Vascular Pathology and HTN Flashcards
Layers of the veins?
Internal: intima
Middle: media
External: adventitia
Where is the media thickest and why?
Arteries because it is composed of smooth muscle cells and ECM
It needs to be able to withstand high blood pressure
What is the intima composed of?
Endothelial cells and elastic connective tissue
Where is there the most elastic tissue?
Media because it needs to be flexible to the change in blood pressure
What is the aventitia composed of?
Mainly connective tissue and contains nerves and blood vessels!!!!!
What is the purpose of the aventitia?
To supply nutrients and oxygen to cells that are farther away from the blood and lumen
Which arteries are the most elastic?
Pulmonary
What arteries are the most muscular?
Coronary or renal
****What are the smallest arteries called and what happens here?
Arterioles and it is the site where regulation of blood pressure occurs
Define Peripheral resistance
Resistance that is encounterd by blood during blood flow in the arteries
Related to diameter size
Drugs that cause vasodilation do what? Vasoconstriction?
Lower blood pressure; increase blood pressure
What are capillaries important?
They are within every tissue and are drug targets
Nutrients and oxygen can only be carried?
100 mcL so lots of capillaries to make sure everyone gets what they need
What doesn’t have all three layers?
Pericytes and endothelial cells
What happens in the veins?
Blood slows down because there is an exchange of oxygen and nutrients
Most disease effect?
Arteries not veins
What is the major pump of the heart?
Left ventricle, that is why it has such a large myocardium
Where does the left ventricle send blood?
Through the aorta to the organs and tissues
Define pulmonary circulation
Veins collect the blood and return it to the right ventricle
What is the cause of pulmonary HTN?
Increased pressure in the lungs, somewhere between the blood being sent from the right ventricle to the lungs to the left ventricle
What if something happens to the left ventricle?
Hypoperfusion to the tissues or the return of the lungs from the LV will be impaired and it will be stuck in the lungs (stasis)
When could you see decrease in elasticity of the arteries?
Age or atherosclerosis –> cannot expand during systole or recoil during diastole
What are the regulating mechanisms of blood pressure?
Autonomic nervous system (Sympathetic) Metabolic factors (lactic acid) Cellular interactions
How does lactic acid do anything for the blood pressure?
It decreases extracellular pH leading to vasodilation bc you need more oxygen and blood
Where does the exchange of nutrients and oxygen occur?
Portal cells
Define hydrostatic pressure
Keep fluid in homeostasis; increased pressure would lead to accumulation of fluid in the tissue (edema)
Veins
2/3 blood is stored here
Are easily penetrated by tumors
Deep veins typically have really slow blood flow
Define Lymphatics
Draining system for returning interstitial tissue fluid and inflammatory cells to the blood
Define thoracic duct
Vessels that take the fluid back to the circulation
Lymph nodes are
where the collected viruses are sent
Fenestrated endothelium is important?
for filtration in the kidney and liver
The less amount of fenestrae is important because?
That prevent thrombosis and coagulation would occur immediately if it comes in contact with that layer
Define plasminogenosis
Breakdown of the clot
Blood clot =
Blood cells + plasminogen
Important to prevent hemorrhage
Define thrombus
Blood clotting in NORMAL blood vessels
Platelet Derived Growth Factor
Produced by endothelial cells and induce the proliferation of smooth muscle cells
- Seen in injury and atherosclerosis
TGFbeta does what?
Stops proliferation of smooth muscle cells; contribute to ventricular remodeling in hear failure
LDL can be oxidated to?
Be incorporated into the wall of blood vessels (atherosclerosis)
What prevents thrombosis?
Prostacyclin NO Thrombomodulin Heparin Plasminogen activator
What causes clotting?
vWF
tissue factor
plasminogen inhibitor
Turbulent blood flow leads to?
Increased tendency for coagulation
Smoker differentiation
Endothelial cells can be damaged by smoke leading to thrombosis and increased permeability of endothelial surface
Normal SM cells
Do not divide or proliferate
The repair injured blood vessels
What is the response to injury process that causes artherosclerosis?
Recruitment of SM cells to the intima
SM cells mitosis
Elaboration of extracellular matrix (SM cells die and become debris)
Three types of vascular pathologies
Stenosis or complete obstruction of blood vessels
Thrombus or embolus
Artherosclerosis
Four types of vascular pathologies
Weakening of vessel walls
Congenital
Vasculitis
Atherosclerosis
Chest pain is a symptom of
MI or infarction
Peripheral edema is a symptom of
Right sided heart failure
SOB is a symptom of
Pulmonary congestion or left sided heart failure
Fatigue is a symptom of?
CHF
Palpitations, dyspnea, hypoTN, syncope are symptoms of?
Arrhythmias
Why is it important to control blood flow?
Pressure determines flow and flow has a range it must be within and it will increase and decrease when needed?
What if we suddenly increased blood pressure?
Increased blood flow in tiny capillaries would cause damage to tissues and organs
**Blood pressure =
CO (Q) X Peripheral vascular resistance
******* Cardiac output =
Blood volume X heart function
Blood volume is dependent on?
The amount of fluids we intake and excrete
Hematocrit is based on
The amount of cells in the body
Higher cells = higher hematocrit
What decreases peripheral resistance?
NO
Prostacyclin
Kinins
Histamine
What increases peripheral resistance?
Ang II
Catecholamines
Endothelin
ADH
Sympathetic nervous system does what to BP?
Increases
Non-sympathetic nervous system does what to BP?
Decrease by inhibiting the sympathetic
Stretch receptors
When stretched, trigger the brain to decrease BP and cause vasodilation
Sympathetic Nervous System
Uses neurotransmitters
Epi- Beta - dilation
NE- Alpha- constriction
NE & Epi do what?
Postganglionic nerve is producing NE which binds to alpha 1 receptor and causes vasoconstriction & Epi binds beta 2 and causes vasodilation
Pharmacological aspect of receptors?
Stimulate B2 and inhibit A1
Beta 1
Increased CO
Increased BP
Alpha 1
Increased sodium reabsorption
Increased BP
Beta 2
Increased renin
Decreased BP
Renin cleaves?
Angiotensinogen to Ang1
ACE cleaves?
Ang 1 to Ang 2
Aldosterone is
Created from Ang 2 and causes sodium reabsorption and increased blood volume
Increased blood pressure –> increased stretch receptors –> ?
Naturetic peptide –> Na and water ecretion
What stimulates renin secretion?
Decreased NaCl
Decreased pressure or stretch
SNS stimulation
What inhibits renin secretion?
Increased NaCl
Increased stretch
AngII
How is renin secreted?
SNS innervates the juxtaglomerular cells which act on baroreceptors
Decreased Na to the distale tubule activates these cells
What are baroreceptors?
Stretch receptors!!
Increased sodium excretion leads to?
Slower flow so more can be reabsorbed
Vascular relaxing factors?
NO
Prostaglandins
Define Hypertensive vascular disease
Systole > 139
Diastole > 89
Define essential HTN
Don’t know the cause
Define secondary HTN
Related to a disease (CKD, tumor, etc)
Risk Factors
Age Race Obesity >30 High NaCl Low Ca, K, D Alcohol Stress Low physical activty Family history High cholesterol Diabetes
HTN doubles the risk of what CV diseases?
Coronary heart disease Congestive heart failure Stroke Renal failure Peripheral arterial disease and aortic dissection
Define Atherosclerosis
Wall thickens up in hyaline arteriolosclerosis
- Important bc they regulate blood pressure → changes to lumen to regulate the BP would not happen at all or very little
Define Malignant HTN
Systole >200
Diastole >120
Leads to death within 1-2 yrs
Malignant HTN leads to
brain edema, renal failure or hemorrhages
Arterial HTN if left untreated will lead to death via
Ischemic heart disease
CHG
Stroke
