In 1822, the Canadian fur trader Alexis St. Martin was accidentally shot with a musket. The shot entered his left chest, fractured a rib, damaged the lungs, lacerated the diaphragm, perforated the stomach, and finally exited his body. Amazingly he survived, but the hole in his belly never completely healed. This allowed Dr. William Beaumont direct access to his stomach for experiments, and led to his discovery of the importance of stomach acid in digestion. Which body cavities did the musket shot pass through?

Question

A.  The shot entered the dorsal cavity and exited through the ventral cavity.
B.  The shot entered the thoracic cavity and exited through the abdominopelvic cavity.
C.  The shot entered the thoracic cavity and exited through the pleural cavity.
D.  The shot entered the pericardial cavity and exited through the pleural cavity.

Clarify Question
What is the key concept addressed by the question?
What type of thinking is required?

Gather Content
What do you already know about the body cavities? What other information is related to the question?

Choose Answer
Given what you now know, what information is most likely to produce the correct answer?

Reflect on Process
Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray?


Answer 1

B.  The shot entered the thoracic cavity and exited through the abdominopelvic cavity.

Clarify Question
What is the key concept addressed by the question?
        · The concept addressed here is the location of the body cavities relative to the organs contained within.
What type of thinking is required?
        · Analyze level:
            o This question is asking you to identify key factors that qualify something as an occupant of one of the recognized cavities of the body.

Gather Content
What do you already know about the body cavities? What other information is related to the question?
        · The vertebrate body contains two main cavities; the dorsal cavity and the ventral cavity.
        · The dorsal cavity can be divided into the cranial cavity and the vertebral cavity.
        · The ventral cavity can be divided into the thoracic cavity, which contains the pericardial and pleural cavities, and the abdominopelvic cavity, which contains the abdominal and pelvic cavities.
        · The pericardial cavity contains the heart.
        · The pleural cavities contain the lungs.
        · The abdominopelvic cavity contains the stomach and the organs below the diaphragm.

Choose Answer
Given what you now know, what information is most likely to produce the correct answer?
        · The shot never affected the lungs, so the pleural cavities can be ruled out.
        · As the shot never affected the brain or spinal cord, the dorsal cavity can be disregarded.
        · Since the shot is described as entering the chest, the associated cavity is the thoracic cavity.
        · The shot is described as going through the diaphragm and into the stomach, which means it entered the abdominopelvic cavity before it left the body.

Reflect on Process
Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray?
        · Analyze level:
            o Answering this question correctly depended not only on distinguishing between the dorsal and ventral cavities, but on your ability to break down, or analyze, the subdivisions of those cavities. If you got an incorrect answer, did you remember that the dorsal cavity contains the brain and spinal cord, or that the thoracic cavity is the chest cavity? Did you have trouble breaking down the body cavities to determine the correct answer?