Hormonal Control in Females PUBERTY DRAWING Puberty Illustration

Hormonal Control in Females • PUBERTY, DRAWING Puberty. Illustration of the changes observable at puberty in both boys and girls (genitals, weight and height, secondary sex characteristics and other characteristics developped specifically due to the secretion of testosterone in boys and estrogen in girls.

The Ovarian (Menstrual) Cycle • A regular periodic building and destruction of the inner lining of the uterus (endometrium) in correlation with ovulation. • Average cycle: 28 days • Day 1 of the cycle is the first day of menstrual flow

4 Phases of the Cycle • 1. Flow Phase: (days 1 -5) – Menstruation. • 2. Follicular Phase: (days 6 -13) – The follicle develops. – The endometrium thickens and develops. • 3. Ovulation: (day 14) – Oocyte (ovum) bursts from the follicle. • 4. Luteal Phase: (days 15 -28) – Corpus luteum develops. – Endometrium thickens. – If there is no fertilization, the corpus luteum will degenerate and progesterone levels will drop. This will cause the shedding of the endometrium (menstruation) and the cycle will repeat itself.

Toxic Shock Syndrome • What causes it? • TSS is a strain of staph, the bacterium Staphylococcus Aureus • illness that is caused by a toxin released by the bacteria is toxic to the body’s organs • Hyper-absorbent tampons may facilitate the infection because their prolonged intra-vaginal use enhances the bacterial growth. Wearing a diaphragm or sponge for more than 24 hours is not recommended because of possible risk of TSS. • Prevention? • Change tampons/pads regularily

• Does menstruation make women moody?

Hormonal Control of the cycle • FSH: (think Fish= ) • Stimulates follicle growth and development. • Stimulates the follicles to release estrogen. • LH: • • Stimulates follicle growth and development. Triggers ovulation. Maintains corpus luteum development. Stimulates progesterone secretion

Hormonal Control of the cycle • Estrogen: – Secreted from the developing follicle. – Stimulates endometrium thickening. – Stimulates the development of female secondary sex characteristics. – Stimulates the production of LH. – Inhibits the production of FSH.

Hormonal Control of the cycle • Progesterone: Secreted by the corpus luteum. – Maintains endometrium thickening. – Stimulates the enlargement of the mammary glands. – Inhibits FSH production (pituitary). – Inhibits uterine contractions Menstrual cycle Hormone simulation http: //www. abpischools. org. uk/page/ modules/hormones/horm 4. cfm? co. Sit e. Navigation_all. Topic=1 • Do Section 14. 3 Review p. 502 • Do Chapter 14 Review p. 504 -505

QUIZ-- • Male and Female parts and Hormones

Section 15. 1 – Fertilization and Embryonic Development Fertilization, Pregnancy and Birth Fertilization: The ovum remains fertile up to 15 hours after ovulation. Sperm cells can live (in the right environment) up to 72 hours after ejaculation. • This means that if fertilization is to occur, intercourse must take place no longer than 72 hours before or 15 hours after ovulation. • •

Fertilization • The ovum is transported through the fallopian tubes toward the uterus. • Fertilization must occur within the fallopian tubes due to the short life span of the ovum. • Sperm cells move from the vagina to the uterus due to contractions at orgasm. They use their flagella to swim into the fallopian tubes. • Many sperm cells are needed to dissolve the ovum membrane.

Fertilization Sperm. Race Game • Only one sperm penetrates through the outer layer of the ovum. • Acrosome reaction - When a sperm comes in contact with the egg, the acrosome (an enzyme-filled vacuole at the tip of the sperm cell) bursts and releases enzymes that digest the coating of the egg. • Cortical reaction - Once the membranes have fused, a chemical reaction occurs in the egg membrane, making it impossible for other sperm cells to enter the egg. • Nuclei of the sperm and ovum unite to form a zygote.

Cleavage and Implantation: • The zygote continues to grow and move down the fallopian tube and into the uterus. • Within 30 hrs of conception, the first cell division occurs creating 2 cells, which will divide again to make 4 cells, which will divide again… • At 16 cells it is called a morula and is a sphere • 3 -5 days after fertilization, the morula reaches the uterus and begins to fill with uterine fluids

Cleavage and Implantation: • It soon develops into a hollow fluid-filled ball of cells called a blastocyst. • The trophoblast (outerlayer) forms and will soon become the chorion layer which will eventually become the placenta • The inner cell mass will develop into the embryo • Between days 5 -7, the embryo attaches to the endometrium with the help of enzymes produced by the trophobalst • Implantation is completed by the 10 th to 14 th day

• The Great Sperm Race

h. CG • Around the time of implantation, the trophobalst produces the hormone h. CG – human chorionic gonadotropin • http: //ca. youtube. com/watch? v=Dq. X 7 Vx. W 3 w. L 0 • h. CG maintains the corpus luteum like LH past the time the corpus luteum would normally degenerate so, estrogen and progesterone continue to “maintain pregnancy” • high h. CG production for 2 months, then it drops off but not completely until birth • Placenta eventually takes over to produce estrog. & progest.

Implantation

Gastrulation: formation of germ layers • This disk will form 3 layers (endoderm, ectoderm, mesoderm). This is called gastrulation as the 3 layers are called the primary germ layers (embryo is now a gastrula) • Differentiation of cells begins allowing certain cell to have certain functions

Gastrulation • Embryonic development, computer artwork. This shows the process of gastrulation, where cells at one position on the embryo create a groove (blastopore) and migrate into the center. • The cells then differentiate into the 3 germ layers; the ectoderm, endoderm and mesoderm. The ectoderm forms epidermis and nervous tissue, the endoderm forms the digestive tract, glands and lungs and the mesoderm forms the connective tissue, including blood vessels and cartilage.