Since 1910, the urban population has grown by nearly 500 percent while the rural population has grown by 19 percent. ... The Census Bureau estimates that during the same 30-year period, the population of the 49 states grew by more than 82 million people, or 36 percent
Explanation:
So when u take antibiotics you kill lots of the bacteria. however you don't kill all of them. the bacteria that is left over hasn't been killed because they are resistant to the antibiotics taken. if left these bacteria will reproduce and build and species resistant to that type of antibiotics which can be incredibly dangerous. this is why it is necessary to finish your full antibiotics course so even if u feel better just to make sure you kill all the bacteria.
To know where to start and to have a model to follow
During inhalation, you breathe in and this contracts the diaphragm and moves downwards. This increments the chest cavity space which means the lungs are expanding. The intercostal muscles or the muscles in between the ribs also aids in the enlargement of the chest cavity. Both muscles contract to pull your rib cage upward and outward when you inhale. As your lungs expand, air is sucked through your nose and mouth. It then travels down to the windpipe and into the lungs to the bronchus, bronchioles and eventually in the alveoli where air exchange between carbon dioxide and oxygen happens.
The additional accessory muscles of respiration are typically used only under conditions that are of high metabolic demand or respiratory dysfunction. However, in instances where these muscles become stiff and hard, expansion of the rib cage can be quite restricted. The accessory muscles of respiration include sternocleidomastoid and the scalene muscles namely anterior, middle and posterior scalene. Both aid in elevating the rib cage. However, their involvement seems to depend on the degree of respiratory effort. During quiet breathing, the scalenes are consistently active at certain phases while the sternocleidomastoid is quite.
HABITAT- marine environments that range from the shallow estuarine to the deep sea
ADAPTATIONS
1. They are five- sided radial symmetry
2. They are able to regenerate body parts , and some species of sea stars are even able to grow a new body from a severed arm.
3. They have a water vascular system
