Repro Flashcards
(185 cards)
1
Q
what does spermatic ducts include?
A
epididymis
ductus deferens
ejaculatory duct
2
Q
accessory sex glands include?
A
seminal vesicles
prostate
bulbourethral glands
3
Q
functions of repro system?
A
spermatogenesis
production of seminal fluid
steroidogenesis
sex
4
Q
testes are the site of —- and —-.
A
spermatogenesis and steroidogenesis
5
Q
what is the benefit of extra abdominal location of testes?
A
maintains temp 2-3 degrees below body temp==> vital for spermatogenesis, but not necessary for steroidogenesis.
6
Q
what controls the position of testes in relation to temperature?
A
the contraction of cremaster muscle
7
Q
what is the layer of testes that descends down from abdominal cavity?
A
tunica vaginalis
8
Q
tunica vaginalis is a remnant of — which is lined by — and produces — to —- &—.
A
peritoneum
serous membrane
serous fluid to reduce friction and facilitate movement
9
Q
tunica albuginea is a —- which — and forms septa.
A
dense and thick CT capsule
protects
10
Q
what forms the CT septa of testes?
A
t. albuginea
11
Q
what does tunica vasculosa contain?
A
blood vessels
12
Q
what are the prominent structures visible in a low mag of testes?
A
lobules which contain seminiferous tubules
13
Q
what is the site of spermatogenesis?
A
seminiferous tubules
14
Q
what is the tissue in between the seminiferous tubules and what does it contain?
A
CT stroma which contains leydig cells
15
Q
site of steroidogenesis?
A
CT stroma by leydig cells
16
Q
prominent features of leydig cells?
A
abundant lipid droplets
lots of sER, large, polygonal eosinophilic
17
Q
testosterone is synthesised from — which is collected via — in leydig cells.
A
cholesterol
lipid droplets
18
Q
when do leydig cells become active?
A
early in foetal development to secrete testosterone for gonadal development and descent of testes.
19
Q
are leydig cells always active in their secretions?
A
no. they stop in 5 months of foetal life till puberty.
20
Q
what are the effects of testos after puberty?
A
- enlargement of penis, testes and prostate.
- initiation of spermatogenesis
- initiation of accessory sex gland secretions
- development of secondary sex characteristics
21
Q
what are the effects of testos production throughout life?
A
essential for maintenance of structures developed in puberty, maintenance of bone and muscle strength and erectile function
22
Q
seminiferous tubules are lined with spermatogenic epithelium which is a —- epithelium which contain — and —-.
A
complex stratified epithelium
sertoli cells and spermatogenic cells
23
Q
sertoli cells are —- epithelial cells which support the development of —-.
A
true epi cells
spermatogenic cells
24
Q
what tissue surrounds the semi tubules and what is its function?
A
myoid cells
contractile cells which through peristaltic contractions move the sperm and testicular fluid through tubules to excurrent ducts.
25
what does spermatogenic epithelium include?
sertoli cells
| spermatogenic cells/germ cells
26
what are the stages of spermatogenic cell development?
stem cells which are located basally=spermatogonia ==>undergo spermatogenesis to turn into mature sperm==> migrate towards lumen as they mature.
27
what does spermatogenesis consist of?
mitosis (spermatogonium undergo mitosis to form primary spermatocytes), meiosis (from primary to secondary and spermatids) and spermiogenesis (final morphological differentiation from round cell to mature sperm).
28
where are spermatogonia located?
basal lamina of semi tubules
29
types A spermatogonia ?
```
Type A:
• Dark = stem cell reserve
• Mitosis to replace themselves &
maintain stem cell reserve
• Light = renewing stem cells
• committed to differentiate, but first
undergo multiple mitotic divisions to
increase number
```
30
type B spermatogonia?
Type B = last step in
spermatogonial phase
• Condensed chromatin
31
what is the step after formation of type B spermatogonia?
```
Type B spermatogonia undergo mitosis
to produce primary spermatocytes.Immediately replicate their DNA and enter
prophase I of meiosis. (22 days)
• “Crossing Over” occurs, creating new
combinations of DNA within chromosomes.Undergo first meiotic division to
become secondary spermatocytes
• Do not replicate DNA, immediately
enter prophase II of meiosis
• Complete 2nd meiotic division rapidly
(within a few hours) to form
spermatids
```
32
what happens at spermatid stage?
No changes to DNA. No cell division
Morphological transformation
(differentiation) into mature sperm
= spermiogenesis.
33
what occurs in spermiogenesis?
```
• Extensive cellular remodelling
• Spermatids physically attached to Sertoli
cells during this transformation
• Start as small, round cells, round nuclei
• Nucleus condenses
• Formation of acrosome
• Development of flagellum
• Reduction of cytoplasm
• Removal of excess organelles
(Ribosomes, ER, Golgi etc)
-development of spermartozoa
```
34
Final maturation of spermatozoa occurs in?
epididymis
35
what does the head of spermatozoa contain and function if each part?
```
• Acrosome
• Contains enzymes to penetrate zona
pellucida of oocyte → fertilisation
• Nucleus
• Haploid, extremely condensed, inactive
```
36
what does the tail of spermatozoa contain and function if each part?
* Neck → Centriole
* Midpiece → Mitochondria
* Principal piece & End piece → Flagellum
* contains axoneme
37
what determines the sex of the baby?
sperm
38
what cells protect spermatogenic cells and how?
sertoli cells- their processes surround spermatogenic cells for duration of
spermatogenesis.
• Provide nutrients & growth factors, remove
waste
• Phagocytose components of spermatids in
final stage of spermiogenesis
39
how are sertoli cells stimulated?
Stimulated by FSH and testosterone
40
what are secretory functions of sertoli cells?
```
• Exocrine: secrete fluid into seminiferous
tubules, facilitates movement of sperm
along tubules to ducts
• Endocrine: secrete several hormones
including inhibin (-ve feedback FSH)
```
41
immunological function of sertoli cells?
form the blood testes barrier
42
what constitutes the blood testes barrier?
unique sertoli to sertoli junctional complexes attached basolaterally to cells which are exceptionally tight and junctions =zonula occludens
43
function of blood testes barrier?
```
Segregates luminal fluid, allowing strict
control over its composition
Prevents passage of toxic agents from
blood into tubules.
Segregates pre-meiotic and post-meiotic
```
44
why is it important to isolate spermatocytes from blood?
Post-meiotic = different DNA = antigenic
• They Isolate post-meiotic from immune system
Early primary spermatocytes pass through
junctional complex before they cross over.
• Antigens produced by sperm can’t enter
circulation
• Circulating antibodies can’t reach sperm.
If BTB fails, anti-sperm antibodies are
produced ➔ can cause infertility
45
how long does spermatogenesis take?
74 days + 12 days to pass through epididymis and mature.
46
semen is manufactured in ----, -- and --- in epididymis, ejaculation forces sperm into --- which meets the seminal vesicles to form---.
It passes through -- and empties into --- which carries through ---.
```
testes
storage and maturation
vas deferens
ejaculatory duct
prostate
urethra
penis
```
47
the bulk of the seminal plasma is from?
seminal vesicles then prostate
48
what are the phases of ejaculation? explain each.
```
Emission
• Contractions in vas deferens (sperm), seminal vesicles and prostate expel fluid
• Combined and stored in
prostatic urethra (semen)
• Contractions in bulbourethral
gland
Expulsion
• Often associated with orgasm
• Contractions in smooth muscle of
urethra and rhythmic
contractions in striated muscles of
perineum propel semen from
prostatic urethra
• Ejection of combined semen
through penile urethra
```
49
how do sperm become mature?
```
Immature sperm enter at head
(incapable of fertilisation)
• Sperm take ~12 days to travel through
and undergo further maturation
• Gain motility
• Further condensation of nucleus
• Further reduction of cytoplasm
• Decapacitation: Modification of
acrosome to inhibit fertilising ability. This
is reversed during capacitation in
female reproductive tract
```
50
tubules in epididymis are lined with?
pseudostratified epithelium
51
what are the cells inside epididymis epi?
* Basal cells
| * Principal cells => covered with stereocilia
52
function of principal cells of epididymis?
• Absorption of remaining fluid coming
from seminiferous tubules
• (100-fold concentration of sperm).
53
specific functions of epididymis epi?
• Phagocytosis of material released by
maturing sperm and any degenerates
• Secretion of factors that aid in sperm
maturation
54
function of smooth muscle surrounding epididymis epi?
• Head & body: peristalsis to move sperm
along
• Tail: intense contractions at ejaculation
55
function of vas deferens?>
Strong peristaltic contractions at
ejaculation (emission) carry sperm from
epididymis to seminal vesicles
56
vas deferens is a --- tube.
muscular
57
epi of vas deferens?
• Pseudostratified epithelium-covered with stereocilia.
58
what are some features of vas deferens?
```
• Folded lumen
=> Probably due to contraction of
muscle during tissue fixation
• Very muscular wall: 3 layers of
smooth muscle
• Inner longitudinal
• Middle circular
• Outer longitudinal
```
59
what controls the secretions from seminal vesicle?
testosterone
60
what makes up seminal plasma from seminal vesicle?
• Fructose – large amount
• Amino acids, proteins, enzymes, Vitamin C,
Prostaglandins
61
functions of each component in seminal plasma from seminal vesicle?
• Fructose = main energy source for sperm
• Fluid is alkaline, neutralises acidic vaginal
pH to facilitate sperm survival
• Suppresses immune function in female
reproductive tract
62
epithelium of seminal vesicle?
Psueudostratified or simple columnar
| epithelium
63
features of seminal vesicle epi?
• Highly secretory
• Contain many secretory granules,
abundant golgi & rER (TEM).• Lamina propria = CT, v. elastic
• Thick smooth muscle wall
• Contraction during ejaculation (emission
phase)
64
secretions from prostate is controlled by---.
testosterone
65
what are the components of secretions from prostate?
• Prostatic acid phosphatase, fibrinolysin,
| citric acid & prostate-specific antigen
66
functions of secretions from prostate?
* Enzymes liquify semen after ejaculation
| * Also alkaline, neutralise acidic vaginal pH
67
how is retrograde ejaculation prevented from prostate to bladder/
contraction of bladder neck at ejaculation.
68
what is the prominent histo feature of prostate?
Contains 30-50 compound
| tubuloalveolar glands
69
prostate gland tubules are surrounded by ---.
fibromuscular stroma
70
what is the function of fibromuscular stroma in prostate?
• Contractions at ejaculation
(emission) pump alveolar
secretions into urethra
71
prostatic urethra is lined with?
transitional epi
72
tubuloalveolar glands are lined with?
• Generally simple columnar epithelium but can
| vary (simple cuboidal to pseudostratified)
73
alveoli contain material in their lumen. what is this called?
Alveoli can contain prostatic concretions (aka
corpora amylacea)
• = concentric lamellated material
• Thought to be precipitated prostatic secretions
Can become calcified
74
bulbourethral glands empty into ---
penile urethra
75
what controls bulbo gland's secretions
testosterone
76
what do bulbo glands produce and their functions?
mucin
• Mucus-like secretion released during erection
(= pre-ejaculate)
• Neutralise acidity of urethra (due to residual
urine)
• Lubricates penile urethra for passage of
sperm
77
main tissue in penis?
vascular erectile tissue
78
how does the epi of urethra change from bladder to terminal penis?
* Neck of bladder = transitional
* Prostatic urethra = transitional
* Membranous urethra = pseudostratified
* Most of penile urethra = pseudostratified
* Terminal portion of penile urethra = non-keratinised stratified squamous
79
what are the main components of penis?
3 vascular erectile tissues, 2 dorsal-corpora cavernosa
| 1 ventral-corpus spongiosum
80
the primary erectile tissue in penis is?
corpora cavernosa
81
which component of penis contains urethra?
corpus spongiosum
82
what surrounds the corpora of penis?
dense fibroelastic layer-tunica albuginea which also surrounds each.
83
what covers tunica albuginea?
covered by CT and thin skin.
84
90% of blood in penis is within ----.
cavernous sinuses in corpus cavernosum
85
what epi lines the cavernous sinuses?
endothelium
86
what surrounds the cavernous sinuses?
CT trabeculae between- which contains smooth muscle, Helicene arteries, and nerves
87
where are veins positioned inside the corpora?
edge of tunica-peripheraly located.
88
how does the tunica albuginea differ for each corpora-relate to function?
corpus cavernosum-thick, dense CT
corpus spongiosum-thinner and more elastic-to prevent compression of urethra during erection, allowing semen to be released at ejaculation.
89
similarities and differences between the corpora?
both contain similar cavernous sinuses and CT septa. But in spongiosum there's 10% of blood.
Spongiosum contains penile urethra and small mucus glands which empty into urethra.
90
erection is under--- stimulation.
parasymp
91
describe the steps in erection?
* Dilation of helicene arteries
* ↑ blood flow
* Relaxation of SMCs in trabeculae
* Cavernous sinuses fill with blood
* Corpora cavernosa expand
* Veins compressed against tunica albuginea, blocking venous outflow
* Erection achieved (hydraulic pressure)
92
--- ends erection.
symp stimulation
93
describe steps after erection ends.
•Constriction of helicene arteries
•Contraction of SMCs in trabeculae
•↓ blood flow to cavernous sinuses
•↓ pressure on veins, unblocking venous outflow
•Blood drains
•Erection subsides & penis returns to flaccid state
In flaccid penis, SMCs under tonic contraction, limits blood flow into sinuses
94
pacinian corpuscles in penis are responsible for ---,-- and ---.
sensitivity, touch and pressure.
95
what are the striated muscles at base of penis and their function.
bulbospongiosus
ischiocavernosus
Rhythmic contractions increase pressure in corpus spongiosum, propelling semen through urethra =expulsion phase of ejaculation
96
role of estrogen?
```
– Growth, maturation of sex
organs
– Female sex characteristics
at puberty
– Breast development,
adipose accumulation
```
97
roles of progesterone?
– Prepare uterus for
pregnancy
– Prepare mammary gland
for lactation
98
Gametogenesis is production of --- .
eggs
99
what is the epi of ovary?
germinal epi:simple cuboidal cells
100
what are the layers of ovary?
```
Germinal epithelium
Tunica albuginea
Cortex – follicles
Medulla – large
blood vessels
```
101
germinal epi is continuous with ---.
mesothelium that covers mesovarium
102
how do germ cells develop in foetus?
Migrate from embryonic yolk sac into
| embryonic gonad
103
when do the oocytes stop mitosis?
at birth-they are arrested at prophase 1.No new oocytes are produced after birth
104
what are the three types of ovarian follicles?
- primordial follicles;
- growing follicles, which are further subcategorized as primary and secondary (or antral) follicles; and
- mature follicle or Graafian -follicles.
105
when do primordial follicles appear during development?
3rd month
106
where are primordial follicles located, their feature?
found in the stroma of the cortex just beneath the tunica albuginea. A single layer of squamous follicle cells surrounds the oocyte
107
how do primordial cells become primary follicle?
As a primordial follicle develops into a growing follicle, changes occur in the oocyte, in the follicle cells, and in the adjacent stroma. Initially, the oocyte enlarges, and the surrounding flattened follicle cells proliferate and become cuboidal/granulosa cells. At this stage—that is, when the follicle cells become cuboidal—the follicle is identified as a primary follicle.
-zona pellucida forms from the proteins secreted by the oocyte
-Stromal cells surrounding follicle become
theca interna, theca externa cells
-Move deeper into ovary due to proliferation of
granulosa cells
108
zona pallucida is composed of?
ZP glycoproteins secreted by the oocyte: ZP-1,ZP-2,-3,-4.
109
zona pellucida is --- staining.
acidophilic
110
how does late primary follicle develop?
follicle cells give rise to stratified epi-granulosa cells.
| extensive gap junctions develop between granulosa cells and oocyte.
111
characteristics of theca interna?
```
– Highly vascularised
– Cuboidal secretory cells
– Steroid-producing
– LH receptors – synthesise
and secrete androgens
```
112
feaTures of theca externa?
– Outer layer of CT
– Collagen, smooth muscle
fibres
113
how to we classify secondary follicles?
presence of antrum
114
how does secondary follicle develop?
When the stratum granulosum reaches a thickness of 6 to 12 cell layers, fluid-filled cavities appear among the granulosa cells (Fig. 23.6). As the hyaluronan-rich fluid called liquor folliculi continues to accumulate among the granulosa cells, the cavities begin to coalesce, eventually forming a single, crescent-shaped cavity called the antrum. The follicle is now identified as a secondary follicle or antral follicle.
115
the follicular antrum contains ?
the fluid is called liquor folliculi, rich in Hyaluronana
116
what is required for transition from primary follicle to secondary?
FSH
GF
Ca ions
117
Maximum diameter of oocyte ?
125 microns
118
what theca interna cells and granulosa cells secrete after secondary follicle development and their path?
Theca interna:
-has LH receptors, LH from pituitary binds to this and secretes androgens. The androgens go to granulosa cells.
Granulosa cells
– Have FSH receptors-FSH binds to these and stimulates the conversion of androgens from Theca interna into estrogens.
– have enzymes Convert testosterone (type of androgen)
into estrogens.
119
What occurs after secondary follicle maturation?
mature Graafian follicle develops.
120
features of Graafian follicles?
-Large – 10mm or more diameter-quite large
-Single fluid filled antrum taking up most of
volume of follicle
Specialisations of granulosa cells-formation of
– Cumulus oophorus
– Corona radiata
121
what's involved in ovulation?
High level of estrogens (from follicles) lead
to surge in LH and FSH (positive feedback)
– Proteolytic enzymes
– Resumption of meiosis 24hrs before ovulation
– Secondary oocyte – arrested at metaphase II
until fertilisation
Oocyte + corona radiata + fluid ovulated
122
what remains after ovulation?
corpus luteum-granulosa cells and theca cells
123
what occurs after ovulation to the granulosa cells and theca cells of ovaries?
they undergo luteinisation-increase in size and lipid accumulation.
Steroid secreting – abundant sER, mitochondria with tubular cristae.
124
where does the yellow appearance of c.luteum come from?
Lipochrome – lipid soluble pigment, yellow
| appearance
125
types of cells in corpus luteum and their secretions?
```
Granulosa lutein cells
– Develop from granulosa
cells of follicle
– 30µm diameter
– Secrete estrogens,
progesterone and inhibin.
```
```
Theca lutein cells
– Develop from theca
interna
– Smaller (15µm diameter),
darker staining
– Secrete androgens,
progesterone
```
126
what signals to stop FSH from pituitary in females?
inhibin released from c.luteum
127
if no fertilisation occurs, --- develops.
corpus albicans-gross white scar, intercellular hyaline material accumulation which get absorbed into ovary later
128
what happens to rest of the follicle cells that haven't developed into primary or secondary follicles?
undergo atresia -can occur at any stage.
129
what does atresia involve?
```
Apoptosis of granulosa cells
Degeneration and autolysis of oocyte
Zona pellucida folded, collapses,
phagocytosed by macrophage
Basement membrane forms glassy
membrane – wavy hyaline structure
```
130
what type of CT surrounds uterine tube?
```
External serosal layer
– Mesothelium, thin layer
connective tissue
Muscular layer
– Inner circular
– Outer longitudinal
```
131
describe the mucosa of uterine tube.
```
Highly folded (in ampulla), highly
vascularised
Simple columnar
epithelium
– Ciliated cells
– Nonciliated peg cells
```
132
which part of the uterine tube has more foldings?
ampulla
133
how does the uterine tube change during menstrual cycle?
Hypertrophy during follicular phase (during development of oocyte)
Atrophy during luteal phase (after ovulation)
Estrogen – ciliogenesis to move the egg down
Progesterone – increase in secretory cells-after ovulation, need nourishment
Peak height of epithelial cells 30µm at time
of ovulation
– Half height just before menstruation
134
What lining covers Uterus?
perimetrium -serosa
135
layers of myometrium?
```
3 layers (indistinct)
– Inner longitudinal
– Middle circular
– Outer longitudinal
```
136
function of myometrium?
```
During pregnancy
– Hypertrophy (50µm to 500µm
in length)
– Hyperplasia
– Differentiation of
undifferentiated cells
```
137
why there are changes in endometrium during menstrual cycle?
```
Cyclical changes during
menstrual cycle
– Prepare for implantation of
embryo and subsequent fetal
development
```
138
layers of endometrium?
```
– Functional layer
Thickest part, closest to lumen
-Can be called Stratum functionalis
– Basal layer
Retained during menstruation
Regeneration of functional layer
Stratum basalis
```
139
what is endometrial epithelium?
Luminal epithelium
– Simple columnar
– Secretory and ciliated
cells
140
prominent histo feature of endometrium?
```
Endometrial stroma
– Highly cellular
– Simple tubular glands
invaginations of luminal
epithelium
```
141
luminal epi cells of endometrium are continuous with ---.
glandular epi cells
142
what is the unique feature of uterine luminal epi cells?
Only cells in body that transform from nonreceptive to receptive in short time frame (attachment or non-attachment of blastocyst).
143
how does the uterine luminal epi cells change ?
change with menstrual cycle-after ovulation you get flattening of the simple columnar cells, accumulation of vesicles inside, making them become receptive.
144
describe the vasculature of the uterus and their location.
```
the uterine artery comes in, becomes arcuate then radial within myometrium.
Straight artery – basal
layer of endometrium.
Spiral artery – extends
into functional layer (stratum functionalis)
– Highly coiled
– Important in menstruation
Arterioles, capillaries,
venules…
```
145
what influences the functional layer of endometrium to grow?
estrogen.
146
when does proliferative phase of uterus occur, what happens and what causes it?
synced with follicular phase of ovarian cycle, endometrium grown to 3mm in thickness via the control of estrogen. Day 5-14
147
prior to ovulation the phase is called---, after is called---.
proliferative phase
| secretory phase
148
features of proliferative phase of endometrium?
```
Regeneration of endometrium
– Mitotic figures in epithelium
Spiral arteries
– Lengthen, not in upper 1/3rd of endometrium
Glands
– Narrow, relatively straight
– Some glycogen in basal glands
```
149
when does secretory phase of uterus occur and what controls it?
```
Luteal phase of ovarian cycle
Days 15-26
Progesterone controls it
Endometrium 5-6mm thick
Oedematous stroma
```
150
features of endometrium structure in secretory phase
```
Glands
– Enlarged
– Corkscrew shape
– Sacculated appearance
Glycogen rich secretory products.
```
Spiral arteries
– Lengthen to nearly reach surface
– More coiled
Stromal cells
– Transform into decidual cells
– Large pale cells
– Rich in glycogen
151
what is secreted during secretory phase?
estrogen and progesterone
152
what causes the menstrual phase to initiate?
Decline in estrogens and
progesterone
through degeneration of corpus luteum
153
what occurs during menstrual phase?
```
Periodic contractions of spiral arteries caused by decline in estrogen and progesterone.
– Ischaemia of functional layer,
blood flow remains to basal layer
– Necrosis of stromal cells
– Disruption of surface epithelium
and rupture of blood vessels
```
154
what does the menstrual discharge consist of?
– Blood, uterine fluid, stromal cells and
| epithelial cells of functional layer
155
what is inhibited during menstrual phase?
blood clotting factors and fibrinolysis.
156
what is endometriosis?
```
-Presence of
endometrial tissue
outside uterine cavity
-Retrograde
menstruation
```
157
how does cervix compare with uterus?
```
More connective tissue, less smooth muscle
than body of uterus
Elastic fibres
Large branched glands
No spiral arteries
```
158
epi of different parts of cervix?
```
Epithelium
– Endocervix – simple
columnar (continuous
with uterus)
– Ectocervix – stratified
squamous (continuous
with vagina)
```
159
does the mucosa of the cervix change during menstrual cycle?
nope. – No change in thickness
during menstrual cycle
– Not sloughed off during
menstruation
160
what produces cervical mucus and their function?
Produced by glands
| Lubrication of vagina
161
what controls cervical mucus and why?
Change during menstrual cycle, under
hormonal control
Most stages – prevents passage of sperm
into uterus
162
how does the mucus change during mestrual cycle?
Ovulation time
– Mucus production increased 10x
– Less viscous, ‘egg white’ consistency
– Favourable for sperm migration
163
are nabothian cysts pathological?
no their normal. become more as you age, they are basically blocked cervical glands.
164
all cases of cervical cancer is asso with---.
HPV
165
type of mucosa epi of vagina?
– Non-keratinised stratified
squamous epithelium
– Connective tissue papillae
166
what CT covers vagina?
Adventitia
– Inner dense CT
– Outer loose CT
167
what are the features of vaginal mucosa?
```
Stratified squamous
epithelium
– Glycogen
Source of energy for
lactobacillus – maintain
vaginal pH. Unlike hyaline granules of keratin in skin.
```
```
Lamina propria
– Highly cellular, loose ct
– Deeper region
has dense submucosa
Some erectile tissue – thin
walled blood vessels.
```
168
what inhibits development of male mammary glands?
testosterone at puberity
169
During development, multiple glands develop along paired--- thickenings called --- that extend from the developing --- to the developing ---.
epidermal
mammary ridges
axilla
inguinal region
170
what controles mammary gland growth in females?
estrogen
171
how does the mammary gland grow in females?
- estrogen stimulates further development of mesenchymal cells.
- The mammary gland increases in size, mainly due to the growth of interlobular adipose tissue.
- The ducts extend and branch into the expanding connective tissue stroma.
- Proliferation of epithelial cells is controlled by interactions between the epithelium and the specialized intralobular hormone-sensitive loose connective tissue stroma.
- By adulthood, complete ductal architecture
172
what is the mammary gland composed of and their epithelia?
- 15-20 irregular lobules (tubuloalveolar glands)
- Lactiferous duct-keratinised stratified squamous epi
- Lactiferous sinus-2 layers cuboidal epi
- Duct-simple columnar or cuboidal epi
- fibrous CT in between
- adipose tissue
173
what are the structures in an adult nipple?
- opening of lactiferous ducts
- sebaceous glands, sweat glands, montgomery glands (intermediate between sweat glands and mammary glands)
- nerves
174
what constitutes the TDLU?
– Successive branching of lactiferous ducts
– Terminal ductules (or secretory alveoli)
– Intralobular collecting duct
– Intralobular stroma
175
what are the cell types in TDLU?
```
– Glandular
-Line duct
– Myoepithelial
-Between epithelial cells
and basal lamina
-Contraction – milk
ejection
```
176
main feature of inactive mammary gland histo?
lots of dense CT
177
how does the mammary gland changes during menstrual cycle?
Follicular phase
– Intralobular stroma less dense
– Terminal ductules – cuboidal cells, no lumen
Luteal phase
– Epithelial cells increase in height
– Lumina appear in ducts – some secretion
– Oedematous connective tissue
==>May explain breast tenderness and increase size during luteal phase
178
what are the hormones required to complete the development of mammary gland during pregnancy?
```
– Estrogen and progesterone
from Corpus luteum and placenta
– Prolactin
from Pituitary gland
– Gonadocorticoids
from Adrenal cortex
```
179
how does the mammary gland grow during pregnancy?
First trimester
– Terminal ductules form;
Elongation, branching
Proliferation and differentiation of epithelial and myoepithelial cell
```
Second trimester
– Alveoli form from terminal ductules
– Immune cell infiltration
– Growth of alveoli
==>Large Increase mass of breast.
```
Third trimester
– Maturation of alveoli-can produce milk
– Glandular epithelial cells become Cuboidal, basal nuclei, develop Secretory vesicles and lipid droplets
– Breast size increase due to
1. Hypertrophy of secretory cells
2. Accumulation of secretory products in lumen
180
difference between pregnant and inactive mammary gland?
inactive; lots of CT
| active; lots of glandular tissue, less CT, large intralobular duct
181
what are the hormones required to produce the milk and when are they released?
prolactin and human placental lactogen- which were suppressed during pregnancy by estrogen and progesterone. They are released at birth due to sudden drop in estro and proges by delivering the placenta.
Also, oxytocin is also released which is involved in contraction of myometrium at birth and myoepi cell contraction for milk production.
182
stages of milk production at a cellular level?
```
Merocrine secretion
– Protein component
– Extensive rough ER
– Secretory vesicles to Golgi
– Packaged for exocytosis
```
Apocrine secretion;
– Fatty or lipid component of milk
– Lipid droplets accumulate at top of cell, being pinched off surface
183
what does a lactating mammary gland look like?
even less CT, majority is glandular and intralobular ducts, secretions in lumen, large epi cells.
184
what is produced from mammary glands immediately following birth?
Colostrum-Alkaline yellowish secretion
Higher protein, lower lipid, carbohydrate
content than breast milk, Secretory IgAs (and other antibodies)
– Passive immunity to newborn
– From immune cells in stroma of glandular component
– Important for establishing gut microbiome of
infant.
185
how is lactation initiated after birth?
```
-Suckling (and looking at, talking about,
hearing baby cry)
-Signals to hypothalamus – inhibits
prolactin-inhibitory factor (dopamine)
-Release of prolactin from ant pituitary
– Milk production
Release of oxytocin from posterior pituitary
– Myoepithelial cell contraction
– Contractions of uterine wall
```
