2.1 Sexual Repro. - HUMANS Flashcards
The male reporductive system consists of 4 parts. Name each part.
a) There are a PAIR of testes that are contained in a sac called the ‘scrotum’.
b) The PENIS.
c) There are ducts connecting the testes with the penis.
d) There are 3 accessory glands. These glands secrete fluid that mixes with the sperm that’s produced by the testes.
Each teste contains roughly 500 _______ tubes called _________ tubules? What are the cells called that LINE these tubules? What do these cells undergo? The developing spermatozoa towards the WHAT that is the middle of the tubule. From the middle of the tubule the developed sperm move through the tubule collecting WHERE?
a) Each teste contains roughly 500 COILED tubes called the seminiferous tubules.
b) The cells lining the seminiferous tubules are called the germinal epithelium cells and these cells under go sperm formation.
c) Throughout the sperm formation process the cells move to the LUMEN or the middle of the seminiferous tubule. From their they migrate/move and collect in the VASA EFFERENTIA.
What is the ‘VASA EFFERENTIA’? They are _____ tubues that carry the sperm WHERE?
The vasa efferentia are coiled tubes that carry the sperm to the head of the epididymis.
The sperm remain WHERE until they are MOTILE (i.e. capable of motion)? Once they’re motile where do they go (during ejaculation)?
a) The sperm remain in the head of the epididymis for a SHORT time until they’re motile.
b) Once motile they move to the VAS DEFERENS during ejaculaiton.
WHat is the function of the VAS DEFERENS? When the sperm is being carried to the penis WHAT is the first accessory gland that secretes WHAT? The secretion is a mixture of WHAT that is used as a respiratory substrate by the sperm cells? What is the next vesicle along the way? WHat does it secrete - and what is the pH of the fluid (why is it this pH)?
a) The VAS DEFERENS are ducts connecting the head of the epididymis to the PENIS.
b) When the sperm is being carried to the penis the first gland on the way is the SEMINAL VESICLE which secretes MUCUS into the vas deferens.
c) The secretion is a mixture of fructose which is respired by the sperm cells allowing the sperm to maintain its motility.
d) The sperm and mucus fluid then move to the PROSTATE gland where where a zinc-containing fluid is secreted. The secretions are ALKALINE - this is to neutralise the acidity of the urine left over as well as the vaginal tract.
The female reproductive system.
There are 2 ovaries. The oocytes mature in follicles which develop from the ________ ________ that is found around the periphery of the ovary. Mature follicles migrate to the _______ of the ovary. This is where the secondary oocyte is released at ovulation. The ovaries ________ each month in releasing the oocyte. What lines the fallopian tubes allowing for the secondary oocyte to be swept from the ovaries. What are the names of the 3 layers of the uterus wall - comment on the thickness of the layers? Which of the3 layers is well supplied with blood and builds up and sheds each month?
a) The oocyte matures in follicles that develop from the germinal epithelium found at the periphery of the ovary. Mature follicles migrate to the surface of the ovary. This is where the secondary oocyte is released at ovulation. The ovaries alternate each month in releasing the oocyte. The epitheliated cells lining the fallopian tubues allow for the secondary oocyte to be swept from the ovaries and taken to the uterus.
b) The uterus consists of 3 layers
1. The perimetrium which is a THIN layer around the outisde the uterus.
2. The myometrium which is found in the middle - it’s a muscular layer.
3. The endometium which is the inner-most layer that is well supplied with blood. It’s this layer that builds and sheds each month unless and oocyte is fertilised in which case the embryo implants itself into the endometrium establishing pregnancy.
What is the narrow ring of connective tissue and muscle opening into the vagina from the uterus?
What is the name of the opening between the walls of the vagina?
a) The cervix.
b) The vulva.
Spermatogenesis.
What is the ploidy number of the cells making up the germinal epithelium. They divide by WHAT to make diploid spermatogonia and more of themselves. The spermatogonia then divide themselves by WHAT to make more of themeselves? Some of the diploid spermatogonia become _______ to form diploid PRIMARY speratocytes. The primary spermatocytes are diploid and therefore undergo WHAT number 1 to form haploid secondary spermatocytes? What do the haploid spermatocytes do subsequently to form haploid spermatids? The newly formed spermatids then MATURE into WHAT?
Once they become this they move towards the lumen of the seminiferous tubule and then move towards the VASA EFFERENTIA which is a series of coiled tubes that lead to the head of the epididymis.
a) The cells of the germinal epithelium are diploid (2n). They divide by MITOSIS to make diploid spermatogonia as well as more of themselves.
b) The diploid spermatogonia undergo mitosis to make more of themselves. Some of the diploid spermatogonia then ENLARGE to form diploid spermatocytes.
c) The priamry spermatocytes are diploid and undergo MEIOSIS 1 to form haploid secondary spermatocytes.
d) The haploid spermatocytes then undergo meiosis 2 to make haploid spermatids. The spermatids then mature into spermatozoa.
We shall now look at the structure of the sperm. Firstly, provide us with the length of the entire sperm in micrometers. Then give the length of the head, middle and tail.
a) What is the name of the anterior end of the sperm. What enzymes are found here? What is the purpose of the enymes found here?
b) The acrosome membrane does WHAT next which causes WHAT more to be released? WHAT does this do to zona pellucida?
c) The middle of the sperm cell is where there are many WHAT that make WHAT? These sprial around the microtubules (the microtubules extend out from the centrioles and into the axial filament that’s found in the tail.
d) The end of the sperm is the tail called the WHAT which makes lashing movements to move the sperm.
a) The sperm is 63 micrometers in length. The head is 5 micrometers, the middle is 8 micrometers and the tail is 50 micrometers.
b) The head of the sperm cell at the anterior end is called the acrosome and contains lysosyme enzymes that are used at fertilisation to digest the cells of the corona radiata.
c) Subsequently, the membrane of the acrosome RUPTURES releasing MORE enzymes that HYDROLYSE (i.e. hydrolysis) the zona pellucida. Enzymes include protease (acrosin)
d) The middle of the sperm cell is where there are many MITOCHONDRIA who make ATP. The mitochondria spiral around the microtubules which extend from the centriole and into the axial filament.
e) The end of the sperm cell is where the tail is found. The tail is called the flagellum.
Now we shall delve into OOGENESIS.
Before birth, in the developing WHAT, do the cells of the germinal epithelium of the ovary divide by WHAT to make diploid oogina and more germinal epithelial cells? The diploid oogina created then divide themselves many times by WHAT as well as _______, making diploid primary oocytes and more diploid oogina.
The diploid primary oocytes then divide by WHAT becoming WHAT ploidy number? This is all occuring in the foetus developing foetus which at birth contain millions of primary oocytes that have begun prophase 1 of meiosis 1 but have stopped. The germinal epithelial cells divide to form diploid FOLLICLE cells who surround the primary oocytes making primary follicles.
When does meiosis begin once again in the primary follicle? Just before ovulation (i.e. the release of the egg) the primary oocyte completes meiosis 1 making WHAT two things (one contains more WHAT than the other?).
a) Before birth in the developing foetus, cells of the germinal epithelium divide by mitosis to make oogina and more germinal epithelial cells.
b) The oogina themselves divide many times by mitosis as well as ENLARGE, making diploid primary oocytes and more diploid oogina.
c) The diploid oocytes then begin MEIOSIS 1 but stop at PROPHASE 1 in the ovaries. Meiosis begins again once the girl has reached the age of puberty.
The girl’s hormones stimulate the primary follicle to develop further.
d) Before ovulation the primary oocyte complete meiosis 1 creating two things. 1. POLAR body and 2. the secondary oocyte which contains most of the cytoplasm.
The secondary oocyte begins WHAT number 2 but stops at METAPHASE 2 unless WHAT happens…?
a) The secondary oocyte begins MEIOSIS 2 but stops at MEIOSIS 2 unless fertilisation occurs.
After fertilisation, meiosis 2 is completed, making an ovum contaning most of the WHAT. Another WHAT is made that holds less WHAT?
Circling back to after ovlation the GRAAFIAN follicle becomes WHAT. If fertilisation occurs what does it produce?
a) After fertilisation, meiosis 2 is completed, making and ovum that contains most of the CYTOPLASM. Another POLAR body is made that holds less CYTOPLASM.
b) The graafian follicle becomes the corpus luteum/yellow body. If fertilisation does happen the yellow body produces hormones.
Let’s look at the secondary oocyte released at ovualtion.
There is a glycoprotein layer of cells called the WHAT that surrounds the cell membrane of the secondary oocyte? If the chromosomes are in metaphase 2 of meiosis 2, where are the chromosomes located and WHAT are they attached to which shall pull them to the poles of the cell? The periphery of the secondary oocyte’s cytoplasm conatins WHAT that is involved in what’s known as the corticol reaction. What is the point of the corticol reaction - what does it STOP?
a) Zona pellucida surrounds the cell membrane of the secondary oocyte.
b) The chromosomes are located at the equator of the cell and are attached to the microtubules that shall eventually pull the chromatids to each pole of the cell.
c) The periphery of the cell has corticol granules that are involved in the corticol reaction (the last step of fertilisation).
d) This reaction STOPS polyspermy.
Before the glycoprotein layer that is the zona pellucida (a layer of cells that surround the secondary oocyte’s cell membrane) you will find the cells of the WHAT? These cells provide nutrients. How does the penis become erect - we know that there is a build up of blood - therefore what happens to the arterioles entering the penis and what happens to the venules (venules recieve blood from the capillaries) leaving?
Movement of the penis during intercourse cause the contraction of the muscles in the walls of WHAT 3 things causing ejaculation of semen into the vagina? The WHAT is enough to propel the sperm thorugh the narrow ring of connective and muscular tissue that make up the cervix?
a) The cells of the corona radiata provide nutrients to the secondary oocyte.
b) The lumen of the arterioles DIALATE (i.e. become increasing the diameter of the lumen). Meanwhile the venules (the blood vessels where blood from the capillaries collects) CONSTRICT. This builds-up blood in the spaces within the penis causing it to become erect.
c) Movement of the penis causes the contraction of the smooth muscle in the walls of the 1. PENIS 2. VAS DEFERENS 3. VASA EFFERENTIA.
d) The force of ejaculation is enough to propel the sperm through the narrow ring of connective and muscular tissue that make up the cervix.
The movement of sperm up a chemical and thermal gradient is an example of both WHAT?
a) CHEMOTAXIS - This is the migration of a cell towards a chemical stimulus. Therefore, in this case the chemical stimulus is the egg cell. The cell that migrate are the sperm cells.
b) THERMOTAXIS - A cell directs its locomotion (i.e. its movement) up or down a temperature gradient. In this case those cells are the sperm cells.
Now we shall delve into fertilisation. There are 5 parts of fertilisation. List the names (the second isn’t labelled but tell us generally what happens here). The next few cards shall ask more detail about each part.
a) CAPACITATION
b) The deposition of sperm in the vagina
c) ACROSOME REACTION
d) SPERM HEAD ENTERS
e) CORTICOL REACTION
The first part of fertilisation is ‘capacitation’. Define what capacitation is. Sperm can only do WHAT once capacitation is done? During capacitation what layer of the cell membrane is removed which is over the acrosome found at the anterior end of the sperm cell. How is the sperm’s movement/motility increased?
a) Capacitation is when the sperm cell changes certain aspects of its cell membrane allowing it to be more fluid as well as allowing the acrosome reaction to occur.
b) The glycoproteins and cholestrol are removed from the cell membrane over the acrosome.
c) Sperm motility is increased by the falgellum changing its motion. It changes to a whipping movement.
The sperm has now reached the oocyte. It has travelled up the chemical and thermal gradient. The sperm cells swim through the rings of muscular and connective tissue that make up the WHAT?
The acrosome reaction occurs next. Define ‘acrosome reaction’. What do the enzymes in the acrosome of the sperm cell hydrolyse?
The sperm now enters the secondary oocyte and it sinks into the cytoplasm of the secondary oocyte. Now, we call the secondary oocyte and ovum…
The cortical reaction is the last part. What is the point o fthis reaction? How do the corticol granules fuse with the secondary oocyte’s membrane? By what process do the digestive enzymes get released (think about y12)? What does the zona pellucida do to prevent polyspermy?
a) Cervix
b) The acrosome reaction is the use of the digestive enzymes to digest the cells of the corona radiata (cells that provide nutrition to the secondary oocyte) and the glycoprotein layer called the zona pellucida. This allows the sperm cell to fuse its membrane with the oocyte. The enzymes hydrolyse the zona pellucida around the secondary oocyte.
c) The cortical reaction prevents POLYSPERMY.
d) They (the cortical granules) fuse with the membrane after the smooth ER releases Ca2+ ions into the cytoplasm.
e) The cortical granules are released by EXOCYTOSIS.
f) The zona pellucida hardens after chemical modification.
We know that the oocyte stops at meiosis 2 metaphase 2 until the secondary oocyte is fertilised. Once the sperm enters it stimulates the completion of the 2nd meiotic division of the ovum nucleus. The 2nd polar body is expelled.
Within the first 24 hrs the first mitosis combines the genetic material of the parents to make the 2n cell of the embryo.
NO CARD - ANSWER CARD
Now we shall delve into IMPLANTATION.
As the embryo moves down the fallopian tube, it divides many time by WHAT? This process of division is called WHAT? A solid ball of 16 cells, called a _______ forms within 3 days. The WHAT process continues and the cells move in relation to one another.
At 7 days the ball becomes hollow due to a fluid-filled sac being formed in the middle called the WHAT? This ‘entity’ is called a WHAT? What are the cells around the fluid-filled sac called? They divide to form an inner cell mass.
The endometrium thickens after fertilisation due to the increased supply of WHAT? This prepares the endometrium for implantation. There is a period of 6-10 days called the WHAT window when the endometrium is RECEPTIVE?
The fluid-filled sac and the cells around it called the WHAT forms protrusions called WHAT that provide an increased WHAT allowing the absorbtion of nutrients in the endometrium layer?
a) Mitosis
b) Cleavage
c) A solid ball of 16 cells called a morula forms within the first 3 days.
d) CLeavage continues and the cells move in relation to one another.
e) The blastocoele is the fluid-filled sac and the cells around the blastocoele are called trophoblasts. The trophoblasts divide by mitosis to form an inner cell mass. This ‘entity’ is called the blastocyte.
f) The endometrium thickens due to increased blood supply. This prepares it for implantation. The 6-10 day period is called the implantation-window were the endometrium layer is most RECEPTIVE.
g) The blastocyte forms protrusions calledtrophoblastic villi that provide and increased SA. allowing the blastocyte to absorb nutirents from the endometrium layer.
Now we shall look at the PLACENTA.
What is the ‘placenta’?
What does the trophoblast develop into? What is this new thing that surrounds the embryo?
Cells of this new thing move into the trophoblastic villi and form much larger WHAT villi?
a) The placenta connects the embryo and then the foetus to the uterus wall.
b) The trophoblast devlops into the ‘chorion’ which is an outer membrane surrounding the embryo
c) Chorionic villi
The chorionic villi aquire blood from the capillaries which are connected to the WHAT arteries and vein? These are blood vessels that connect the WHAT to the uterus wall through the umbilical cord?
Projections from the endometrium between the chorionic villi are the maternal tissues of the placenta.
a) Umbilical
b) Embryo
Now we shall assess the major roles of the placenta.
a) An endocrine organ, that produces WHAT to support pregnancy?
b) Exchange between the mother’s blood and the foetal’s WHAT that also includes _______, ________, and ________. Inter-chorionic villus spaces, called lacunae contian the MOTHER’s blood. The chorionic villus cells have WHAT villi that provides a larger SA to contact the mother’s blood. There is a SHORT diffusion distance - efficient. The concentration grad. between the 2 circulations is maintained by WHAT flow enhancing exchange efficiency?
c) The placenta acts as a physical barrier between the foetal and maternal WHAT? This protects the fragile foetal WHAT from damage due to the high blood pressure of the mother.
d) The placenta provides WHAT to the foetus: maternal antibodies cross the placenta and attack the pathogens but ensure NOT to attack foetal cells despite them carrying the father’s antigens!
e) Protection against the mother’s WHAT system?
a) An endocrine organ produces HORMONES to support pregnancy.
b) Exchange between the mother’s blood and the foetal’s BLOOD that also includes WASTE PRODUCTS, RESPIRATORY GASES and NUTRIENTS. Inter-chorionic villus spaces called lacunae contain the MOTHER’s blood. The chorionic villus cells have MICRO villi providing them with a large SA to contact the mother’s blood. There is a short diffusion pathway which is to maintain effieciency. The conc. grad. between the 2 circulations is maintained by COUNTER-CURRENT flow enhancing exchange efficiency.
c) The placenta acts as a physical barrier between the foeta; and maternal BLOOD. This protects the fragile foetal blood vessels/capillaries from damage due to the high pressure of the maternal blood.
d) The placenta provides immunity to the foetus: maternal antibodies cross the placenta and attack the pathogens but ensure NOT to attack foetal cells despite them carrying the father’s antigens.
e) Protection against the mother’s IMMUNE system.
The umbilical cord: develops from the WHAT with a length of about 60cm. It transfers WHAT between the foetus and mother? The blood comes to the placenta through the umbilical cord in the two umbilical arteries. They are called arteries as the blood is coming AWAY from the feotus’s heart! This blood is LOW in WHAT and is also WHAT regarding oxygen? The blood exchanges materials with the mother’s blood at the WHAT villi and returns to the foetus in a single umbilical WHAT? Returning blood is HIGH in what and is also WHAT regarding oxygen?
a) The umbilical cord develops from the PLACENTA with a length of about 60cm. It transfers BLOOD between the foetus and mother. The blood comes to the placenta through the umbilical cord in the 2 umbilical arteries. They are called arteries as the blood is coming AWAY from the feotus’s heart… This blood is LOW in nutrients as well as OXYGEN (i.e. its deoxygenated).
b) The blood exchanges materials with the mother’s blood at the CHORIONIC villi and returns to the foetus in a single umbilical VEIN. Returing blood is OXYGENATED and HIGH in nutrients!
Now we shall look at the ‘menstrual cycle’.
In the absence of an implanted embryo into the endometrium what happens? The endometrium detaches from if a blostocyte does not implant.
The endometrium has a good BLOOD supply so when menstruation occurs blood passes thorugh the WHAT and thus exiting the body?
What are the 4 significant hormones involved in the menstrual cycle?
a) The ednometrium lingin sheds thorugh menstruation.
b) Exits the body via the ‘vagina’.
c) Follicle Stimulating Hormone (FSH), Luteinising Hormone (LH), Oestrogen and Progestrone
The start of the cycle is day number This is by definition when the WHAT occurs and passes thorugh the vagina - exiting the body as a result. The concentration of all relevant hormones is at a WHAT concentration?
The hypothalamus releases WHAT hormone (GnRH) that stimulates the anterior pituitary gland to release FSH and LH?
a) Day 0
b) Period
c) LOW
d) Gonodotrophic Releasing Hormone (GnRH)
Follicle Stimulating Hormone (FSH) - This hormone stimulates the development of WHAT that hold the primary oocyte who is still is prophase 1 of meiosis 1 since the development of the girl in the mother’s WHAT?
How many primary follicles mature?
The primary follicle form an outer layer of cells called the WHAT. This outer layer secretes fluid into the WHAT cavity? What does FSH stimulate these outer layer of cells to produce (WHICH hormone) once the mature graafian follicle (or secondary follicle) becomes the corpus luteum after ovulation?
a) This hormone stimulates the development of the primary follicle that holds the primary oocyte who is still in in prophase 1 of meiosis 1 since the development of the girl in the mother’s WOMB.
b) ONE
c) The primary follicle forms an outer layer of cells called the THECA. The THECAL cells secrete a fluid into a cavity called the antrum. FSH cause the thecal cells to produce OESTROGEN once the mature graafian follicle (or secondary follicle) becomes the corpus luteum after ovulation takes place.
Luteinising Hormone (LH) - is also released by the anterior pituitary gland as a result of the secretion of gonodotrophic releasing hormone by the hypothalamus. LH reaches a max. conc. RIGHT before WHAT occurs on about day 12 (ovualtion usually occurs on day 14). LH induces WHAT on day 14? Its HIGH conc. causes the follicle to rise WHERE in order to do WHAT on day 14?
a) Right before day 12.
b) LH induces OVULATION on day 14. Its HIGH conc. causes the follicle to rise to the surface of the ovary to release the secondary oocyte on day 14.
The remains of the graafian follicle, once ovulation has taken place, turns into the WHAT which is know as WHAT in latin?
This new entity secretes which 2 hormones? The release of these 2 homrones cause the inhibition of LH & FSH secretion by the anterior pituitary gland. Therefore, the conc. of LH and FSH after day 14 goes WHAT way (up or down)?
a) The remains of the graafian follicle, once ovulation has taken place, turns into the YELLOW BODY which is also known as the CORPUS LUTEUM in latin. This entity releases OESTROGEN and PROGESTERONE. The release of these 2 hormones causes the inhibition of LH and FSH secreted by the anterioir pituitary gland. Therefore, the conc. of LH and FSH after day 14 goes DOWN.
We say that FSH stimulates the WHAT cells (a fiborous OUTER layer) that is produced by the primary follicle producing oestrogen? As oestrogen conc. rises in the blood plasma 3 things are triggered… Name + explain them.
We say that FSH stimulates the THECAL cells to produce oestrogen. As the conc. of oestrogen RISES in the blood plasma
a) Triggers the build-up of blood in the endometrium - the endometrium is built up again.
b) Inhibits FSH release.
c) Stimulates LH production.
The corpus luteum secretes what 2 hormones? One of the hormones is important in keeping the endometrium lining maitained in the case the the secondary oocyte is WHAT and therefore implants…?
No fertilisation means that the yellow body WHAT due to the low levels of FSH and LH. As a result, of this occurance to the yellow body, the production of oestrogen and progesterone GOES WHERE (i.e. down or up)?
a) Progesterone and oestrogen
b) Progesterone maintains the endometrium lining. Maintained in case the secondary oocyte implants…
c) No fertilisation means that the yellow body DEGENERATES due to the low levels of FSH and LH.
d) Production of oestrogen and progesterone as a result goes DOWN!
a) Endometrium NO LONGER is WHAT and is therefore shed - exiting the body as a result.
b) Since oestrogen production is LOW FSH production begins to WHAT again - oestrogen is low so can’t inhibit the production of FSH! This causes the cycle to restart!
a) Endometrium NO LONGER is MAINTAINED and is therefore SHED.
b) RISE
Now we shall look at PREGNANCY itself. What is pregnancy in terms of what time period till what time period?
The amnion:
b) The embryo, later becomes the WHAT?
c) The new entity develops and grows in the uterus, enclosed in the WHAT which is a membrane that’s derived from the inner -cell mass of the blastocyte.
a) Pregnancy is defiend as the period between the first day of the last period till the birth.
b) Later becomes the foetus.
c) The amnion.
Initially, the amnion is in contact with the foetus until around 4-5 weeks when WHAT fluid accumilates and increases its volume around the 6-7 month period? The fluid is made by the mother initially, although from 4 months, the foetus contributes WHAT waste fluid? The fluid pushes the amnion OUT.
Amniotic fluid is 98% WHAT. It’s a solution of 4 things. List them. Some of the foetal cells have sloughed off (this means it’s been shed). The foetus swallows about 500 cm^3 of amniotic fluid a day. What can the volume of the amniotic fluid indicate regarding the foetus’s swallowing reflexes if we know that it should be ingesting 500cm^3 per day?
What are the 5 major funcitons of the amniotic fluid?
a) Amniotic fluid.
b) 98% water and is a solution of urea, proteins, salts and a trace of sugar.
c) The volume of the amniotic fluid can indicate the condition of the foetus’s swallowing reflexes…
d) The amniotic fluid acts as a lubricant - too little amniotic fluid can cause the fingers and toes to become webbed…, The amniotic fluid maintains the foetal temperature, The amnitotic fluid contributes to LUNG development, The amniotic fluid allows movement allowing muscle and bones to function appropriately BEFORE birth…, finally The amniotic fluid acts as a SHOCK absorber protecting the foetus from injury from outside the UTERUS….
