Trigger 7 - Hypertension and Dementia Flashcards
Define: Homeostasis
Homeostasis is defined as the condition of constancy of the “internal environment” in terms of its cells, tissues, and organs.
Describe: Circulatory System
The circulatory system is a closed-loop system in which cardiac output is dependent upon adequate venous return.
Blood pressure is a function of: Cardiac output (CO) = __________ * __________.
Heart rate (70bpm) * Stroke volume (70ml)
Blood pressure is determined by which of the following factors?
A) Heart rate and stroke volume
B) Cardiac output and systemic vascular resistance
C) Sympathetic stimulation and parasympathetic stimulation
D) Renin and aldosterone levels
B) Cardiac output and systemic vascular resistance
True or False: Blood pressure homeostasis relies solely on positive feedback loops.
False
Describe: Neurohumoral Control of Blood Pressure
The neurohumoral control of blood pressure involves various systems such as autonomic baroreflex, renin-angiotensin-aldosterone system, and anti-diuretic hormone (ADH) or vasopressin. These systems detect changes in pressure, leading to responses such as increased sympathetic stimulation, vasoconstriction, and sodium and water absorption in the kidneys. All these systems operate through negative feedback loops, with no specific set point for triggering the loop.
Define: Baroreceptor Reflex
The baroreceptor reflex is a physiological mechanism that regulates blood pressure by sensing changes in arterial pressure and initiating appropriate responses to maintain homeostasis.
Baroreceptor reflex reacts to the tension of the __________.
Arteries
When the baroreceptor reflex is activated, which of the following occurs?
A) Decreased arteriolar tone
B) Reduced sympathetic nervous system activity
C) Increased parasympathetic activity
D) Decreased cardiac contractility
C) Increased parasympathetic activity
True or False: High blood pressure leads to increased sympathetic activity and decreased parasympathetic activity, resulting in decreased cardiac output and vasodilation.
True
Describe: Effect of High Blood Pressure on Baroreceptor Reflex
High blood pressure triggers a response opposite to the normal baroreceptor reflex. It leads to a depression of sympathetic activity and stimulation of parasympathetic activity, causing a decrease in cardiac output and vasodilation, ultimately reducing blood pressure.
Define: Renin-Angiotensin-Aldosterone System (RAAS)
The Renin-Angiotensin-Aldosterone System (RAAS) is a hormonal system that regulates blood pressure and fluid balance in the body by controlling the volume of fluids and electrolytes in the blood.
Renin is released in response to sympathetic nerve stimulation in JG cells, reduced NaCl concentration in the distal tubule, and reduced ___________.
Afferent arteriole pressure
Which of the following are functions of angiotensin II mediated by specific angiotensin II receptors (AT1)?
A) Decreasing systemic vascular resistance
B) Inhibiting sympathetic adrenergic activity
C) Decreasing aldosterone release
D) Stimulating thirst centers
D) Stimulating thirst centers
True or False: Angiotensin II stimulates sodium reabsorption by acting directly on renal tubules.
True
Describe: Action of Vasopressin (ADH)
Vasopressin, also known as Antidiuretic Hormone (ADH), stimulates water reabsorption by the kidneys by increasing water permeability in the collecting duct, thereby permitting the formation of concentrated urine. Additionally, it constricts arterial blood vessels, which helps to increase blood pressure.
Define: Renin
Renin is an enzyme produced by the kidneys that acts upon angiotensinogen to initiate the Renin-Angiotensin-Aldosterone System (RAAS).
Angiotensin-converting enzyme (ACE) cleaves off two amino acids from angiotensin I to form the octapeptide ___________.
Angiotensin II
What is the effect of angiotensin II on the adrenal cortex?
A) Decreases aldosterone release
B) Stimulates cortisol production
C) Inhibits renin secretion
D) Signals kidneys to increase sodium and fluid retention
D) Signals kidneys to increase sodium and fluid retention
True or False: Vasopressin stimulates the release of aldosterone from the adrenal cortex.
False
Describe: Action of Angiotensin II on Arterial Blood Vessels
Angiotensin II constricts resistance vessels, thereby increasing systemic vascular resistance and arterial pressure. This vasoconstrictive effect helps to elevate blood pressure.
True or False: Renin is released in response to increased sodium concentration in the distal tubule.
False
Define: Aortic Elasticity
Aortic elasticity refers to the ability of the aorta to expand and contract with each heartbeat, which is associated with increased compliance.
Describe: Compliance of Arteries
Compliance redirects heart energy to the arterial wall by storing energy during systole and releasing it during diastole, thereby pushing blood forward and facilitating circulation towards peripheral tissues.
Types of arteries include compliance arteries, impedance mismatch arteries, and those that facilitate smooth blood flow to the __________.
Capillaries
True or False: The cardiovascular system maintains smooth blood flow by solely relying on neurohumoral control mechanisms.
False
Which of the following are involved in neurohumoral control of blood pressure?
A) Compliance of arteries
B) Smooth blood flow to capillaries
C) Autonomic baroreflex
D) Impedance mismatch in arteries
C) Autonomic baroreflex
Describe: Risk of Pulse Pressure
Organs closer to the heart are more likely to be at risk of pulse pressure, which refers to the difference between systolic and diastolic blood pressure and reflects the pulsatile nature of blood flow in arteries.
Define: Compliance of Arteries
Compliance of arteries refers to their ability to expand and contract in response to changes in blood pressure, allowing them to accommodate changes in blood volume and maintain smooth blood flow.
Aortic elasticity is associated with increased ___________.
Compliance
True or False: Compliance arteries store energy during diastole and release it during systole, aiding in the redirection of heart energy to the arterial wall.
False
Which type of artery is associated with the reduction in pulse pressure from the heart to peripheral circulation?
A) Compliance arteries
B) Impedance mismatch arteries
C) Arteries facilitating smooth blood flow to capillaries
D) Elastic arteries
B) Impedance mismatch arteries
Describe: Smooth Blood Flow in Arteries
Arteries facilitate smooth blood flow to the capillaries by maintaining their elasticity and compliance, which allows them to dampen the pulsatile nature of blood pressure generated by the heart’s contractions.
True or False: Organs located farther away from the heart are more likely to be at risk of pulse pressure
False
Define: Baroreflex
The baroreflex is a physiological mechanism involving mechanoreceptors that relay information concerning blood pressure within the autonomic nervous system, primarily located in the aortic arch and carotid sinuses.
Describe: Mechanism of Baroreflex
Baroreceptors are stretch-sensitive mechanoreceptors primarily located in the aortic arch and carotid sinuses. They regulate blood pressure in response to short-term events, such as sudden changes like standing up quickly. The baroreflex is a quick reflex mechanism that operates through a negative feedback loop, completing its response in just a couple of heartbeats.
True or False: Baroreceptors are primarily located in the kidneys.
False
The main function of the baroreflex mechanism is to regulate blood pressure in response to:
A) Long-term events
B) Hormonal changes
C) Short-term events
D) Respiratory rate
C) Short-term events
The baroreflex regulates blood pressure through a __________ loop.
Negative feedback
Describe: Speed of Baroreflex Response
The baroreflex is a quick reflex mechanism that is complete in just a couple of heartbeats, allowing for rapid adjustments to changes in blood pressure.
Define: Renin-Angiotensin-Aldosterone System (RAAS)
The Renin-Angiotensin-Aldosterone System (RAAS) is a hormonal system that regulates blood volume and systemic vascular resistance, thereby influencing cardiac output and arterial pressure.
Describe: Mechanism of Action of RAAS
The RAAS regulates blood pressure by releasing renin, a proteolytic enzyme primarily from the kidneys. Renin acts on angiotensinogen to form angiotensin I, which is then converted to angiotensin II by angiotensin-converting enzyme (ACE). Angiotensin II functions to constrict resistance vessels, release aldosterone to increase sodium and fluid retention, and release vasopressin to increase fluid retention in the kidneys.
True or False: Renin release is stimulated by increased sodium delivery to the distal tubules of the kidney.
False
Which of the following are functions of angiotensin II?
A) Dilates resistance vessels
B) Reduces fluid retention in the kidneys
C) Increases sodium delivery to the distal tubules
D) Releases aldosterone
D) Releases aldosterone
Release of vasopressin increases fluid retention in the __________.
Kidneys
Describe: Negative Feedback Loop in RAAS
The release of natriuretic peptides (ANP/BNP) by the heart acts as a negative feedback mechanism in the RAAS, decreasing renin release and helping to regulate blood pressure.
Define: Renin
Renin is a proteolytic enzyme produced primarily by the kidneys, which plays a crucial role in the regulation of blood pressure by initiating the RAAS.
Renin acts on angiotensinogen to form the decapeptide ___________.
Angiotensin I
True or False: Angiotensin II functions to dilate resistance vessels, thereby reducing arterial pressure.
False
Renin release is stimulated by which of the following?
A) Increased sodium delivery to the distal tubules
B) Increased blood pressure in the renal arteries
C) Decreased sympathetic nerve activation
D) Increased angiotensin II levels
B) Increased blood pressure in the renal arteries
Describe: Role of Aldosterone
Aldosterone, released in response to angiotensin II, increases sodium and fluid retention in the kidneys, thereby contributing to an increase in blood volume and blood pressure.
True or False: The RAAS is essential only for chronic blood pressure adjustments, not for acute changes.
False
The release of natriuretic peptides by the heart acts as a negative feedback mechanism to decrease ___________ release.
Renin
Define: Anti-diuretic Hormone (ADH)
Anti-diuretic hormone (ADH), also known as arginine vasopressin (AVP), is a hormone involved in the regulation of blood pressure and the control of water reabsorption in the kidneys.
Describe: Synthesis of ADH
ADH is a nonapeptide synthesized in the hypothalamus, specifically in the supraoptic and paraventricular nuclei.
True or False: Osmoreceptors in the hypothalamus detect fluctuations in blood pressure and respond by shrinking, which increases nerve impulse frequency to the posterior pituitary gland.
True
ADH binds to which type of receptors on the basal lateral cell membranes of the principal cells in the nephron?
A) V1 receptors
B) V2 receptors
C) Alpha receptors
D) Beta receptors
B) V2 receptors
ADH increases the expression of aquaporins, specifically __________, in the apical membrane of principal cells in the nephron.
Aquaporin-2
Describe: Movement of Water in the Kidneys
After ADH increases the expression of aquaporins, water moves osmotically from the tubular fluid into the cell and then into the peritubular fluid. Finally, it moves into the surrounding interstitial fluid and into the blood, increasing blood volume and blood pressure.
True or False: Increased blood volume due to ADH secretion leads to a decrease in blood pressure.
False
Define: Osmoreceptors
Osmoreceptors are specialized cells located in the hypothalamus that detect changes in the concentration of solutes in the blood and play a role in regulating water balance and blood pressure.
ADH is synthesized in the __________ nuclei of the hypothalamus.
Supraoptic and paraventricular
True or False: ADH controls the movement of water from the tubular fluid into the renal tubular cells.
True
What stimulates the release of ADH from the posterior pituitary gland?
A) Increased blood pressure
B) Decreased extracellular fluid levels
C) Decreased osmolality of the blood
D) Increased sodium levels
B) Decreased extracellular fluid levels
Describe: Action of Aquaporins
ADH increases the expression of aquaporins, specifically aquaporin-2, in the apical membrane of principal cells in the nephron. These water channels facilitate the movement of water from the tubular fluid into the cell.
True or False: ADH secretion leads to a decrease in blood volume.
False
Water moves from the peritubular fluid into the surrounding __________ fluid and eventually into the bloodstream.
Interstitial
Define: Normal Adult Blood Pressure
Normal adult blood pressure is typically defined as systolic blood pressure less than 130 mm Hg and diastolic blood pressure less than 85 mm Hg.
Describe: Life Trajectory of Blood Pressure
Blood pressure tends to increase continuously from early adulthood until late life, with an initial increase in early adulthood, acceleration after the fourth decade, and a slower increase and possible decline later in life.
True or False: With aging, individuals lose the ability to maintain their blood pressure within a healthy level over time.
True
The prevalence of hypertension increases with age. What percentage of adults over the age of 65 are affected?
A) 32%
B) 50%
C) 70%
D) 90%
C) 70%
Describe: Impact of Hypertension
Hypertension is associated with various health issues such as dementia, physical disability, falls/fractures, and increased risk of developing other comorbidities.
Define: Essential Hypertension
Essential hypertension accounts for 95% of all cases and is characterized by high blood pressure without an identifiable cause.
Describe: Cardiovascular Vascular Aging
Cardiovascular vascular aging involves changes to the arterial wall, including increases in wall thickness and decreases in vessel elasticity, particularly in the aorta and systemic vasculature.
True or False: In essential hypertension, individuals typically have normal cardiac output but increased peripheral resistance.
True
Describe: Renal Hypertension
Renal hypertension is an exception to essential hypertension and occurs due to low blood flow to the kidneys, leading to activation of the Renin-Angiotensin-Aldosterone System (RAAS) and subsequent hypertension.
Define: Hypertension
Hypertension is defined as a condition where blood pressure measurements exceed 140/90 mmHg.
Describe: Prevalence of Hypertension with Age
The prevalence of hypertension increases with age, with 32% of adults aged 40-59 affected, and 70% of adults over the age of 65 affected.
True or False: Hypertension is associated with adverse health outcomes such as dementia, physical disability, and an increased risk of falls and fractures.
True
What are some factors contributing to hypertension?
A) Genetic factors
B) Environmental factors
C) Lifestyle factors
D) All of the above
D) All of the above
Describe: Study by Bert et al.
Bert et al. analyzed 8,636 patients over a 10-year period and found a rapid decline in kidney function associated with hypertension. In the 60-69 age group (n=4,128), they observed a significant decline in kidney function.
True or False: Essential hypertension accounts for 95% of all hypertension cases and has an identifiable cause.
False
In hypertension, changes to the arterial wall include an increase in wall thickness and a decrease in vessel __________.
Elasticity
Define: Renal Hypertension
Renal hypertension is characterized by low blood flow to the kidneys, leading to the activation of the Renin-Angiotensin-Aldosterone System (RAAS) and subsequent hypertension.
True or False: Blood pressure typically increases throughout life until around age 70 and then declines.
True
Describe: Mechanism of Blood Pressure Increase with Age
With aging, individuals typically experience an increase in blood pressure due to changes in arterial wall thickness and elasticity, as well as alterations in cardiac output and peripheral resistance.
Define: Aortic Stiffness
Aortic stiffness refers to a reduction in the ability of large arteries, particularly the aorta, to readily accommodate the increase in blood ejected from the heart during systole.
Describe: Characteristics of a Compliant Aorta
A compliant aorta exhibits slow pulse wave velocity (PWV), low-amplitude forward wave, and predominantly diastolic arrival of wave reflections to the aortic root, leading to augmentation of diastolic pressure with minimal augmentation of systolic pressure.
True or False: Elastin deposition in the arterial wall continues throughout adulthood.
False
What contributes to progressive elastin fragmentation/loss in aging arteries?
A) Increased elastin deposition
B) Mechanical fatigue
C) Reduced vascular smooth muscle tone
D) Collagen deposition
B) Mechanical fatigue over the lifetime (cyclic stress); Elastase-mediated proteolysis
Describe: Characteristics of a Stiff Aorta
A stiff aorta exhibits fast pulse wave velocity (PWV), high-amplitude forward wave, and systolic arrival of wave reflections to the central aorta. This leads to pronounced augmentation of mid-to-late systolic pressure with reduced augmentation of diastolic pressure.
True or False: Medial calcification in aging arteries is predominantly mediated by the osteochondrogenic differentiation of vascular smooth muscle cells (VSMCs).
True
Reduced ___________ production by the endothelium may play a role in regulating vascular smooth muscle cell stiffness/tone in distal aortic segments like the abdominal aorta.
nitric oxide (NO)
Define: Inflammation
Inflammation refers to the body’s response to injury or infection, and there are interconnections between inflammatory pathways and various mechanisms of large artery stiffening, including elastin degradation, medial calcification, and endothelial dysfunction.
Define: Pulse Wave Velocity (PWV)
Pulse wave velocity (PWV) is the speed at which the pressure wave travels along the arterial tree, reflecting arterial stiffness.
Describe: Elastin Fragmentation
Elastin fragmentation refers to the progressive breakdown of elastin fibers in the arterial wall due to mechanical fatigue over the lifetime and elastase-mediated proteolysis.
True or False: Collagen deposition primarily occurs at sites of elastin breakdown in the arterial wall.
True
Vascular smooth muscle cell (VSMC) stiffening is primarily caused by:
A) Elastin fragmentation
B) Collagen deposition
C) Calcification
D) Endothelial dysfunction
C) Calcification
Describe: Endothelial Dysfunction
Endothelial dysfunction refers to impaired functioning of the endothelium, leading to reduced production of nitric oxide (NO) and altered regulation of vascular smooth muscle tone.
True or False: Inflammatory pathways are interconnected with various mechanisms of large artery stiffening, including elastin degradation, medial calcification, and endothelial dysfunction.
True
A compliant aorta exhibits slow pulse wave velocity (PWV) and predominantly __________ arrival of wave reflections to the aortic root.
Diastolic
Define: Medial Calcification
Medial calcification is the process of calcium deposition in the medial layer of arterial walls, primarily mediated by the osteochondrogenic differentiation of vascular smooth muscle cells (VSMCs).
True or False: Arterial stiffness increases with age due to the progressive breakdown of elastin fibers and the deposition of collagen in the arterial wall.
True
Define: Arteriosclerosis
Arteriosclerosis refers to the thickening and hardening of the arterial walls, typically associated with aging and characterized by adverse structural and functional changes within the vessel wall.
Describe: Components of Arterial Walls
Arterial walls consist of three layers: the tunica intima (inner layer), tunica media (middle layer), and tunica adventitia (outer layer).
True or False: With aging, there is a loss of elastin function in the arterial wall, contributing to increased stiffness.
True
Which component primarily contributes to arterial stiffness?
A) Increased collagen deposition
B) Loss of smooth muscle stiffness
C) Calcification in the tunica media
D) Genetic determinants
C) Calcification in the tunica media
Describe: Genetic Determinants of Arterial Stiffness
The genetic determinants of arterial stiffness are not fully understood.
True or False: Fatty degeneration of larger arteries contributes to vessel stiffening.
True
Fatty degeneration and vessel stiffening cause a patchy intramural thickening of the __________.
Subintima
Define: Xanthoma
Xanthoma is a type of fatty deposit or accumulation of cholesterol-laden foam cells in the arterial wall.
Tue or False: Plaque rupture or erosion can lead to fibrotic lesions with calcification.
True
Describe: Tunica Media
The tunica media is the middle layer of the arterial wall, primarily composed of smooth muscle cells and elastic fibers.
Which of the following contributes to the increased stiffness of arterial walls?
A) Increased elastin function
B) Reduction in collagen deposition
C) Calcification in the tunica adventitia
D) Loss of smooth muscle stiffness
C) Calcification in the tunica adventitia
Plaque rupture or erosion can lead to the formation of __________ with calcification.
Fibrotic lesions
Define: Atheroma
Atheroma refers to the accumulation of cholesterol, calcium, and other substances in the arterial wall, leading to the formation of a plaque.
Describe: Tunica Intima
The tunica intima is the innermost layer of the arterial wall, composed of endothelial cells and connective tissue.
Vessel stiffening results in a patchy intramural thickening of the __________.
Subintima
Define: Plaque Rupture
Plaque rupture refers to the tearing or breaking of atherosclerotic plaque in the arterial wall, which can lead to thrombosis and other complications.
Define: Elasticity Gradient
The elasticity gradient refers to the variation in elasticity across different segments of the arterial tree, with proximal arteries having higher elasticity and distal arteries having lower elasticity.
Describe: Aortic Elasticity
Aortic elasticity refers to the ability of the aorta to expand and recoil in response to changes in blood pressure, which increases compliance.
True or False: Arterial stiffness is characterized by decreased compliance, leading to reduced energy storage in the arterial wall.
True
With arterial stiffness, what happens to the energy stored in the arterial wall during systole?
A) Increases
B) Decreases
C) Remains unchanged
Describe: Transmission of Pulsatile Flow
Arterial stiffness leads to an increase in wave reflection and impedance mismatch, resulting in the transmission of excessive flow pulsatility into the microvasculature of target organs such as the brain and kidneys.
true or False: Increased aortic stiffness leads to a decrease in wave reflection and impedance mismatch.
False
Pulsatile energy is transferred to small arteries and microvasculature in target organs such as the __________ and kidneys.
Brain
Describe: Carotid Pulsatility
Carotid pulsatility refers to the variation in blood flow pulsations in the carotid arteries, which can increase due to increased arterial stiffness.
Define: Compliance
Compliance refers to the ability of arteries to expand and recoil in response to changes in blood pressure, with increased compliance allowing arteries to store more energy during systole.
Describe: Effect of Compliance on Arterial Wall
Compliance redirects energy from the heart to the arterial wall, where energy is stored during systole and released during diastole to maintain smooth blood flow.
Excessive flow pulsatility, resulting from arterial stiffness, can affect which organs?
A) Liver and pancreas
B) Lungs and spleen
C) Brain and kidneys
D) Stomach and intestines
C) Brain and kidneys
Describe: Marked Stiffening of the Aorta
Marked stiffening of the aorta is associated with the transmission of excessive flow pulsatility into the microvasculature of target organs, impacting their perfusion and function.
Define: Impedance Mismatch
Impedance mismatch refers to the discrepancy between the characteristics of blood flow and the arterial wall, leading to wave reflections and alterations in blood pressure.
Describe: Impact of Arterial Stiffness on Peripheral Tissues
Arterial stiffness leads to increased pulsatile energy transferred to small arteries and microvasculature in peripheral tissues, affecting their perfusion and function.
Describe: Normal Arterial Function
In normal conditions, large arteries such as the aorta expand during systole to accommodate blood ejected from the left ventricle, and during diastole, blood is drained towards smaller capillaries to perfuse organs.
True or False: Arterial stiffness, known as arteriosclerosis, increases with age, reducing the ability of arteries to expand during systole.
True
Which of the following factors contributes to arterial stiffness?
A) Increased elastin function
B) Decreased extracellular matrix metalloproteinases (MMPs)
C) Reduced inflammation
D) Elastin fragmentation and collagen deposition
D) Elastin fragmentation and collagen deposition
Describe: Role of Inflammation
Increased inflammation with aging, possibly due to metabolic disorders, can cause vascular endothelial damage and play a mediating role in arterial stiffness.
True or False: Stiffer arteries result in faster pulse wave velocity, making pulse wave velocity a good measure of arterial stiffness.
True
Calcification occurs in the intima and tunica media of the artery and is associated with __________.
Atherosclerosis
True or False: Arterial stiffness decreases wave reflections, leading to an increase in pulsatile pressure in smaller arteries.
False
Describe: Relationship Between Hypertension and Arterial Stiffness
Hypertension and arterial stiffness have a bidirectional relationship, forming a positive feedback loop that exacerbates arterial stiffness.
Define: Hypertension
Hypertension refers to high blood pressure, which is a major risk factor for cardiovascular mortality and morbidity.
Describe: Hypertension Mechanism of Organ Damage
Hypertension leads to decreased arterial elasticity, increased wall damage, and cholesterol/fat deposition in vessels, resulting in obstruction and damage to target organs.
True or False: Hypertension can lead to cardiac hypertrophy, where the heart increases in mass and thickness due to increased vascular resistance.
True
Which condition is considered the most important risk factor for stroke?
A) Diabetes
B) Hypercholesterolemia
C) Hypertension
D) Obesity
C) Hypertension
Describe: Hypertensive Retinopathy Phases
Hypertensive retinopathy occurs in phases: vasoconstrictive, sclerotic, and exudative, characterized by changes in retinal vessels due to increased blood pressure.
True or false: Hypertension can accelerate the loss of kidney function in individuals with renal disease, contributing to a cycle of worsening hypertension.
True
Kidneys play a crucial role in regulating blood pressure by maintaining sodium balance and __________.
Extracellular fluid volume
define: Cardiac Hypertrophy
Cardiac hypertrophy refers to an increase in the mass and thickness of the heart muscle due to prolonged pressure overload, often seen in hypertension.
True or false: Hypertension can lead to alterations in the blood-brain barrier, increasing permeability and contributing to thrombi formation and ischemic lesions in the brain.
True
Describe: Effects of Hypertension on Retinal Vessels
Hypertension can cause damage to retinal vessels, leading to hypertensive retinopathy characterized by phases of vasoconstriction, vessel wall changes, and retinal hemorrhage.
Define: Dementia
Dementia is a syndrome characterized by the loss of brain function, affecting memory, thought processes, and the ability to make decisions, and is not a normal process of aging.
Describe: Alzheimer’s Dementia
Alzheimer’s dementia, the most common form of dementia, is characterized by the presence of amyloid-β plaques and neurofibrillary tangles, leading to the loss of synapses and neurons, particularly in the hippocampus.
True or false: Aβ peptide, present in both the blood and the brain, normally supports synaptic function, neuronal growth, and protects against oxidative stress.
True
What are the different mechanisms of vascular damage associated with dementia?
A) Atherosclerosis only
B) Infarcts and lacunar infarcts only
C) Atherosclerosis, infarcts, amyloid angiopathy, and brain hemorrhages
D) White matter lesions only
C) Atherosclerosis, infarcts, amyloid angiopathy, and brain hemorrhages
Describe: Vascular Dementia
Vascular dementia represents a group of brain disorders attributed to cerebrovascular causes, leading to altered cognition ranging from subtle deficits to full-blown dementia.
True or false: Research has shown that hypertension increases the risk of dementia, with higher blood pressure associated with poorer cerebral health.
True
Carotid-femoral pulse wave velocity (cfPWV) is used to measure arterial stiffness, with high cfPWV associated with a __________% increased risk of incident dementia.
57%
Define: Amyloid-β Plaques
Amyloid-β plaques are extracellular deposits of abnormal protein fragments that accumulate in the brain of individuals with Alzheimer’s disease.
True or false: There is a dose-response relationship between the number of risk factors and the risk of dementia, with a greater number of risk factors leading to an increased risk of dementia.
True
Define: White Matter Hyperintensities
White matter hyperintensities are areas of increased signal intensity seen on brain imaging, indicative of small vessel disease and often associated with vascular risk factors such as hypertension.
True or false: Peripheral blood pressure measurements, particularly high systolic blood pressure, are associated with brain damage such as increased white matter hyperintensities and decreased hippocampus volume.
True
Cardiovascular disease is one of many _________ for dementia.
risk factors
Which of the following is not a type of dementia?
A) Alzheimer’s dementia
B) Vascular dementia
C) Frontotemporal dementia
D) Parkinson’s disease
D) Parkinson’s disease
Describe: Mechanisms of Alzheimer’s Disease
Alzheimer’s disease is characterized by the presence of amyloid-β plaques and neurofibrillary tangles, leading to synaptic and neuronal loss, particularly in the hippocampus.
True or false: Aβ peptide, normally present in the blood and brain, supports synaptic function, neuronal growth, and protection against oxidative stress.
True
Define: Pulse Wave Velocity
Pulse wave velocity is a measure of arterial stiffness, reflecting the speed at which pressure waves travel along the arterial tree.
Describe: Impact of Hypertension on Dementia Risk
Hypertension increases the risk of dementia, with a dose-response relationship observed, indicating that a higher number of risk factors are associated with a greater risk of dementia.
True or false: High carotid-femoral pulse wave velocity (cfPWV), a measure of arterial stiffness, is associated with a 57% increased risk of incident dementia.
True
Different mechanisms of vascular damage in dementia include small vessel atherosclerosis, large vessel arteriosclerosis, cortical and subcortical infarcts, amyloid angiopathy, and __________.
Small brain hemorrhages
True or false: Numerous studies have found an association between hypertension and the development of cognitive impairment and dementia.
True
Define: Vascular Dementia
Vascular dementia is a type of dementia caused by impaired blood flow to the brain, often associated with hypertension and other cardiovascular risk factors.
Age and hypertension have been associated with a reduction in brain structure volume, particularly in the __________ regions.
Temporal and occipital
Which of the following is not a potential causal mechanism linking hypertension and dementia?
A) Brain structure changes
B) Decreased oxidative stress
C) Amyloid beta accumulation
D) Blood-brain barrier dysfunction
B) Decreased oxidative stress
Describe: Blood-Brain Barrier Dysfunction association with hypertension
Hypertension has the potential to compromise the permeability of the blood-brain barrier, altering the passage of substances between the brain and bloodstream and increasing the risk of harmful substances entering the brain.
True or false: Hypertension is a common risk factor for ischemic stroke, with the risk increasing gradually as blood pressure rises above 115/75 mm Hg.
True
Stroke-related dementia is a significant risk, with approximately 1 in __________ patients who have a recurrent stroke developing dementia.
3
Describe: Potential Mechanisms of Hypertension-Induced Brain Damage
Potential mechanisms include brain structure changes, inflammation and oxidative stress, amyloid beta accumulation, blood-brain barrier dysfunction, apoptosis, neuronal cell death, and hypertension’s role as a risk factor for stroke.
True or false: Hypertension may contribute to the accumulation of beta-amyloid plaques in the brain, a major pathophysiological process in Alzheimer’s disease.
True
Define: Vascular Damage
Vascular damage refers to structural and functional impairments in blood vessels, often resulting from conditions such as hypertension, diabetes, or atherosclerosis.
True or false: Hypertension has been consistently associated with cognitive decline and an increased risk of dementia.
True
Chronic hypertension may lead to mitochondrial dysfunction and brain structure decline due to increased __________.
Oxidative stress
Which type of dementia is characterized by the presence of amyloid-β plaques and neurofibrillary tangles?
A) Vascular dementia
B) Lewy body dementia
C) Alzheimer’s dementia
D) Frontotemporal dementia
C) Alzheimer’s dementia
Describe: Role of Hypertension in Brain Damage
Hypertension can lead to structural and functional changes in the brain, including decreased cerebral blood flow, inflammation, oxidative stress, and damage to the blood-brain barrier, all of which contribute to cognitive decline and an increased risk of dementia.
True or false: Hypertension may compromise the integrity of the blood-brain barrier, allowing harmful substances to enter the brain and contribute to neurodegenerative processes.
True
Hypertension is a major risk factor for __________, which in turn increases the risk of developing vascular dementia.
Stroke
How does hypertension typically affect brain structure?
A) Increases brain volume
B) Decreases white matter hyperintensities
C) Leads to volume reduction, particularly in vulnerable regions such as the temporal and occipital lobes
D) Improves cognitive function
C) Leads to volume reduction, particularly in vulnerable regions such as the temporal and occipital lobes
Define: Vascular Dementia
Vascular dementia is a type of dementia caused by reduced blood flow to the brain, often resulting from conditions like hypertension, stroke, or small vessel disease
True or false: Hypertension is associated with a reduction in brain volume, particularly in regions such as the temporal and occipital lobes.
True
Define: Hypotension
Hypotension refers to abnormally low blood pressure, typically defined as systolic blood pressure below 90 mmHg and diastolic blood pressure below 60 mmHg.
True or false: In older adults, there is typically a higher systolic blood pressure and a lower diastolic blood pressure, reflecting the progression of arterial stiffening and reduced cerebral blood flow.
True
Describe: Arterial Stiffening
Arterial stiffening occurs with age due to factors like elastin degradation and collagen deposition, leading to reduced arterial compliance and increased resistance against which the heart must pump blood.
Aging is associated with decreased cardiovagal ________ sensitivity, which is linked to changes within the baroreceptor mechanisms, resulting in increased blood pressure variability and an increased risk of sudden cardiac death.
baroreflex
True or false: The Honolulu Heart Program found that men who developed dementia had an additional age-adjusted increase in systolic blood pressure compared to survivors without dementia.
True
Arterial stiffening increases the resistance against which the heart must pump blood, leading to:
A) Decreased cardiac output
B) Increased stroke volume
C) Enhanced arterial compliance
D) Reduced left ventricular hypertrophy
A) Decreased cardiac output
: Impaired baroreflex sensitivity and increased pulsatile energy transmission into the brain due to arterial stiffening can lead to __________, contributing to cognitive decline.
brain damage
True or false: Chronic inflammation, characterized by elevated levels of inflammatory markers, is associated with aging and various health conditions, including cardiovascular diseases.
True
Describe: Endothelial Dysfunction
Endothelial dysfunction refers to impaired function of the vascular endothelium, which plays a key role in regulating arterial health and function. It can result from factors like arterial stiffness, reduced nitric oxide bioavailability, oxidative stress, and chronic inflammation.
Hypertension is associated with various risk factors, including obesity, diet, salt intake, alcohol consumption, and __________.
Smoking
Define: Stroke Volume
Stroke volume refers to the volume of blood ejected from the heart’s left ventricle with each heartbeat.
True or false: Arterial compliance decreases with age due to factors like elastin degradation and collagen deposition.
True
Describe: Cardiovagal Baroreflex Sensitivity
Cardiovagal baroreflex sensitivity refers to the responsiveness of the vagus nerve (parasympathetic nervous system) to changes in blood pressure, helping regulate heart rate and blood pressure.
The Honolulu Heart Program found that men who developed dementia had an additional age-adjusted increase in systolic blood pressure compared to survivors without dementia, indicating a potential link between hypertension and __________.
Cognitive decline
Arterial stiffening can lead to left ventricular hypertrophy, which is characterized by:
A) Decreased cardiac output
B) Increased ventricular wall thickness
C) Enhanced baroreflex sensitivity
D) Reduced arterial compliance
B) Increased ventricular wall thickness
Aging is associated with increased levels of inflammatory markers such as interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-α), contributing to chronic __________.
inflammation
Which of the following is NOT a risk factor for hypertension?
A) Obesity
B) Low salt intake
C) Alcohol consumption
D) Smoking
B) Low salt intake
Arterial stiffening increases resistance against which the heart pumps blood, leading to increased systolic blood pressure and decreased __________.
Diastolic blood pressure
Which of the following is a symptom of dementia?
A) Increased memory
B) Reduced memory
C) Enhanced decision-making abilities
D) Unchanged thought processes
B) Reduced memory
What are the potential risk factors associated with dementia?
Risk factors for dementia include genetics, BMI (body mass index), and hypertension. There are multiple types of dementia, including Alzheimer’s dementia and vascular dementia.
Research evidence suggests a potential _________ relationship between systolic blood pressure (SBP) and dementia.
U-shaped
What opposing evidence challenges the link between declining systolic blood pressure and dementia?
Increased blood pressure has been associated with increased white matter lesions (WML) and brain atrophy, suggesting a complex relationship between blood pressure and dementia.
What are some areas for future research regarding the relationship between blood pressure and dementia?
Prospective cohort studies, longitudinal studies investigating SBP variation and dementia, and investigations into the optimal type and duration of antihypertensive drugs for dementia prevention are needed. Additionally, understanding the mechanisms linking changes in blood pressure and dementia requires further exploration.
Which of the following is a major risk factor for dementia?
A) High cholesterol
B) Hypertension
C) Diabetes
D) Obesity
B) Hypertension
Describe the treatment options for vascular dementia.
Treatment options for vascular dementia may include care plans, lifestyle changes such as diet and exercise, medications to manage high blood pressure and cholesterol, and therapies like occupational and psychological therapies.
Preventing hypertension is important in reducing the risk of _______.
dementia
What are some challenges associated with the treatment of vascular dementia?
Challenges include the difficulty in reversing arterial stiffness and calcification, the risk of cognitive decline from overly aggressive hypertension treatment, incomplete understanding of the mechanisms linking blood pressure and dementia, and variability in individual responses to blood pressure changes.
How can preventing hypertension help reduce the risk of dementia?
Preventing hypertension can help maintain healthy blood flow to the brain, prevent arterial stiffness and microvascular ischemia, and reduce the risk of developing dementia.
What are the two main loops of the cardiovascular system?
A) Pulmonary and systemic
B) Arterial and venous
C) Aortic and pulmonary
D) Coronary and peripheral
A) Pulmonary and systemic
Define autoregulation in the context of arterial regulation.
Autoregulation refers to the ability of arteries to adjust their diameter based on local conditions such as oxygen levels, pH, and metabolic activity.
Describe the structure and function of elastic arteries.
Elastic arteries are located close to the heart and have thicker walls with a high percentage of elastic fibers. They function to accommodate and propel the flow of blood ejected from the heart by expanding and recoiling due to abundant elastic fibers to maintain pressure gradients.
_______ regulates capillary exchange, alters blood flow, and releases endothelins that can influence blood pressure
Endothelium
What are some mechanisms involved in arterial regulation?
Arterial regulation involves autoregulation, sympathetic nervous system (SNS) activation, hormonal regulation, endothelial regulation, and myogenic response.
How do arterioles contribute to regulating blood flow to target tissues?
Arterioles control blood flow resistance and pressure by adjusting the diameter of their lumens, thereby regulating blood distribution to target tissues.
Which layer of blood vessels is primarily composed of collagenous fibers?
A) Tunica Intima
B) Tunica Media
C) Tunica Externa
D) Endothelium
C) Tunica Externa
Define pulmonary circulation and its role in the cardiovascular system.
Pulmonary circulation is the part of the cardiovascular system that carries deoxygenated blood from the heart to the lungs for gas exchange, and then returns freshly oxygenated blood to the heart for systemic circulation.
Describe the structure of arterioles and their function in the circulatory system.
Arterioles are small arteries connecting to capillaries. They have a reduced thickness of tunic layers and their muscle fibers are slightly contracted to maintain vascular tone. Arterioles control blood flow resistance and pressure, regulating blood distribution to target tissues by adjusting the diameter of their lumens.
Which layer of blood vessels contains layers of smooth muscle supported by elastic fibers?
A) Tunica Intima
B) Tunica Media
C) Tunica Externa
D) Endothelium
B) Tunica Media
Define autoregulation in the context of arterial regulation.
Autoregulation refers to the ability of arteries to adjust their diameter based on local conditions such as oxygen levels, pH, and metabolic activity to maintain a steady blood flow.
Describe the function of elastic arteries in the cardiovascular system.
Elastic arteries, also known as conducting arteries, are located close to the heart and have thicker walls with a high percentage of elastic fibers. Their function is to accommodate and propel the flow of blood ejected from the heart by expanding and recoiling due to abundant elastic fibers, thereby maintaining pressure gradients and facilitating efficient distribution of blood to smaller branches.
The __________ releases norepinephrine, which causes vasoconstriction.
Sympathetic Nervous System (SNS)
What are the implications of decreased sympathetic nervous system activity on arterial regulation?
Decreased sympathetic nervous system activity leads to vasodilation, which can result in decreased blood pressure and increased blood flow to tissues. This can have implications for overall cardiovascular function and may contribute to conditions such as orthostatic hypotension.
