Chapter 18 Flashcards
Arteries have 3 layers, what are they?
Tunica Externa- collagen
Tunica Media- smooth muscle and elastin
Tunica Intima- single Endothelium layer
Tunica Externa
protective layer for artery
collagen
*anchors vessel to surrounding tissue
*small nerve fibers and VASA VASORUM
Tunica Media
smooth muscle and elasting
- perfusion of tissue around it
- controlled by nerve signals from externa, (Norepinephrin) Neurotransmitter that binds to receptors on smooth muscle
Tunica Intima
single layer of endothelium cells & small layer of connective tissue that sits beneath endothelial layer
- Prevents clotting and big mediators of inflammation!
One of the most important functions of the endothelium:
transports O2 to cells and takes waste away
Primary Hyperlipidemia
genetic based.
- develops bc of mutation on LDL receptor
- Prevents LDL from being taken up to tissue so you get a high serum LDL level.
- creates Xanthomas
Xanthoma
cholesterol deposits on tendons, skin, elbows
Secondary Hyperlipidemia
attributed to high calorie diet, ^ triglycerides levels.
- Converts VLDL to LDL (bad cholesterol)
- LDL’s don’t get taken up in blood so ^ LDL serum levels
- need to exercise to prevent this.
- diabetes, thyroid disease, renal disorders, Cushing syndrome, obesity, alcohol, estrogen.
Hyperlipidemia
high cholesterol
* can be categorized by which lipid is elevated.
fats are carried in the blood through____
lipoproteins
Lipoprotein structure
- phospholipid membrane
* Apoliproteins- stabilize structure, activate enzymes necessary for lipoproteins to metabolize.
Apolipoproteins
- stabilize lipoprotein structure
- activate enzymes necessary for lipoprotein to metabolize
- REACTIVE sites for receptors on tissue
- Bind lipoproteins together.
LDL
low-density lipoproteins (bad)
- Lower density: less protein, more cholesterol
- transports cholesterol from liver to cells
- can be oxidized and deposited
HDL
high-density lipoproteins (good)
- Higher density: more protein, less cholesterol
- transports cholesterol from cells to liver
Risk factors for developing hyperlipidemia or atherosclerosis:
smoking diabetes coronary artery disease heart disease low activity level / sedentary lifestyle
HDL lower than___ puts you at risk for hyperlipidemai
40
Health LDL us under
< 160
Endothelial Dysfunction
reversible changes in endothelial function that occur in response to environmental stimuli
- thrombosis, atherosclerosis, hypertensive vascular lesions
- smoking/^BP/Insulin resistance/Diabetes etc..
- produces inflammatory cytokines, GF, ROS, and other disease producing substances in endothelium
Disorders of Arterial Circulation- Large, Medium, small arteris
large- aorta
medium- coronary and renal
small- arteries and arterioles that pass through the tissues
because lipids aren’t soluble in plasma, they get ___ by ___ for transport in blood
encapsulated, lipoproteins
4 types of lipoproteins
- Chylomicrons
- VLDL- very low density (^ triglycerid, not much chol/pr
- LDL- low density ( main carrier of cholesterol)
- HDL- high density ( 50% protein, less chol/tri)
2 pathways in generation and transport of lipoproteins:
- Exogenous Intestinal- transport dietary cholesterol and lipids from intestine to liver chylomicron
- Endogenous Hepatic- Processing of triglycerides and cholesterol in liver and distributed to body for energy.
small, dense, LDL are more ___ and ___ to endothelium that larger LDL
atherosclerotic, toxic
Small LDL are:
more likely to enter the endothelium wall, become oxidized, and trigger atherosclerosis
Defect in HDL clearing system, results in accelerated atherosclerosis and little or no HDL
Tangier Disease
Hypercholesterolemia
^ levels of cholesterol in blood
2 categories:
1. Primary- genetic defect ( Familial Hypercholesterolemia)
- Secondary- obesity, high calorie diet, sendary life, diabetes
Developmental Pathway of Atherosclerosis
- Fatty Streaks
- Fibrous Atheromatous Plaque
- Complicated Atherosclerotic Lesions
Fatty Streaks
thin yellow lines that run along the major arteries
- made of smooth muscle cells filled with cholesterol and macrophages
- begin in children 10-14 and develop till you’re 20.
Fibrous Atheromatous Plaque
basic lesion of atherosclerosis
- characterised by: accumulation of intracellular and extracellular lipids, proliferation of smooth muscle cells, formation of scar tissue, and calcification.
- appear as grey, white or pearly elevated thickening in the intima
Complicated Atherosclerotic Lesions
when the plaque breaks open/off, producing hemorrhage, ulceration, and scar tissue deposits.
- THROMBOSIS occurs at area of plaque break off
Atherosclerosis process at a cellular level:
- macrophages attach to endothelium
- macrophages release ROS which damages endothel
- the damage creates a hole, exposing collage for platelet adhesion to area
- fibrin deposits in the area
- Deposition of extracellular matrix follows
- some macrophages die after eating cholesterol, then release the oxidized cholesterol back into the lesion (plaque build up)
Non-traditional risk factors for atherosclerosis
C-Reactive protein (CRP)
Serum Homocysteine
Lipoprotein A
Unstable plaques
- thin fibrous caps that break off easily
- plaque rupture –> clot formation (thrombus)
- may completely block the artery or break free to become embolus
Peripheral Arterial Disease (PAD)
atherosclerotic blockages of large arteries that supply peripheral structures, NOT central structures like heart, brain.
- mainly effects men (60-70’s)
Principle symptom of chronic obstructive arterial disease:
Claudication
Claudication
pain when walking (bc of large clot in extremity)
symptoms: weak popliteal/pedal pulse, foot numb
- seen in gastrocnemius bc of highest O2 consumption when walking
- when blood flow is cut off completely: can get ischemic ulceration, gangreen, bc of loss of blood flow
Thromboangitis Obliterans (Beurger Disease)
nonatherosclerotic inflammation and thrombosis
* effects blood flow to extremities but in small arteries/veins. Tobacco use is main predisposing factor.
- predominant symptom: pain in lower extremity just sitting
- weak pulse in pedal/popliteal
- skin atrophy, ulceration, and gang green
Raynaud Phenomenon
- intense vasospasm of arteries, arterioles in fingers and toes.
- Primary- hyper activity in sympathetic NS. emotional response. attacks all 10 fingers/toes at once. NOT asymetric.
- Secondary- assoc. with previous vessel injury, collagen disease, asymmetric finger involvement, very painful
- frostbite, occupational trauma, intense heat/cold
Aneurysm
pathological outpouching or sac-like dilation in the wall of a blood vessel usually caused by weakening of the vessel wall.
- most common in arteries
The weakness in epithelium that creates aneurysms is caused by:
congenital defectors Trauma Infections atherosclerosis ^BP
True Aneurysm
Fals Aneurysm
- bounded by a complete vessel wall. Blood remains in vascular compartment
- localized dissection or tear in the inner wall of the artery w/formation of an extravascular hematoma that causes vessel enlargement
Berry Aneurysm
small, spherical dilation of the vessel bifurcation
* Circle of Willis*
Fusiform Aneurysm
involves entire circumference of the vessel and is characterized by a gradual and progressive dedication of the vessel.
- thoracic or abdominal aorta aneurysm*
Sacular Aneurysm
appear saclike over part of the vessel
Dissecting Aneurysm
false aneurysm
results from a tear in the intima layer of the vessel that allows blood to enter the vessel wall, dissecting its layers to create a blood-filled cavity
thoracic and abdominal aneurysms
worst thing it can do is rupture
- thoracic- mainly due to atherosclerosis. usually asymptomatic
- BUT* may present as substernal, neck, or back pain.
Arterial BP healthy number:
Diastolic:
Systolic:
Pulse Pressure:
120/80
diastolic: ventricular relaxation ( ^ BP: above 120)
Systolic: ventricular contraction (^ BP: above 180)
Pulse Pressure: (systolic - diastolic)
Mean Arterial Pressure:
1/3 systolic + 2/3 diastolic
Cardiac output:
HR x SV
Blood pressure:
CO x total peripheral resistance
Systolic
measures the pressure in your blood vessels when your heart beats
Diastolic
Measures the pressure in your blood vessels when your heart rests
short term Blood Pressure Regulation is meant to:
- correct temporary imbalances in BP (exercise, body position)
- maintain BP at survival levels during life-threatening situation
the neural control of BP is vested in centers that are located in the ____ of the ___ and lower third of the ___ where integration and modulation of _____ response occurs
reticular formation
medulla
pons
autonomic NS
Parasympathetic pathway for nerve impulses to the heart
vagus nerve
Sympathetic pathway for nerve impulses to the heart
Spinal cord and peripheral sympathetic nerves
Extrinsic reflexes for ANS
- mediate the cardiovascular response to stimuli originating from outside body. ( Pain, Temp)
- response channeled through hypothalamus
Intrinsic reflexes for ANS
- baroreceptor (pressure) and chemoreceptor (chemical)
- stimuli originates iwthin the cardiovascular system
- essential for rapid short-term regulation of BP
Baroreceptors
high and low pressure reeptors.
-low pressur baroreceptors ^ BP by telling kidney to reabsorb salt and water
Chemoreceptors
sense an imbalance in gas levels and change respiratory rate
* too much CO2, slow down breathing*
Epinephrin
- sympathetic neuro transmitter
- ^ HR, Cardiac Contractility, and vascular tone
Renin- Angiotensin- Aldosterone System
renin–> Angiotensin I –> Angiotensin II
- renin released due to ^ in sympathetic NS activity and low BP/fluid volume
- Renin converts Angiotensinogen to Angiotensin I.
- Angiotensin I goes to lungs __> Angiotensin II.
Angiotensin II does what?
- Strong vasoconstrictor of arterioles to ^ BP
_ Reduces sodium excretion by ^ sodium reabsorption by kidney. - Stimulates Aldosterone secretion from adrenal gland (long term regulation of BP) ^ salt and H2O retention.
Vasopressin
Antidiuretic Hormone (ADH)
- released to Increase BP and act as vasoconstrictor.
- tells kidney to not release any water.
Hypertension is classified as:
- consistent 140/ 90 mmHg or higher
Hypertensive Crisis
Hypertensive Urgency
Hypertensive Emergency
- crisis: >180/120mm Hg either/or, doesn’t have to be both
- Urgency: have ^ BP but don’t see organ damage yet.
- Emergency: see organ damage and neurological effects. Vision, kidney, heart damage, very bad.
Hypertension is classified as:
- consistent 140/ 90 mmHg or higher
Treatment of Hypertension: (drugs)
- Beta Blockers- Lower HR, decrease release of renin. Long term effect is a chronic cough.
- ACE inhibitors- inhibit conversion of angiotensin I to II.
- Calcium Channel blockers- decrease peripheral vascular resistance. inhibit movement of calcium to smooth muscle cells
- a-2 Agonists: decrease sympathetic outflow from CNS
Hypertension in Pregnancy
- Pre-eclampsia/eclampsia- hypertension after 20 wks. Proteinuria, elevated serum creatinin and liver enzymes, decreased platelets
- Gestational Hypertension- ^BP after 20 weeks. NO proteinuria, resolves by 12 weeks postpartum
- Chronic Hypertension- occurs during pregnancy but regular hypertension
Orthostatic Hypotension
abnormal drop in BP that occurs when a person stands after having been in seated or supine position.
Vericose Veins
most commonly seen vein issue.
- more women than men (pregnant women especially)
- veins that are dilated and twisted in legs, overfilled, and have lack of movement of blood in them.
the most common cause of secondary varicose veins
Deep vein thrombosis
Primary varicose veins
Secondary varicose veins
primary- superficial saphenous veins
secondary- deep venous channels
A patient with a systemic bacterial infection is at risk of developing ___
Immune Thrombocytopenic Purpura
