ch 15 Flashcards
what do each side of the heart act as
independent pump
right heart receives
deoxygenated blood
pulmonary circuit
blood pumping from left to right side gathering oxygen
pressure reservoir
elastic systemic arteries
left ventricle
pushes blood into body
60% of blood
resides in venous side of circ
arterioles are designated with
screws
metarterioles are responsible for
variable resistance
capillaries only have
endothelium
smooth muscle
vasoconstriction/dilation
arteries/ arterioles
carry blood away
what are arteries made of
fibrous and elastic connective tissue
diff between arterioles and arteries (think about responsibility
less elastic more musclular for controlling variable resistance
metarterioles
partial smooth muscle layer
capillaries
primary site of exhcange
what is the exchange between
plama and interstitial fluid
pericytes
contractile cells associated with capillaries
what do pericytes contribue to
capillary impermeability
what do pericyte secrete
paracrine factors for vasular growth and differentiation
venule
convergent pattern of flow, little connective tissue
veins
volume reservoir
veins are
more numerous that arteries
what can help with contraction in veins
skeletal muscle
blood pressure is highest in
arteries
Heart is
main generator of mechanical force
Pulse pressure
pressure wave produced by contraction of ventricular muscle, left ventricular muscle
pulse pressure decreases
because of friction
venous return
helped by valves, action of legs (kinda), skeletal muscle, respiratory pump
MAP
diastolic pressure + ⅓ (pulse pressure)
Hypotension
lower than normal MAP
BP measured by
sphygmomanometer
Flow
proportional to pressure gradient
capillaries have
the slowest velocity
kidney is responsible for
removing excess fluid volume
if bv decreases
pressure decreases
MAP is determined by
blood volume
CO
Resistance
dist of blood
drink more water
more urine
cardiovascular comp
decreasing CO or Vasodilation
kindey comp to inc pressure
ANP, lowering blood volume
myogenic auto regulation
vascular smooth muscle regulates its own state of contraction
what is secreted by vascular epithellium
paracrine signals
important paracrine signals
nitric oxide, histamine
hyperemia
locally mediated increase in blood flow
why does hyperemia a thing
to get nutrients to and wastes away from tissue
active hyperemia
increase in blood flow towards cells and tissues that are more metabolically active
reactive hyperemia
Response to some kind of occlusion/block in blood flow
Sympathetic Branch
Controls Most Vascular Smooth Muscle
ANP
signaling molecule produced by atria of heart
Angiotensin II
from angiotensinogen precursor, in liver
Most systemic arterioles
sympathetic innervation
arteriolar tone
Norepinephrine
what do norepinephrine need to bind to to lead to vasoconstriction
alpha adrenergic receptors
what do norepinephrine need to bind to to lead to vasodilation
beta adrenergic receptors
Adrenal medulla
releasing epinephrine into blood
norepinephrine
neurons
epinephrine
from blood supply
flow is reliant on
pressure gradient and resistance
pressure gradient
Mean arterial pressure - right atrial pressure
blood dist varies based on
metabolic need of tissue
how is circulation arranged
parallel circuit
Cerebral blood flow
14% total body circulation
CVCC
cardiovascular control center
Baroreceptor reflex
controls BP
what dies baroreceptor look for
stretch in vessels
If blood vessels are stretching a lot
there is more blood flowing through the blood vessel
Orthostatic hypotension
Drop in BP due to change in position, triggers baroreceptor reflex
when are you susceptible to orthostatic hypotension
But when you wake up jump off bed brush teeth
vasovagal syncope
triggered fainting from a neural stimulation
vasoconstriction
norepinephrine , serotonin, endothelin, vasopressin, angiotensin II
vasodilation
Epinenephrine, acetylcholine, nitrous oxide , bradykinin, adenosine, histamine, ANP, vasoactive intestinal peptide
increase in MAP
actiivates baroreceptor reflex which increases
what is activated by low O2
chemoreceptors
adaptive integration
respiratory and cardiovascular systems
Not just baroreceptors, but also emotional responses
can cause drop in blood pressure
Blood pressure
closely tied to body fluid balance
2 types of capillaries
continuous, fenestrated
what is metabolic activity of cells
capillary density
which blood vessel has the thinnest walls
capillaries
what are the walls of capillaries
single layer of flattened endothelial cells
sinusoids
modified capillary vessel
where are sinusoids
bone marrow, liver and spleen
continuous capillaries
more tightly sealed, inm the blood brain barrier
fenestrated capillaries
more leaky capillaries,have more pores so larger scale
most capillary exchange occurs through
diffusion and transcytosis
exchange between plasma and interstitial fluid
paracellular pathway and endothelial transport
Capillary Filtration and Absorption
bulk flow
Filtration
movement of fluid from capillaries into interstitial fluid (hydrostatic > osmotic)
Absorption
always fluid into the capillaries(osmotic>hydrostatic)
net pressure
Ph - pi
Net filtration at arterial end
capillary hydrostatic pressure is greater than colloid osmotic pressure
Net absorption at venous end
capillary hydrostatic pressure is lower than colloid osmotic pressure
lymphatic system
System of lymph vessels, network of lymph vessels
3 systems involved in lymphatic system
circulatory, immune, digestive
edema
accumulation of fluid in interstitial space
CVD
Increased circulating levels of cholesterol and triglycerides
heart failure
leads to pulmonary edema
diastolic HF
heart has trouble pulling blood
diastolic dysfunction
Wall of ventricle has reduced compliance, meaning it is able to stretch less
If not able to stretch well, that can result in reduced filling during diastole, meaning EDV would be lower
systolic hf
Can result from heart attack, could be because of reduction in contractility; due to some scar tissue being produced in heart muscle it is not able to produce enough force, so it is not able to produce enough force, not able to pump out the stroke volume
what leads to pulmonary edema
mismatch of pumping b/w right ventricle and left ventricle
If baroreceptor reflex works normally
CVCC should lead to reduction in cardiac output or dilation of arterioles
hypertension
chronically elevated blood pressure meaning that homeostatic feedback loop has failed
High BP risk factor
atherosclerosis
Ca 2+ channel blocker treats hypertension
Gonna slow down contraction of cardiac muscle, reduce heart work
diuretics
Reduces volume of blood by excreting it as urine thru kidneys
beta blockers
block beta adrenergic receptors causing lower bp
ACE inhibitor
blocks increase in blood pressure from the ras pathway
