8 Flashcards
1
Q
What is the SRY gene?
A
The sex-determining part of the Y chromosomes.
Acts during early development; signals to produce testis.
2
Q
How are can individuals with the gametes XY possess primary and secondary female characteristics?
A
They have a missing/mutated SRY gene
3
Q
How many autosomes do oocytes and spermatozoons contain?
A
22
4
Q
Where do embryonic gonads develop from?
A
Bipotential primordia – called genital ridge primordia
5
Q
What type of tissue forms the structure of the gonads but doesn’t contain the germ cells?
A
Mesenchymal tissue
6
Q
Where do gametes originate?
A
Embryonic yolk sac
7
Q
What do gametes originate as?
A
PGC – primordial germ cells
8
Q
Where to germ cells migrate from and to?
A
From hindgut.
To gonad rudiment.
9
Q
In normal males, what do the primordial germ cells (PGC) colonise?
A
The medulla
10
Q
In normal females, what do the PGCs colonise?
A
The cortex
11
Q
What do PGCs expand by?
A
Mitosis
12
Q
Do PGCs differ in both sexes?
A
No
13
Q
What are coelomic epithelia?
A
Epithelium lining surface of body and abdominal organsIt constitutes the outermost layer of the male and female gonads, thus forming the germinal epithelium of the female / male.
14
Q
In males, what does the coelomic epithelia form?
A
A network of cords which surround and envelop the PGCs
15
Q
Why doesn’t coelomic epithelium not form cords in females?
A
Because they lack SRY
16
Q
What does PGCs in the cortex form?
A
Most tissues of ovaries
17
Q
What does PGCs in the medulla form?
A
Most tissues of testis
18
Q
In females, what happens to the medulla?
A
Degenerates
19
Q
What does the sex cords lack in females?
A
Structure, they condense and cluster around PGCs (forming primary oogonia)
20
Q
Once SOX9 is present what happens?
A
SRY is no longer needed as SOX9 is self-sustaining.
SOX9 initiates expression of PGD2
21
Q
What does PGD2 drive production of and what does that do?
A
FGF9;
Drives migration of mesonephric cells
22
Q
What do sertoli cells produce?
A
AMH (Anti-Mullerian hormone).
Which prevents Mullerian duct development (they differentiate to form the fallopian tubes, uterus, the uterine cervix, and the superior aspect of the vagina)
23
Q
Name 2 hormones essential for male development
A
AMH and androgen
24
Q
Which cells maintain the Wolffian duct?
A
Leydig cells
25
What does lack of androgen lead to in male development?
Wolffian duct regression
26
What do mesonephric primordia make in males and females?
Males – myoid cells, vascular tissue, Leydig cells.
Females – theca cells, vascular tissues
27
How do reproductive tracts of females and males differ?
Females – vagina, uterus, oviduct.
Males – vas deferens, seminal vesicles
28
What does androgen exposure after birth lead to?
Defeminisation; no change in internal or external genitalia
29
What does castration after birth lead to?
Demasculisation; no change in genitalia
30
What does removal of foetal ovaries lead to?
WD degenerate and MD develop
31
What role does the hypothalamus play in sex?
Role in secondary sexual characteristics
32
What is Turner’s syndrome?
X unpaired,
Infertile
Female
33
Describe Klinefelter’s syndrome
XXY.
Essentially maleInfertile
Underdeveloped testes
34
What is AIS?
Androgen insensitivity syndrome.
Androgen secreted by testes but target issues doesn’t respond
35
What determines the male phenotype (external appearance and secondary sexual characteristics)?
Testosterone levels and testosterone receptors.
Testis produce testosterone
36
What is congenital adrenal hyperplasia?
XX.
Foetal adrenal hyperactivity to overcome low production of corticosteroids which leads to WD and MD being retainedE.
xternal male genitalia
37
If Y chromosome is not present, what does the gonad become?
Ovaries
38
Which disease is the most common cause of erectile dysfunction?
Vascular – atherosclerosis
39
In the male reproductive system which embryological ducts remain in place and which degrade?
* Mesonephric (Wolffian) ducts remain
| * Paramesonephric (Mullerian) ducts degrade
40
What is the embryological origin of the prostate?
Urethra
41
What are the muscles of the pelvic diaphragm?
Levator ani
• Ileococcygeus
• Pubococcygeus
• Puborectalis(Ischio)coccygeus
42
Nerve supply to levator ani (pelvic floor muscles)?
S3, S4
43
Describe the histology of the male urethra
Prostatic urethra
• Transitional epithelium
Membranous urethra
• Pseudostratified columnar epithelium
Penile urethra
• Pseudostratified columnar epithelium
44
What is found in the superficial perineal pouch?
Erectile tissue
• Corpus cavernosum
• Corpus spongiosum
Muscles
• Ischiocavernosus
• Bulbospongiosum
• Superficial transverse perineal muscle
45
What muscles are in the deep perineal pouch?
* External urethral sphincter
* Deep transverse perineal muscle
* Sphincter urethrovaginalis (Only in women)
* Compressor urethrae (Only in women)
46
What structure travels through the opening in the perineal membrane?
Urethra
47
What are the characteristics of Turner’s syndrome (X)?
* Ovaries present but infertile
* Poor breast development
* No menstruation
* Low hairline
* Short stature
48
What do the medulla and cortex of the gonads develop into in males?
Males
* Medulla develops into testis
* Cortex degenerates
49
What do the medulla and cortex of the gonads develop into in females?
Females
* Cortex develops into ovary
* Medulla degenerates
50
What do primary follicles consist of?
Oocyte surrounded by granulosa cells
51
What is the allantois?
Small sausage-shaped outpouching from the caudal wall of the yolk sac of the early embryo
52
Which 3 pairs of tubes drain into the bladder in the embryo?
Pronephros, mesonephros, metanephros
53
Which embryological tubes that drain into the bladder are the ones we keep in the adult urinary system?
Metanephros
54
Via which ducts does the gonads drain into the bladder?
Mesonephric (Wolffian) duct
55
What drains the kidneys into the bladder?
Ureters
56
What duct system is left behind for the gonads (testes)?
Epididymis (collecting tubules within testicles)
57
What is the mesonephric duct now called in adult males?
Ductus deferens (runs from epididymis into bladder)
58
What runs from the epididymis into the bladder?
Ductus deferens
59
Where are the testes located?
Between posterior abdominal wall and peritoneum
60
What do the testes descend through and into?
Inguinal canal into scrotal sac
61
What does the vas deferens loop over?
Ureter
62
Where do the ductus deferens from R and L testes come together?
Ejaculator duct
63
What does the ejaculatory duct pass into?
Prostate gland (at base of bladder)
64
Which 2 accessory glands open into the prostate?
Seminal vesicles
65
What are the 2 regions of the prostate gland?
Central zone – inner part; where ducts are located.
Peripheral zone – cortex layer on outside
66
Which part of the prostate tends to enlarge in benign prostatic hypertrophy?
The central zone of the prostate gland
67
What type of epithelium is found in the glans penis?
Stratified squamous
68
What is the perineum?
A diamond shaped region at the pelvic outlet
69
What is the perineal diamond subdivided into?
2 triangles:
- anterior urogenital triangle
- posterior anal triangle
70
What forms the roof of the perineum?
The pelvic diaphragm muscles
71
What is the deep perineal pouch?
A space enclosed by the perineal membrane and pelvic diaphragm
72
What are the major hormones involved in regulating female reproductive cycle?
LH, FSH, GnRH
73
What is the precursor of cholesterol?
Acetate
74
Name the structural unit in which oocytes develop.
Follicle
75
At what state in development are oocytes at birth?
Arrested in prophase 1, termed primary oocytes, residing in primordial follicles
76
What is the pattern of GnRH release in the prepubertal female and post-pubertal females?
Pre- Irregular.
Post - Regular pulses at approx. hourly intervals
77
At what stage of follicle development does ovulation occur?
Tertiary, preovulatory stage
78
What triggers follicle growth?
LH and FSH
79
What does oestrogen stimulate?
The secretion of LH by the anterior pituitary
80
What does progesterone promote?
Thickening of the endometrium
81
What does progesterone inhibit?
Secretion of FSH and LH by the anterior pituitary
82
What gonadotropins act at the ovary?
FSH and LH
83
What does inhibin do?
Inhibits FSH secretion from the anterior pituitary
84
What do sertoli cells secrete?
ABP – stimulates spermatogenesis
85
Define primordial follicle
Single layer of squamous granulosa cells; oocyte non-growing
86
Which gonadotrophin acts on granulosa cells?
FSH
87
What is the main hormone produced by the corpus luteum?
Progesterone
88
Function of progesterone.
Maintains pregnancy and supports luteal phase of the cycle
89
What are the main functions of the ovary?
Oogenesis
Folliculogenesis .
Corpus luteum formation
90
What is the effect of LH action at theca cells?
Androgen production
91
What is the effect of FSH at granulosa cells?
Oestrogen production
92
What cells does LH act on?
Theca cells
93
During what phase of meiosis is an oocyte released?
Metaphase II
94
How long does the corpus luteum last?
10 days
95
What do luteal cells produce?
Progesterone primarily and bits of oestrogen
96
After ovulation, what do the granulosa cells become?
Luteal cells
97
From day 1-14 of the menstrual cycle what phase occurs?
Follicular phase
98
What is the stimulus for the retention of the corpus luteum?
Beta HCG (pregnancy)
99
What are therapies for hot flashes in menopause?
HRT, SSRIs
100
What is the cell that implants in the uterine wall?
Blastocyst
101
When is premature menopause?
Below age 40
102
What do sertoli cells secrete?
ABP – stimulates spermatogenesis
103
If a woman has a uterus, what do you give her for HRT? What about if she doesn’t have a uterus?
Uterus: oestrogen and progesterone Hysterectomy: oestrogen
104
What are negative complications of HRT?
Increased MI, blood clots, breast cancer, stroke risk
105
In males, when is the initiation of spermatogenesis?
Puberty
106
What does ovulation normally occur?
14 days before the onset of menses
107
What is the source of HCG in the body?
Trophoblast
108
What is done in a male sterilisation?
Ligation/cauterisation of the vas deferens
109
What are some risks of vasectomy?
Soreness/bruising.
Not immediately effective
110
What techniques are used for female sterilisation?
Laparoscopic rings, clips or cautery.
Mini-laparotomy.
Tubal ligation at the time of the C-section.
Essentially mechanical blockage of the tubes
111
What is a copper IUD used for?
EC and normal contraceptive
112
How long is a copper IUD used for?
10 years
113
What is the mechanism of a copper IUD?
Copper ions inhibit the motility of sperm
114
What are the risks of using the levonorgestrel system?
Perforation, expulsion, infection
115
What are the non-contraceptive benefits of the IUS?
Decreased risk of PID, amenorrhea
116
What are the disadvantages of the implant?
Irregular bleeding
117
What are contraindications for a copper IUD?
Pelvic infection, uterine anomalies
118
How long is the implant used for?
3 years
119
What are contraindications for the implant?
Hepatic tumour, liver disease, breast cancer, allergies
120
What are contraindications of the progesterone only oral contraceptives?
Breast cancers
121
What are the non-contraceptive benefits of depo?
Decreases risk of seizuresAmenorrhea
122
How many times per month do you place a vaginal ring?
Once
123
How many times per month do you use the patch?
3 times (once a week and none for 1 week)
124
What type of lubricant can you use w/ latex condoms and why?
Water-based or silicone-based because oil-based lube will degrade the condom
125
How soon after unprotected coitus do you have to take levonorgestrel?
Within 72 hours
126
What is the mechanism of spermicides?
Destroys the sperm cell membrane
127
To have effectiveness w/ fertility awareness, what is a requirement?
1. Abstaining on fertile days
| 2. Regular menses to predict fertile days
128
What are the advantages of the barrier methods?
STI protection
129
What is the axis that Is involved w/ the production of testosterone?
HPT axis:
- Hypothalamus
- Pituitary
- Testis
130
What is the axis that Is involved w/ the production of oestrogen?
HPO axis:
- Hypothalamus
- Pituitary
- Ovaries
131
Where does LH act at the testis?
Leydig cells
132
Which cells produce testosterone?
Leydig cells (stimulated by LH)
133
Where does FSH act in the testis?
Sertoli cells
134
What is the function of FSH?
Regulate spermatogenesis
135
What is the function of the sertoli cells?
Spermatogenesis regulation
136
How is testosterone transported from the testes to circulation?
Through diffusion
137
What is the effect of testosterone and its metabolites on the: kidney, bone marrow, bone, skin and liver?
Kidney – stimulation of EPO
Marrow – stimulation of stem cells
Bone – accelerated linear growth and closure of epiphyses
Skin – hair growth, balding, sebum
Liver – synthesis of serum proteins
138
What is the action of testosterone in the male sexual organs?
Penile growth, spermatogenesis, prostate growth and function
139
What are the metabolites of testosterone?
DHT: dihydrotestosterone oestradiol
140
When is the 1st meiotic division completed?
Upon ovulation
141
When is the 2nd meiotic division completed?
Upon fertilisation
142
What does the corpus luteum become is there is no fertilisation?
Corpus albicans
143
What are the functions of oestradiol?
Breast tissue and bone formation
144
What enzyme is responsible for the production of DHT?
5 alpha reductase
145
What is the effect of testosterone on bone density and what mediates this effect?
Increases bone density Oestradiol mediates this
146
Where is the adrenal glands in the body?
Small, conical organs on top of kidneys
147
What do adrenal glands produce?
Variety of hormones including adrenaline, aldosterone, cortisol
148
What is the functional unit of the ovary?
Single ovarian follicle
149
What are the developmental steps that occur in the transformation of primordial germ cells to primary oocytes?
Primordial germ cell
- mitosis
- oogonia
- enter prophase of meiosis I
- primary oocyte
150
What are the stages in the development of the primordial ovarian follicles to mature follicle?
Primordial ovarian follicle
- primary follicle (remains until puberty)
- secondary follicle
- graafian follicle
- ovulation
151
Why can’t theca cells produce oestradiol?
Contain cholesterol desmolase (stimulated by LH) thus can produce testosterone, but not androgen aromatase
152
How is oestradiol produced in the ovaries?
LH stimulates theca cells to produce androgens.
Androgens diffuses to granulosa cells and is converted to 17 beta-oestradiol using androgen aromatase (stim by FSH).
153
What cells produce inhibin B and what affect does this have on the anterior pituitary?
Granulosa cell; -ve feedback on FSH production in anterior pituitary
154
What does low and high oestrogen conc. do?
Granulosa cell; -ve feedback on FSH production in anterior pituitary
155
What does low and high oestrogen conc. do?
Low – inhibits LH secretion.
High – stimulates LH secretion from anterior pituitary this triggers ovulation and granulosa cells to produce progesterone
156
How does oestrogen conc. increase in the follicular phase of the menstrual cycle?
Androgen acts on granulosa cells to cause proliferation.
As granulosa cell numbers increase they produce more oestrogen collectively
157
What increases granulosa cell numbers?
Androgen
158
What does the LH spike stimulate?
Ovulation of the most mature follicle in the ovary
159
What enzyme does granulosa cells express?
Androgen aromatase in response to FSH
160
What are abdominal cramps caused by?
The contraction of the uterine and abdominal muscles to expel the menstrual fluid
161
After ovulation levels of what drops?
LH drops
FSH and GnRH will also decrease
162
What does corpus luteum secrete?
Oestrogen, inhibin, progesterone
163
What does an increase in progesterone do?
Negative feedback on hypothalamus which inhibits GnRH secretion
164
What happens once the corpus luteum has fully degenerated?
Progesterone decreases so GnRH levels increases then new menstrual cycle can occur
165
What happens to the endometrial lining in decreased levels of progesterone and oestrogen?
Lining not maintained and sheds
166
Which hormone prepares the endometrium lining of the uterus for implantation?
Progesterone
167
What are the stages of the uterine cycle?
Proliferative and secretory
168
What are the 2 types of HRT?
E2 (oestrogen) only and Combined E2/P4 (progesterone)
169
What causes menopause?
Falling E2 levels due to follicle depletion
170
What are the major hormones regulating the female reproductive cycle?
GnRH, FSH, LH, E2, P4, Inhibin, AMH
171
What are the phases of the ovarian cycle?
Follicular and luteal stages
172
What is the hormone profile of the ovarian cycle?
Rising levels of LH and FSH lead to E2 surge causing LH surge which induces ovulation then LH levels falling again and P4 levels rise
173
What is the purpose of menstruation?
Shed the lining of the endometrium in the absence of pregnancy
174
What is oocyte maturation?
Progression from PI to MII, resulting in haploid gamete
175
How does DEPO (progesterone only injection) work?
Inhibits ovulation
176
What happens in the follicular phase?
Maturation of follicles in ovary due to FSH being released from pituitary gland
177
What should you warn patients about if they are using the coitus interruptus method?
Pre-ejaculate contains sperm
178
What is the MoA of the combined oral contraceptive?
Inhibits ovulation via action on hypothalamo-pituitary-ovarian axis to decrease LH and FSH; alters cervical mucus and endometrium
179
What is migraine w/ aura a contraindication of?
Oestrogen containing contraceptive
180
What is thelarche?
Breast development as part of puberty
181
Define pubarche
Pubic hair development as part of puberty
182
Define adrenarche
Adrenal development towards puberty
183
What is menopause defined as?
The last menstrual bleed (12 months ago)
184
How does menopause affect FSH and LH hormone levels and why?
They increase; because there is no negative feedback from the ovaries
185
What is the critical weight for onset of menarche?
46 kg
186
How has age of menarche change and why?
Decreased due to health and nutrition improvement
187
Where is oestradiol produced?
Granulosa cells around each oocyte
188
List 5 menopausal symptoms
Hot flushes, menstrual irregularity, mood swings, forgetfulness, dry skin and vagina
189
How does blindness affect menarche?
Lack of sunlight leads to later menarche
190
What is precocious puberty?
Menarche <9 yrs
191
What is delayed puberty?
Menarche >16 yrs
192
Why can puberty be delayed?
Low body weight
E.g. athletes, congenital, chromosomal abnormalities
193
Where is oestradiol produced?
Granulosa cells around each oocyte
194
List 5 menopausal symptoms
Hot flushes, menstrual irregularity, mood swings, forgetfulness, dry skin and vagina
195
What can unopposed oestrogen(s) stimulate?
Endometrial hyperplasia and carcinoma
196
How does smoking affect fertility?
Negatively; reduces number of oocytes
197
What happens to the pronephros in embryo?
Degenerates; only leaves behind mesonephros (males)
198
Which ducts are lost in males?
Paramesonephric ducts
199
Which ducts are lost in females?
Mesonephric ducts
200
What are the collecting tubules within each testicle called?
Epididymis
201
What does the mesonephric duct become eventually in men?
Ductus deferens
202
What slips down between the abdominal wall and peritoneum to the floor of the pelvis and emerge from the anterior abdominal wall?
The testes
203
What does the kidneys use to drain into the bladder?
Ureters (metanephros in embryo)
204
Name the 2 histological zones of the prostate gland
Central zone (inner part where all ducts are located).
Peripheral zone (cortex layer on the outside)
205
Where is the prostate relative to the bladder?
Inferior
206
Where does the superficial perineal pouch lie?
Between perineal membrane and (superficial fascia and skin)
207
Which nerve provides most of the somatic motor and sensory innervation of the dorsal penis and scrotum?
Pudendal nerve
208
Where does autonomic fibres for vasodilation and stimulation of erection come from?
Parasympathetic fibres; inferior hypogastric plexus; from S2,3,4
209
Where does sympathetic fibres for smooth muscle contraction, internal urethral sphincter, reproductive tract, glands and muscle come from?
T10-L2
210
Which spinal levels does the pudendal nerve come from?
S2,3,4
211
Where does autonomic fibres for vasodilation and stimulation of erection come from?
Parasympathetic fibres; inferior hypogastric plexus; from S2,3,4
212
Where does sympathetic fibres for smooth muscle contraction, internal urethral sphincter, reproductive tract, glands and muscle come from?
T10 - L2
213
What does the internal pudendal artery supply?
Everything except the testes
214
Where does the testes get their blood supply?
Anterior division of internal iliac A (abdo vessels) because they developed from posterior abdominal wall
215
Where to the testes drain to and via what?
Testicular/spermatic vein from testis to IVC via pampiniform plexus
216
What is the pampiniform plexus?
A network of small veins found in human male spermatic cord and female ovaries
217
Where does the right ovary drain blood to?
From pampiniform plexus to ovarian vein to IVC
218
What does the left ovary drain blood to?
From pampiniform plexus to ovarian to L renal vein to IVC
219
What hormone raises uterine threshold to contractile stimuli during pregnancy?
Progesterone – until foetus is ready to be delivered
220
What hormone affects body temperature during what part of the menstrual cycle?
Progesterone raises body temp during the luteal phase
221
Where is the pancreas located?
Across the back of the abdomen, behind the stomach
222
What is the pancreas connected to?
Duodenum and spleen
223
What regions is the pancreas divided into?
Exocrine – 98%
Endocrine – 2% (arranged in Islets of Langerhans)
224
What does the exocrine pancreas secrete?
Bicarbonate – pH buffering
Zymogens – inactive precursor of enzyme
Enzymes – food digestion
225
Describe the structure of the exocrine pancreas?
Acinus – clusters of cells that resembles lobed berries Intercalated ducts – lead directly from acinus to striated duct, lined by ductal cells
Striated duct – gland duct which connects intercalated duct w/ intralobular duct
226
What do ductal cells secrete?
Bicarbonate
227
Where is secretin produced?
Small intestines
228
Describe the secretion of bicarbonate?
Secretin from SI changes levels of ATP produced in duct cells.
This increased ATP acts in ATP sensitive CFTR ion channels and changes potential of the cell which induces a movement of ions
229
Which hormones control secretions of the exocrine pancreas and how?
Secretin – released from s cell of duodenum; binds to ductal cells leading to secretion of HCO3-CCK – digestion of fat and protein, binds to acinus cells, triggers enzyme release
230
What does the endocrine pancreas secrete?
Insulin, glucagon, somatostatin – regulate blood glucose.
| Pancreatic polypeptide, ghrelin – increases appetite
231
Describe beta cell
Secrete insulin which decreases blood glucose.
Found in the centre of the islets
232
Describe alpha Islets of Langerhans cells
Secrete glucagon which increases blood glucose.
Found on outer ridges of the islets; less numerous than beta cells
233
Describe delta cells?
Less common than alpha and beta cells.
Secrete somatostatin which inhibits insulin and glucagon secretion; dotted around islets
234
Describe epsilon cells
Uncommon; secrete ghrelin which increases appetite
235
Describe PP cells
Secrete pancreatic polypeptide which promotes satiety and inhibits pancreatic secretions
236
What is the pituitary gland attached to?
Base of brain (hypothalamus) by infundibulum
237
How many lobes does the pituitary gland have?
2 – anterior and posterior
238
What is the main function of the pituitary gland?
Master endocrine gland, secretes several hormones that control other endocrine glands
239
Describe the histology of the anterior pituitary lobe
Cell types based on staining:
- Chromophobes (unstained)
- Chromophils (stained) - subdivisions: acidophils and basophils
240
List the 5 basic secretory cells in the anterior pituitary lobe
Somatotrophs, mammotrophs, corticotrophs, thyrotrophs, gonadotrophs
241
List the acidophils in the anterior pituitary lobe
Somatotrophs and mammotrophs
242
List the basophils in the anterior pituitary lobe
Corticotrophs, thyrotrophs, gonadotrophs
243
What do corticotrophs secrete?
ACTH – which stimulates secretion of glucocorticoids from the adrenal cortex via the HPA axis
244
What does thyrotrophs secrete?
Thyroid stimulating hormone (TSH)
245
What does gonadotrophs secrete?
FSH and LH
246
What does mammotrophs secrete?
Prolactin which initiates lactation in mammary glands
247
Describe the histology of the posterior pituitary lobe
Essentially neural tissue, mainly non-myelinated axons, pituicytes – glial cells of posterior pituitary lobe
248
What is the arterial supply of the thyroid gland?
Superior and inferior thyroid artery (from common carotid)
249
What is the venous drainage of the thyroid gland?
Superior, middle, inferior thyroid vein
250
What is the importance of the venous drainage of the thyroid gland?
It’s how secretory products are put into the body
251
Describe the histology of the thyroid gland
Composed of many follicles, stores part of the secretory product.
Follicular cells are a single layer of epithelium around follicles.
Parafollicular cells secrete calcitonin
252
What do parafollicular cells of the thyroid gland secrete?
Calcitonin
253
What do follicular cells in thyroid produce and secrete?
Thyroid hormones thyroxine (T4) and triiodothyronine (T3)
254
Where are the parathyroid glands located?
On the posterior surface of the thyroid gland
255
What are parathyroid glands contained within?
Connective tissue capsule
256
How many parathyroid glands are there?
42 superior and 2 inferior
257
What do the ovaries produce?
Gametes and hormones (progesterone, oestrogen, inhibin, relaxin)
258
What ligaments are associated w/ the ovaries?
Broad ligament, suspensory ligament, ovarian ligament, round ligament, transverse cervical ligament
259
When do testes begin to descend into scrotum?
7th month of foetal development
260
What do the testes produce?
Sperm and testosterone
261
What does the tunica albuginea surround?
Layer of connective tissue covering the testicles and ovaries
262
What are seminiferous tubules lined w/?
Sertoli cells (columnar type cell)
263
What does the scrotum contain?
A pouch that contains 1 testis
264
What does the spermatic cord connect?
Testis to abdominal cavity
265
Where is the epididymis found?
Posterior border of each testis
266
Where is the site for sperm maturation?
Epididymis
267
What is the histology of the epididymis?
Pseudostratified columnar epithelium
268
What does the ductus deferens loop over?
The ureter and passes down the posterior side of the urinary bladder
269
What do the seminal vesicles store and produce?
Some of the liquid portion of semen
270
What do the seminal vesicles secrete?
Alkaline fluid, fructose, prostaglandins, clotting proteins
271
What is the function of fructose secreted by seminal vesicles?
ATP production
272
What is the function of prostaglandins secreted by seminal vesicles?
Contribute to sperm motility and viability
273
What is the function of alkaline secreted by seminal vesicles?
Help sperm survive acidic environment of the vagina
274
What is the function of clotting proteins secreted by seminal vesicles?
Help semen coagulate after ejaculation
275
What are the 2 main muscles of the scrotum?
Dartos – smooth muscle Cremaster – skeletal muscle
276
What do the muscles of the scrotum do?
Act to regulate temperature of the testes
277
What does the ductus deferens loop over?
The ureter and passes down the posterior side of the urinary bladder
278
What do the seminal vesicles store and produce?
Some of the liquid portion of semen
279
What is the ejaculatory ducts formed from?
Union of the seminal vesicles and ampulla of the ductus deferens
280
Where does the ejaculatory ducts pass through?
Inferiorly through prostate
281
What is the blood supply to the reproductive system?
Testes/ovaries – gonadal arteries from abdominal vessels.
Rest – internal pudendal artery from internal iliac artery
282
What is the corpus spongiosum?
Contains and spongy urethra and keeps it open during ejaculation
283
What are the corpus cavernosa?
Erectile tissue which contains most of the blood in the penis during an erection
284
What does the perineum contain?
Anal canalDistal urethra.
External genitaliaSpaces between
285
What is the bulb?
Posterior continuation of the base of the corpus spongiosum
286
What encloses the bulb?
Bulbospongiosus muscle
287
Describe the venous drainage of the male repro system.
Internal pudendal vein (except deep dorsal vein drains into prostate plexus)
288
What are the 2 pouches in the peritoneal cavity?
Recto-uterine pouch.
Vesico-uterine pouch
289
What is the endometrium made up of?
Stratum basale – provides base.
Stratum functionale – changes depending on phase
290
What is myometrium?
The smooth muscle layer of uterus
291
Describe the arterial supply to the uterus
Aorta – Supplies ovarian branch for ovariesInternal iliac – Gives off uterine, vaginal, and internal pudendal arteries for vagina/uterus
292
Describe the histology of the cervix
Epithelial transformation zone
- Lower part of cervix – stratified squamous epithelium.
- Upper part – simple columnar epithelium.
293
In females, what does the internal iliac artery give off?
Uterine, vaginal and internal pudendal arteries
294
Which artery supplies the ovaries?
Ovarian branch from aorta
295
Via which nerve is most somatic, motor and sensory info of the uterus transmitted?
Pudendal nerve
296
Describe the autonomic innervation of the uterus
Parasympathetic – S2-4
Sympathetic – T10-L2
297
What does the mesonephric duct become?
Ductus deferens
298
In females, what does the paramesonephric ducts become?
Uterine tubes and uterus
299
What is the hymen?
A thin membranous covering at distal end of vaginal canal;
Remnant of connection between vaginal canal and urogenital sinus
300
What is the broad ligament?
2 layers of peritoneum that drapes over the uterus and underneath uterine tubes
301
What is the significance of the gap between the ovary and infundibulum?
The zygote (after fertilisation) can fall between these cracks and attach to the abdominal cavity rather than the uterus.
Ectopic!
302
What sits inside the infundibulum?
Ovary
303
Where does the round ligament attach?
Ovary It runs along rim of the pelvic and passes through inguinal canal, ending up in the labia majora
304
What does the words ‘anteflexed’ and ‘retroflexed’ mean in relation to the uterus?
Anteflexed – uterus flopped forward to the cervix.
Retroflexed – uterus flopped backwards towards rectum
305
What is the fornix?
Little gully that goes around edge of cervix
306
What does the external iliac artery supply?
Lower limbs
307
Name the 2 openings in the perineal membrane in females
Vaginal opening and urethral opening
308
How is BMI calculated?
kg/m2
309
What is obesity linked to?
Poor socio-economic class; deprivation; men; ‘thrifty’ gene
310
What health conditions is obesity associated w/?
High BP, high glucose, high insulin (insulin resistance), low HDL, high plasma triacylglycerol, high LDL
311
What is leptin associated w/?
Reducing appetite
312
Where is leptin secreted from?
Adipose tissue
313
What is associated w/ increased appetite?
Ghrelin
314
What is a satiety hormone?
Hormone which is released once you’re fed; reduce appetite
315
Which structure releases satiety hormones after a meal?
GIT; it reduces appetite
316
Name 2 satiety hormones
PYY and GLP-1
317
What does direct calorimetry measure?
Heat output from the body
318
What does indirect calorimetry measure?
Oxygen consumption
319
What is type 1 diabetes caused by?
Damage of beta pancreatic cells leads to no insulin production
320
What is type 2 diabetes?
Insulin resistance.
Efficacy of insulin is reduced and glucose not taken up by muscles and organs leading to hyperglycaemia
321
What is the benefit of the genes related to type 2 diabetes?
Enabled people in famine environments to survive
322
Name 2 factors which are key factors for the basis of type 2 diabetes
Foetal and early nutrition – greater extent
Genetic (Mt16189 gene associated w/ insulin resistance) – smaller extent
323
What forms in the hypophyseal diverticulum?
The pituitary gland
324
What is the embryonic origin of the anterior pituitary lobe?
Oral ectoderm from roof of mouth
325
What is the embryonic origin of the posterior pituitary lobe?
Neuro-ectoderm from diencephalon
326
What is the isthmus?
Where the R and L lobe of the thyroid gland joins
327
How does the posterior and anterior pituitary gland differ in the way they release products into the bloodstream?
Anterior – neurohormones from hypothalamus enter arterial supply of the lobe, endocrine cells within the anterior lobe secretes products from endocrine cells into venous drainage, e g GH, PR, ACTH, MSH, TSH, FSH, LH.
Posterior – made of neural tissue not endocrine tissue; serves as a site for the secretion of neuro-hypophysial hormones directly into venous blood to body, e g oxytocin, ADH
328
What do chief cells of parathyroid glands secrete?
PTH – parathyroid hormone
329
What are parafollicular cells aka and what do they secrete?
Calcitonin, C cells
330
How does the parathyroid glands differ from the thyroid?
Structurally – para doesn’t have follicles, 4 glands rather 1 bi-lobed glandVasculature usually same
331
What does the follicular cells of the thyroid secrete?
T4 93%
T3 7%
332
What are the physiological effects of thyroid hormones on the CV system?
Increased HR, contraction force, CO, peripheral vasodilation
333
What are the physiological effects of thyroid hormones on the CN system?
Needed for normal brain development (cerebellar growth and nerve myelination), normal intellectual development in infants, emotional stability in adults
334
What is the effects of thyroid hormone on RR?
Increases RR and depth of respirations
335
How do thyroid hormones effect growth?
Indirectly promotes growth formation by actions on the pituitary gland; acts synergistically w/ growth hormone and other growth factors that promote bone formation
336
What effects do thyroid hormones have on the GI?
Increases appetite, secretion of digestive juices, gastric motility
337
What effect does PTH have on the intestine, kidney and bone?
Intestine – increases calcium absorption from food Kidney – promotes activation of vitamin D and ↑ Ca reabsorptionBone – activates osteoclasts; Ca2+ and K+ released into blood
338
What hormone is released in response to hypocalcaemia?
Parathyroid hormone (PTH)
339
Where are parathyroid glands located relative to thyroid gland?
Posterior, 2 on each side
340
Where is the thyroid gland located?
Anterior to the trachea, below and lateral to thyroid cartilage, wraps around the cricoid cartilage
341
What is the arterial supply of the thyroid gland?
Superior thyroid artery – a branch of external carotid artery.
Inferior thyroid artery – a branch of thyrocervical trunk
342
What is the venous drainage of the thyroid gland?
Superior and middle thyroid vein – into internal jugular vein.
Inferior thyroid vein – drains into L and R brachiocephalic veins
343
How does PTH act on the renal system?
Promotes renal Ca2+ and PO43- reabsorption
344
How are thyroid hormones synthesised?
In follicles, iodine added into tyrosine residues at thyroglobulin (where synthesis of TH takes place)
345
What is thyroid peroxidase?
Catalyses ionisation of tyrosine residues (production of TH)
346
What would happen is thyroid peroxidase is inhibited?
Autoimmune hypothyroidism
347
List the signs of hypothyroidism
Dry and scaly skin, dry and thin hair, puffy eyes, anaemia
348
What is the thyroid gland composed of?
Follicles (main secretory cells) – functional units of thyroid; secrete thyroid hormones and store TH in colloid within follicles.
C cells – less numerous and larger (secrete calcitonin)
349
What hormone inhibits osteoclast activity in bone?
Calcitonin – from follicular cells of thyroid gland
350
How does calcitonin act on the renal system?
Inhibits renal Ca2+ and PO43- reabsorption
351
What is diabetes insipidus?
Low levels of vasopression leading to polyuria.
Treat with desmopressin (vasopressin analogue)
352
Which 2 hormones control growth hormone secretion?
GHRH – increases GH from anterior pituitary.
Somatostatin – inhibits GHRH-mediated GH release
353
What is Addison’s disease?
Autoimmune primary adrenal insufficiency leading to.
Hypocortisolism
354
What is Cushing’s disease?
Secondary hypercortisolism (due to pituitary tumour)
355
What is Cushing’s syndrome?
Primary excess cortisol (hypercortisolism)
356
What is primary hyperparathyroidism?
Overactive parathyroid glands --> hypercalcaemia
357
How does carbimazole (treats hyperthyroidism) work?
Reduces TH synthesis by inhibiting thyroperoxidase which normally iodinates tyrosine residues in thyroglobulin to give the precursors of T3 and T4
358
What is the epidemiology of hypothyroidism and hyperthyroidism?
More prevalent in. women
359
How is hyperthyroidism treated?
Medication – carbimazole (thionamides) interfere w/ thyroid hormone production
Radioactive iodine – Destroys part of the gland by emitting X rays and beta radiation that is cytotoxic to local thyroid cells.
Surgery – reduces amount of functioning thyroid tissue
360
What controls the regulation of thyroid hormone secretion?
HPT – axis controls thyroid hormone releaseH - secretes TSH.
Anterior pit - secretes THT - secretes T3 and T4; inhibits hypothalamus and anterior pit secretions
361
How does hyperthyroidism affect TSH, T4 and T3 levels?
TSH – decrease and T4 and T3 – increase
362
What usually causes primary hyperparathyroidism?
Single benign parathyroid adenoma
363
What is the tail of the pancreas also known as?
Splenic end
364
What is the head of the pancreas also known as?
Duodenal end
365
What happens when pancreas is removed from the body?
It digests itself within 30 seconds
366
What causes insulin dependent diabetes mellitus?
Destruction of beta pancreatic cells
367
What is the endocrine pancreas surrounded by?
Exocrine pancreas
368
Which type of pancreas has large nuclei?
Endocrine
369
What does exocrine pancreas secrete?
Bicarbonate (pH buffer).
Zymogens – inactive precursor to enzymes
E.g. pepsinogen, trypsinogen Enzymes – food digestion
370
What does endocrine pancreas secrete?
Insulin, glucagon, somatostatin – regulate blood glucose levels.
Pancreatic polypeptide – induces hunger
371
What are intercalated ducts?
Portion of the exocrine gland leading directly from the acinus to striated ducts. Forms part of the intralobular duct
372
What is the function of intercalated ducts?
Makes and released bicarbonate into the duct via ductal cells which buffers acidic environment to optimal pH for enzyme function
373
What is secretin?
A hormone that regulates water homeostasis and secretions in the stomach and duodenum
374
Which cells produce secretin?
S cells in duodenum
375
What causes cystic fibrosis?
Frameshift mutation in the CFTR channel gene
376
What does CF cause?
No movement of Cl- into cell and expulsion of HCO3- and H2O
- Forms thick, viscous secretions that block exocrine movement of digestive enzymes Leads to LT fibrosis (collagen in pancreas)
377
What is CCK?
Cholecystokinin.
A hormone released from duodenum; acts on the pancreas; responsible for digestion of fat and protein
378
Which hormone binds to acinus cells and triggers digestive enzyme release?
CCKProduced when food is in stomach
379
What is pancreatin?
Drug used as substitute to natural enzymesIt is used for digestion of fat and protein
380
What do pancreatic delta cells produce?
Somatostatin – growth hormone
381
What do pancreatic alpha and beta cells produce?
Alpha – glucagonBeta – insulin
382
What do pancreatic epsilon cells produce?
Ghrelin which increases appetite
383
What do PP cells secrete?
Pancreatic polypeptide
384
Which endocrine pancreatic cells are more common?
Insulin-secreting beta-cells
385
Which organ doesn’t have insulin receptors?
Brain.
Glucose uptake not controlled by insulin
386
Upon release from the pancreas where does insulin travel and act?
Enters portal circulation and is carried to the liver Liver – prime target organ
387
Where does the proportion of insulin not broken down in the liver go?
Kidneys
388
In which 2 forms does insulin exist in?
Hexametric (inactive) and monomeric (active)
389
Where is hexametric insulin stored?
Secretory granules
390
In hexametric insulin, what holds together the 6 insulin molecules?
Central zinc moleculeHistidine bonds
391
Why does monomeric insulin have a high diffusion rate?
Because it’s a small molecule
392
What is insulin synthesised as?
A single 22aa polypeptide chain called pre-proinsulin
393
What does CCK do to hunger?
Suppresses it
394
What signal releases insulin from granules to blood?
Vagal nerve stimulation
395
Name the 29aa polypeptide produced by alpha cells
Glucagon
396
What is glucagon cleaved into in intestinal L cells?
GLP-1 (an incretin), GLP-2 (promotes intestinal growth), IP-2
397
What is GLP-1?
Glucagon like peptide 1
398
What is the function of incretin hormones?
Reduce appetite by acting on hypothalamus, Slow gastric emptying,Reduce glycogenolysis, Stimulates insulin secretion
399
How is type 2 diabetes controlled?
Anti-hyperglycaemic agents:
- Metformin
- Sulphonylureas
- Glitazones- GLP-1 agonist
- DPP-4 inhibitor
- Insulin analogues
400
What does incretin promote?
Satiety and reduces appetite
401
What is metformin?
Biguanide
402
How does metformin work?
Improves insulin resistance in skeletal muscles and liver so more glucose uptake In GIT prevents glucose absorption leading to lowering blood glucoseDecreases gluconeogenesis and glycolysis
403
What are side-effects of metformin?
Lactic acidosis – rare but 50% mortality rate once acquired.
Vitamin B12 deficiency – LT
404
What are PPAR γ agonists?
Peroxisome proliferator-activated receptor agonists.
Nuclear receptor that modulates transcription of insulin sensitising genes and insulin sensitised in liver, muscles and adipose tissue
405
What is the pampiniform plexus?
Venous network in the scrotum; drains testes to testicular vein
406
What do theca cells correspond to in males?
Leydig cells (found in males)
407
What do sertoli cells correspond to in females?
Granulosa (found in females)
408
How does sildenafil work?
Phosphodiesterase (E5) inhibitor PDE5 is inhibited in cavernosal smooth muscles through 2nd messengers he smooth muscle contracts and penis becomes erect
409
Name 3 drugs for erectile dysfunction
1. Phosphodiesterase (E5) inhibitors – sildenafil
2. Prostaglandin-E1 agonists – alprostadil
3. Dopamine receptor agonists – apomorphine
410
Why is oxytocin important in pregnancy?
Contracts uterine muscles (delivery), and breast muscles (milk)
