1. Before giving a speech to the class, Johnny becomes very nervous: His eyes dilate, glands release sweat, and his blood vessels become wider. How will this affect Johnny s blood flow before his speech
a. The larger blood vessels will decrease the vessel diameter and increase blood flow throughout his body
a. His nervousness will have no effect on his blood flow
a. There will be too much blood so his blood will flow slowly.
a. His blood will become too viscous to flow through, causing Johnny to faint before his speech.

mammal

explanation:

thrombocytopenia, which is a deficiency in blood platelets, can cause bleeding and bruising in the dermis similar to senile purpura. other possible causes include: exposure to ultraviolet rays and aging skin are common causes of senile purpura. senile purpura may also be a sign of collagen loss in the skin and bones.

hypoxemia refers to a below usual concentration of oxygen in the blood, mainly in the arteries. hypoxemia is an indication of an issue associated with circulation or breathing and may lead to various symptoms like shortness of breath.  

the condition is identified by determining the level of oxygen in the blood sample obtained from an artery. it can also be predicted by determining the oxygen saturation of the blood with the application of a pulse oximeter.  

the normal arterial oxygen is about 75 to 100 mm hg. the values underneath 60 mm hg is generally considered with the requirement for supplemental oxygen. the normal pulse oximeter readings generally range between 95 to 100 percent. the values under 90 percent are regarded as low.  

in the given case, the oxygen saturation is measured at 93 percent, hence, there is no need to administer oxygen, that is, one should withhold oxygen.