These are all part of the head or skull. The cavities of the
skull surround and protect the brain and sensory organs. There are five kinds
of cavities of the skull which are:
nasal cavity (paranasal sinuses is included here) - The
nasal septum split the respiratory system into two lateral halves, the nasal
cavity is also part of the respiratory system.
<span>cranial cavity - The large cranial cavity is split
into a posterior cranial fossa and an anterior cranial
fossa, a middle cranial fossa. Its function is to support the
brain.</span>
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oral cavity - The oral, or buccal, cavity (commonly called
the mouth) is a cavity of the head rather than a cavity of the skull because of
its fleshy and muscular floor.
orbital cavity - supports and defends an eyeball and its linked
muscle, vessels, and nerves.
<span>middle ear cavity - From outer to inner, three small bones-malleus,
incus, and stapes are situated within the middle-ear cavities in the
petrous part of the temporal bones.</span>
Metabolic pathways stimulate cell division.
Infection is the invasion of an organism's body tissues by disease-causing agents, their multiplication, and the reaction of host tissues to these organisms and the toxins they produce. Infectious disease, also known as transmissible disease or communicable disease, is illness resulting from an infection.
This might have been the cause of not being exposed to this specific pollen during his years in Chicago. Allergic reactions can develop when the stimuli presented even when its not contagious causes the immune system to trigger and act in a defensive stance. This delayed effect may have been the cause of the sudden expression of the immune system.