Uterine glands grow and elongate in the ........... phase of the menstrual cycle while they secrete progesterone in the ..............phase of the menstrual cycle.

Explanation

To answer the question regarding the phases of the menstrual cycle in which uterine glands grow and elongate, and when they secrete progesterone, we can break it down into the following steps:

### Step-by-Step Solution:

1. **Identify the Phases of the Menstrual Cycle**: The menstrual cycle consists of several phases, primarily the follicular phase (also known as the proliferative phase), ovulation, and the luteal phase (also known as the secretory phase).

2. **Understand the Follicular Phase**: During the follicular phase, which lasts from day 0 to day 14, the ovarian follicles mature. This phase is characterized by the growth and elongation of uterine glands in preparation for a potential pregnancy.

...