Female Reproduction

The Menstrual Cycle and Embryonic Development

Menstrual Cycle Notes

Purpose is to prepare the female body for babyLength is approximately 28 days4 phases: Ovulation, Luteal, Menstruation, Follicular4 hormones: FSH, LH, Estrogen, Progesterone

Menstrual Cycle PhasesOvulation- a mature egg is released from the ovaryLuteal- uterus lining is beginning to thicken to prepare for babyMenstruation- if fertilization does not occur, the uterus lining will be shedFollicular- a new egg is becoming mature in the ovary

Menstrual Cycle HormonesFSH (follicle-stimulating)- hormone that stimulates the maturation of eggs in the ovariesLH (luteinizing)- hormone that starts ovulationEstrogen- hormone that allows uterus lining to thicken, develops follicles, and will form placentaProgesterone- hormone that allows milk production, helps with onset of labor, and lowers immune response to accept pregnancy

Menstrual Cycle Themes

The menstrual cycle is a highly complex processThe menstrual cycle is achieved by 4 hormones working like an orchestra to play a symphonyThese hormones are subject to feedback mechanismsAny changes in these hormones will impact the menstrual cycle, like birth control pills, for example

Every Picture Tells A Story

As you go through the pictures that follow, see if you can understand what the stories they are trying to tell.

Menstrual Cycle and Feedback Mechanisms

Feedback Mechanisms help us understand how hormones workThe pituitary gland and the thyroid gland produce the 4 menstrual cycle hormonesThe nervous system monitors the hormones and detects changes in the female bodyOnce a change is detected and the hormone has carried out its function, the nervous system will send a message back to the endocrine system (pituitary/thyroid gland) to stop producing the hormones.

Embryonic Development as a Story

One cell to a trillion cells4 themes to the story: cleavage, patterning, differentiation, and growthEgg + Sperm unite = fertilizationHuman: 23 + 23 = 46 chromosomesZygote -> embryo -> fetus -> newborn

Embryonic Development Themes of the Story

Cleavage- the divisions that begin with the fertilized egg (mitosis)Patterning- the early organization of those cells (morula, blastula, gastrula)Differentiation- the cells are no longer the sameGrowth- the cells get bigger and develop into: tissues, organs, organ systems, highly complex organism

Placenta

Placenta is the world where the baby developsWhat happens to the mother, happens to the baby