Term
|
Definition
|
|
Term
|
Definition
| receive blood from venous system |
|
|
Term
|
Definition
|
|
Term
|
Definition
| separates 2 pumps on 2 sides of the heart |
|
|
Term
| flow of blood in the heart |
|
Definition
| tissues-> superior and inferior vena cava -> right atrium -> right ventricle -> pulomonary arteries -> lungs |
|
|
Term
|
Definition
| layer of dense connective tissue b/w atria and ventricles |
|
|
Term
|
Definition
| 1 unit formed from myocardial cells of atria attaching to top of fibrous skeleton |
|
|
Term
|
Definition
| rings formed by fibrous skeleton to hold heart valves |
|
|
Term
|
Definition
| path of blood from right ventricle through lungs and back to heart |
|
|
Term
|
Definition
| path of blood from left ventricle to body and back to heart |
|
|
Term
| 3 pathways in which blood flow is regulated |
|
Definition
extrinsic pathway
paracrine regulation
intrinsic regulation |
|
|
Term
|
Definition
sympathetic
parasympathetic
endocrine |
|
|
Term
|
Definition
nitric oxide
bradykinin
prostacyclin
endothelin-1 |
|
|
Term
| intrinsic regulation of blood flow |
|
Definition
myogenic control mech.
metabolic control mech. |
|
|
Term
|
Definition
in viscer, skin, etc
-alpha adrenergic stimulation: Norepinephrine=vasoconstricion
in skeletal muscle:
-beta adrenergic stimulation: epinephrine = vaso dilation |
|
|
Term
| parasympathetic regulation |
|
Definition
digestive tract, external genitalia, salivary glands
-causes vasoDILATION |
|
|
Term
|
Definition
| molecules produced in one tissue will help to regulate antoher tissue in the same organ |
|
|
Term
| Paracrine pathway: VASODILATORS |
|
Definition
nitric oxide
bradykinin
prostacyclin |
|
|
Term
| paracrine pathway: vasoconstrictors |
|
Definition
|
|
Term
| myogenic control mechanism |
|
Definition
| changes in arterial pressures compensated in some organs by appropriate changes in vascular smooth muscle |
|
|
Term
| Example of myogenic control mechanism |
|
Definition
| in the brain a DECREASED BLOOD PRESSURE is counteracted by vasoDILATION to keep blood flow constant |
|
|
Term
|
Definition
| accumulation of various chemicals which are metabolic byproducts signal the blood vessels to increase blood flow to remove accumulation of toxic molecules |
|
|
Term
| factors that may trigger vasoDILATION and increased blood flow (metabolic control) |
|
Definition
1. decreased O2 concentrations
2. increased CO2 concentrations
3. decreased tissue pH
4. released adenosine or K+ from cells
ex: exercise |
|
|
Term
| sponteous depolarizaion is caused by |
|
Definition
| Na+ flowing through channel that opens when hyperpolarized (HCN channel) |
|
|
Term
|
Definition
| open at threshold creating upstroke and contraction |
|
|
Term
|
Definition
| repolarization by opening these channels |
|
|
Term
| parasympathetic (vagal) activation |
|
Definition
release ACh onto SA node
DECREASES pacemaker rate
INCREASES K+
DECREASING slow inward Ca++ and gNa+
pacemaker current (If) is suppressed
-these ionic conductance changes DECREASE the slope of phase 4 of the AP, thereby INCREASING time required for threshold
hyperpolarizes the pacemaker cell during phase 4, results in longer time to reach threshold |
|
|
Term
| depolarization of MYCARDIAL |
|
Definition
| opens calcium channels in SR (calcium induced calcium release) |
|
|
Term
|
Definition
troponin
and stimulates contraction |
|
|
Term
| during depolarization, Ca++ |
|
Definition
| pumped out of cell and into SR |
|
|
Term
| myocardial AP sequence of events |
|
Definition
Membrane potential reaches threshold when stimulated by action potential
2. volt gated Na (fast)channels open
3. volt gated K+ open
4. volt gated slow Ca+ open
5. Rapid repolarization by K+ channels |
|
|
Term
|
Definition
| a multinucleated mass of cytoplasm resulting from fusion of cells |
|
|
Term
|
Definition
aggegate in plaques with the purpose to propagate wave of depolarizaion and reploarizaion
connexons
-homo or heterohexomeric
gated
-chemical, voltage, docking
act as pores connecting cytoplasm of 2 neighboring cells
permeability is NOT selective: limited by size; Ca+, cAMP, cGMP, IP3 |
|
|
