Disorders of Blood Vessels Flashcards
Describe the sounds heard in BP
- First sound is systolic number
* After you stop hearing is diastolic
Define hypertension
a systolic BP greater than 140 and/or diastolic blood pressure over 90
What happens to BP as we age?
- As we age we are not as elastic- increase in stiffening in arteries- increases resistance and it naturally elevated
- 150/90 for older patients
What are the 4 types of arteries?
- Elastic
- Muscular
- Small Arteries
- Arteriole
Describe elastic arteries
- Large and include the aorta and initial branches, and the pulmonary artery
- Elastic and this makes them springy
Describe muscular arteries
- Middle size and include the renal and coronary arteries
- Has encircling smooth muscle cells
- Regional flow and pressure are regulated by lumen size
- Contract to narrow the lumen (Vasoconstriction)
- Relax to enlarge it (Vasodilation)
- Vasoconstriction and vasodilation are controlled by the autonomic nervous system (hormones, local metabolic factors)
Describe small arteries
- Less than 2 mm in diameter
- Retinal Arteries
Describe Arterioles
- Tiny pre-capillary arteries
- Less than 0.1 mm
- Wrapped in a thin layer of smooth muscle
Describe veins
- Carry low pressure, non-pulsing blood to the heart
- Larger diameter compared to arteries, larger lumen, and thinner wall
- Pliable and expand easily (to accommodate the changes in volume with little pressure change)
- 2/3 of blood is in the veins
- One way venous valves (prevent back flow)
Describe capillaries
- Smallest of vessels, lie in tissues and join the arterial network to the venous network
- Composed of only endothelial cells resting on the basement membrane
- Promote free exchange of gases and fluids
- As blood flows down the arterial tree, the cross sectional area of each vessel becomes smaller, the total cross sectional area becomes larger
- Most numerous
- Flow rate is very slow
What are the 3 layers of large vessels
o Adventura Supporting fibrous tissue o Media Composed of mainly smooth muscle o Intima A single layer of endothelial cells
What are the 2 functions of endothelial cells?
o Control diffusion of substances across the wall to adjacent tissues
o In constant contact with blood and keep blood in a smooth, unclotted state
What is the equation for BP?
• Blood pressure= Cardiac output * vascular resistance
Define CO
the volume of blood per unit of time ejected from the left ventricle into the aorta
What is the equation for CO
o Cardiac output= SV and HR
Define vascular resistance
the resistance to the flow that must be overcome for blood to flow though the circulatory system
What kind of relationship do resistance and flow have?
Inverse
What regulates flow
Peripheral arterioles
sense blood pressure and act to change peripheral resistance and blood volume
Kidneys
What 2 things does the kidney do to regulate BP
o It decreases the amount of blood passing through the kidney
o Renin
Describe the effect of vasoconstriction
o It decreases the amount of blood passing through the kidney
Lowers urine output
Preserves water
Increases blood volume
Describe the effects of renin
Causes peripheral and renal vasoconstriction
Stimulates aldosterone
Expands blood volume
Increases CO and BP
Lipids that are attached to plasma proteins
Lipoproteins
plasma proteins that makes lipid soluble in the blood
Apoprotein
Describe High Density Lipoproteins
o Half protein, half lipid
o Lipid is phospholipid and cholesterol
o “Good Cholesterol”
o Like a garbage truck- it gets the bad stuff out
Normal values for HDL
o Normal levels Men- greater than 40, women above 50
This is associated with less risk of atherosclerosis
HDL
Describe LDL
o 22% protein
o Most of the lipid is cholesterol
o Smaller amounts of phospholipid and cholesterol
o “Bad” builds up in your arteries and is plaque
Normal values of low density lipoproteins
- Normal levels= less than 130
- If you are diabetic- less than 100
- Heart disease- less than 70
Characteristics of LDL
- High levels promote atherosclerosis
- Diet in saturated fat
- Trans fats
Describe VLDL
o Only 10% proteins
o “Very bad”- not really used in clinic
o Most of lipids are triglycerides
o Small amounts of phospholipid and cholesterol
Describe cohort score
o 10 year risk would be to have a cardiovascular event (stroke, MI)
o Helps guide treatment
When your score is ___ or mre, you should be put on a statin
7.5
What is the effect of a statin?
o Statins lower cholesterol and have an anti-inflammatory infect and reduce risk of cardiovascular event
What is includes in a cohort score?
Male or female Age Total cholesterol • Bad and good collected together • Less than 200 is normal • Liver synthesizes this • Need it in cells HGL BP (systolic) Smoker Diabetic Treated for hypertension
Describe primary hypertension
o 95% of hypertension is unknown
o Not associated with any identified cause
Describe secondary hypertension
o Where there is something causing the hypertension
o Many causes and if you treat the problem the high BP will go away
Examples of things that cause secondary hypertension
- Renal Artery Stenosis
- Obstructive Sleep Apnea
- Pheochromacytoma
- Tumors of the Adrenal cortex
- Drugs
- Beta agonists
Describe the effects of Renal Artery Stenosis
- Narrowing of the renal arteries
- Decreased profusion
- Increase Renin
- Starts RAA system
- Seen in young patients with high blood pressure
- Most common cause of surgery correctible hypertension
Describe the effects of obstructive sleep apnea
- Uncontrolled sleep apnea can lead into hypertension
- Keeps airways open, body isn’t in stress mode, and your body goes back to normal
- Hypoxic mode and increases sympathetic act
Describe the effects of pheochromacytoma
- Very rare adrenal tumors that secrete a ton of catecholamine’s (norep and ep- fight and flight response)
- Sweating and always anxious
Describe the effects of Tumors of the Adrenal cortex
• High Aldosterone or cortisol
o See low potassium if high aldosterone
Describe the effects of drugs
• Any kind of stimulants
• Aderol, rinalin, nicotine
-Increases BP
Describe the effects of Beta agonists
• Increases HR and increases BP
What can uncontrolled hypertension cause?
• Causes problems in eyes and kidney
Describe hypertensive kidney disease
o High pressure destroys commonly afferent arterioles (bc high hemodynamic pressure)
o If you slice the walls of the kidneys you can see…
o Hyaline Arteriolosclerosis
o Hyperplastic Arteriosclerosis
Describe hyaline Arteriosclerosis
Fingerprint of hypertension
Narrowing of the arteriolar lumen and waxy (hyaline) degenerative changes of the arteriolar walls
Glassy appearance
Increased elastic because of increased pressure
Can cause atrophy and damage of glomeruli and kidney
Describe Hyperplastic Arteriosclerosis
- Severe hypertension
- Concentric layers of hyperplastic cells (like onion skinning)
- Increasing arteriole wall thickness
Where does Atherosclerosis start?
The crib- begins when you are young and processes due to out habits
-Starts by vascular endothelial cell injury or damage- some sort of inflammation
What things contribute to atherosclerosis
o Smoking- little injuries stimulate inflammatory response
o Hypertension- increased pressure can damage lining
o Hypergylcemia- leads into development of plaques
o Diabetes can accelerate this
What is the Leading etiology for aneurisms
atherosclerosis
What are some risk factors for atherosclerosis
- Age
- Gender
- Genetics
- Hypertension
- Smoking
- Diabetes
- Cholesterol
- Homosystein
- C-reactive protein
Describe the effect of Age
Increases atheriosclerosis by -40-60 increases MI by 5 times
Describe the effect of gender
- Men are more at risk
- Women have an increased risk after menopause
- Because cause estrogen protects us
Describe the effect of genetics
Familial hypercholesterolemia
Causes hyperlipidemia
Family cardiac disease
• Male in your family over 50 with MI is significant and same with woman
Describe the effects of smoking
Smoking also lowers HDL levels
Describe the effects of hypergylcemia
High sugars and high cholesterol
What are the effects of cholesterol
Increased LDL or low HDL increased risk
What are the effects of homosystein
Toxic to endothelial cells Causes platelet aggregation Genetic predisposition have strokes and MI in their 20s • Aspirin- life of a platelet • Folic Acids
What are the effects of C- reactive protein
Indicated of inflammation
What are the 2 kinds of atheromas?
- Young
- Old
Describe young atheromas
o Squishy and spontaneous
Describe old atheromas
o Calcified and stuck
This is a loss of integrity of the blood vessels
-Abnormal dilation of blood vessels
Aneurysms
Characteristics of aneurysm
- Most common place is the circle of Willis
- Get weakness, traumatic, and infection
- Increasing radius increases the wall tension
- Start getting ballooning
Describe ruptured aneurysms
high pressure and you bleed out
o NEVER GOOD
o Only symptom is a rupture
o Asymptomatic until they rupture
Describe cerebral aneurysms
o Maybe dizziness o Pain- headache o Large hemorrhage o Family history you have to be screened MRA- every 5 years o High mortality rates
Describe aortic aneurysm
o Smoking increases risk (with hypertension or hyperlipidemia)
o Can have back or abdominal pain
o Ultrasound screening- looking at caliber of the aorta
o High rate of rupture greater than 5 years
What is the goal of a coronary catherization?
-See narrowing of the lumen and put a stent in
What can a hematoma cause?
False Lumen
