Blood Flow & Blood Pressure (Ch. 26)-- Definition First Flashcards
Exam 2
- Asymptomatic
- Swelling and/or pain in affected extremity
- ⇡ WBCs
-
⇡ Erythrocyte sedimentation rate (ESR)
- Inflammation indicator
Diagnosis– Ultrasound, CT, D-dimer (⇡ Blood clot fragments → Hypercoagulation)
Treatment– Prevention (SCDs, Ambulation, Anticoagulants)
Deep Vein Thrombosis Clinical Manifestations
-
PANS
- Vagus nerve → Impulses to heart
- ⇣ HR
- Vagus nerve → Impulses to heart
-
SANS
- Spinal cord & peripheral nerves → impulses to heart & blood vessels
- ⇡ HR & Contractility → ⇡ CO, SV, & BP
- Vasoconstriction (small arteries) → ⇡ PVR
Acute BP Regulation– Neural Mechanism
True Aneurysm
- Small
- Spherical
- Located @ bifurcation
- Circle of Willis (brain)
Berry Aneurysm
Amount of blood the heart pumps through circulatory system in one minute
~4-6 L
CO = SV x HR
Cardiac Output (CO)
- ⇣ Vascular volume
- Diuretics
- ⇣ SANS
-
Beta-blockers
- ⇣ HR & CO
- Block renin (juxtaglomerular cells of kidneys)
- ⇣ Vasoconstriction
-
Beta-blockers
- RAAS System
-
ACE (Angiotensin Converting Enzyme) Inhibitors
- ⇣ Angiotensin II → ⇣ Vasoconstriction & ⇣ Aldosterone
- AEs: Chronic cough, Angioedema
- ⇣ Angiotensin II → ⇣ Vasoconstriction & ⇣ Aldosterone
-
ARBs (Angiotensin II Receptor Blockers)
- ⇣ Binding of Angiotensin II → ⇣ Vasoconstriction & ⇣ Aldosterone
- Less AEs than ACE-Is
- ⇣ Binding of Angiotensin II → ⇣ Vasoconstriction & ⇣ Aldosterone
-
ACE (Angiotensin Converting Enzyme) Inhibitors
- Vasodilation
-
Calcium Channel Blockers
- ⇣ Ca2+ into SMCs → Smooth muscle stays relaxed
-
Hydralazine
- Interferes w/ Ca2+ movement
-
Calcium Channel Blockers
Hypertension Pharmacologic Treatment
Long-Term effects of HTN on organs
- CKD → Renal Failure
- PVD → Endothelial cell damage → Atherosclerosis
- Retinopathy
- CVD → TIA/Stroke
- Cardiac
- ⇡ Afterload → LV Hypertrophy → HF
- MI
- Sexual Dysfunction
- ED
Target-Organ Damage
⇣ LDL receptors → Dyslipidemia
Hypothyroidism
Sustained elevation of BP w/i arterial circuit
Primary risk factor for CVD
Leading cause of death worldwide
-
Primary
- HTN w/o evidence of cause
-
Secondary
- HTN d/t presence of another disease/condition
- ex: Renal Failure
- HTN d/t presence of another disease/condition
Hypertension (HTN)
Hardening of the arteries due to fibrofatty lesions in the tunica intima of large and medium-sized arteries
Atherosclerosis
- Visual assessment
- Lower extremity pain & edema
-
Stasis dermatitis
- CO2-rich blood sits in dependent areas
- Acidic gas damages tissue
- CO2-rich blood sits in dependent areas
-
Venous ulcers
- Skin easily injured
Treatment– Sclerotherapy, Prevention (Compression stockings, Avoid standing for extended periods, Weight loss)
Varicose Veins Clinical Manifestations
- Two major determinants
-
CO
- Adjustments accommodate changes in PVR
-
⇡ CO = ⇡ BP
- ⇡ Blood volume → ⇡ Pressure on arterial walls
- & vice versa
- ⇡ Blood volume → ⇡ Pressure on arterial walls
-
CO
-
PVR
- Adjustments accommodate changes in CO
-
⇡ PVR = ⇡ BP
- ⇡ Vasoconstriction + ⇡ Blood viscosity → ⇡ Pressure on arterial walls
- & vice versa
- ⇡ Vasoconstriction + ⇡ Blood viscosity → ⇡ Pressure on arterial walls
Blood Pressure (BP) Maintenance
Migration of Inflammatory Cells
Leukocytes migrate & adhere to endothelial wall → Macrophages enter tunica media & endocytose LDL
Second Step of Atherosclerosis Development
Three factors that promote venous thrombosis
-
Venous stasis
- Prolonged immobility
- Leg dependency
-
Venous endothelial damage
- Trauma
- Medications
- Surgery
- Fractures
-
Hypercoagulable states
- Genetic disorders
- Malignancies
- Pregnancy
- Oral contraceptives
- HRT
- Antiphospholipid syndrome
Triad of Virchow
Independent of other health problems
- Genetic (autosomal dominant)
-
Heterozygous
- LDL= 350 mg/dL
- S/S in adulthood
- Xanthomas
-
Homozygous
- LDL= 1000 mg/dL
- S/S in childhood
- ⇡ Risk of death d/t MI in young adulthood
-
Heterozygous
Primary Dyslipidemia
Endothelial Cell Injury
d/t– smoking, ⇡ LDL, HTN, inflammatory mediators
Hemodynamics (mechanical stress)
First Step of Atherosclerosis Development
Structure–
- Thinner layers
- Smaller lumen
Function–
- Transport blood away from heart
- To capillary beds
- Vasoconstriction/Vasodilation
Arteriole Structure & Function
- 3rd largest lipoprotein
- “bad” cholesterol when high levels in blood
- Much denser
- TGs (10%)
- Protein (25%)
- Cholesterol (50%)
- Endogenous
- Synthesized in liver
LDL
True Aneurysm
-
Entire circumference of vessel
- Gradual & progressive vessel dilation
Fusiform Aneurysm
Structure–
- Thick tunica media
- Contractile & elastic
Function–
- Transport blood away from heart
- Toward capillary beds
- BP maintenance
Artery Structure & Function
-
Fatty streaks
- Thin, flat, yellow discolorations of the tunica intima
- Macrophages
- Foam cells
- Form in childhood for everyone
- Stop or regress @ age 20
- Thin, flat, yellow discolorations of the tunica intima
-
Fibrous atheromatous plaque
-
Necrotic core
- Foam cells
- Necrotic SMC
-
Fibrous cap
- SMC→ ECM
-
Necrotic core
-
Complicated lesion
- Deposits from:
- Hemorrhage
- Ulceration
- Scar tissue
- Thrombosis
- Deposits from:
Types of Atherosclerotic Legions
Atherosclerotic Disorder
-
Occlusive disease
- Lower extremities
d/t– Hypercholesterolemia, ⇡ Blood LDL levels, Smoking, DM, other atherosclerosis risk factors…
Peripheral Artery Disease (PAD)
- Largest lipoprotein
- Least dense
- TGs (80-90%)
- Protein (2%)
- Dietary
- Absorbed in SI
Chylomicrons
- Reduce risk
- Evaluate for coronary or cerebrovascular atherosclerosis
- Smoking
- HTN
- Dyslipidemia
- DM
- Reduce symptoms
- D.A.S.H. or Mediterranean diet
- Anti-platelet medication
- Statins
- Move until point of claudication
- Walk until it hurts
- Surgery
- Disabling claudication
- Limb-threatening ischemia
Peripheral Artery Disease Treatment
- Skin color change
- Palor → cyanosis
- Cold sensation
- Parasthesia
- Numbness/tingling
- Ischemic episode
- Pale → blue → redness, throbbing, parasethesia → normal color
Severe–
- Brittle nails
- Skin on tips of fingers thickens
- Arthritis
- Ulceration
-
Superficial gangrene
- Fingers
Raynaud Disease/Phenomenon Clinical Manifestations
- Energy storage
- Protection
- Insulation
- Cellular communication
- Phospholipid membrane
- Lipoproteins
Lipid Function
d/t– HTN, Degeneration of tunica media, Connective tissue disease (Marfan syndrome), Pregnancy, Congenital aortic defect, Cardiac surgery complication
Classifications–
-
Type A
- Proximal legions
- Ascending aorta
- Ascending AND Descending aorta
- Proximal legions
-
Type B
- Distal to subclavian artery
-
Acute
- w/i 14 days of S/S onset
-
Chronic
- longer than 14 days of S/S onset
Aortic Dissection
- Tunica Externa
- Outermost
- Collagen & elastin fibers
- Tunica Media
- Middle
- Smooth muscle cells (SMCs)
- Vasoconstriction/Vasodilation
- Synthesis of biomolecules (elastin, collagen…)
- Vascular repair
- Tunica intima
- Innermost
- Endothelial cells
3 Layers of Blood Vessels
Lipid Accumulation and SMC Proliferation
-
Foam cell formation
- Lipid-filled macrophages
- Release growth factors
- Lipid-filled macrophages
-
SMCs secrete ECM
- Stimulated by growth factors
- Release collagen & elastin
- Stimulated by growth factors
-
Reactive oxygen species
- Toxic ROS cause damage
Third Step of Atherosclerosis Development
Fibrous Atheromatous Plaque Structure
- Foam cells
- Lymphocytes
-
Necrotic core
- Necrotic SMCs
- Foam cells
-
Fibrous cap
- SMCs
- ECM (elastin & collagen)
- Endothelial layer
- SMCs
Plaque Rupture → Hemorrhage or Thrombosis (Clot formation) → Lumen blocked (Occlusion)
Fourth Step of Atherosclerosis Development
⇡ Venous Hypertension (⇡ Hydrostatic Pressure) → Reflux through incompetent veins → Pooling of blood in lower extremities → Dilation & stretching of vessel walls
d/t– Prolonged standing, Incompetent valves, DVTs, Inflammation, Endothelial dysfunction (atherosclerosis), ⇣ Skeletal muscle pump function
Venous Insufficiency
- Elimination of tobacco/nicotine
- Vasodilation
-
Injury prevention
- Difficult for injuries to heal w/ reduced blood flow to extremities
Buerger Disease (Thromboangiitis Obliterans) Treatment
- Secrete cytokines & enzymes
- ⇣ Platelet aggregation
- ⇡ Vasodilation
Endothelium Function
Difference between systolic and diastolic BP
- Affected by
- SV
- Arterial distensibility (elasticity)
- ⇣ Distensibility → ⇡ BP
Pulse Pressure
Inflammatory Disorder
Segmental, thrombosing, acute & chronic inflammation
-
Thrombus formation
- Medium-sized arteries
- Lower extremities
- Plantar
- Digital
- Upper extremities
- Arms
- Hands
- Lower extremities
- Medium-sized arteries
d/t– Smoking/Vaping (seen in < 35 y.o), Genetics
Buerger Disease (Thromboangiitis Obliterans)