An image sensor module comprising: a circuit board including a center section located between a first side section and a second side section, the first side section and the second side section each extending in a respective plane transverse to a plane of the center section to define a module interior volume there between, the module interior volume extending from a forward end of the circuit board and a rearward end of the circuit board; an image sensor having a bottom planar surface and a top planar surface; a turning prism having a mounting surface and an image receiving surface, wherein the mounting surface is secured to the top planar surface of the image sensor within the module interior volume with the image receiving surface facing at least one of in a direction from the rearward end of the circuit board to the forward end of the circuit board and in a direction towards an outer end of a distal head comprising the image sensor module; an electronic component arrangement operatively mounted on the inner face of the circuit board between the image sensor and the rearward end of the circuit board; and one or more cables or a cable assembly, the one or more cables or the cable assembly including a number of wires entering the module interior volume at the rearward end of the circuit board, the image sensor module characterised in that: the bottom planar surface of the image sensor is securely mounted on an inner face of the circuit board within the module interior volume; and wherein the wires are operatively connected to contacts located on the circuit board in the center section, first side section, and second side section between the electronic component arrangement and the rearward end of the circuit board. a circuit board including a center section located between a first side section and a second side section, the first side section and the second side section each extending in a respective plane transverse to a plane of the center section to define a module interior volume there between, the module interior volume extending from a forward end of the circuit board and a rearward end of the circuit board; an image sensor having a bottom planar surface and a top planar surface; a turning prism having a mounting surface and an image receiving surface, wherein the mounting surface is secured to the top planar surface of the image sensor within the module interior volume with the image receiving surface facing at least one of in a direction from the rearward end of the circuit board to the forward end of the circuit board and in a direction towards an outer end of a distal head comprising the image sensor module; an electronic component arrangement operatively mounted on the inner face of the circuit board between the image sensor and the rearward end of the circuit board; and one or more cables or a cable assembly, the one or more cables or the cable assembly including a number of wires entering the module interior volume at the rearward end of the circuit board, the image sensor module characterised in that: the bottom planar surface of the image sensor is securely mounted on an inner face of the circuit board within the module interior volume; and wherein the wires are operatively connected to contacts located on the circuit board in the center section, first side section, and second side section between the electronic component arrangement and the rearward end of the circuit board. the bottom planar surface of the image sensor is securely mounted on an inner face of the circuit board within the module interior volume; and wherein the wires are operatively connected to contacts located on the circuit board in the center section, first side section, and second side section between the electronic component arrangement and the rearward end of the circuit board.