Reproduction Flashcards
(31 cards)
Testes
The male gonads, which produce spermatozoa.
Bulbourethral Gland
Secrete a clear mucus. It acts as a lubricant and much of it precedes the emission of the semen, with only a small amount in the semen.
Labia Majora
Cover and protects the inner structure of the vulva i.e. Collective name for the external genitalia.
Scrotum
Climate-control system for sperm production. Muscles of scrotum relax and contract to cool down the testis and warm up the testis respectively.
Seminiferous Tubules
Sperm cells mature from spermatogonia within the tubules due to the interstitial cells secreting testosterone.
Vas Deferens
Transports sperm from the epididymis to the urethra.
Urethra (in men)
This serves a dual function in males. It transports urine and semen to the exterior.
Semen
Created from the seminal vesicle, prostate gland, and bulbourethral gland. Aids with nourishment and development.
Seminal Vesicle
Secrete a thin fluid, rich in sugars and makes up 60% of the volume of semen.
Prostate Gland
Secretes a thin, milky, alkaline fluid.
Penis
The erectile tissue fills with blood during sexual arousal. This causes the penis to become erect. Transports sperm to the vagina.
Ovaries
Produce ova (eggs).
Uterine Tube
Funnel in which cilia and smooth muscle move egg to uterus.
Uterus
Protects and nourishes developing fetus.
Cervix
Connects uterus to the vagina/forms the birth canal with the uterus and vagina.
Vagina
Receives the penis during intercourse and with it, the sperm also.
Fimbriae
Passage of ovum from ovary to uterine tubes.
Labia Minora
Primarily protective of the inner structures of the vulva, also produces oily secretions for protections and lubrication.
Clitoris
Pleasure.
Urethra (in women)
Passageway for urine excretion.
Spermatogenesis
+ Seminiferous tubules lined with spermatogonia - divide by mitosis to make more.
+ Some spermatogonia move towards the centre of the tubule - become primary spermatocyte (at puberty).
+ Undergoes Meiosis I and produces two secondary spermatocytes.
+ Undergoes Meiosis II and produces 4 spermatids (haploid).
+ Then mature into spermatozoa (sperm).
+ Takes 72 days.
Oogenesis
+ Millions of oogonia (immature diploid cells) in ovaries from birth.
+ At birth they are in early Prophase I.
+ Surrounded by layer of follicular cells, referred to as a primary follicle.
+ At puberty, it completes Meiosis I - producing 2 cells. + - Secondary Oocytes (half DNA, nearly all cytoplasm).
+ - Polar Body (half DNA, nearly no cytoplasm).
+ Meiosis II begins - pauses at metaphase II (lining up at the middle, from pole to pole.)
+ It is expelled from the ovary in ovulation - the follicle ruptures.
+ Enters uterine tubes in ovulation - the follicle ruptures.
+ Enters uterine tube - if penetrated by sperm, it quickly completes meiosis II becomes ovum. Other becomes second polar body - that then disintegrates.
Hormones
Chemical messengers that are released by endocrine glands and travel throughout the blood.
Follicle-stimulating hormone (FSH)
+ Stimulates the development and maturation of the ovarian follicle in women. During development, the ovarian follicle releases its own hormone, oestrogen. FSH secretion is limited as the level of oestrogen increases in the blood.
+ FSH stimulates the epithelial tissue of the seminiferous tubules in the testes to produce sperm.