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Aim: How are humans adapted for sexual reproduction?. Do Now. The process of meiotic cell division in a human male usually forms one diploid cell, only four diploid cells one monoploid cell, only four monoploid cells. HW:. Castle learning “Reproduction”. Humans have:.
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Aim: How are humans adapted for sexual reproduction? Do Now • The process of meiotic cell division in a human male usually forms • one diploid cell, only • four diploid cells • one monoploid cell, only • four monoploid cells HW: Castle learning “Reproduction”
Humans have: • Reproductive systems • Two versions: • Male reproductive system • Female reproductive system
The term gonads refers to the ovaries in females and testes in males
Male Reproductive System • An organ system that is controlled by the endocrine system and it’s hormones • This system allows for sexual reproduction • The main functions of the system is to produce and deliver sperm
The main structures of the male reproductive system are the • testes • epididymis • vas deferens • urethra • penis • Regulated by the hormones: • FSH – follicle stimulating hormone • LH – Lutenizing Hormone • These hormones stimulate the production of Testosterone
Epididymis Structure that is responsible for storing sperm before leaving the organism Vas Deferens • A.K.A. sperm ducts • Tube used for sperm transport • Merges with the urethra
Urethra • A tube that is responsible for two functions: • Elimination of urine • Elimination of semen Leads to the outside of the body Located in the center of the penis
Penis Male sex organ Extends off of the lower abdominal cavity Consists of erectile tissue Function – deposition of the semen inside the female reproductive tract
Glands Seminal Vesicle Prostate Gland Cowper's Gland ????? Produce and secrete a nutrient rich fluid calledseminal fluid When the sperm and the seminal fluid combine it forms a fluid known as semen
Which process is represented • by the diagram? • fertilization • production of gametes • cloning • evolution
A male sex hormone is produced within • structure A • structure B • structure E • structure F
When asked to relate the terms sperm, scrotum, testes, and zygote, a student wrote the statements below. • (A) They all contain homologous pairs of chromosomes.(B) The location of the testes within the scrotum aids in the production of sperm needed for zygote formation.(C) Mitotic cell division in involved in the formation of the testes and scrotum, and meiosis is involved in the production of sperm, which is involved in the formation of a zygote.(D) Formation of the testes, scrotum, and sperm occurs in human males; zygote formation occurs in females. • Which statements are correct? • A, B, and D, only • B, C, and D, only • B and D, only • A, B, C, and D
How are females adapted for sexual reproduction? GIRLS: We run the WORLD!!
Female Reproductive System • An organ system that is controlled by the endocrine system and it’s hormones • This system allows for sexual reproduction • The main functions of the system is to produce an egg for continuation the life • **There would be no perpetuation of life**
Ovary/Ovaries • Are egg-producing reproductive organs • often found in pairs • Ovaries in females are homologous to testes in males Ovaries are oval shaped and, in the human, measure approximately 3 cm
Contain approximately 250,000 immature eggs, called follicles, at birth • Once follicles mature and are released they are called ova/ovum.
OVIDUCTS A.K.A. Fallopian Tubes two very fine tubes leading from the ovaries of female mammals into the uterus In humans, the Fallopian tubes are about 7–14 cm long and as “thick” as three strands of hair Function: Transport egg to the uterus
UTERUS • A.K.A. the womb • Muscular organ • Connected to the fallopian tubes and the vagina * Outside of pregnancy, its size in humans is several centimeters in diameter
Function • accept a fertilized ovum which becomes implanted into the uterine wall • Obtains nourishment from blood vessels for the developing embryo
CERVIX The cervix is the lower, narrow portion of the uterus where it joins with the top end of the vagina During menstruation the cervix stretches open slightly to allow the uterine wall to be shed During childbirth, contractions of the uterus will dilate the cervix up to 10 cm in diameter to allow the fetus to pass through.
VAGINA A.K.A. Birth Canal is a fibromuscular tubular tract leading from the uterus to the exterior of the body in female mammals Functions: acts as a canal for fetus to exit the mother and location for semen to be deposited
Summary continued Which two glands in the diagram produce gametes? • glands A and B • glands B and E • glands C and F • glands E and F
This structure releases estrogen into the circulatory system. • structure 1 • structure 2 • structure 3 • structure 4 • structure 5
Menstruation involves the periodic shedding of the lining of • Structure 1 • Structure 2 • Structure 3 • Structure 4
AIM: How does the female menstrual cycle work? DID YOU KNOW>>>the ovum is the largest cell of the body (with a diameter of about 0.5 mm) Do Now: Handout
Menstrual Cycle is a recurring cycle of physiologic changes that occurs in reproductive age females of several mammals 28 days Frequency – approximately ___________ Named is derived from the latin word menses which means month
The menstrual cycle is under the control of the hormone system and is necessary for reproduction What "horomone system"? The Endocrine system
The menstrual cycle may be divided into several phases. The length of each phase varies from woman to woman and cycle to cycle. • Phases of the menstrual cycle • Menstruation • Follicular phase • Ovulation • Luteal phase
Menstruation • Menstruation is also called menstrual bleeding, a period • regular menstruation that lasts for a few days usually 3 to 5 days • the average blood loss during menstruation is 35 milliliters
FOLLICULAR PHASE • the lining of the uterus thickens • stimulated by gradually increasing amounts of estrogen • Follicles in the ovary begin developing • after several days one or occasionally two follicles become dominant (non-dominant follicles atrophy and die) • The dominant follicle releases an ovum or egg in an event called ovulation
OVULATION • When the egg has matured, it triggers the release of luteinizing hormone (LH). • In the average cycle this LH surge starts around cycle day 12 and may last 48 hours. • The release of LH matures the egg and weakens the wall of the follicle in the ovary. This process leads to ovulation: the release of the now mature ovum • The egg is swept into the fallopian tube
Luteal phase After ovulation, the residual follicle transforms into the corpus luteum The corpus luteum is the solid body formed in the ovaries This corpus luteum will produce progesterone in addition to estrogens for approximately the next 2 weeks
Progesterone plays a vital role in preparing the uterine wall to wither support a pregnancy or to be secreted In the absence of a pregnancy, progesterone levels fall. This will set the stage for the next cycle….. Progesterone withdrawal leads to menstrual shedding If fertilization of an egg has occurred, it will travel to the uterine cavity and implant itself 6 to 12 days after ovulation.