What is the difference between the axial and appendicular skeleton?

The axial skeleton is the central line of the body like skull, ribs, sternum whereas the appendicular skeleton comprises the rest of bones like limbs and appendages.

Explanation:

The skeleton system can be divided into two major divisions - Axial and appendicular skeleton. Axial skeletons form the central part, or the bones lying midline of the body. These bones are ribs, skull, spine and the sternum. These bones are protected vital organs of the body.

The rest of bones other than axial skeleton are part of the appendicular skeleton. These bones have mainly limb and appendages. These bones provide support to the body.

Thus, the major differences are mentioned above.

the level of progesterone is low at the pre-ovulatory phase of the cycle but it gradually increases and the levels are high at the luteal phase. if pregnancy occurs, the level of progesterone will be high throughout the pregnancy.

if egg is fertilized and the mother gets pregnant, progesterone starts preparing the uterus for the implantation. it starts building up the lining of uterus and make it hostile of the period of pregnancy.