Chapter 28 - Reproductive Systems Flashcards
Reproduction
Process by which new individuals of a species are produced & genetic material is passed from generation to generation
Testes
Male gonads; suspended in scrotum
Scrotum
- AKA “Scrotal sacs”
- Keeps testes at 34-35 C
- If colder than 34 C, contraction of cremaster muscles raises testes + contraction of dartos muscle reduces volume of pouches
- If warmer than 35 C, sperm cell survival decreases; cremaster & dartos muscles relax
Scrotal Septum
Fascia of dartos muscle
Dartos Muscle
SubQ smooth muscle
Raphe
External median ridge of the scrotum
Cryptorchidism
Condition in which testes do not descend into scrotum -> sterility & increased risk of cancer
Tunica Vaginalis
Membrane sheath covering testis
Hydrocele
Excessive fluid within tunica vaginalis
2 Functions of the Testes
- Sperm cell production (Done by seminiferous tubules)
2. Testosterone production (Done by Leydig cells)
Tunica Albuginea (Male)
Has septa which divides testes into lobules
Duct System within Testes
Seminiferous tubules -> straight tubules -> rete testis -> efferent ducts -> epididymis
Epididymis
- Very long coiled tubule outside each testis
- Function: Sperm transport, maturation & storage
Histology of the Epididymis Wall (3 Layers)
- Mucosa: Pseudostratified columnar epithelium w/ stereocilia + lamina propria
- Muscularis: Smooth muscle; propels sperm into ductus deferens via peristalsis
- Adventitia: Outermost covering
Ductus Deferens
-AKA “Vas Deferens”
=A tubule that starts at epididymis & ascends into body cavity via inguinal canal
-Function: Stores & conducts sperm from epididymis toward urethra
Spermatic Cord
=Ductus deferens, blood & lymph vessels, cremaster muscle, nerves
Histology of the Ductus Deferens Wall
- Mucosa: Pseudostratified columnar epithelium + lamina propria
- Muscularis: Inner + outer = longitudinal; middle = circular
- Adventitia: Outermost covering
Ampulla (Ductus Deferens)
- Dilated terminal portion of ductus deferens
- Joins seminal vesicle duct -> ejaculatory duct to prostatic urethra
Varicocele
Dilation of testicular veins; a major cause of male infertility
Vasectomy
Cutting of the ductus deferens; results in sterilization + development of immunity to sperm cells
Vasovasostomy
Reversal procedure for a vasectomy
Ejaculatory Duct
- A union of a ductus deferens w/ a duct from a seminal vesicle
- Function: Receives/mixes sperm cells & seceretions of seminal vesicle + eject the mixture into prostatic urethra
Urethra (Male)
A tube shared by both urinary & reproductive systems in males
3 Divisions of the Male Urethra
- Prostatic Urethra: Runs along prostate
- Intermediate Urethra: Passes through urogenital diaphragm
- Spongy Urethra: Runs within the corpus spongiosum; leads to the external urethral orifice
3 Functions of the Male Urethra
- Conduct sperm from ejaculatory duct to exterior via penis
- Receives secretions of prostate gland, seminal vesicles & bulbourethral glands
- Excretes urine
Seminal Vesicles
- 2 Glands that secrete viscous alkaline fluid
- Alkaline fluid made of glucose, prostaglandins & semen clotting protein
- Alkaline pH neutralizes acids
Prostate Gland
- Found below urinary bladder
- Increases size at puberty
- Second growth spurt at around 45 years of age (Ratio of free testosterone/total estradiol falls by 50%)
Benign Prostatic Hyperplasia
Enlargement of the prostate gland
3 Components of Prostatic Secretions
- Citric Acid: Makes ATP for sperm cells
- Enzymes: Prostate specific antigen (digests semen clotting proteins), acid phosphatase, pepsinogen, lysozyme, amylase, hyaluronidase
- Seminalplasmin: An antibiotic agent
* Prostatic ducts carry secretions to urethra
Bulbourethral Glands
- AKA “Cowper’s Glands”
- Secrete alkaline fluid + mucous into spongy urethra
Penis
=Male organ of copulation
- Contains spongy erectile tissue
- Filling of blood sinuses -> erection
Semen
=Mixture of sperm + seminal fluid
- Seminal fluid produced by seminal vesicles, prostate gland, and bulbourethral glands
- Volume of ejaculate = 2.5 -5.0 mL x 150 mil. sperm/mL
- pH of semen = 7.2 -7.7
- Clots & reliquifies
3 Parts of the Penis
- Root
- Body/ Shaft
- Glans Penis
Root (Penis)
=Bulb + crura
- Bulb attaches to urogenital diaphragm via bulbospongiosus muscle (Aids ejaculation)
- Crura attach to ischiopubic rami via ischicavernosus muscles (Aids erection)
- Also has fundiform & suspensory ligaments
Body/ Shaft (Penis)
- Corpora Cavernosa: Dorsolateral cylinders
2. Corpus Spongiosum: Midventral cylinder; extends to glans penis; surrounds spongy urethra; contains tunica albuginea
Glans Penis
- Enlarged distal part of corpus spongiosum
- Corona = Circumference of glans penis
- External urethral orifice = Hole leading to body exterior
- Prepuce = Foreskin
Circumcision
Surgical removal of foreskin
Male Erection
- Parasympathetic fibers release nitric oxide (NO)
- NO relaxes blood sinus walls & vasodilates feed arterioles -> sinus expansion & penile vein compression
Impotency
Erectile dysfunction
Priapism
Persistent, prolonged, painful erection
Penile Emission
Peristalsis of epididymis, ductus deferens, seminal vesicles, ejaculatory duct & prostate = emission
ANS Control of Erection & Ejaculation
- Parasympathetic dishcarge = erection
- Sympathetic discharge = ejaculation
Ejaculation
- Rhythmic contraction of male reproductive tubules, ducts & glands which eject semen through spongy urethra to exterior
- After ejaculation, erection is lost
- Blood sinus walls contract & feed arterioles constrict -> decompression of penile veins
Meiosis
A type of cell division restricted to sexual gamete production & involves 2 successive nuclear divisions that result in daughter cells w/ haploid no. of chromosomes
Mitosis
Human somatic cell division that ends w/ each daughter cell having a diploid no. of chromosomes
Spermatogenesis
- Primordial cells of yolk sac -> seminiferous tubules & become spermatogonia
- Spermatogonia become active at puberty
- Prior to mitosis, spermatogomium goes through “S” phase; each chromosome = 2 sister chromatids
- Spermatogonium -> 1 Primary spermatocyte & 1 Daughter cell spermatogonium
- Daughter spermatogonium = stem cell reserve
- Prior to meiosis 1, Primary spermatocyte goes through “S” phase; each has 46 duplicated chromosomes
Meiosis 1 (Sperm)
- AKA “Reduction Division” of primary spermatocyte
- 1 Primary spermatocyte (diploid) -> 2 secondary spermatocytes (haploid)
- 2 recombination events:
1. Independent Assortment: Formation of tetrads
2. Crossing Over: Exchanging genetic info from tetrads - Prior to meiosis 2, no “S” phase occurs
Meiosis 2 (Sperm)
- AKA “Equatorial Division” of secondary spermatocytes
- 2 secondary spermatocytes -> 4 spermatids (haploid)
- A mitosis starting w/ 23 duplicated chromosomes
- Each sister chromatid becomes a daughter chromosome
- Has cytoplasmic bridges (incomplete cytokinesis)
Spermiogenesis
- Final stage of spermatogenesis
- 1 spermatid -> 1 spermatozoan
- Spermatogenesis: 1 primary spermatocyte = 4 haploid spermatozoa
Sustentacular Cells
- AKA “Nurse Cells”/ “Sertoli Cells”
- Form the blood-testis barrier
- Joined together by tight junctions
7 Functions of the Blood-testis Barrier
- Support, nourish & regulate spermatogenic cells (since sperm cells are immunogenic)
- Phagocytosis
- Spermiation
- Produce fluid to float sperm cells
- Secrete inhibin (inhibits FSH release)
- Receive testosterone & FSH signals
- Secrete androgen-binding protein
Mature Sperm Cells
- AKA “Spermatozoa”
- 2 Parts: Head & Tail
- Function to fertilize secondary oocyte
- Life expectancy in female reproductive tract = 48 hours
3 Steps of Fertilization
- Penetration of secondary oocyte cell membrane by sperm cell head
- Completion of meiosis 2 -> 1 ovum + 1 polar body
- Syngamy = Fusion of sperm cell pronucleus w/ ovum pronucleus -> zygote
Head of the Sperm Cell (2 Parts)
- Nucleus
2. Acrosome w/ proteinase & hyaluronidase enzymes
Tail of the Sperm Cell (4 Parts)
- Neck contains centrioles -> microtubules
- Midpiece (AKA “Middle Piece”) w/ mitochondria -> ATP
- Principal piece = Flagellum (9+2)
- End piece
Hormonal Regulation of Testes
- Hypothalamus -> gonadotropin-releasing hormone (GnRH) -> stimulation of anterior pituitary ->
1. FSH: Leads to spermatogenesis
2. LH: Stimulates testosterone production by Leydig cells
Analogue of Testosterone
- Dihydrotestosterone (DHT); 5-Alpha reductase enzyme converts testosterone into DHT
- Testosterone & DHT both bind to same androgen receptor (But has a higher affinity for DHT)
6 Functions of Testosterone & Analogues
- Development of male reproductive systems
- Testicular descent
- Development of male external genitalia
- Prenatal development of hypothalamus’ GnRH production & brain regions concerned w/ sex drive
- Sperm maturation in testes & epididymis
- Development/ maintenance of secondary male sex characteristics
- Testosterone is converted to estrogen (estradiol) in brain (by aromatase)
- Androgens -> libido in males & females
- Androgen-Binding Protein (ABP keeps testosterone levels high in seminiferous tubules)
5 Types of Secondary Male Sex Characteristics
- Muscular & skeletal growth (anabolic)
- Closure of epiphyseal plates (18-21 years of age)
- Facial, chest, axillary & pubic hair growth
- Larynx & vocal cord enlargement
- Acne & body odor
Negative Feedback Controls (2 Types-Males)
- Testosterone inhibits both GnRH & LH secretion
2. Inhibin directly inhibits FSH release; released when spermatogenesis is adequate
Ovaries
=Female gonads
- Has 3 supporting ligaments
- Hilum = exit point for blood & lymphatic vessels
3 Supporting Ligaments of the Ovaries
- Broad Ligament: Part of parietal peritoneum; extends to mesovarium
- Ovarian Ligament: Runs from ovary to uterus
- Suspensory Ligament: Runs from ovary to pelvic wall
4 Parts of The Ovary
- Germinal Epithelium: In embryo, progenitor cells of oogonia from yolk sac move to interior of ovary
- Tunica albuginea: CT capsule
- Stroma: Cortex = dense CT; medulla = loose CT
- Ovarian Follicles & Derivatives
4 Types of Ovarian Follicles
- Primordial Follicles
- Primary Follicles
- Secondary Follicles
- Graafian (AKA “Mature”) Follicles
- These 4 types show primary oocytes + follicular cells
- Follicular cells of primary, secondary & tertiary follicles =granulosa cells; produce estrogens
- Before ovulation, primary oocyte of Graafian follicle -> secondary oocyte + polar body
Thecal Cells
Cells that surround granulosa cells
Antrum
- A cavity filled w/ follicular fluid
- Present in Graafian & secondary follicles
2 Types of Ovarian Derivatives
- Corpus Luteum: Formed from Graafian follicle after ovulation; secretes porgesterone, estrogen, relaxin & inhibin
- Corpus Albicans: White scar
2 Functions of the Ovaries
- Production & discharging of secondary oocyte
2. Secrete hormones
Production & Discharging of Secondary Oocyte
- Oogenesis begins during fetal period
- Primordial cels from yolk sac -> ovaries & differentiate into oogonia
- In infant, each ovary contains up to 2 mil. follicles
- By puberty, around 40k follicles
- Only around 400 fillicles mature
4 Primary Female Hormones
- Estrogens
- Progesterone
- Inhibin
- Relaxin
Estrogens (4 Functions)
- Development /maintenance of primary & secondary female sex characteristics
- Inhibition of GnRH, FSH & LH secretion
- Protein anabolism
- Lower blood cholesterol
*Estradiol, estrone & estriol are the 3 estrogens
5 Types of Secondary Female Sex Characteristics
- Body hair distribution (axillary & pubic hair)
- Fat distribution
- Pelvic enlargement
- Mammary gland development & enlargement
- Pitch of voice
Progesterone
- Made by corpus luteum
- Progestational hormone
- Prepares endometrium for implantation
- Prepares mammary glands for lactation
- Inhibits GnRH & LH secretion (high blood levels)
Inhibin
- Made by secondary follicles & corpus luteum
- Blocks FSH release (post-ovulation: inhibits any further follicle development)
Relaxin
- Increases sperm motility
- Inhibits uterine smooth muscle during pregnancy
- At parturition, relaxes pubic symphysis & helps to dilate uterine cervix
Oogenesis
Oogonium -> Primary oocyte -> Secondary oocyte -> Ovum
Development of Ovarian Follicles
Primordial follicle -> Primary follicle -> Secondary follicle -> Graafian follicle -> Release fo secondary oocyte
8 Phases of Oogenesis & the Ovarian Cycle
- Beginning of Oogenesis
- Prophase 1/ Start of Meiosis 1
- Formation of Primary Follicles
- Development of Secondary Follicles
- Graafian Follicle Development
- Completion of Meiosis 1
- Meiosis 2
- Ovulation
Beginning of Oogenesis
Beginning around 3rd month of fetal life, mitosis of each oogonium (diploid) -> 2 primary oocytes (diploid)
Prophase 1/ Start of Meiosis 1 (Oogenesis)
- During gestational months, meiosis 1 begins, but stops at prophase 1
- No further development of primary oocyte until AFTER puberty
- Primordial follicle = primary oocyte within simple squamous epith.
Formation of Primary Follicles
- Starting at puberty, each month several primary oocytes stimulated by FSH -> Primary follicles (stratified cuboidal/low columnar epith. surrounding primary oocyte)
- Zona pellucida forms around primary oocyte
- Outside zona pellucida are the granulosa cells (follicular cells)
- Around granulosa cells, stromal cells -> thecal cell layer (theca folliculi)
Development of Secondary Follicles
- Thecal cell layer differentiates into 2 layers:
1. Theca Interna: Inner layer; produces androgens which are converted to estrogen by aromatase enzyme from granulosa cells
2. Theca Externa: Outer layer; aids in rupture of mature oocyte - Follicular fluid accumulates in antrum between cell layers
Graafian Follicle Development
- By day 8-10 of ovarian cycle, usually only one secondary follicle develops further
- By day 10-14, has become a Graafian follicle
- In Graafian follicle, primary oocyte w. surrounding zona pellucida & corona radiata projects into antrum
Completion of Meiosis 1
- As LH increases, meiosis 1 resumes in primary oocyte (diploid, duplicated chromosomes) in Graafian -> one secondary oocyte (haploid, duplicated) & one polar body (haploid, duplicated)
- Secondary oocyte has most of cytoplasm
Meiosis 2 (Oogenesis)
- Secondary oocyte enters meiosis 2, but is arrested at metaphase 2
- Only completed if secondary oocyte membrane is penetrated by sperm cell head
- If not penetrated, oocyte -> ovum + 2nd polar body
- Dissolution of nuclear membranes -> pronuclei
- Syngamy: Fusion of pronuclei ovum (haploid) + sperm cell (haploid) -> zygote (diploid)
- Meiosis 2 of 1st polar body -> 2 haploid polar bodies
- Before these events can occur, secondary oocyte must first be released from ovary
Ovulation
=Process where the Graafian follicle ruptures & discharges a secondary oocyte
-Occurs on Day 14 due to LH Surge
LH Surge
- Occurs due to increased estrogen via a positive feedback mechanism
- Anterior pituitary releases LH
- Hypothalamus GnRH -> Increased LH Release
- Lasts 2 days
Corpus Hemorrhagicum
=Remnant of Graafian follicle
- Becomes corpus luteum
- Secretes mostly progesterone & some estrogen; leads to decreased LH & GnRH release
Corpus Luteum
=Remnant of corpus hemorrhagicum
- Has a life expectancy of 10-14 days if no pregnancy occurs (turns into corpus albicans)
- If pregnancy occurs, LH is replaced by human chorionic gonadotropin (hCG)
Human Chorionic Gonadotropin
- Maintains corpus luteum -> Continued progesterone, estrogen, inhibin & relaxin outputs
- P & E maintain uterine endometrial lining -> conceptus (blastocyst) remains anchored
- Eventually, placenta begins to make P & E to maintain the pregnancy, then, corpus luteum -> corpus albicans
- W/o implantation -> No HCG -> No P & E -> Menstruation
RU486 (mifepristone)
A progesterone receptor blocker
Menopause
- At age 45-50 years, ovaries stop responding to FSH & LH
- No more follicles produced
- Menstruation ceases
Uterine Tubes
=AKA “Fallopian Tubes”/”Oviducts”
- Main function is to transport spermatozoa, secondary oocyte or possibly zygote
- Also the normal site of fertilization
- Secondary oocyte must encounter viable sperm within 12-24 hours of ovulation
- Zygote/embryo propelled by cilia & peristalsis towards uterus (undergoes “cleavage” -> morula -> enters lumen of uterus -> blastocyst)
Histology of the Uterine Tubes (3 Parts)
- Mucosa: Simple ciliated columnar epith. + Peg cells (nonciliated cells that secrete a fluid for nourishing the ovum)
- Muscularis: Inner layer = circular smooth; Outer layer = longitudinal smooth
- Serosa: The serous outer membrane
4 Parts of the Uterine Tubes
- Fimbriae: Finger-like ends of the uterine tubes
- Infundibulum: Funnel-shaped portion of the tubes
- Ampulla: The longest portion
- Isthmus: The more medial, short, narrow portion joining the uterus
Uterus
=Inverted pear-shaped organs which normally display anteflexion (bending forward)
- Retroflexion = uterus tipped backwards
- 4 supporting ligaments: broad, cardinal uterosacral & round
Uterine Prolapse
Sagging of the uterus into the vagina; caused by weakening of ligaments & pelvic floor muscles
4 Parts of the Uterus
- Fundus: Dome-shaped portion, superior to uterine tubes
- Body: Tapering, central portion
- Isthmus: Region between body and cervix
- Cervix: Inferior narrow portion, opens into vagina
4 Parts of the Cervix
- External Os: Opening from cervical canal into vagina
- Cervical Canal: Interior of the cervix
- Internal Os: Opening from cervical canal into the uterine cavity
- Cervical Mucus: Protects & nourishes sperm cells + begins sperm capacitation (increasing motility & destablilizing head membrane)
3 Uterine Layers
- Perimetrium
- Myometrium
- Endometrium
Perimetrium (Uterus)
Outer serosa of the uterus
Myometrium (Uterus)
=Middle smooth muscle layer
- Near parturition, estrogen -> Prostaglandin synthesis -> early myometrial contractions
- Oxytocin-induced myometrial contractions eject infant from uterus
Endometirum (Uterus)
=Inner glandular uterine mucosa
- Blastocyst implantation -> Pregancy
- Components: Simple ciliated columnar epith., lamina propria & endometrial glands
2 Layers of the Endometrium
- Stratum Functionalis: Lines uterine cavity & sloughs off during menstruation
- Stratum Basalis: Gives rise to new functionalis layer after each menstruation
5 Functions of the Uterus
- Sperm transportation
- Menstruation
- Blastocyst implantation
- Development site of embryo-fetus
- Labor
Hysterectomy
Surgical procedure to remove part/all of the uterus
Uterine Blood Supply
Abdominal aorta -> Common Iliac artery ->Internal Iliac artery -> Uterine artery -> Arcuate artery -> Radial artery -> Straight arterioles & Spiral arterioles -> Capillaries -> Venules of stratum functionalis & basalis -> Radial veins -> Arcuate veins -> Uterine veins -> Internal Iliac veins -> Common Iliac veins -> Inferior vena cava
Female Reproductive Cycle
=Ovarian + Uterine Cycles
- Uterine Cycle = Menstrual cycle
- Ovarian changes -> variation in levels of estrogen & progesterone -> endometrial changes
- Function: to prepare endometrium for possible pregnancy
3 Phases of the Ovarian Cycle
- Follicular Phase: Follicles secrete estrogen
- Ovulation: Discharge of secondary oocyte (Day 14)
- Luteal Phase: Estrogen & progesterone increase, if no pregnancy, menstruation occurs
3 Phases of the Uterine Cycle
- Mensturation
- Pre-ovulatory Phase
- Post-ovulatory Phase
Menstruation
- AKA “Menses”; occurs on days 1-5 due to decreased progesterone & estrogen
- Ovarian events: FSH -> Follicle development
- Uterine events: Stratum functionalis is shed, decreased P & E -> prostaglandin release > Spiral arteriole vasospasm -> Ischemic necrosis
- Stratum basalis is not shed
Pre-ovulatory Phase
- AKA “Proliferative Phase”
- Ovarian events: Secondary follicles -> Increased E & inhibin -> Decreased FSH -> Slowing follicle development or atresia (but Graafian follicle not affected)
- Uterine events: Stratum basalis -> New stratum functionalis
5 Signs of Ovulation
- Increased basal temperature
- Clear, elastic cervical mucus
- External cervical os opens
- Mittelscherz (“Ovulation Pain”)
- Increased urinary LH
Post-Ovulatory Phase (Ovarian Events)
- Days 15-28, blood levels of P increase, then decrease (if no pregnancy)
- Graafian remnants -> Corpus hemorrhagicum -> Corpus luteum
- W/o fertilization and implantation, corpus luteum degenerates -> corpus albicans (signals menstrual slough)
- W/ fertilization and implantation, corpus luteum persists due to hCG
Post-Ovulatory Phase (Uterine Events)
- Endometrium thickens
- Endometrial glands grow, coil & secrete glycogen
- Increased tissue fluid
- Vascularization of stratum functionalis
- If no pregnancy -> corpus luteum breakdown -> decreased E & P levels -> Prostaglandin release -> Vasospasm -> Endometrial breakdown -> Menstruation
Vagina
=Mucous-membrane-lined tube
-Fornix = A recess that surrounds the vaginal attachment to the cervix
4 Functions of the Vagina
- Birth canal
- Female copulatory organ
- Passageway for sperm
- Passageway for menstrual flow
Histology of the Vagina (3 Parts)
- Mucosa: Non-keratinized stratified squamous epith. + areolar CT; rugae = transverese folds of mucosa; acid pH caused by organic acids from glycogen breakdown
- Muscularis: Inner layer = longitudinal; outer layer = circular
- Adventitia: Superficial layer, made of areolar CT
Vulva (6 Parts)
=External female genitalia
- Mons pubis
- Labia minora
- Labia majora
- Clitoris
- Vestibule
- Bulb of vestibule
Mons Pubis
Fat pad cushioning the pubic symphysis
Labia Minora
- Homologous to male spongy urethra (Female equivalent)
- Smaller skin folds medial to the labia majora
Labia Majora
- Homologous to male scrotum
- Two longitudinal skin folds
Clitoris
- Homologous to male glans penis
- Has a prepuce, erectile shaft & glans
- Small cylindrical mass composed of small erectile bodies
Vestibule (Vulva)
- Homologous to male intermediate urethra
- Has 3 main parts
3 Parts of the Vestibule (Vulva)
- Hymen
- Urethral & vaginal orifices
- Openings of ducts of Skene’s paraurethral glands & Bartholin’s greater vestibular glands
Skene’s Paraurethral Glands
Homologous to male prostate; secrete mucous
Bartholin’s Greater Vestibular Glands
Homologous to male Bulbourethral glands; produce mucous during sexual arousal
Bulb of Vestibule
-Homologous to male bulb of penis & corpus spongiosum
-Made of elongated masses of erectile tissue
-Function: Becomes engorged w/ blood during sexual
arousal, narrowing the vaginal orifice and placing pressure on the penis during intercourse
Perineum
- Diamond-shaped space containing anus & external genitalia
- Urogenital triangle = anterior half
- Anal triangle = posterior half
Episiotomy
Incision fo perineal tissues made prior to delivery
Mammary Glands
=Modified sudoriferous glands located over the pectoralis major muscles
- Coopers suspensory ligaments run between he skin & fascia to support the breasts
- Lobes = Compartments separated by adipose tissue
- Lobules = Smaller compartments found within each lobe
- Alveoli = Grape-like clusters of of milk-secreting glands within the lobules
Alveoli Pathway (Mammary Glands)
-Secretory alveoli -> Secondary tubules -> Mammary ducts -> Lactiferous sinuses -> Lactiferous ducts -> Nipple
Areola
Skin surrounding the nipple
Myoepithelial Cells
Cells that surround the alveoli and propel milk towards the nipples
Milk Secretion
- Prolactin is main hormone responsible
- High E & P during pregnancy prevented milk production
- At parturition, milk production begins
Colostrum
- A form of milk produced by the mammary glands
- Rich in carbohydrates, lactoferrin, antibodies, etc.
Milk Ejection
- Oxytocin is main hormone responsible
- Child suckling -> Milk ejection (“let down” reflex)
- Stimulate myoepithelial cells
Fybrocystic Breast Disease
- Accumulation of fluid-filled cysts in alveoli
- Occurs due to decreased progesterone or increased estrogen
