Why is the pharynx considered to be part of the digestive system and the respiratory system?

The primary function of the respiratory system is to supply the blood with oxygen in order for the blood to deliver oxygen to all parts of the body. the respiratory system does this through breathing. when we breathe, we inhale oxygen and exhale carbon dioxide. this exchange of gases is the respiratory system's means of getting oxygen to the blood.respiration is achieved through the mouth, nose, trachea, lungs, and diaphragm. oxygen enters the respiratory system through the mouth and the nose. the oxygen then passes through the larynx (where speech sounds are produced) and the trachea which is a tube that enters the chest cavity. in the chest cavity, the trachea splits into two smaller tubes called the bronchi. each bronchus then divides again forming the bronchial tubes. the bronchial tubes lead directly into the lungs where they divide into many smaller tubes which connect to tiny sacs called alveoli. the average adult's lungs contain about 600 million of these spongy, air-filled sacs that are surrounded by capillaries. the inhaled oxygen passes into the alveoli and then diffuses through the capillaries into the arterial blood. meanwhile, the waste-rich blood from the veins releases its carbon dioxide into the alveoli. the carbon dioxide follows the same path out of the lungs when you exhale.the diaphragm's job is to pump the carbon dioxide out of the lungs and pull the oxygen into the lungs. the diaphragm is a sheet of muscles that lies across the bottom of the chest cavity. as the diaphragm contracts and relaxes, breathing takes place. when the diaphragm contracts, oxygen is pulled into the lungs. when the diaphragm relaxes, carbon dioxide is pumped out of the lungs. write one paragraph (at least 6 sentences) describing the path of oxygen through the respiratory system. also include why this "order of operations" is the way it is!

Poliovirus is an rna virus of the picornavirus group, which uses its rna as mrna. at its 5' end, the rna genome has a viral protein (vpg) instead of a cap. this is followed by anontranslated leader sequence, and then a single long protein-coding region (~7000 nucleotides), followed by a poly-a tail. observations were made that used radioactive amino acid analogues. short period use of the radioactive amino acids result in labeling of only very long proteins, while longer periods of labeling result in several different short polypeptides. what conclusion is most consistent with the results of the radioactive labeling experiment? a) host cell ribosomes only translate the viral code into short polypeptides.b) the rna is only translated into a single long polypeptide, which is then cleaved into shorter ones.c) the rna is translated into short polypeptides, which are subsequently assembled into large ones.d) the large radioactive polypeptides are coded by the host, whereas the short ones are coded for by the virus.

How can someone meet the need to belong in a healthy way?