Term
| Name structures of electrical system |
|
Definition
| SA Node, internodal tracts (3- PMA), Bachmann's bundle, AV Node, Bundle of His, Right BB, Left BB (anterior and posterior), Purkinje network, fibers |
|
|
Term
| Overall, it takes _____ for the electrical impulse to travel from the SA Node to the Purkinje fibers in the myocardium |
|
Definition
|
|
Term
| Name the 3 parts of the Atrioventricular junction/node-- and which part contains pacemaker cells vs. slows conduction |
|
Definition
| Atrionodal region, middle (nodal) region, lowed nodal-His region -- atrionodal and lower nodal-his region contain cells, middle nodal region slows conduction |
|
|
Term
| Name accessory conduction pathways and types/surnames of each |
|
Definition
| 1. atrioventricular pathways (type A WPW- left posterior atrium, posteroseptal WPW- posterior walls L/R atriums near node, type B WPW- anterior right atrium wall) 2. Atrio-his: aka 'James' fibers: atria-> lower av node/His region 3. nodoventricular/fasciculoventricular: "mahaim fibers": lower av->ventricles, BOHis->ventricles |
|
|
Term
| The ability of cardiac cells to conduct electrical impulses is called: |
|
Definition
|
|
Term
| Two basic kinds of cells of the heart and their function: |
|
Definition
| Myocardial (contraction/mechanical) cells- contraction and relaxation + specialized cells- generation and conduction of electrical impulses |
|
|
Term
| Contractile protein filaments present in myocardial cells are: |
|
Definition
|
|
Term
| The ability of myocardial cells to shorten and return to original length when stimulated by an electrical impulse is: |
|
Definition
| property of contractility |
|
|
Term
| Drugs that INCREASE the ability of myocardial contractility are: |
|
Definition
| digitalis, sympathomimetics |
|
|
Term
| Drugs that DECREASE the ability of myocardial cells to contract are : |
|
Definition
| quinidine, B-blockers, potassium, procainamide |
|
|
Term
| Hypocalcemia decreases/increases the myocardial force of contraction |
|
Definition
|
|
Term
| Hypovolemia and anemia decrease/increase force of myocardial contraction: |
|
Definition
|
|
Term
| Name the three layers of the ventricular walls |
|
Definition
| Endocardium, myocardium (muscular layer), epicardium (aka visceral pericardium) |
|
|
Term
| Name the layers of pericardium and its major space/cavity |
|
Definition
| visceral pericardium, (pericardial cavity w/ pericardial fluid) and parietal pericardium, *which make up* the serous pericardium, fibrous pericardium |
|
|
Term
| Name and define the 4 properties of cardiac cells: |
|
Definition
| (1) Property of conductivity- ability of cells to conduct electrical impulses (ALL) (2) property of contractility- the ability of myocardial cells to shorten and return to normal length (myo only) (3) property of automaticity-ability to spontaneously depolarize w/o external stimulation (pacemaker Only) (4) property o excitability- capability of resting cell to depolarize in response to stimulus |
|
|
Term
| The difference in concentration of ions across the cell membrane at any given time (measured in millivolts) |
|
Definition
|
|
Term
| All cardiac cells electrical potential @ rest is: ____ except in the ________ where it is ______ |
|
Definition
| -90mV ; SA and AV nodes ; -70mV |
|
|
Term
| A polarized cardiac cell has _____ on the outside, when depolarized ______. Then comes the period called______, in which potential is ____. |
|
Definition
| higher conc. positive; electrical potential has reached 0 mV ; 'the overshoot' ; +20mV |
|
|
