The central ray for the transthoracic lateral for the proximal ...

[luminitza]

The central ray for the transthoracic lateral for the proximal humerus is directed:
 
 to enter the mid humerus and MCP
  to exit the mid humerus and MCP
  to enter the surgical neck of the affected arm and on MCP
  to exit the surgical neck of the affected arm and on MCP

Question 2

Shape distortion is a result of:
 
 angulation of the tube
  decreased OID
  decreased SID
  increased OID

[Chou]

Answer to Question 1

to exit the surgical neck of the affected arm and on MCP

Rationale: The transthoracic lateral humerus will set the CR to exit the surgical neck of the affected side as it passes through the MCP.

Answer to Question 2

angulation of the tube

Rationale: Shape distortion results when the part is not aligned parallel to the image receptor and the central ray cannot intersect the part perpendicularly.

[luminitza]

Great answer, keep it coming

[Jossy]

Excellent