Overview of the CV system Oct31 M1 Flashcards
homeostasis def
process of maintaining constancy of our internal environment (pH, Temp, O2, etc.)
three compartements making up the total body water (TBW)
IC, EC interstitial, EC plasma
TBW % and vol
45L 60%
IC fluid % and vol
30L, 67% of TBW
EC fluid% and vol
15L, 33% of TBW
Interstitial fluid % of TBW and vol
12L, 80% of EC fluid
Plasma % of EC and vol
3L, 20% of EC fluid
pulmonary circulation compartments
right heart pum + lungs
systemic circulation compartments
left heart pump + systemic organs
pulm circulation is in ___ with systemic circ
series
organs of the systemic circulation are in ________ with each other
parallel
exception to systemic organs being in parallel
GI tract and liver are in series (but liver still receives fresh blood)
Blood conditioning organs def + 3 ex.
Receive blood in excess to maintain basal metabolic needs (lungs, kidneys, skin)
organs that are not conditionning, examples
heart, brain, skeletal muscle
relationship between P, flow and R
P = flow * R
Formula for resistance
R=(8viscL)div. (Pi*R4)
how can adapt flow equation to understand how it changes with diff parameters
In flow = P div. R, replace R by its formula.
blood pathway in right heart and pulm arteries
IVC or SVC, right atrium, tricuspid valve, right ventricle, pulm valve, pulm arteries
blood pathway in pulm veins and left heart
pulm veins, left atrium, mitral valve, left ventricle, aortic valve, aorta
how many pulm arteries and veins
2 pulm arteries
4 pulm veins
cardiac output def
Amount of blood pumper per minute from each ventricle
CO: 2 determinants
Heart rate and stroke volume
pacemaker in the heart
sinoatrial node
3 structures the AP in the heart gets through (start to end)
sinoatrial node, atrioventricular node, Purkinje fibers
AV node and Purkinje fibers conductance
AP slow to let ventricle fill in AV node. Rapid conduction in Purkinje for synchronized contraction
How AP spreads in the heart
via gap junctions
SA node contains specialized ________
muscle cells
Starling’s Law of the heart
if cardiac filling increases during diastole, stroke volume increases
stroke volume is proportional to ______ and ____
end diastolic volume (so CO too)
SS influences what portion of the heart
all
SS ntr on the heart and receptor
norepinephrine. beta-1 receptor
4 effects of SS on heart
- HR (SA node)
- AP conduction velocity
- force of contraction of atrial and ventricular muscles
- rate of contraction and relaxation
PSS influences what portions of the heart
SA node, AV node, atrial muscle
PSS ntr on heart and receptor
Ach. M2
4 effects of PSS on heart
- HR (SA node)
- AP conduction velocity (AV node)
- Force of contraction of ATRIAL muscle
- Rate of contraction and relaxation
Increase in PSS activity generally accompanied by ________
decrease in SS activity
5 requirements for effective ventricular pumping
- adequate filling at diastole
- synchronized contraction
- forceful contraction
- valves fully open
- valves don’t leak
arteries behavior (wall thickness, systole, diastole)
thick wall, expand at systole to store blood, recoil at diastole to supply blood downstream
arteries wall composition
SM, elastin, collagen
arteries are the _____ vessels
conduit
how arteriole walls differ from arteries walls
thicker, more SM, less elastic material.
why more SM cells in arterioles
can control lumen diameter to regulate blood flow
arterioles are the ___________ vessels
resistance
capillaries are the ______ vessels
exchange
how cross sectional area (total) varies in CV system
greater as go towards capillaries
venules and veins walls charact
thin, contain SM, very distensible, diameter changes actively
veins are called the _______ vessels
capacitance
why veins capacitance vessels
more than 50% blood volume stored there
Special stucture found in larger veins
one-way valves that prevent blood from flowing backwards
3 mechanisms of resistance control
- SS innervation to arterioles
- local mediators of arteriolar SM
- SS innervation to venules and veins
how SS affcts arterioles
alpha 1 R, NE, contraction of SM, reduced blood flow
how local mediators affect arterioles
increased metabolism=arteriolar relaxation and increased flow
how SS affects veins and venules
constriction, decreased venous volume, increased cardiac filling (increased SV).
Arteries and capillaries ANS innervation
none
blood cells 3 types + abundance + origin
RBCs (most abundant), platelets, WBCs (least abundant). Bone marrow is origin
serum def
plasma without clotting proteins
plasma contents
electrolytes, proteins*, nutrients, wastes
electrolytes in the blood
Na+, K+, Cl-, HCO3-
Proteins in the blood (3 categories)
albumins, globulins, fibrinogen
blood proteins functions
clotting, immune reaction, carrier proteins (fat, iron, copper, vitamin D, hormones)
most abundant plasma protein
albumin
proteins important function in plasma and why
osmotic role bc don’t cross at capillaries so more concentrated in plasma
