Reproductive system Flashcards
What is the biological sex of males and females?
Female: XX
Male: XY
What are the sex gonads in males and female?
Female: Ovaries
Males: Testes and associated tubing
When does puberty begin?
Stage 2 (8-11) years old
What stimulates puberty in individuals?
Increased levels of FSH (follicle stimulating hormones) and LH (luteinizing hormone) - secreted from hypothalamo-pituitary gonadotropin axis
How is spermatogenesis stimulated?
Begins at puberty - in the seminiferous tubules stimulated by FSH
What are the major functions of the testes?
Exocrine - production of sperm
Endocrine - secretion of testosterone
What are the major functions of the ovaries?
Exocrine - production of oocytes
Endocrine - secretion of estrogen and progesterone
What is the major circulating form of inhibin in adult male?
Inhibin b - secreted by Sertoli cells
Mention all of the parts of the male duct system
- Epididymis - temporary storage for sperm- sperm mature
- Ductus deferens - propel live sperm from epididymis to…
- Ejaculatory duct - sperm empties here from ductus deferens
- urethra - sperm ejects
Where is testosterone synthesized from in the testes?
Interstitial cells of Lydig
Explain process of ejaculation
Thick layers of smooth muscle create peristaltic-like waves that squeeze sperm out
Explain and mention the accessory glands
Prostate - produces some seminal fluid that activates sperm (encircles upper part of urethra)
Bulbourethral gland - produces thick, clear mucous into penile urethra
Seminal vesicle - produces 60% of seminal fluid (joins ductus deferens and ejaculatory duct)
- Extra: seminal fluid and sperm enter urethra together
What is the function of seminal fluid?
Give nutrients to sperm
What are the external genitalia of the male?
Scrotum: skin sac that hangs in the abdominopelvic cavity
Penis: consists of 3 columns of erectile tissue for erection
Explain the male reproductive functions
Spermatogenesis - sperm formed in seminiferous tubules
-> involves meiosis: halves chromosomal number in resulting spermatids -> daughter cell type B is primary spermatocyte for meiosis II -> separates in meiosis II
Spermatogonium: rapid mitotic division to build up stem cell line
Spermiogenesis: removal of excess cytoplasm on spermatids
What steps are involved in testosterone production?
Seminiferous tubules stimulated by FSH -> interstitial cells activated by LH
1. Hypothalamus produces gonadotropin releasing hormone (GnRH)
2. GnRH stimulates anterior pituitary to release gonadotropins (FSH;LH)
3. FSH stimulates spermatogenesis
4. LH stimulates interstitial cells = testosterone
5. Increase levels of testosterone exerts negative feedback control to hypothalamus and pituitary
What stimulates follicles? Explain process
Stimulated by FSH -> during monthly cycle:
1. Primary follicle
2. Secondary follicle
3. Graafian follicle: ready to be ovulated - ruptures to release oocyte
Once ruptured: turn to corpus luteum which produces estrogen
Mention parts of female duct system
Uterine (fallopian) tube: Receives ovulated oocyte and provides a site for fertilization
Uterus: Pear shaped muscular organ in which embryo implants
- endometrium: (mucosa) where implantation
- myometrium: smooth muscle/childbirth
- perimetrium: outermost serosa layer
Explain female reproductive functions
Oogenesis: occurs in ovarian follicle
- activated by FSH and LH
- ovum formed if fertilized by sperm
Primary oocyte arrested in prophase I -> meiosis I of primary oocyte -> creates secondary oocyte -> (polar body) - day 14: ovulation ->meiosis II completed ovum and secondary polar body
Primary oocyte arrested in prophase I -> primary follicle -> growing follicle -> graafian follicle (LH release) -> ovulated secondary oocyte
What produces hormones in female reproductive functions?
Follicle cells produce estrogen - in response to FSH
Corpus luteum produces progesterone - in response to LH
Explain phases of menstrual cycle
Day 1-5 (luteal phase): Endometrial lining shed
Day 6-14 (proliferative phase): Estrogen level rise; growing follicle; endometrium base layer
Day 15-28 (secretory phase): Progesterone level increase; endometrial gland growth
What does the sperm do when met with the egg?
Sperm releases acrosomal enzyme to break down oocyte plasma membrane
Explain cleavage
Rapid series of mitotic division without interfering growth -> cells become smaller with each division
What does the corpus luteum to continue hormone production?
Human chorionic gonadotropin prods corpus luteum (prevents period)
