Lymphatic Circuit
specialized system of channels and tissues; reabsorbs fluid that leads from vascular network into the interstitium and return it to the general circulation
artery structure
tunica intima
innermost layer of endothelial cells in direct contact with blood; smooth muscle helps blood flow
tunica media
muscular layer of artery; smooth muscle, thickest section in arteries; helps pulse circulate blood
tunica adventitial
tough outermost layer of collagenous connective tissue (thickest section in veins)
atherosclerosis
results from formation of fatty lesions in the INTIMAL lining of large and medium sized arteries
atherosclerosis in a nutshell
lipids get into the vasuclar endothelium
WBC clear them away, making foam cells
WBCs and vascular endothelium release growth factors that promote plaque formation
plaques block the arteries
lipoproteins
more protein = higher density
more lipid =lower density
dietary lipids absorbed as __________.
chylomicrons
what do chylomicrons do?
enables fat and cholesterol to move within the water based solution of bloodstream
HDLs
made in liver
go out to the peripheral tissues and pick up lipid
carry it back to the liver
true aneurysm
involves all 3 layers of the artery wall i.e. atherosclerotic
false aneurysm
a collection of blood leaking out of the lumen, but confined next to the vessel
systolic pressure
reflects the amount of blood (SV) ejected with each heart beat and the compliance of the aorta and large arteries
stroke volume
volume of blood pumped from 1 ventricle with each beat (usually L-ventricle)
cardiac output
volume of blood being pumped by the heart, in particular by a left or right ventricle in 1 minute.
diastolic pressure
reflects the closure of the aoritc valve, the energy stored in the elastic fibers of the large arteries, and the resistance t flow through arterioles into the capillaries
--Left Ventricle Relaxing
baroreceptors
located throughout the heart and they sense pressure changes in the arteries
BP control involves...
1. cardiovascular system
2. renal system
PNS
lowers BP
lowers HR
vasodilation
HTN
most common of all health problems in adults in the US and is the leading risk factor for cardiovascular disorders
stage 2 HTN
> or = 160 systolic
> or = 100 diastolic
Primary/Essential HTN
idiopathic disorder = the chronic elevation of BP occurs without evidence of other disease
Primary HTN
90-95% of hypertension
physiologic mechanism of anti-hypertension drugs reducing BP...
reduce SV
reduce systemic vascular resistance, decrease HR
diuretics - lower vascular volume, HR, CO
ACE inhibitors
calcium channel blockers
vasodilators
Secondary HTN
attributed to a specific identifiable pathology or condition
5-10% of hypertensive cases
coarctation of aorta
narrowing of the aorta, thus ejetion of a large stroke volume into a narrowed aorta increases systolic BP
Heart Failure
the most common reason for hospitalization i those >65 years of age
Myocardial ischemia is the most common cause of ______ _______.
heart failure
HF results from...
impaired ability of myocardial fibers to contract, relax, or both
R-sided heart failure
impairs ability to move deoxygenated blood from systemic to pulmonary circulation
L-sided heart failure
impairs pumping of blood from the low pressure pulmonary to the high pressure arterial circulation
Frank -Starling Curve
the heart increases stroke volume by increasing ventricular EDV, which increases myocardial fiber stretch to optimize actin and myosin overlap
preload
stretching of ventricles or atria while filling of blood (just before contraction)
Preload treatments
ACE inhibitors
diureics
Afterload treatments
beta adrenergic blocking agents
contractility = digitalis drugs
beta blockers
blocks affects of stress hormones, decreases HR
pericardial disorders
coronary heart disease
myocardial diseases
disorders that usually appear to affect the whole heart
exudate
fluid with high protein content and cellular debris from circulatory system into lesions or areas of inflammation
Pericarditis
serous exudate
cardiac tamponade
fibrous scar tissue----constrictive pericarditis
pericardial effusion
fluid in pericardial cavity
Coronary heart disease can be divided into 2 types:
1. chronic ischemic heart disease
2. acute coronary syndrome = represents the spectrum of ischemic coronary disease ranging from unstable angina through myocardial infarction
chronic ischemic heart disease
#NAME?
stable angina
pain when heart's oxygen demand increases
variant angina
pain when coronary arteries spasm
silent myocardial ischemia
myocardial ischemia without chest pain
Acute Coronary Syndromes
ECG changes
Serum cardiac markers (proteins released from necrotic heart cells)
Acute Myocardial Infarction
chest pain
sympathetic nervous system response
hypotension and shock
An Acute MI leaves behind...
an area of yellow necrosis, soft and sharply demarcated
hypertrophic cardiomyopathy
ventricles are thick
not a normal amount of room for blood inside them, lumen smaller
restrictive cardiomyopathy
ventricles are too stiff to stretch and fill with blood
dilated cardiomyopathy
heart becomes weakened and enlarged and cannot pump sufficient blood
Valvular Disorders
disorders which usually appear to affect one side of the heart
semilunar valves
aortic valve
pulmonary valve
stenosis
valves dont open all the way
low pitch sound
regurgitation
valves dont close all the way
high pitch sound
atrial septal defects
congenital heart defect present at birth
allows blood flow between the atrias
ventricular septal defects
allows blood flow between the ventricles
endocardial cushion defects
no separation between the chambers of the heart
patent ductus arteriosus
after birth defect
ductus arteriosus
before birth defect
connects aorta and pulmonary artery (remains open)
transposition of the great vessels
2 major vessels that carry blood away from the heart (aorta and pulmonary artery) are switched (transposed)
shunt
an opening or connection that lets blood move from one side of the circulation to the other
because the left side is stronger, blood is usually pushed from the left to the right side
shunts are normal before birth
true
Foramen ovale
lets blood go from the R atrium to the L atrium to bypass the lungs
ductus venosus
lets blood go from the visceral veins to the vena cava, bypassing liver
Right to Left shunt
deoxygenated blood goes to body
Left to Right shunt
more blood goes to lungs, less blood goes to body
If blood kept leaking through the mitral valve after it had closed, when would you hear the sound of the blood moving
after mitral valve closed
after first heart sound (systole)
During stenosis, the murmur occurs when the valve is open because blood is rushing through the narrowed opening. When would you hear a murmur of mitral stenosis?
during diastole
mitral valve opens; fluid filling