Component 2: Human Sexual Reproduction Flashcards
Name all the parts in the female reproductive system
Ovary, uterus, cervix, fallopian tube (oviduct), bladder, urethra and vagina
What are the 3 layers of the uterus?
- Perimetrium (outer layer)
- Myometrium (middle layer)
- Endometrium (inner layer)
What is the function of the ovary?
Produce female gametes (secondary oocytes) and secrete oestrogen & progesterone
What is the function of the uterus?
nourishes and protects a growing foetus
What is the function of the fallopian tubes (oviduct)?
connects ovary to uterus, finger like projection ends collect oocyte after ovulation and the ciliated epithelial cells move oocyte to uterus
What is the function of the endometrium?
embryo implants here and sheds every month if there is no embryo (menstruation)
What is the function of the cervix?
muscular ring that closes the entrance to the uterus and dilates during birth
What is the function of the vagina?
muscular tube that leads to the outside of the body
What is the function of the urethra in women?
allows passage of the urine
Name all the parts of the male reproductive system?
scrotum, testis, seminiferous tubule, epididymis, vas deferens, seminal vesicle, prostate gland, urethra, penis
What is the function of the scrotum?
the external sac that holds the testes outside the body to provide sperm production the optimum temperature of 35ºC
What is the function of the testes (testis)?
Produce the male gametes, spermatozoa
What is the function of the epididymis?
sperm collect and mature here
What is the function of the vas deferens?
tube that takes sperm from the testis to the urethra during ejaculation
What is the function of the seminal vesicle?
glands that secrete a mucus into the vas deferens that contains nutrients (e.g. fructose used for respiration to provide energy)
Whats is the function of the prostate gland?
(at the base of the bladder) produces an alkaline secretion that neutralises any urine left in the urethra and aids sperm in motility
What is the function of the urethra in men?
transfers semen and urine to the outside (not at the same time)
What is the function of the penis?
used to pass semen into female reproductive system, penetration of the vagina
What is the function of the tissue in the penis?
- allows penetration of vagina
- fills with blood
- makes penis erect
Draw and label the parts of a mature sperm?
Acrosome, Nucleus -> Head
Neck
Mitochondria -> Midpiece
Plasma membrane and flagellum -> Tail
What is spermatogenesis?
Occurs in the seminiferous tubules of testes
Sequence of events involving mitosis and meiosis to form male gametes (spermatozoa)
Haploid spermatozoa from diploid spermatogonia
What are the 4 stages of spermatogenesis (generally)?
- Multiplication
- Growth
- Maturation (meiosis)
- Differentiation
- these just give structure to the process, don’t learn them as stages
What happens in multiplication in spermatogenesis?
- Germinal epithelium cells (diploid) on the outer layer of the seminiferous tubule undergo mitosis to produce diploid spermatogonia
- spermatogonia undergo mitosis to make many of them (multiplication)
What happens in the growth stage of spermatogenesis?
- spermatogonia that have divided by mitosis grow into diploid primary spermatocytes
What happens in the maturation stage of spermatogenesis?
- diploid primary spermatocytes undergo meiosis I to produce haploid secondary spermatocytes
- secondary spermatocytes undergo meiosis II to produce haploid spermatids
What happens in the differentiation stage of spermatogenesis?
- haploid spermatids differentiate into spermatozoa, forming a midpiece and tails
- throughout they obtain nutrients from the sertoli cells
Draw the summary diagram of spermatogenesis?
(check in book)
Germinal epithelial cells (2n) <=Mitosis=> Spermatogonia (2n) -mitosis and growth-> Primary Spermatocytes (2n) -meiosis I-> Secondary Spermatocytes (n, n) -meiosis II-> spermatids (n,n,n,n) -differentiation-> Spermatozoa (mature sperm)
What is the job of the sertoli cells?
Nourish and protect the spermatozoa once they are formed
- protection from WBC/immune cells as meiosis changes the DNA (non identical cells = recognised as foreign)
Where are the sertoli cells found?
Inside the seminiferous tubule
What is the job of the leydig cells?
secrete testosterone (male sex hormone) which is involved in stimulating the process of spermatogenesis
Where are the leydig cells found?
Outside/between the seminiferous tubules
What is another name for the leydig cells?
Interstitial cells
What is oogenesis?
Occurs in the ovary and is a sequence of events involving mitosis and meiosis to form a secondary oocyte
What are the process of oogenesis before birth (1)?
- Germinal epithelial cells (2n) in the ovary divide to form more germinal epithelial cells and oogonia (2n) by mitosis
- Oogonia undergo mitosis and cytoplasm growth to form primary oocytes (2n)
- Primary oocytes start meiosis I but stop at prophase I
- Primary oocytes surrounded by follicles cells forming primary follicles