Building models doesn't actually help scientists observe phenomena. Scientists build models to describe how nature and systems operate then make observations to see if their models match what they observe. Models which don't match what they observe are either alterated or scrapped. Good models are kept and used by the scientific community.
Answer: There are a total of 22 bones in the skull. The skull is not only made up of bones but also cartilages and ligaments. The facial skeleton does not include the teeth and the cartilage of the nose. The skull contains foramina or canals scattered throughout the skull bones.
Answer: lymphatic circulatory; respiratory
Explanation:
The autonomic nervous system controls the internal body functions and responses which are not under the voluntary control. The functions control by the autonomous nervous system are heart rate, body fluid circulation, respiration, urination, sexual arousal and pupillary response.
The lymphatic system is one of the part of the circulatory system, it consists of a network of connected tubes called as lymphatic vessels. These vessels distribute the lymph fluid throughout the body. The lymph fluid consists of white blood cells which provide immunity against the pathogen.
The respiratory system is the system which controls the exchange of gases (Carbon dioxide and oxygen) between the body and the environment.
Both lymphatic circulation and respiration are the two functions controlled by the autonomic nervous system.