Comprehensive Review of Male and Female Reproductive Systems and Cycles

Male reproductive system functions

Detect females in estrus; Inseminate the female; Produce and maintain sperm

Detection of estrus

Pheromones and visual cues (swollen vulva, discharge, vocalization, lock up in pigs)

Fibroelastic penis

Found in bulls and boars; high collagen, low blood flow

Vascular penis

Found in stallions; low collagen, high blood flow

Spermatogenesis

Process of sperm production

Location of spermatogenesis

Testes → seminiferous tubules

Supporting cells of spermatogenesis

Sustentacular (Sertoli) cells

Transport of sperm

Muscle contractions and water absorption

Testosterone production

Interstitial (Leydig) cells

Functions of testosterone

Maintains male tract; stimulates secondary sex characteristics; maintains libido

Spermatogonium

Diploid starting cell

Primary spermatocyte

Diploid; undergoes meiosis I

Secondary spermatocytes

Haploid; produced after meiosis I

Spermatids

Haploid; produced after meiosis II

Spermiogenesis

Transformation of spermatids into sperm

Spermiogenesis steps

DNA condenses; acrosome forms; tail develops; mitochondria align; cytoplasm removed

GnRH origin

Hypothalamus

GnRH function

Stimulates anterior pituitary to release FSH and LH

LH function

Stimulates interstitial cells to produce testosterone

FSH function

Stimulates sustentacular cells to produce androgen-binding protein

Androgen-binding protein (ABP)

Binds testosterone to maintain high levels in testes

Inhibin

Produced by sustentacular cells; inhibits FSH

Negative feedback in males

Testosterone and inhibin reduce GnRH, LH, and FSH

Female reproductive system functions

Produce oocyte; support fetus; recycle for pregnancy; provide nutrients; facilitate fertilization; regulate organs; transport gametes

Infundibulum

Catches oocyte

Ampulla

Transports oocyte; site of fertilization

Ampullary-isthmic junction

Specific site of fertilization

Isthmus

Provides nourishment

Primordial follicle

Developed at birth

Primary follicle

Resting stage

Secondary follicle

Surrounded by granulosa cells

Late secondary follicle

Surrounded by granulosa and theca cells

Ovarian cycle definition

Monthly changes in ovary; follicular phase, ovulation, luteal phase

Follicular phase

Follicle development and estrogen increase

Ovulation

Triggered by LH surge

Luteal phase

Corpus luteum produces progesterone

Estrogen function

Stimulates uterine lining growth

Progesterone function

Maintains uterus; blocks contractions; supports embryo

PGF2α

Kills corpus luteum if no pregnancy

Uterine cycle phases

Resorptive, Proliferative, Secretory

Resorptive phase

Endometrium reabsorbed; low hormones

Proliferative phase

Uterine lining rebuilds; estrogen driven

Secretory phase

Progesterone prepares uterus for embryo

Sperm movement mechanisms

Muscular contractions; thermotaxis; chemotaxis

Mammary system function

Produces milk for offspring

Mammary gland type

Exocrine gland

Lactation cycle

Mammogenesis; Lactogenesis; Galactokinesis; Galactopoiesis

Mammogenesis

Development of mammary glands

Lactogenesis

Milk production

Galactokinesis

Milk ejection (letdown)

Galactopoiesis

Maintenance of milk production

Fetal mammogenesis hormone

Growth hormone

Primary sprout forms

Gland cistern, teat cistern, teat canal

Secondary sprout forms

Major ducts

Canalization

Forms lumen

Allometric growth

Mammary grows faster than body

Isometric growth

Mammary grows at same rate as body

Puberty mammogenesis

Driven by estrogen; duct development

Pregnancy mammogenesis

Alveoli growth; estrogen, progesterone, prolactin

Lactation changes

Alveoli expand

Involution

Alveoli undergo apoptosis

Milk components

Water, lactose, lipids, protein

Lactose synthesis

Golgi; glucose + galactose; stimulated by prolactin

Lipid synthesis

Smooth ER; released by membrane budding

Protein synthesis

Rough ER; exocytosis

Galactokinesis process

Suckling → hypothalamus → posterior pituitary → oxytocin → myoepithelial contraction → milk release

Galactokinesis feedback

Positive feedback loop

Galactopoiesis regulation

Prolactin and regular milk removal

Milk removal effect

Maintains prolactin and milk production

Milk production feedback

Negative feedback loop

3X milking effect

Increases prolactin stimulation and milk yield

vas deference

moves sperm

testis

production of sperm

transport sperm

water absorption and muscle contractions

testosterone production

interstitial endocrine cells

interstitial endocrine cells

stimulate second sex characteristics, maintain male repro tract

seminiferous tubules

sperm is produced here

tete testes

placing sperm together

efferent ductules

epididymis

sperm will mature here

blood supply

plampiniform plexus

muscles in temp regulation

dartos wrinkles up, cremaster muscle to hlep pull testies closer

sustentacular cells

produce inhibin, develop sperm

interstitial endocrine cells

produce testosterone and other androgens

seminal vesicles

viscous alkaline

bulbourethral gland

clear thick fluid

prostate

milky acidic fluid, enzymes

ovary

cite of cytogenises

oviduct

connecting, transport of egg

uterus

transport sperm to ovaduct

cervix

provide barrier for sperm

vagina

portion of birth cannel

suberetnral diverticulum

interaction between repro and urinary system

vulva

external portion of female genetaila

ampullary - isthmic junction

cite of fertilization

utero-tubal junction

prevent multi sperm fertilizing