Reproductive system Flashcards
1
Q
Which bones make up the pelvis?
A
Ilium Ischium Sacrum Coccyx Pubis
2
Q
Which joints make up the pelvis?
A
Pubic symphysis
Sacroiliac joint
3
Q
What does the false/greater pelvis contained?
Position?
A
GI tract
Superior region of pelvis
4
Q
What does the true/lesser pelvis contain?
Position?
A
Reproductive organs
Inferior region of pelvis
5
Q
Compare the female and male pelvis
A
- Subpubic angle
- Females broader, males narrower - Coccyx
- Females straighter, males curved - Inlet
- Females oval, males heart-shaped
6
Q
What muscles make up the pelvic floor?
A
- Levator ani
2. Coccygeus
7
Q
What does the pelvic floor close over?
A
The pelvic outlet
8
Q
Openings in the pelvic floor
A
Urethra
Anal canal
Vagina
9
Q
What does the scrotum contain?
A
2 testes + 2 spermatic cords
10
Q
What do testes produce?
A
Sperm, testosterone + inhibin
11
Q
What are the testes surrounded by? What is this?
A
Tunica albuginea, a dense fibrous capsule
12
Q
Seminiferous tubules
- Located where?
- Lead to?
- Contains which cells?
A
- In the lobules of the testes
- Join to form rete testis
- Leydig cells, Sertoli cells, spermatogenic cells (spermatozoa)
13
Q
What do Leydig cells produce?
A
testosterone
14
Q
What do Sertoli cells produce?
A
Inhibin
15
Q
Epididymis
- 3 sections?
- Sperm enter at and exit via?
- Site of what?
A
- Head, body, tail
- Enter from seminiferous tubules (via rete testis then tubules)
- Exit via ductus deferens
- Site of sperm maturation
16
Q
What is the ductus deferens covered by?
A
Smooth muscle
17
Q
What does the ductus deferens dilate to form?
A
The ampulla
18
Q
What do the spermatic cords contain?
A
- Ductus deferens
- Venous plexus
- Testicular artery
- Nerves
- Lymphatics
- Cremastor muscle
19
Q
What are the ejaculatory ducts formed by?
A
The duct from the seminal vesicle + the ampulla
20
Q
Urinary sphincters in males
A
External: skeletal muscle; voluntary control of urination
Internal: detrusor muscle; closes bladder to ensure no sperm is ejaculated through urethra
21
Q
What is retrograde ejaculation?
A
Sperm end up in bladder (bc internal sphincter didn’t close)
22
Q
Path of sperm
A
Testes –> seminiferous tubules –> rete testis –> efferent ductules –> epididymis –> ductus deferens –> ampulla –> ejaculatory duct –> prostatic urethra –> membranous urethra –> spongy/penile urethra
23
Q
3 sections of the penis
A
root, body, glans
24
Q
What are the 3 cylindrical erectile tissues in the penis? Which contains the urethra and what does it form?
A
- Corpora cavernosa (2); main
- Corpus spongiosum; contains urethra, forms bfulb + glans
25
Function of scrotum; lined by which muscle?
- Thermoregulation (maintain temp at ~34 degrees)
| - Dartos muscle
26
Function of dartos muscle?
Contracts the skin covering the scrotum for heat conservation
27
What are the 3 male RS accessory glands?
| - Function
1. Seminal vesicles
2. Prostate gland
3. Bulbourethral glands
28
Seminal vesicles:
- Components of secretion?
- Function?
Viscous secretion:
- 60% of semen
- Fructose to nourish sperm
- Alkaline to protect sperm
29
Prostate gland
- Components of secretion?
- Function
```
Secretion:
- 30% of semen
- Acidic
- Citrate to nourish sperm
Contributes to sperm activation, viability and motility
```
30
Bulbourethral glands
- Opens into?
- Contributes how much to semen vol.?
- Function of secretions?
- Spongy urethra
- 5% of semen vol.
- lubrication
- Alkaline to neutralise acidity in urethra prior to ejaculation
31
What is a vasectomy?
| Does it change seminal fluid vol.?
- Contraception; cut/tie ductus deferens
| - No, bc doesn't affect accessory glands
32
What is spermatogenesis?
The formation of mature spermatozoa from spermatogonia
33
What cell is formed at each stage of meiosis for spermatogenesis?
```
Diploid: primary spermatocyte
- Meiosis I
Haploid: secondary spermatocyte (2)
- Meiosis II
Haploid spermatid (4)
```
34
Spermatogonia:
- Migrate from? To?
- Remain dormant until?
- Yolk sac to testes
| - Puberty
35
What happens to spermatogonia at puberty?
- Divide by mitosis into type A and B spermatogonia
| - Type B differentiate into primary spermatocyte (then continue meiosis)
36
What is spermiogenesis?
| - Process?
- Differentiation of spermatids into spermatozoa
1. Appearance of acromosomal vesicle + flagellum in spermatid
2. Growth of acromosome + flagellum
3. Shedding of excess cytoplasm
4. Mature sperm
37
What is a gonadotropin?
Hormone that acts on the gonads
38
GnRH
What is it?
What is it released from?
Stimulates release od?
- Gonadotropin releasing hormone
- Released from hypothalamus
- FSH + LH
39
```
Males:
LH:
What is it?
What is it released from?
Stimulates?
```
- Luteinising hormone (a gonadotropin)
- Released from anterior pituitary
- Production of testosterone
40
```
Males:
FSH:
What is it?
What is it released from?
Function?
```
- Follicle releasing hormone (a gonadotropin)
- From anterior pituitary
- Stimulates spermatogenesis
41
What are androgens?
Hormones which develop male characteristics (e.g. gonads --> testes)
42
What does testosterone do?
- stimulates spermatogenesis
| - Inhibits LH + GnRH (negative feedback)
43
Males:
| What does inhibin do?
Inhibits FSH secretion, thus inhibiting spermatogenesis
44
What makes up the female perineum?
```
Urogenital triangle
- urethral and vaginal opening
- external genitalia (vulva)
Anal triangle
- anal canal and fat
```
45
Components of the female external genitalia
1. Mons pubis
2. Labia majora + minora (vestibule b/w)
3. Vestibular glands (lubricate vaginal orifice)
4. Clitoris (glans, body, crura (2), bulbs (2))
46
Structures of the female reproductive tract?
```
Ovary
Uterine tubes
Uterus
Cervix
Vagina
```
47
3 Parts of the uterine tube + characteristic of each
1. Infundibulum (most lateral; fimbriae)
2. Ampulla (site of fertilisation)
3. Isthmus (most medial)
48
Functions of uterus
- Movement of sperm
- Implantation of blastocyst
- Retain and nourish embryo + fetus through pregnancy
- Allow parturition
49
3 layers of the uterus wall + composition
1. Endometrium
- Columnar epithelium
- Uterine glands + arteries
2. Myometrium
- Smooth muscle
3. Perimetrium
- Connective tissue
50
Blood supply to uterus
Abdominal aorta --> common iliac artery --> internal iliac artery --> uterine artery --> uterus
51
Blood supply to vagina
Abdominal aorta --> common iliac artery --> internal iliac artery --> vaginal artery --> vagina
52
Blood supply to ovary
Abdominal aorta --> ovarian artery --> ovaries
53
Blood supply in myometrium and endometrium
Uterine artery --> arcuate arteries --> radial arteries (through myo) --> spiral and straight arteries
54
Regions of the ovaries + what they contain
1. Outer cortex
- follicles
2. Inner medulla
- connective tissue, blood vessels, nerves, lymphatics
55
What occurs in the ovaries
Oogenesis + hormone production
56
Female ligaments
1. Broad ligament
2. Ovarian ligament
3. Suspensory ligament
4. Round ligament
57
Which ligaments does the broad ligament form?
1. Mesometrium (uterus)
2. Mesosalpinx (tube)
3. Mesovarium (ovary)
58
Female pouches
1. Vesicouterine pouch: fold of broad ligament over bladder (anterior)
2. Rectouterine pouch: fold of broad ligament over rectum (posterior)
59
What is oogenesis?
development of the oocyte from oogonia w/in an ovarian follicle
60
Oogenesis: type of cell at each stage of meiosis
| - incl. when they're halted if relevant
1. (Diploid) primary oocyte
- Meiosis I (halted at prophase I until puberty)
1. (Haploid) secondary oocyte + polar body
- Meiosis II (halted at metaphase II until fertilisation)
Haploid oocyte + 3 second polar bodies
61
How are polar bodies formed?
By the uneven distribution of the cytoplasm during meiosis
62
Layers of follicle inside ovary
```
Oocyte
Zona pellucida
corona radiata
antrum
Ganulosa cells (attach to corona radiate on one side of the oocyte)
Basement membrane
Theca folliculi
```
63
What is released from the ovary during ovulation
Oocyte + corona radiata
64
Females:
FSH
- released from?
- function?
- Anterior pituitary
| - Signals to ovary to stimulate the growth of ovarian follicles and initiate estradiol production
65
Females:
LH
- Released from?
- Function?
- Anterior pituitary
- Stimulates completion of follicle and oocyte growth (estrogen secretion by follicle)
- Stimulates ovulation
- Causes formation of corpus luteum from ruptured follicle (progesterone and oestrogen secretion by corpus luteum)
66
Prolactin:
- Released from?
- Function?
- Anterior pituitary
| - Stimulates milk production in mammary glands
67
Estradiol
- Released from?
- Function?
- developing follicles in ovary
- Assists in follicular, bone, muscle and endometrial growth
- feedback to anterior pituitary to alter circulating levels of FSH/LH
68
Inhibin
- Released from?
- Function?
- granulose cells in ovary
| - negative feedback to anterior pituitary to suppress FSH
69
Progesterone
- Released from?
- Function?
- Corpus luteum in ovary
- Negative feedback to suppress GnRH (thus FSH/LH)
- Endometrial maturation, maintains pregnant state
70
Oxytocin
- Released from?
- Function?
- Posterior pituitary
| - Acts on breasts to cause milk let-down (ejection)
71
What is menarche? What is it caused by?
- First menstrual period
| - due to increased estrogen production
72
What is menopause? caused by?
- Cessation of menstruation
| - Decreased estradiol and progesterone due to decreased responsiveness of follicles // FSH/LH high
73
Ovarian cycle:
| 2 phases + what happens
1. Follicular phase: day 1-14
(i) increased FSH from AP
- Follicular growth
(ii) Growing follicles secrete of estradiol + inhibin
- decreased FSH
- Growing follicles atresia
(iii) Dominant follicule secretes large amount of estradiol
- Surge of LH
(iv) Follicle ruptures + ovulation occurs
- oocyte released into peritoneal space
2. Lucteal phase: day 15-28
(i) Ovulated follicle collapses and forms corpus luteum
- secretes progesterone, estradiol, inhibin
(ii) Decreased FSH + LH secretion
(iii) Progesterone stimulates maturation of endometrium
- Glands become secretory
(iv) If no pregnancy
- corpus luteum involutes
- menstruation
- removes negative feedback on FSH and LH
74
Menstrual cycle:
| Phases + what happens
1. Proliferative phase: Day 1-14
(i) Estradiol stimulates endometrial growth from days 6-14
- Rapid tissue growth (incl. glands + vasculature)
2. Secretory phase: day 15-28
(i) Corpus luteum secretes progesterone
(ii) Progesterone promotes endometrial maturation (prepare for a zygote)
- spiral arteries grow + coil
- glands become secretory
3. No pregnancy
- corpus luteum degenerates
- decreased progesterone levels
- spiral arteries contract,
- uendometrial tissues break down and bleeding occurs
- Menstruation
75
Breasts:
- Function?
- Position?
- What stimulates development of tissue?
- Nourish infants
- Lie on pectorals major muscles
- Estradiol and progesterone
76
Structure of breasts
lobes --> lobules --> alveoli --> lactiferous ducts --> lactiferous sinuses
77
Breast feeding stages
1. Lactation (milk production)
- Rapid decrease in estradiol and progesterone after birth allows breasts to respond to prolactin
- Prolactin stimulates milk production
- Suckling stimulates continued production of prolactin (amount determined by strength/duration of nipple stimulation)
2. Milk ejection reflex
- Suckling also stimulates oxytocin secretion
- Oxytocin stimulates contraction of smooth muscle around alveoli
- Milk goes into lactiferous ducts, allowing infant to feed
78
What forms layers surrounding the erectile tissues in the penis?
What are these layers?
Fascia
1. Tunica albuginea: innermost
2. Deep (Buck's) fascia (surrounds tunica albuginea)
3. Superficial fascia: outermost, surrounds deep fascia
79
What 2 structures make up erectile tissue?
- Trabeculae: smooth muscle fibres
| - Lacunae: Cavernous space
80
Blood supply to the penis (pathway)
Abdominal aorta --> common iliac artery --> internal iliac artery --> internal pudendal artery
81
Males:
What does the internal pudendal artery supply blood to?
Which arteries branch off to supply the penis?
- Perineum and external genitalia
- Branches:
Artery to bulb
Urethral artery
Dorsal artery
Deep (cavernosal) artery
82
Veins draining the penis?
- Subtunical veins (in corpora cavernosa)
- Deep dorsal vein
- Superficial dorsal vein
83
How does the blood supply to the penis change during erection?
Increased blood flow:
- Cavernous spaces swell
- Lacunae fill
84
What is the nerve supply to the penis?
1. Pudendal nerve
- supplies sensory and somatic motor innervation to perineum (incl. penis) --> dorsal nerve of penis
2. Pelvic plexus
- supplies autonomic innervation
- Parasympathetic and sympathetic
85
What is the parasympathetic NS response in males?
Erection
| - Stimulates production of NO (vasodilator) by deep arteries of penis
86
What is the sympathetic NS response in males?
Ejaculation
| - Stimulates contraction of smooth muscle in reproductive ducts and accessory glands
87
What is the somatic motor NS response in males?
Ejaculation
| - Stimulates contraction of skeletal muscles around bulb of penis
88
Neural control of the sexual act
1. Erection
- Parasympathetic response to stimuli
- Afferent signals: from brain (E.g. visual, tactile) via somatic pudendal nerve (stimulation of genital region/glans)
- Efferent signals (psychological stimulation): to penis (deep artery dilation, erectile tissues fill w/ blood, erection) + bulbourethral gland (secretes bulbourethral fluid)
2. Ejaculation
(i) Emission (Sperm and seminal fluid --> urethra)
- Sympathetic response
- Efferent signals: to ductus deferens (peristalsis; ampulla contracts; sperm to urethra) + seminal vesicles (seminal fluid) + prostate gland (seminal fluid)
(ii) Expulsion (ejection of sperm)
- Somatic and sympathetic reflexes
- Afferent signals: to spinal cord (stimulated by semen in urethra)
- Efferent signals: to accessory glands (additional secretion + smooth muscle contraction of internal urethral sphincter) + bulbocavernosus muscle (contracts to compress bulb/root of penis + urethra)
3. Resolution
- Sympathetic reflex
- Efferent signals to: internal pudendal artery (constricts to reduce blood flow) + trabecular muscles (contract, squeeze blood from erectile tissues) + Penis (flaccid)
89
Female sexual response
1. Autonomic stimulation: engorgement of corpora of clitoris, bulbs of vestibule, labia and vagina
2. Lubricating fluid secreted through vagina wall + secretion of mucus in vestibule
3. Increased length + width of vagina (tactile stimulation, uterus elevates up)
4. Rhythmic contraction of vaginal, uterine + perineal muscles (in response to pudendal nerve)
90
Natural methods of contraception
| + how they work/characteristics
1. Rhythm method (periodic abstinence)
- Relies on timing of coitus
2. Withdrawal method
- Relies on behaviour during coitus
3. Lactational infertility
- Relies on timing of coitus
91
Artificial methods of contraception: physical barriers
| + how they work/characteristics
1. Caps
- Need spermicidal creams, etc.
- Must leave in for 6+ hours
2. Condoms
- Cheap
- Readily available
- Easy to use
- Reduce risk of STDs
92
Artificial methods of contraception: steroidal contraception - Combined oral contraceptives
- Contain estrogen + progestin
| - Suppress ovulation + mucus production by cervix
93
Artificial methods of contraception: surgical contraception
| + how they work
1. Tubal ligation
- Cut uterine tubes
2. Vasectomy
- Cut ductus deferens
3. Hysterectomy
- Removes entire uterus
94
How long does an ovum survive for?
Approx. 24 hours
95
Process of fertilisation:
1. Capacitation
2. Fertiisation
3. Oocyte changes
4. Pronuclei fusion
1. Capacitation
- Sperm undergoes changes in female tract (increased motility + softens acrosome)
- 6-8 hours
2. Fertilisation
(i) Penetration of corona radiata
(ii) Penetration of zona pellucida
(iii) Penetration of the oocyte cell membrane
3. Oocyte changes
- Zona pellucida becomes impenetrable (blocks polyspermy)
- Meiosis II completes to form haploid ovum (+ polar body)
- Female pronucleus forms
- Spermatozoon tail degenerates
4. Pronuclei fuse
- Becomes zygote (46 chromosomes)
- Sex determination
- Initiation of cleavage
96
Stages of ovum cleavage (+ time length)
Blastomere: 2 cells approx. 30 hours
4 cells approx. 40 hours
Morula: 16 cells (morula) approx. 3 days
97
Process of ovum --> blastocyst
1. Mitotic division of ovum to form blastomere (approx. 30h)
2. Continued division to form 16 cell morula (approx. 3 days)
3. Cells of morula rearrange to form an inner mass (epiblast) and an outer mass (trophoblast)
4. Fluid-filled blastocyst formed (days 4-5)
98
What do the 2 layers of the blastocyst form?
1. Inner cell mass (embryo blast) --> embryo
| 2. Outer cell mass (trophoblast) --> placenta
99
Process of implantation (incl. which day/s where relevant)
1. Blastocyst breaks out of zona pellucida
2. Days 6-7: blastocyst moves to endometrium, implantation begins
3. Day 10: blastocyst completely implanted
4. Trophoblast forms 2 layers
- inner: cytotrophoblast
- outer: synctiotrophoblast
5. Outer cells invade endometrium, which envelops blastocyst
6. Trophoblast secretes hCG
7. Corpus luteum maintained
100
What is an ectopic pregnancy
Implantation outside of uterine cavity
101
What is the development of the cell during week 2
- Bilaminar disc formation
- Cavity formation
- Bilaminar disc formed from embryblast/inner cell mass (layers: epiblast (ectoderm) + hypoblast)
- 2 cavities form: amniotic cavity (surrounds and protects developing embryo) + yolk sac (primordial germ cells arise near here; used for early nutrient transfer)
102
Placenta:
- Function?
- Occurs where?
- Composed of?
- Allows diffusion of maternal fetal blood by week 4; Exchange occurs across chorionic villi (chorion formed by trophoblast) which contain blood vessels carrying fetal blood, which bathe in maternal blood
- Anchors/protects fetus
- Allows gas and nutrient exchange
- Made up of maternal tissue AND fetal tissue
103
Process of parturition
1. Dilation of cervix to allow fetal head through; contractions; rupture of the fetal membranes
2. Short contractions; birth of baby
3. Placenta detaches; contractions close the maternal arteries
104
Potency of morula cells
Totipotent
105
Potency of embryonic stem cells
Pluripotent (all but placenta cells)
106
What is gastrulation?
Formation of 3 germ cell layers from the bilaminar disc
107
Gastrulation: what happens at week 3?
- Primitive streak forms in the epiblast
- Cells of epiblast move towards primitive streak and migrate downwards, pushing the old hypoblast out + forming the mesoderm and endoderm
108
What does the ectoderm form?
- Epidermis
- Brain and spinal cord
- Nerve cells
109
What does the mesoderm form?
- Muscle
- Bone
- Kindey
- Gonads
- Connective tissue
110
What does the endoderm form?
- GI tract lining
| - Respiratory system (lining of lungs and bronchi)
111
What is neurulation? Process?
- The formation of a neural tube from a piece of ectoderm
- Process:
1. Ectoderm rises up at the edges to form the neural folds
2. Neural folds converge together
3. Neural folds fuse to form the neural tube
112
Sensitivity to environmental chemicals:
1. 0-2 weeks (fertilised egg --> embryonic disc)
2. 3-8 weeks (embryo)
3. 9-38 weeks (fetus)
1. Usually not sensitive; high rate of lethality may occur
2. greatest sensitivity; development of organ systems
3. Decreasing sensitivity; period of functional maturation
113
Stages of reproductive tract development
1. Gonad development
2. Oocyte + sperm development from germ cells
3. Development of the male + female ducts
4. Development of structures to deliver sperm to oocyte
114
Which germ cell layer does the repro tract form from? Where do the cells migrate from?
- Mesoderm
| - Yolk sac
115
What is SRY? What happens in its presence/absence?
- Sex determining region on the Y chromosome
- If present; gonads --> testis
- If absent; gonads --> ovary
116
What is the mesonephros?
Mesoderm tissue from which the gonads and kidneys are developed from
117
Duct development
| Before + after differentiation
1. Before differentiation, 2 tubes from mesoderm
- Mesonephric (Wolffian) duct; associated with gonads
- Paramesonephric (Müllerian) duct; separated from gonads
2. After differentiation
- The duct not associated with the person's sex degenerates
- SRY gene = Androgens present = male duct kept
- No SRY gene = no androgens present = female duct kept
118
How is the uterus formed from the paramesonephric duct?
The lower parts of the paramesonephric ducts fuse
119
What is müllerian inhibiting substance (MIS) / anti-müllerian hormone (AMH)?
Produced in males
| causes paramesonephric duct to degenerate
120
How do the testes pass through the abdominal wall to the scrotum?
Using the inguinal canal
121
Genitalia development
1. Indifferent stage
| 2. Presence/absence of androgens; differentiation
122
How can abnormalities of external genitalia arise?
1. Female fetus exposed to androgen
2. Male fetus cannot respond to androgen (e.g. mutated receptor)
3. XY females lack a functional SRY gene
123
Example of an androgen
Testosterone, DHT
124
Differentiation of genital ridge/gonads
Male: testis
Female: Ovary
125
Differentiation of germ cells
Male: spermatozoa
Female: oocyte
126
What genitalia does the Müllerian/paramesonephric duct differentiate into?
- Vagina
- Uterus
- Uterine tubes
127
What genitalia does the Wolffian/mesonephric duct differentiate into?
- Epididymis
- Ductus deferens
- Seminal vesicles
128
Differentiation of genital tubercle
Male: penis
Female: clitoris
129
Differentiation of genital folds
Male: spongy urethra
Female: labia minora
130
Differentiation of genital swellings
Male: Scrotum
Female: labia majora
131
What happens in the ovaries of females during childhood? (b/w birth and puberty)
Follicular cells develop around each primary oocyte, to form primary follicles
132
Development of the oocyte in the ovary incl. the follicle after ovulation.
1. Primary oocyte
2. Primary follicle
3. secondary oocyte + secondary follicles
4. Mature follicle
5. Ovulation
6. Corpus luteum
7. Corpus albicans
133
What happens to the primary oocytes in the ovaries of females after puberty?
- Primary oocytes resume meiosis to form secondary oocytes
- Follicle cells develop to form secondary follicles
- Outer layer granulose cells differentiate to form theca cells
134
What is copulation?
The insertion of an erect penis into the vagina for the purpose of reproduction.
135
The process of sperm being deposited into the vagina?
Insemination
136
Artificial methods of contraception: steroidal (Progesterone-only) contraception
Progesterone-only pill
(i) Progesterone-only pill
- Low doses of progestin
- Effects on cervical mucus
137
Artificial methods of contraception: steroidal (Progesterone-only) contraception
Subdermal implant/injectables
- Long acting (years)
| - Disrupt follicular growth + ovulation
138
Artificial methods of contraception: steroidal (Progesterone-only) contraception
Copper IUD
- Low grade inflammation
- toxic to oocyte + zygote
- Impairs implantation
139
Artificial methods of contraception: steroidal (Progesterone-only) contraception
Hormonal IUD (Mirena)
- Affects cervical mucus
- Thickens endometrium
- May affect ovulation
