Answer:
Over 800,000
<em>Arthropods are found in all parts of the world in a wide variety of environments, from the deep sea to the frozen arctic regions. Over 800,000 species of arthropods have been identified, but scientists estimate that there may be tens of millions of species in this phylum, many of them yet to be discovered!</em>
Explanation:
correct me if im wrong
Answer: the factors that increase cardiac output include:
--> Nervous stimulation and
--> Hypertrophy of the heart.
Explanation:
Cardiac output can be defined as the quantity of blood pumped into the aorta each minute by the heart. This is also the quantity of blood that flows through the circulation. There are factors that can cause increased cardiac output or that can lead to a hypereffective heart. They are:
--> NERVOUS STIMULATION: The combination of sympathetic stimulation and parasympathetic inhibition does two things to increase the pumping effectiveness or cardiac output of the heart. These include:
• it greatly increase the heart rate from the normal level of 72 beats/mum up to 180 to 200 beats /mom.
• it increases the strength of heart contraction, which is called increased contractility to twice it's normal strength.
--> HYPERTROPHY OF THE HEART: A long term increased workload, but not so much excess load that it damages the heart, causes the heart muscle to increase in mass and contractile strength in the same way that heavy exercise causes skeletal muscles to hypertrophy. This effect of increased muscle mass of the heart, allows the heart to pump much greater than usual amounts of cardiac output.
