IP-ch15

artery

has endothelium, elastic tissue, smooth muscle, fibrous tissue

arteriole

has endothelium, smooth muscle

capillary have

has endothelium

venule

has endothelium, fibrous tissue

vein

has endothelium, elastic tissue, smooth muscle, fibrous tissue

capillaries lack

lack smooth muscle and elastic tissue reinforcement which facilitates exchange

metaarterioles

regulate flow into capillary bed

Angiogenesis

need for blood vessel development, wound healing and uterine lining growth, controlled by cytokines, collateral circulation

Elastic recoil in arterioles- ventricular contraction

ventricle contracts, semilunar valve opens, aorta and arteries expand and store pressure in elastic walls

elastic recoil in artereis- ventricular relaxation

ventricles relax, semilunar valve shuts, prevent flow back into ventricle, elastic recoil of arteries sends blood forward to circulatory system

pressure, flow and resistance

blood flows if pressure gradient is present, blood flows from high to low pressure, blood flow is opposed by resistance

factors affecting resistance

radius of blood vessels, viscosity of blood, length of system

pressure in system circulation

blood pressure is highest in arteries and decreases as it flows through circulatory system

blood pressure

pulse pressure is systolic p minus diastolic p, valves ensure one way flow in veins

mean arterial pressure

diastolic p plus 1/3 times systolic p minus diastolic p, a function of cardiac output and resistance in arterioles

blood pressure definition

fast response from the cardiovascular system and slow response by kidneys

blood pressure chart

increase blood volume leads to increase blood pressure triggers compensation by cardiovascular system is fast response for compensation by kidneys for slow response

factors that influence MAP

blood volume, heart pump effectiveness, resistance of system to blood flow, distribution of blood between arterial and venous blood vessels

arteriolar resistance

influenced by local and system control mechanisms, sympathetic reflexes, hormones

myogenic autoregulation

ability to regulate own state of contraction

paracrines

hyperemia blood flow increase metabolic activity

sympathetic control

sns norepinephrine, adrenal medulla epinephrine

hyperemia steps

high tissue metabolism, high release of metabolic vasodilators, arterioles dilate, low resistance creates high blood flow, oxygen and nutrients increase to tissue

reactive hyperemia steps

low blood to tissue, metabolic vasodilators accumulate, arterioles dilate, remove occlusion, low resistance creates high blood flow, blood flow normal

tonic control of arteriolar diameter

high norepinephrine blood vessel constricts, low norepinephrine blood vessel dialates

blood flow in precapillary sphincters

relaxes blood flows through all capillaries, constrict blood flow bypasses capillaries completely and flow thru metaarterioles

capillaries exchange

plasma and cells exchange across thin capillary wall

bone marrow, live spleen

do not have capillaries but sinusoids

exchange of plasma and interstial fluid

occurs by paracellular pathway or endothelial transport

small dissolved solutes and gases

move by diffusion

larger solutes and proteins

move by vesicular transport

bulk flow

mass movement cause of hydrostatic or osmotic pressure gradient

absorption

fluid movement into capillaries

filtration

fluid movement out of capillaries

lymphatic system

return fluid and proteins to circulatory system, absorbed fat and transfer to circulatory system, filter for pathogens

edema

caused by inadequate drainage of lymph, filtration more

edema disruption of balance between filtration and absorption

increase hydrostatic pressure, decrease plasma protein concentration, increase interstitial proteins

input to cardiovascular center

from high brain centers, propioceptors, baroreceptors, chemoreceptors

output to effectors

vagus nerve, cardiac accelerator, vasomotor nerves

chemoreceptor reflex

in aorta and carotid arteries, sense changes in blood gas and h levels, communicate with cardiovascular and respiratory

renin angio tensin aldosteron

increase blood pressure

epinephrine and norepinephrine

increase blood pressure

antidiuretic hormone

increase blood pressure

atrial natriuretic peptide

reduce blood pressure

cardiovascular not controlleable risk

sex, age, family history

cardiovascular controllable risk

smoking, obesity, sedentary lifestyle, untreated hypertension

cvd modifiable risk

blood lipids and diabetes mellitus

hypertension

carotid and aortic baroreceptor adapt, risk for atherosclerosis, heart muscle hypertrophies

hypertension treatment

calcium channel blockers, diuretics, beta blocking drugs