Flashcards
Human Reproductive System
Flashcards do conjunto (103)
- 1Diagram of Male reproductive system
- 2What is a gonad?It is an organ that produces sex cells in animals
- 3What is a gamete?It is a haploid cell capable of fertilisation
- 4Where is sperm produced?In the testes. Sperm is produced by meiosis and as a result they are haploid and have only 23 chromosome.
- 5Diagram of sperm structure
- 6What is the function of Testis?Produces sperm and testosterone
- 7What is the function of Epididymis?Matures and stores sperm
- 8What is the function of sperm duct?Carries sperm from the epididymis to the urethra
- 9What is the function of seminal vesicles, Cowper's gland and prostate gland?Produces seminal fluid which feeds the sperm and allows them to swim. Sperm and seminal fluid are collectively called semen
- 10What is the function of Urethra?Allows the passage of either urine or sperm
- 11What is the function of Penis?Places sperm inside the body of a female
- 12What is the function of scrotum?Keeps testes at a lower temperature (35 degree). This is the optimum temperature for meiosis to occur
- 13What are male hormones called?Androgens
- 14What are examples of male hormones?Follicle Stimulating Hormone (FSH)
Lutenising Hormone (LH)
Testosterone - 15Describe the FSHFSH is made in the pituitary gland. FSH is made from the onset of puberty until the end of life. Puberty takes place around the age 12-13 in males
Functional of FSH is it stimulates meiosis as a result it causes sperm to be produced - 16Describe LHMade in the pituitary gland. Made from puberty until the end of life. Function of lutenising hormone is it stimulates the production of the made hormone testosterone
- 17Describe TestosteroneIt is made in the testes. It is produce in small amount by the tests before puberty. The production of testosterone increases enormously at puberty causing thr enlargement of penis, tests and other reproduction party. Functions of testosterone is that It initially it triggering the formation of the primary male traits and at puberty It causes the secondary male traits
- 18What are primary male trait?They include the growth of the male sex organs and the movement of testosterone outside of thr body cavity
- 19What are secondary male traits?Traits that distinguish male from females, apartment from the sex organs themselves
- 20What are examples of secondary male traits?->growth of body hair
->growth of the larynx voice deepns
->growth of muscle and bone
->general body growth
->increased production of sebum - 21What is infertility?It is the inability to produce offspring
- 22What is the cause of infertility?Low sperm count may be due to one or more of the following: persistent smoking of cigarettes, alcohol abuse, use of marijuana or anabolic steroids or lack of FSH
- 23What is the treatment for infertility?Depending on cause the treatment May involve stopping taking cigarettes, alcohol, marijuana or steroid. Sometimes FSH May be injected. If all of these fail in-vitro fertilisation may be tried
- 24Diagram of the female reproductive system
- 25What is the function of an ovary?To produce the egg (ova) and to produce the hormones oestrogen and progesterone
- 26What is the function of the fallopian tube?Catches the egg from the ovary and transports it to uterus. Site of fertilisation
- 27What is the function of the uterus?Site of implantation. Holds the developing embryo. Has a lining enriched with blood vessels to nourish the embryo. Forms the placenta
- 28What is the function of the Vagina?Allows entry of sperm and exit of baby at birth
- 29What is the lining of the uterus called?Endometrium
- 30Describe the life of eggs in the female ovariesAt birth the ovaries contain a large number of potential eggs. These potential eggs are diploid as they have not yet divided by meiosis. By puberty number of potential eggs has fallen to about 40,000. Each egg is enclosed by a cluster of cells called a follicle. After puberty about 20 eggs are produced by meiosis each month. Usually only one egg will continue to grow the rest will die off
- 31How does the ovary release the egg?The graafian follicle forms the hormone oestrogen during the first half of the menstrual cycle. When the graafian follicle is mature it moves to the surface of the ovary. At ovulation the graafian follicle bursts to release an egg. The graafian follicle then enlarged, moves back into the ovary and becomes filled with yellow cells. This yellow structure is then called the corpus luteum or yellow body. The corpus luteum forms the hormone progesterone during the second half of the menstrual cycle
- 32What is the menstrual cycle?It is a series of events that take place every 28 days in the female body if fertilisation has not taken place
- 33When does the menstrual cycle begin?Puberty
- 34When does the menstrual cycle end?Menopause (45-55)
- 35Summary of what happens in day 1-5 of the menstrual cycleThe old lining of the uterus breaks down and is shed from the body. The loss of this blood and tissue is called menstruation (period). A new egg is produced in the ovary by meiosis. This new egg is surrounded by the Graafian follicle
- 36Summary of what happens in day 6-14 of the menstrual cycleThe hormone oestrogen is produced by the developing Graafian follicle. This has two function:
-> It causes the lining of the uterus to build up again in preparation for implantation
-> Oestrogen also prevents the development of any more eggs so that only one Graafian follicle develops during each menstrual cycle - 37Summary of what happens in day 14 of the menstrual cycleOvulation occurs when the Graafian follicle bursts to release the egg into the fallopian tube. The egg is normally only available for fertilisation for up to 48 hours ovulation
- 38What is ovulation?It is the release of an egg from an ovary
- 39Summary of what happens in day 14-28 of the menstrual cycleThe Graafian follicle now develops into the Corpus Luteum. This makes hormones progesterone (and some oestrogen).
-> It causes the endometrium to thicken even further
-> It also prevents new eggs from forming
If the egg is not fertilised corpus luteum starts to degenerate around day 22. This results is a reduction of progesterone levels which causes lining of the uterus to break down on day 28 and a new cycle begins again - 40What is day 11-16 known as?Fertile period as the egg that was released will die by day 16 if not fertilised. Sperm can survive for a period of time hence the fertile period begins on the 11th.
- 41What do oestrogen and progesterone both do?Both prevent eggs from developing this is why they are used in contraceptive pills. Combination of both at puberty causes the secondary sexual characteristics
- 42What do high levels of estrogen do at puberty?Causes the production of primary sexual characteristics, these are the growth of the sex organs
- 43What do both hormones do to the endometrium?Oestrogen causes the endometrium to thicken in the first half of the menstrual cycle. Progesterone continues this in the second half of the cycle
- 44What are examples of female secondary characteristics?-> Maturing and enlarging of the breast
-> Widening of the pelvis to allow for birth
-> Increased body fat
-> Growth of pubic and underarm hair
-> Growth spurt - 45What is the most common type of female infertility?is the inability to ovulate
- 46What causes female infertility?Sometimes no obvious cause. In other cases can be caused by a hormonal disorder, stress or problems with the ovary such as a tumour
- 47What are some corrective measures to be taken with female infertility?Depends on the cause. Hormonal treatment for endocrine gland failure, stress relief or surgery in other cases. As a last resort IVF may be used
- 48Describe Follicle Stimulating HormoneMade in pituitary gland, made from puberty to the menopause. Produced early in the cycle days 1-5. It stimulates meiosis, causes the production of an egg and causes the formation of the Graafian follicle, each Graafian follicle will secrete oestrogen, so FSH can be said to causes the production of oestrogen.
- 49Describe OestrogenMade in the Graafian follicle in the ovary. Made between days 5-14 of menstrual cycle. It causes the endometrium to develop. Inhibits FSH by negative feedback. High levels of oestrogen just before day 14 stimulates the release of LH
- 50Describe Lutenising HormoneMade in pituitary gland. Made in day 14. It causes Ovulation, causes the Graafian follicle to convert into the corpus luteum. Inhibits the production of oestrogen. Stimulates the production of progesterone
- 51Describe ProgesteroneMade in Corpus Luteum in the ovary. Made on day 14-28. It maintains the structure of the endometrium. Inhibits LH. Prevents the uterus from contracting. Inhibits FSH by negative feedback which prevents further eggs from developing
- 52What happens in the body if pregnancy does not occur?The corpus luteum begins to break down around day 22. By day 28 low levels of progesterone (and oestrogen) causes FSH secretion by pituitary no longer inhibited. As the FSH level rises, new eggs begin to develop. The uterus contracts and the endometrium is shed from the body. Menstruation and a new cycle have begun
- 53What is an example of a Menstrual disorder?Fibroids
- 54What are symptoms of fibroids?They are benign tumours of the uterus. They range in size from the size of a pea to the size of a grapefruit. They are most common in females age 35-45. Small fibroids produce no symptoms. Larger ones can cause severe menstrual bleeding, loss of iron (anaemia), pain, miscarriage or infertility
- 55What are the causes of fibroids?The cause of fibroids is uncertain but they seem to be linked to high levels of oestrogen, i.e they are more common in those who take contraceptive pills
- 56What are Preventation of fibroids?Avoidance of contraceptives
- 57What are treatments of fibroids?Small fibroids do not require any treatment apart from regular observation to see if they have grown. Larger fibroids are removes by surgery
- 58Graph of hormones during menstrual cycle
- 59Wsexual intercourse
- 60Describe copulationSexual arousal in the male, there is an increased blood flow to the penis. As a result the penis becomes erect. In females arousal causes the vagina to enlarge and become lubricated. During the process the penis moves inside the vagina. Breathing and heart rate increases in both partners. Copulation may result in to a climax in sexual excitement called orgasm, In males, orgasms results in semen being expelled from the penis, a process called ejaculation
- 61What is insemination?It is the release of semen into the vagina, just outside the cervix
- 62What moves the sperm along the fallopian tube?Contractions of the uterus and fallopian tubes
- 63What happens if ovulation has occurs when insemination occurs?If an egg is present, it releases a chemical that attracts the sperm. The sperm swims toward the chemical released by the egg. This is called chemotaxis
- 64How does fertilisation occur?Enzymes from the head of the sperm break down the membrane of the egg. The head of the sperm enters the egg. A new membrane forms around the egg preventing any more sperm from entering
- 65What is fertilisation?It is the union of the nuclei of the sperm and egg to form a diploid zygote. It occurs in the Fallopian tube around day 14/15
- 66What is the fertile period?Eggs can survive 2 days. Sperm can survive 3 days in female system. An egg is normally released on day 14. Fertilisation can occur if the sperm enter 3 days before this. Hence day 11-16 represent the fertile period
- 67What is the name of the solid ball of cells formed 3 days after fertilisation and the mitosis of the zygote?Morula
- 68What is the name of the hollow ball of cells around day 5?Blastocyst
- 69What will the outer cells of the blastocyst later form?The membranes around the embryo
- 70What will the inner cells of the blastocyst later form?the embryo
- 71How is the blastocyst moved down the fallopian tube?movement of the cilia
- 72What is implantation?I
- 73What happens after implantation?The trophoblast forms finger like projections (villi) which grow into the endometrium. These villi absorb oxygen and food from the blood. Around day 10, the inner cell mass becomes arranged to form 3 original layer of cells. Humans are said to be triploblastic because they arise from 3 germ layers
- 74What are germ layers?They are basic layers of cells in the blastocyst from which all adult tissues and organs will form
- 75Diagram of germ layer
- 76What does the ectoderm form?Skin, nails, hair, nervous system
- 77What does the mesoderm form?Muscles, skeleton, excretory system, respiratory system, circulatory system, reproductive system
- 78What does the endoderm form?Inner lining of digestive, respiratory and excretory
- 79What is implantation?The embedding of the fertilised egg into the lining of the uterus
- 80Describe Placenta formationDuring implantation, trophoblast forms a membrane called the amnion around the developing embryo. Amniotic fluid is formed to protect the embryo by acting as a shock absorber. After implantation the embryo form an outer membrane called a chorion. This chorion develops projections (chorionic villi) which together with the blood vessels of the mother in the endometrium form the placenta. The placenta does not become functional till the about 12 weeks. The umbilical cord connects the embryo at the naval to the placenta
- 81What are the functions of the placenta?-> Exchange: The placenta allows for materials to pass from the mother's blood to the embryo and from the embryo's blood to the mother.
-> Mother to embryo: oxygen, food, antibodies, some hormones
-> Embryo to Mother: carbon dioxide, urea salts
->Barrier: The blood of the mother and embryo do not mix. This is important as:
-the blood groups of the mother and baby might not be compatible
- the blood pressure of the mother's system may cause damage to the embryo
-> Endocrine gland: The placenta makes the hormone progesterone from about week 12 of the pregnancy - 82What develops in the embryo in the first month?The heart, brain and umbilical cord form
- 83What develops in the embryo in the fifth week?The body organs and limbs start to form
- 84What develops in the embryo in the sixth week?the eyes, ears and mouth form
- 85What develops in the embryo in the eighth week?The body organs have formed. Ovaries or testes have formed. The embryo now looks like a human and is called a foetus
- 86What develops in the embryo in the twelfth week?By the end of the 12th week the placenta is fully working, bones are beginning to replace cartilage, nerve and muscles become coordinated and the baby start to move its limbs
- 87What is gestation?It is the length of time the baby spends in the uterus. Gestation lasts 9 months from the time of fertilisation
- 88Describe what happens at birthInitially progesterone is produced by corpus luteum in the ovary, but from about 12 weeks of pregnancy it is produced by the placenta. Progesterone inhibits FSH and Inhibits contractions of the uterus. Around the time of the birth, the placenta stops producing progesterone. This allows the uterus to start contracting. As the levels of progesterone drops the pituitary of the mother produces the hormone oxytocin. It greatly increases the contraction of the uterus walls
- 89Describe labourContractions of the uterus cause the amnion to burst and amniotic fluid to be released. Soon after this the baby's head is forced out. The umbilical cord is clamped and cut. A little while later, the afterbirth is expelled from the uterus
- 90What is lactation?is the production of milk by the breasts of the female
- 91What is Colostrum?Towards the end of the pregnancy the mother produces a liquid called colostrum. This is high in proteins, minerals and antibodies
- 92What is prolactin?The reduction in progesterone around the time of the birth allows the pituitary of the mother to produce the hormone prolactin. Prolactin stimulates the production of milk. Prolactin is produced as long as the mother continues to breastfeed the baby
- 93What are the benefits of breastfeeding?->Milk contains the ideal balance of nutrients needed for the baby
->Breast milk supplies the baby with antibodies which offers extra resistance against infection
->Safer for the baby- less risk of microbes from bottles
->May reduce the risk of breast cancer in the mother - 94What is birth control?It means the steps that are taken to limit the number of children that are born
- 95What is contraception?It prevents fertilisation or pregnancy
- 96What are the 4 types of contraception?1. Natural
2. Mechanical
3. Chemical
4. Surgical - 97What is natural contraception?In natural contraception intercourse is avoided on the days immediately before or after ovulation (day 11-16)
Methods used to predict ovulation include:
->Recording temperature (rises at ovulation)
->Observing changes in the nature if the mucus at cervix at ovulation
->Predicting the day of ovulation based on previous menstrual cycles - 98What is mechanical contraception?Physical barriers used to prevent sperm from reaching the egg. These methods are about 97% effective. A condom is placed over the top of the penis (also protects from STI). A diaphragm or cap is placed in the vagina and over the cervix. A coil or IUD is placed in the uterus. This prevents implantation
- 99What is chemical contraception?Hormonal methods are about 99% effective. Contraceptive pill consists of a combination of oestrogen and progesterone. These hormones can be implanted under the skin. Spermicides kill sperm. They are usually used in conjunction with the mechanical methods of contraception
- 100What is surgical contraception?These methods are normally permanent and result in sterilization. Almost 100% effective. In females fallopian tubes are cut and tied in a process called tubal ligation. This prevents sperm reaching the egg. In males the sperm ducts are cut and tied in a process called a vasectomy. This means there are no sperm present in the semen
- 101What is in vitro fertilisation?Used to treat male or female infertility. IVF involves removing the eggs from an ovary and fertilizing them outside of the body
- 102What is the IVF process?Normally female is given hormones at start of her cycle to stimulate egg production. Around the middle of the cycle the eggs are removed from the ovary and mixed with sperm in a glass container. It is normal for a number of eggs to be fertilised and develop into embryos. The embryos may be genetically screened. Some of the embryos are placed in the uterus in the hope that implantation will take place for one or more. If plantation takes place, the pregnancy follows the normal path
- 103What are the ethical issues of IVF?Concerns with unused embryos that are not placed in the uterus. At present they are frozen for a long time and then destroyed
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- Leaving Certificate Biology (Human Reproductive System) FlashCards sobre Human Reproductive System, criado por Adrianna Bialecka em 14-03-2023.
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- Adrianna Bialecka
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