In a typical ECG (Electrocardiogram) the first wave obtained is P wave; The P wave represents the depolarization of the atria. After this, the QRS complex is formed. The QRS wave represents the depolarization of the ventricles. During the depolarization phase, the ventricles contracts and pushes the blood into the atria. Hence, the correct answer is depolarization of the ventricles.
1. They are easy to raise.
2. Have many offspring during per mating.
3. It can fertilize itself.
4. It has varieties in genotype that is easy observable.
5. It has phenotype that is also easy observable.
Answer:
Myogenic mechanisms
Hormones
Sympathetic nervous system
Explanation:
Myogenic mechanisms work in the arterioles that serve the glomerulus.
They cause the smooth muscle cells in the arterioles to contract and relax in response to blood pressure changes.
The sympathetic nervous system increases blood flow through the kidneys during resting conditions.
At times of stress, it decreases blood flow through the kidneys, making it more available to the rest of the body.
The hormones angiotensin and aldosterone regulate blood volume by controlling retention of Na⁺ and water.
C is wrong. The parasympathetic nervous system mainly controls visceral organs such as glands.
The average red blood cell lives for 120 days.
2. There are 2.5 trillion (give or take) of red blood cells in your body at any moment. To maintain this number, about two and a half million new ones need to be produced every second by your bone marrow.That's like a new population of the city of Toronto every second.
3. Considering all the tissues and cells in your body, 25 million new cells are being produced each second.That's a little less than the population of Canada - every second !
4. A red blood cell can circumnavigate your body in under 20 seconds.
5. Nerve Impulses travel at over 400 km/hr (25 mi/hr).
6. A sneeze generates a wind of 166 km/hr (100 mi/hr), and a cough moves out at 100 km/hr(60 mi/hr).
7. Our heart beats around 100,00 times every day.
8. Our blood is on a 60,000-mile journey.
