Coronary Intervention (PCI)
- Restore blood flow
- Expands chronic plaque stenosis
61
Precipitates Acute Myocardial Infarction
- Chronically narrowed coronary artery
- Occluded by thrombus in lumen
- Overlying chronic plaque
62
Primary Hypertension
- Vast majority of cases
- Multifactorial etiology (genetic, lifestyle)
- Treatable not curable
62
Old/Healed Myocardial Infarct
- Leads to chronic congestive heart failure
- Scar tissue build up on vessels
62
Secondary Hypertension
- Uncommon
- Endocrine
- Drugs/medications
- Kidney disease
- Tumours
- May be curable if cause eliminated
62
Arterial Hypertension Complications
- Risk factor for atherosclerosis
- Contributes to related diseases
63
Arteriolar Hypertension Complications
- Hyaline arteriolosclerosis in kidney
- Intraparenchymal brain hemorrhage
- Chronic renal failure
64
Left Ventricular Hypertrophy
- Increases load due to hypertension
- Wall thickness increases
- Heart mass increases
- Increased demand on coronary blood flow
- Heart failure/ischemic/arrhythmias