During week 2 of the menstrual cycle (day 8 to day 14 or
ovulation), estrogen levels rise until it reaches its peak. Typically, days
12-14 have the highest levels of estrogen, which causes an increase in Luteinizing Hormone, which is responsible for the release of the egg cell. If
hormone levels fail to reach its peak before day 14, ovulation is not possible
because the egg cannot be released. Pregnancy may be highly unlikely.
thylakoids
Chloroplasts contain saclike photosynthetic membranes called thylakoids, which are interconnected and arranged in stacks known as grana. Pigments are located in the thylakoid membranes. The fluid portion outside of the thylakoids is known as the stroma.
Hypothalamus is a part of the brain that links the nervous system to the endocrine system via the pituitary gland. It helps maintain the internal environment constant by regulating major processes in the body such as the heart rate and the body temperature. It is therefore, both a neural and endocrine organ.