Answer;
- P-R interval
Explanation;
-P-R interval is the period of time from the onset of the P wave to the beginning of the QRS complex . This period normally ranges from 0.12 to 0.20 seconds in duration.
-The P-R interval represents the time between the onset of atrial depolarization and the onset of ventricular depolarization. A prolonged PR interval indicates delayed conduction of the sino-atrial, or SA, nodal impulse to the ventricles and is called first-degree AV block. A short PR interval can be seen when the AV node delay is bypassed.
B right atrium it receives both from the superior vena cava venea cavae
The middle layer of the Earth’s atmosphere, is called the Mesosphere. The Mesosphere is indeed where meteors will burn as the enter. The Mesosphere is the coldest layer of the atmosphere, while as you know, meteors at hot. Hope this helps you, good day.
Happy thanksgiving!
1. Mattias Schleiden
2. Robert Hooke
3. Microscope
4. Cell membrane
5. Nucleus
6. Nuclei
7. Nuclear membrane
8. Endoplasmic Reticulum
9. Ribosomes
10. Endoplasmic Reticulum
11. Lysosome
12. Vacuole
13. The Cell Wall- provides the plant structure
Chloroplasts- preform photosynthesis
Larger Vacuole- holds excess water for the plant to use later