Cardiac Physiology
Quiz yourself by thinking what should be in
each of the black spaces below before clicking
on it to display the answer.
Help!
|
|
||||
|---|---|---|---|---|---|
| Properties of Cardiac Muscle | -Striated -contraction occurs using same sliding filament mechanism.
-cardiac are diff b/c they are short, fat, branched + interconnected
-Cardiac muscle fibers have only 1-2 nuclei. More mitochondria.
🗑
|
||||
| Properties of Cardiac Muscle II | Desmosomes - hold cells together + prevent separation during contraction
Gap Junctions - Allow for AP to pass freely from cell to cell so whole heart contracts instead of a few cells
-all cells in heart are coupled electrically by gap junctions
🗑
|
||||
| Cardiac Action Potential | 1% cardiac muscle = authorhymic -> start own depolarizations which leads to dp of rest of the Heart (pacemaker cells)
-Cardiac muscle = all or none effect
-abs refractory period of card. musc. longer - almost as long as contraction.
🗑
|
||||
| Cardiac Muscle Contraction | 90%- contractile - resp. for pumping heart
10-20% Ca need for contraction enters extracellular space.
Depolarization -> Na channels opened
Slow Ca opened ->influx of Ca
K+ enters = repolarization * READ NOTES
🗑
|
||||
| Excitation + Electrical Events: Intrinsic Conduction System of Heart | - heart does not depend on nervous system to depolarize/contract. inbuilt mechanism = intrinsic cardiac conduction system. Pacemake cells→self excitory + initiate/distribute impulses.
🗑
|
||||
| Cardiac Conduction System | Sinoatrial Node→R atrium where superior vena cava enters.
Internodal Pathways→direct pathway from SA node to AV - no gap junctions.
AV Node→ fibrous septum btwn R atrium + R vent.
Purkinje Fibres→branch off AV bundle
🗑
|
||||
| Cardiac Conduction System II STEP 1 | Activation of an AP in the SA node first
Time = 0
🗑
|
||||
| Cardiac Conduction System II STEP 2 | Transmitted into the atrial myosites
-Reaches AV Node
Time = 50 sec
🗑
|
||||
| Cardiac Conduction System II STEP 3 | 100-second delay @ AV Node. Atrial Contraction begins.
Time = 150 sec
🗑
|
||||
| Cardiac Conduction System II STEP 4 | Impulse travels along the interventricular septum
within AV bundle. Bundle branches into Purkinje Fibres via moderater band to papillary muscles of R ventricle
time = 175 sec
🗑
|
||||
| Cardiac Conduction System II STEP 5 | Impulse distributed by Purkinje fibres. relayed thruout ventricular myocardium. Atrial contraction completed. Vent. contraction begins
time = 225 seconds
🗑
|
||||
| Cardiac Conduction System III | No gap junctions between cardiomyocites of atria/ventricles. Av Bundle - only electrical connection btwn atria/ventricles. Branches into 2 paths -connects to purkinje fibres - rapid conduction b/c large fibres + large gap junctions
Defects = arrhymias
🗑
|
||||
| Electrocardiography | -diagnostic tests records electrical activity in heart by placing electrodes on body
P-wave-dp of atria, QRS complex-dp of ventricle+rp of atria at same time, T-wave-small rp of ventricle
🗑
|
||||
| Electrocardiography II | P-R Interval = time it takes for impulse to travel from SA>AV thru penetrating fibres down AV bundle Purkinje fibres
O-T Interval - time it takes for ventricle to contract + relax again
🗑
|
Review the information in the table. When you are ready to quiz yourself you can hide individual columns or the entire table. Then you can click on the empty cells to reveal the answer. Try to recall what will be displayed before clicking the empty cell.
To hide a column, click on the column name.
To hide the entire table, click on the "Hide All" button.
You may also shuffle the rows of the table by clicking on the "Shuffle" button.
Or sort by any of the columns using the down arrow next to any column heading.
If you know all the data on any row, you can temporarily remove it by tapping the trash can to the right of the row.
To hide a column, click on the column name.
To hide the entire table, click on the "Hide All" button.
You may also shuffle the rows of the table by clicking on the "Shuffle" button.
Or sort by any of the columns using the down arrow next to any column heading.
If you know all the data on any row, you can temporarily remove it by tapping the trash can to the right of the row.
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
Created by:
zeenat
Popular Physiology sets