16 &21 Reproduction and development
How long can sperm cells live in the female reproductive tract?
they can live for up to 5 days
Describe the maturation process inside an ovary during an average 28 day cycle using at least the following terms:
developing follicle: Gets bigger and bigger in fluid (1) an ovarian follicle is a fluid-filled sac that contains an immature egg, or oocyte. ... While several follicles begin to develop each cycle, normally only one will ovulate an egg. After ovulation, the follicle turns into a corpus luteum. Ovulation: when the follicle ruptures and spits out the egg (about 14 day) (3) oocyte (egg): egg matures takes about 0-14 days (2) An oocyte is the very beginning of human life - in the simplest of terms, it is an immature egg cell. Throughout the process of ovulation, this immature egg cell eventually matures and becomes an ovum, or egg. mature follicle: (5) The secondary oocyte together with the polar body and some surrounding follicle cells are released when the follicle ruptures at the surface of the ovary; this is called ovulation. corpus luteum: (4) The role of the corpus luteum depends on whether or not fertilization occurs. Sometimes, cysts can form in a corpus luteum, which can lead to painful symptoms.
What is an ectopic pregnancy?
ectopic pregnancy — happens when a fertilized egg gets stuck on its way to the uterus, often because the fallopian tube is damaged by inflammation or is misshapen. Hormonal imbalances or abnormal development of the fertilized egg also might play a role.
The process then soon stops, when does it restart?
(restart) puberty
How many egg cells will the average female release per month?
1
How long does it take from start to finish?
10 weeks, 64 days (65-75 days)
Typically, when does this begin in males?
10-16 years old, puberty
Describe the three major phases of birth
1st trimester: This means that by the time you know for sure you're pregnant, you might already be five or six weeks pregnant! A lot happens during these first three months. 2nd trimester: The baby's organs become fully developed during the second trimester. The baby can also start to hear and swallow. ... Later on in the second trimester, the baby will begin to move around. It will develop sleeping and waking cycles that a pregnant woman will begin to notice. 3rd trimester: Fetal development: The 3rd trimester. Fetal development continues during the third trimester. Your baby will open his or her eyes, gain more weight, and prepare for delivery. The end of your pregnancy is near!
How long does it take to develop an egg in the ovary so it is ready to be released?
2 weeks (after initial prophase 1)
How many sperm cells will a healthy male release per ejaculation?
A healthy adult male can release between 40 million and 1.2 billion sperm cells in a single ejaculation, (billions)
How long is an egg cell viable for fertilization once it has been released from the ovary?
After ovulation the egg lives for 12 to 24 hours and must be fertilised in that time if a woman is to become pregnant.
Name some advantages and at least one disadvantage of reproducing asexually.
Asexual Reproduction: reproduction using one set of DNA Advantage: Quick and easy (no gamete formation, no mate, no time developing offspring) Disadvantage: No variation (all offspring are clones)
When does the process of oogenesis begin in females?
Before birth (pause) in prophase
Name and briefly describe the three levels of gender development learned in lecture.
Chromosomal level: XX female (default form) XY male Gondal level: The presence of the Y chromosome causes in different gonads to develop into testes The lack of a Y chromosomes causes indifferent gonads to develop into ovaries Phenotypic level: the development of the tubular systems internally the external genitalia
What is semen and what are its contents?
Composition. Most of the fluid in semen is made up of secretions from male reproductive organs. Semen contains citric acid, free amino acids, fructose, enzymes, phosphorylcholine, prostaglandin, potassium, and zinc.
Name methods of birth control that are not gender specific or are used by both
Condom
Which can prevent pregnancy and STD's?
Condom
Which are barrier methods?
Diaphragm Condom Sponge Cervical cap
For oogenesis, answer the following questions
Happens: ovaries/inside body cavity
How does the pill work?
Hormonal methods Pill Patch Vaginal ring Give you hormones that decrease THE production so you can't make egg cells
Which types of birth control are most effective?
IUD and hormonal ones
If the egg is not fertilized, what happens next?
If you ovulate and a sperm cell doesn't successfully fertilize the egg, the egg will simply move down the fallopian tube, through the uterus, and out through the vagina. You'll menstruate about two weeks later when the uterus lining is shed.
When does it finally end/what is this called?
Menopause (end)
Name the two "cycles" included in the menstrual cycle.
Ovarian cycle Uterine cycle
Name the three stages of human embryonic development, their approximate time frames, and major events in each
Pre-embryonic: fertilization through implantation, (weeks 0-2) Embryonic: Implantation through organ development (weeks 3-7) Fetal: organ development through birth (weeks 8-40)
What is ovulation?
Rupture of ovary
B. Name at least one advantage and some disadvantages of reproducing sexually
Sexual Reproduction: Reproduction using two different sets of DNA Advantages: Variation (all offspring are unique) Disadvantages: Time and energy consuming gamete formation, finding a mate, some time in developing offspring
Compare the relative sizes of egg cell and sperm cel
Sperm- very small egg- very large
For spermatogenesis, answer the following questions:
Spermatogenesis: the process of sperm production; continuous process each spermatogonium (2n) divides by mitosis; produces 2 primary spermatocytes (2n) that undergo meiosis I and II to create 4 spermatids (n); spermatids differentiate and move to the epididymis and become motile. Happens: testes/outside body cavity
Name some methods of birth control used by the male.
Sterilization: Vasectomy
Name some methods of birth control that are female specific.
Sterilization: tubal ligation- major abdominal surgery
External Fertilization/External Development
When the egg and the sperm meet outside of the female body and the embryo would develop externally outside the body too Frogs: going to lay there eggs in the water/ only work for organisms that reproduce in the water The female will lay thousands of eggs cell in the water then the male will lay sperm cells on top Most of the effort is made into making gametes
Briefly describe the function of the following human male reproductive structures:
Testes: external to the body, site of sperm formation. Scrotum: sac that holds the testes. Epididymis: continue maturation, a highly convoluted duct behind the testis, along which sperm passes to the vas deferens. vas deferens: duct that carries sperm from epididymis to penis. seminal vesicle: protect sperm cells as it enters the female reproductive tract, releases seminal fluid to protect it The seminal vesicles (also called vesicular glands, or seminal glands, are a pair of two coiled tubular glands that lie behind the urinary bladder of some male mammals. They secrete fluid that partly composes the semen. prostate gland: large gland; secretes semen into the urethra. bulbourethral/cowper's gland: A short duct from each gland enters the proximal end of the penile urethra. In response to sexual stimulation, the bulbourethral glands secrete an alkaline mucus-like fluid. Urethra: tube that carries semen and urine. Penis: male reproduction
Internal Fertilization/External Development
The egg and the sperm meet inside the female body and the embryo continues outside the female body Reptile and birds: lay the eggs and protect them outside in the environment More effort in the paternal and maternal care in the offspring after fertilization
Internal Fertilization/Internal Development
The egg and the sperm meet inside the female body and the embryo is inside the female body Horses: give birth when it's ready and makes multiple baby animals Effort is put into making development
Where does fertilization occur in the female reproductive tract (specifically)?
The ovaries produce eggs and hormones. Fallopian tubes, Fertilization of an egg by a sperm normally occurs in the fallopian tubes.
When does it end?
They die
What hormone is released by the embryo that can be detected in mom's urine about 2 weeks after fertilization?
This fertilized egg then starts growing into an embryo and releases a hormone called hCG (human chorionic gonadotropin), which builds up in a woman's body during early pregnancy.
When is the optimum time for fertilization in the woman's cycle?
You're most likely to get pregnant if you have sex within a day or so of ovulation (releasing an egg from the ovary). This is usually about 14 days after the first day of your last period, if your cycle is around 28 days long. An egg lives for about 12-24 hours after being released.
Define the following terms:
Zygote: a diploid cell resulting from the fusion of two haploid gametes; a fertilized ovum Cleavage: Cleavage refers to the early cell divisions that occur as a fertilized egg begins to develop into an embryo Implantation: implantation is a process in which a developing embryo, moving as a blastocyst through a uterus, makes contact with the uterine wall and remains attached to it until birth. Placenta: The placenta is an organ which is responsible for nourishing and protecting a fetus during pregnancy. umbilical cord: umbilical cord is a tube-like structure that connects a fetus to the mother's placenta. A placenta is an organ attached to the uterine wall with access to the mother's blood supply. The cord contains one vein and two arteries, housed within its protective Wharton's jelly
What are the 4 hormones that control these cycles? List and describe the function of each (describe where each comes from and what organs/structures they act upon).
luteinizing hormone, follicle-stimulating hormone,estrogen and progesterone
Describe the uterine phase during an average 28 day cycle using at least the following terminology:
menstrual phase: The menstrual cycle occurs due to the rise and fall of estrogen. This cycle results in the thickening of the lining of the uterus, and the growth of an egg, proliferative phase: The proliferative phase is the second phase of the uterine cycle when estrogen causes the lining of the uterus to grow, or proliferate, during this time. As they mature, the ovarian follicles secrete increasing amounts of estradiol, and estrogen secretory phase: The next phase of the menstrual cycle is the luteal or secretory phase. This phase always occurs from day 14 to day 28 of the cycle. Progesterone stimulated by LH is the dominant hormone during this phase to prepare the corpus luteum and the endometrium for possible fertilized ovum implantation
A. Briefly describe the function of the following human female reproductive structures:
ovaries: gonads for female Ovaries are the female gonads — the primary female reproductive organs. These glands have three important functions: they secrete hormones, they protect the eggs a female is born with and they release eggs for possible fertilization. (where eggs are produced) oviducts/fallopian tubes: The oviduct is also known as the fallopian or uterine tube. It is the passageway through which the ovum passes from the ovary to the uterine cavity. The oviducts are part of the genital tract. They have a wall of smooth muscle, an inner mucosal lining and an outer layer of loose supporting tissue (serosa) Uterus: The uterus is a hollow muscular organ located in the female pelvis between the bladder and rectum. The ovaries produce the eggs that travel through the fallopian tubes. Once the egg has left the ovary it can be fertilized and implant itself in the lining of the uterus. Vagina: where the female reproductive system happens
