Module 4: Reproductive System Flashcards
(151 cards)
1
Q
What are gonads?
A
- Ovaries
- Testies
2
Q
Are ovaries connected to the fallopian tubes?
A
No, they’re attach to a ligament
3
Q
Are fallopian tubes unidirectional?
A
No, they’re bidriectional
4
Q
What is the structure of the ovaries?
A
- strong matrix (connective tissue, nerves, lymphatic and blood vessels
- Follicles
- Tunica albuginea
- Surface epithelium
5
Q
What is the name of the follicle that has been developed during birth
A
Primordial follice
6
Q
What are the 7 phases of follicles?
A
- Primordial follicle
- Primary follicle
- Secondary follicle
- Early Antral follicle
- Antral follicle
- Preovulatory follicle
- Ovulatory follicle
7
Q
What size follicle is estrogen produced by?
A
Larger follicles
8
Q
When does menopause start?
A
When there’s about <1000 primordial follicles
9
Q
What are the different cell types during folliculargenesis?
A
- Oocyte
- Granulosa cells
- Basement membrane
- Inner and outer theca cells
- Stromal cells
10
Q
What is the cluster of cells surrounding the oocyte after ovulation?
A
Cumulus cells
11
Q
How does primordial and preantral cells grow?
A
From factors release by the ovary. They are gonadotropin independent (no gonadal receptors)
12
Q
What does exogenous mean?
A
To have external factors affecting your development
13
Q
When are gonadotropin receptors developed?
A
In the early antral and preovulatory phases
14
Q
Where are the gonadotropin receptors developed?
A
On the granulosa cells
15
Q
What factor does follicles create themselves?
A
Inhibin
16
Q
Why do follicles create inhibin?
A
To create a negative feedback loop to the pituitary gland so only 1 egg becomes dominant
17
Q
Which follicles create high oestogen?
A
Early and antral follicles
18
Q
Which follicles creates high amount of oestogen for 24 hours?
A
Preovulatory
19
Q
What are the 4 phases of arrest in meiosis?
A
Prophase
Metaphase
Anaphase
Telaphase
20
Q
When does mitosis happen in oogenesis?
A
Prenatal only
21
Q
When does the primary oocyte arrest?
A
Prophase 1
22
Q
Which follicles grow during prophase 1?
A
Primordial into secondary
23
Q
When is meiosis 1 complete?
A
From childhood to adolescent, becomes an antral follicle.. will arrest at metaphase 2
24
Q
When does meiosis 2 complete?
A
After fertilisation
25
What happens to polar bodies?
They degenerate
26
What is the life cycle of an oocyte?
Primordial germ cell migrates to gonads
Becomes oogonia and begins meiosis
Becomes oocyte
Primordial follicle
Primary follicle
Secondary follicle
Early antral follicle
Antral follicle
Preovulatory follicle
Fetus
Baby
27
What is the hypothalamic-pituitary-gonadal-axis?
The loop relationship between gonadoreleasing hormones and see hormones
28
Describe the hypothalamic-pituitary-gonadal-axis
1. Hypothalamus stimulates anterior pituitary gland to release GnRH
2. Anterior pituitary releases LH and FSH
3. FSH and LH moves to the gonadotropin to stimulate follicle growth
4. Follicles sends negative feedback loop back to AP and Hypo through inhibin to stop the release of FSH and LH
This is done in a pulsatile fashion
29
Why is hypothalamic-pituitary-gonadal-axis done in a pulsatile fashion?
The gonadotrope cells become desensitised to GnRH. Which will reduce LH and FSH release, which will reduce steroid production
30
What will a fast pulse of GnRH achieve?
Increased LH
31
What will a slow pulse of GnRH achieve?
Increase FSH
32
What is the 2 cell gonadotropin hypothesis?
1. Cholesterol is released by the blood to the theca cells where the g couple protein receptor LHR accepts LH. This produces androgen (steroids- testosterone)
2. Androgens move across basement membrane of granulosa cells and triggers the FSHR to accept FSH.
3. Activation causes the enzyme aromatase to release and convert androgens to oestrogens
4. The peptide hormone inhibin creates a negative feedback loop to reduce release of LH and FSH from the pituitary gland
5. This causes smaller eggs to deteriorate and enables and single egg to fertilize
33
How is ovulation initated?
Through a surge of LH via a positive feedback loop due to oestogen.
34
What is the purpose of the corpus luteum?
To crate progesterone, which maintains the pregnancy
35
What happens to the corpus luteum if no pregnancy?
It deteriorates and menstruation occurs
36
What is another name for the menstrual cycle?
Uterine cycle
37
Define the uterine cycle
A cyclic change in endometrium in response to fluctuating ovarian hormone levels
38
Des rive the timeline and phases of the uterine cycle
1. Days 1-5 menstrual phase
2. Days 6-14 proliferative phase (preovulatory)
3. Days 15-28 secretary phase (post ovulatory)
39
What are the 2 layers of the endometrium?
Basal and functional
40
Which layer sloughs from the endometrium?
Functional layer
41
How does endometrium thicken?
1. A spike in endometrium just before ovulation also causes a spike in LH
2. This creates the corpus luteum, and a progesterone spike
3. These spikes cause a thickening of the endometrium
42
Describe the actions of estrogen in reproductive organs
1. Within the ovary thr developing follicle and corpus luteum is the major source of oestrogen
2. It is stimulated by the release of LH and FSH which creates both positive and negative feedback loops to control gonadotropin within the pituitary gland.
3. These factors stimulate growth and maturation of the reproductive organs , promote the proliferative phase of the uterine cycle, stimulate watery mucus production ans activity of fimbrar and uterine tube cilia
4. During pregnancy the mammary glands and genetlilia swell
43
Describe the actions of progesterone on reproductive organs
1. The corpus luteum is the major source of progesterone and is stimulated by the release of LH to create a negative feedback loop of gonadotropin vie the anterior pituitary gland
2. It co-operates with oestrogen to enlarge breasts, promote secretary phase of uterine cycle and creates viscous mucus production
3. It enhances the beating of cilia in uterine tube, promotion sperm and egg meeting.
4. During pregnancy it quietens myometrium and helps mammary glands produce milk
44
At what age does the suspension ligament elongate?
10-15 weeks, in utero
45
Why do testes hangoutsidr of the body?
Thermoregulation
46
What is the life cycle of sperm?
1. Gonacyte (newborns)
2. Spermatogonia
3. Primary spermatoyte
4. Secondary spermatocyte
5. Spermatid
6. Spermatozoon
47
What is the pampiniform venous plexus?
The veins and arteries within the scrotum to draw heat away from the testes
48
What is a cremastor muscle?
The muscle that moves the testes up and down for thermal regulation
49
What is the dartos muscle?
Afascia muscle that causes the scrotum to wrinkle, increasing surface area, allowing for cooling to occur faster
50
Where is sperm produced?
In seminiferous tubules
51
What is the rete testis?
A passage for sperm to move into the epididimus
52
What is the purpose of the epididmus in the male reproductive system?
To give sperm the ability to swim, it takes about 20 days. Before moving into the vas defrens
53
What is the purpose of the vas defrens in the male reproductive system?
Soerm ejaculation
54
What area of the male reproductive system is sperm stored?
The epididmus, for several months
55
Describe the features of the intratubular compartment of the testis
1. Lines with complex stratified germinal cells
2. Contains sperm and sertoli cells
56
Describe the features of the peritubular in the testes
1. Contains androgens made by leydig cells
2. Has neuronal and vascular elements
57
What cells great sperm?
Sertoli cells
58
Where do sperm first start in the sertoli cell?
On the basal layer and move into the lumen
59
Describe the process of spermogenesis
1. Stem cell spermatogonium (diploid) undergoes mitosis
2. Primary spermatocyte (diploid)undergoes meiosis 1
3. Secondary spermatocyte (haploid) undergoes meiosis 2
4. Spermatids undergo spermatogenesis
5. Spermatozoa is formed and moves into epididmus
60
What is the function of sertoli cells?
1. Maintains the blood testis barrier
2. Provides nutrients
3. Moves developing aperm towards lumen
4. Secretes testicular fluid for sperm transport
5. Phagocytosis in the vas defrens
6. Produces androgen binding protein (ABP)
7. Creates inhibit to initiate a negative feedback loop of FSH
8
61
When does meiosis occur in males?
Puberty
62
Why does the sertoli cell have a blood testis barrier?
Meiosis into a hapliod cell makes the sperm a foreign body. The blood will detect it as foreign and try to kill it with WBC
63
What are the 2 areas created from the tight junction in sertoli cells?
1. Basal compartment (vascular)
2. Alumina compartment (avascular)
64
What happens during spermiogenesis?
Cytodifferentiation occurs, for defective delivery of chromosomes into the oocyte
65
What happens during mitosis in a sertoli cell?
1. Type A daughter cells stay in the basal membrane to maintain a pool of viable dividing cells
2. Type B daughter cells move towards the lumen and create spermatocytes
66
Why is there a 15% difference of error between spermatocytes and oocytes?
Age of eggs
67
What happens to a spermatid during spermatogenesis?
1. Becomes more streamline
2. Grows a tail
3. Loses excess cytoplasm
4. Speratid elongates
68
What are the features of a sperm?
1. Head with an cromosome cap (enzymatic knife) and nucleus
2. Midpiece with mitochondria and olfactory epithelium
3. Tail
69
Is the HPG axis the same in men and women?
Yes
70
How does the HPG indirectly stimulate spermatogensis?
Causes sertoli cell to release ABP which concentrates testosterone
71
What does LH stimulate and why?
Stimulates Leydig cells to secrete testosterone
72
How is testosterone created in leydig cells?
From cholesterol being processed in their smooth ER. This enables gonad production
73
What stages of males life is there a testosterone surge?
3-9 months before birth
Puberty until about 60, then starts to wa e slightly
74
How does the oocyte move from ovum to fallopian tube?
It is swept up by cilia on fimbrae and moved into the infundibulum of the fallopian tube
75
Where is an oocyte fertilized in the fallopian tube?
In the ampulla, it is now a zygote
76
Where does the zygote travel after the ampulla
Through the isthmus and into the uterus
77
What facilitates egg transfer across the fallopian tube?
Cillia and muscular contractions
78
Where does capacitation occur in the fallopian tube?
In the isthmus
79
What areas of the fallopian tube support embryonic development?
Ampulla and isthmus
80
How does ovulation affect the beat frequency of the fallopian duct?
High oestrogen increases beat frequency of cilia and smooth muscle contraction
81
Where does the zygote stop after fertilisation?
It halts in the ampulla until the ovary moves into the luteal phase. This creates increased progesterone
82
What happens if there is high levels of P⁴?
Decreases beat frequency and relaxes the smooth muscle
83
Why is there a halt of the zygote in the ampulla?
To allow the early embryo grow to be ready for implantation
84
What hormone does the cumulus cells secrete?
Progesterone
85
What are the functions of the epidimus?
1. Matures sperm cells
2. DNA stabilization
3. Chromatic condensation and concentration
86
What are the seminal vesicles?
70-75% alkaline and fructose rich solution to feed spermatocyte
87
What are the 3 glands of the male reproductive system?
1. Seminal vesicles: nutrients
2. Prostate: enhances sperm motility, antimicrobial, proteases
3. Bulbo-urethral glands: secretes mucus and neutralizes acid from urethra due to urine
88
What is the pathway of sperm?
1. Ducts vans defrens
2. Ampulla of ducts defrens
3. Ejaculated duct
4. Urethra
89
What is seminal plasma?
The non sperm component to create an alkaline environment, neutralizing the acidic vagina
90
What is the role of fibrinogen in ejaculation?
It coagulates the ejaculate to create a sperm deposit in the vagina
91
What is the role of seminal plasma?
1. To create fibrinogen for ejaculate clotting
2. Coat sperm with capacitation inhibitors
3. Activates and augments motility of sperm cells
4. Supplies nutrients for ATP production
5. After 15-20 minutes the enzyme fibrinolsin fluidises the ejaculate by breaking down fibrinogen
92
What is the anatomy of the penis?
1. 3x longitudinal columns of erectile tissue
2. Corpora cavernousa
3. Corpus spongiosum
4. Dorsal vessels and nerves
5. Deep arteries
6. Spongy urethra
93
Why does the penis become erect?
1. The engorgement of corpa cavernosa via vascular and neurological events
2. Non distensible connective tissue causes stiffening
94
What tubes are active during ejaculation?
1. Vas defrens
2. Prostate
3. Seminal vesicles
4. Smooth muscle
5. Seminal glands
95
What happens to sperm during their journey to fertilisation?
1. Swim 16-20cm to ampulla
2. Most either: fall out, killed by acid, die on the way or get lost.
96
How does the uterus aid sperm transport?
1. Endometrial secretion provides nutrients
2. Changes mucus consistency to be more fluid to enable easier transport (decrease P⁴=decrease mucus viscosity
3. Aids capacitation
97
How does the oocyte attract the sperm?
By releasing chemoattractants a s P⁴ (created by cumulus cells), which the sperms olfactory epithelium picks up.
98
What happens to sperm in the isthmus?
Sperm binds to the isthmus to complete capacitation and synchronizes timing between egg and oocyte for arrival to the ampulla
99
Why is capacitation needed?
The non-covalently bound epididymal/seminal glycoproteins and sterols (cholesterol) means that the sperm can't fertilise the egg.
Capacitation removes these from the head of the sperm.
100
What happens to sperm motility during hyperactivstion during capacitation?
It increases motility
101
Why is the female reproductive tract ideal for capacitation?
1. High acid environment
2. Proteolytic enzymes enable sterol-binding albumin
3. High ionic strength increases colubikity to dissolve factors from sperm
102
Explain fertilisation
The acrosome reaction is initiated by the sperm contacting the Zona pellucia. The acrosome swells and multiple points of fusion occur between the outer acrosomal membrane and plasma membrane. The contents of the acrosome is released, inclusive of proteolytuc enzymes.
This enables the sperm to bind with thr plasma membrane of the oocyte
103
Explain fertilisation
1. Acrosome reaction:sperm contacts Zona pellucida and Acrosome swells
2. Multiple sites of fusion occur between plasma membrane and outer acrosomal membrane
3. Acrosome bursts, contents such as proteolytic enzymes are released.
4. Fusion between and oocyte occurs
104
What is Zona pellucida in an oocyte?
An acellular glucoprotein coat around that is synthesis and secreted by the oocyte
105
What is the purpose of the Zona pellucida?
Means the oocyte is viable for 12-24 hours after ovulation and enables fertilisation
106
Describe the process of acrosome reaction ans sperm penetration
1. Hyalurondiase on head of sperm digests matrix between cumulus cells, exposing the Zona pellucida
2. Sperm binds to Zona pellucida receptors triggering Ca2+ channels to open on sperm (catsper channels) triggering hyperactivation and acrosome reaction
3. Acrosine is released which digests the Zona pellucida (can be done by multiple sperms)
4. First sperm successfully inside chemotaxis' to ooleme and binds
5. Only centrioles enter oocyte and a membrane block occurs due to the sperm binding receptors shedding from oocyte membrane
6. A corticol reaction occurs. Where Ca2+ surges from intracellular ER triggering cortical granules to fuse to oocyte plasma membrane and undergo exocytosis into the Zona pellucida.
7. This causes zona reaction: a hardening of the Zona pellucida and destroys the Zona pellucida binding receptors
107
What is a Ca2+ spiking pattern?
A spike of Ca2+ over a couple of hours after ejaculation to facilitate fertilisation
108
What is the result of the Ca2+ spikes?
1. Resumption of meiosis 2 "oocyte reaction"
2. Hardening of Zona pelucia
3. Preservation of euploid
109
What is the process of fertilisation?
1. Meiotic division completes: Ovum and 2nd polar body formed due to Ca2+ spikes
2. Formation of male and female pronuclei
3. DNA from each pronuclei replicate, moves together and forms a mitotic spindle - nuclear envelope
4. Maternal and paternal chromosomes combine to form a diploid zygote
5. Fertilisation!
110
How long after fertilisation does pronuceli form?
4-7 hours
111
What does the sperm contribute to fertilisation?
Centrioles during spindle formation during cytokinesis
112
What does the oocyte contribute to fertilisation?
1. Cell membrane
2. Cytoplasm
3. Organelles
4. Mitochondria
113
What is preimplantation?
1. The movement of the embryo through the fallopian tubes to the uterus
2. Cleavage of the zygote to form bkastomeres occurs at this time too
114
What is clevage?
Rapid mitotic division of zygotes within the Zona pellucia
115
Why does cleavage occur I na zygote?
To increase surface area of the zygote to increase nutrient and oxygen uptake, and waste disposal
116
What does a blastomere turn into after creating about 16 cells?
A morula
117
What is a morula?
A solid ball of cells within a zygote
118
What are the 5 stages of embryonic development?
1. Zygote
2. 4 cell stage
3. Morula
4. Early blastocyte
5. Mature blastocyte
119
What's the difference between early and mature blastocyte?
Mature doesn't have Zona palucia
120
What is the structure of an early blastocyte?
1. Zona pellucida
2. Trophoblast
3. Embryoblast
4. Blastocyte cavity
121
What are the 5 stages of blastocyte implantation?
1. Day 4: early blastocyte hatches from Zona pellucida, floats around for 2-3 days then attaches to the endometrium (nutrients from uterine fluid and glands)
2. Day 6-7 implantation: trophoblast cells adhere to endometrial epithelium. Inflammation initiated
3. Day 7: invasion: trophoblast invades uterine wall, proliferates and differentiates into cytotrophoblast (inner) and syncytiotrophoblast (outer
4. Day 9 continuation: embryoblasts differentiate into 2 layers: epiblast (foetus) + hypoblast (yolk sac) = embryonic disc
5. Day 11-12 complete: blastocyst completes invasion, cells close over of endometrium, corpus luteum maintained by human chorionicgonadotropin ( hCG)
122
What is a cytotrophoblast?
A group of cells that have differentiated from trophoblasts to surround the blastocyte. Has minimal influence on placental development
123
What is Syncytiotrophoblast?
Differentiated cells from trophoblast that has invaded the endometrial wall, creating the placenta
124
What are the 2 types of contraception?
1. Hormonal
2. Non hormonal
125
What are the different ways of administering contraception?
1. Oral
2. Injection
3. Implant
4. IUD
5. Condom
126
Hiw does the combined oral contraceptive work?
1. High plasma oestrogen causes a negative feedback loop but doesn't cause a LH surge.
2. Inhibits secretion of FSH which stops maturation of follicles, so no ovulation
127
Hiw does progestin work for contraceptives?
Inhibits the synthesis of of LH via negative feedback loop. This stop the surge that triggers ovulation
128
How do both types of oral contraception work with the hypothalamus?
They reduce the production of GnRH, which reduces LH and FSH
129
What does high levels of progesterone do to the cervix?
Creates a thick mucus, which forms a plug. This prevents sperm gaining access to the uterus
130
What does high levels of oestrogen do to the uterus?
Creates a watery mucus which enables smooth travel to the uterus
131
How does the oral contraceptive work?
Through monophonic spikes, which is why they need to be taken daily.
132
What are the non oral, hormonal contraceptives
1. Vaginal ring
2. Injection
3. Implant
4. Hormonal IUD
133
What is a LARC?
Long Acting Reversible Contracteptive
E.g. implant, injection, IUD
134
What are the non hormonal contraceptives?
1. Condom
2. Copper IUD
135
What are common causes of infertility in women?
1. Endocrine abnormality (hypothalamic dysfunction/pituitary disease)
2. Ovarian dysfunction (PCOS, abnormal follicle development, pre azure ovarian failure)
3. Implantation abnormality (Luteal phase deficiency, reduced progesterone production, delayed maturation of endometrium)
136
What is the most common endocrine disorder?
Poly Cystic Ovary Syndrome
137
How does PCOS cause I fertility?
Disrupts follicle development from early antral phase and arrests so the theca cell hyperproliferates, creating a lot of androgens (more testosterone)
138
What metabolic features cause infertility in both sexes?
1. Increased obesity
2. Insulin resistance
3. Type 2 diabetes
4. CVS diseasesemesters?
5. Stress
6. Smoking
7. Alcohol
139
What anatomical abnormalities can cause infertility?
1. Tubal disease: inflammatory scarring (STIs, pelvic inflammatory disease)
2. Septic abortion
3. Surgery
4. IUD scalpinitis
140
What is endometriosis?
An abnormal growth of endometrial outside of the uterus
141
What are the symptoms of endometriosis?
Pain and bleeding due to tissue reacting to hormones same wY it would in the uterus
10% women
142
What are the causes of infertility in men?
1. Varicole:dilation of pampiniform plexus (increases temp. Reduce sperm quality)
2. Vas defrens blockage
3. Retrograde ejaculation
4. Hypogonadaltropic hypogonadism (Kallman syndrome)
5. Sperm count, motility, structure, stickiness
143
What is the most common cause of infertility?
A woman's age
144
What is AMH?
Antimullerian Hormone: produced by granulosa cells in primary, secondary and antral follicles.
This inhibits excessive activation of primordial to primary follicles
145
What does blood tests and ultrasounds check for regarding infertility?
1. PCOS
2. Endometriosis
3. Ovulation
4. Fibroids
5. Polyps
6. Ovarian cysts
7. AMH
146
How can semen to analysed to determine fertility?
1. Count
2. Motility
3. Morphology
4. Volume
5. Consistency
6. pH
7. Leukocytes
8. Fructose levels
147
What is ART?
Assisted Reproductive Technology: manipulating both soerm and egg in lab and returning to woman
1 in 25 are art babies
148
What is IVF?
1. Hormones given to woman in controlled manner to hyperstimulate ovulation.
2. About 8 embryos are collected by flushing out the uterus with warm media
3. Put into diskh with capacitated sperm and placed back to woman after 5-6 days
149
What Is ICSI?
IntraCytoplasmic Sperm Injection: male infertility, 1 sperm injected directly to egg
Indicating increased risk of health to children
150
How are hormones controlled in ART?
1. Daily injection of FSH to increase follicle growth (ultrasound monitored)
2. Injection of LH to induce resumption of meiosis in oocyte (36-40 hours after injection
3. GnRH agonist given continuously prior and during gonadotropin to suppress natural ovulation
4. Progesterone given during luteal phase to support embryo after transfer
151
What are the contraindications to ART?
1. Ovarian Hyperstimulation Syndrome (OHSS)
2. PCOS
3. Fatal
4. Multiple borth rate
5. Preterm delivery
6. Low birth weight babies
7. Miscarriage or no pregnancy (20% livebith)
8. Costly
9. Emotionally draining
