Lecture 01: Intro to the CV System (Hayward) Flashcards
How are two circulatory systems connected?
In series: R and L sides push same volume of blood at same time
2 main divisions of circulatory system
pulmonary (R heart, low pressure) and systemic (L heart, high pressure)
4 components of each division of circulatory system
pump (heart), distribution system (arterial system), exchange region (capillaries), and collection system (venous system)
Main fx of atria
receive blood and assist its flow to the ventricles. Also do some pumping
Main fx of ventricles
pump blood. L–> eject blood to systemic circulation, R–> eject blood to pulmonary circulation
semilunar valves
allow for blood flow out of the ventricle into the pulmonary/systemic circulation
tricuspid valve
between RA and RV
Pulmonic valve
between RV and lung
mitral valve
b/w LA and LV
aortic valve
between LV and aorta
is opening/closing of valves active or passive?
passive; depends on pressure gradients only
AV valves
mitral and tricuspid valves
Main fx of arterial system
distribute blood. Also acts as a pressure storage system/regulates tissue blood flow and arterial pressure
Main fx of veins
reservoir of blood for rapid mobilization when additional blood flow/cardiac output is needed
main fx of capillaries
exchange of nutrients and elimination of waste
Primary regulators of BP, HR, and heart contractility
ANS and specific hormonal systems
All preganglionics release what neurotransmitter?
acetylcholine
What NT do parasympathetic postganglionics release?
Ach
What NT do sympathetic postganglionics release?
Norepinephrine
What receptors do parasym. postganglionics act on and where are they located?
Muscarinic receptors; parasym. postganglionic cell bodies located close to target tissues
Where are sympathetic postganglionic cell bodies located?
sympathetic chain or aggregations of postganglionic cells
What receptors do sympathetic postganglionics act on?
alpha or beta receptors
Where do sympathetic preganglionics originate?
TL-L3
Where do parasym. preganglionics originate?
brainstem and sacral cord
Where is vasopressin/ADH produced?
hypothalamus
where is epi produced?
adrenal medulla
RAAS –> CV system?
changes blood volume
What division of ANS innervates the vasculature?
parasympathetic
Which circulating hormones are most important to the CV system? (3)
1) RAAS
2) Vasopressin/ADH
3) Epinephrine
Blood flow
volume of blood that moves past a particular point in the CV system per unit time. Aka cardiac output
2 main factors influencing blood flow
blood pressure and resistance to flow
blood pressure
measure of the driving force propelling blood through the vessels
Flow =
F = (P1-P2)/R. The greater the pressure gradient, the better the flow
