ATLAS (PHOTOS)
MALE REPRODUCTIVE SYSTEM
-consists of gonads/testes, excretory ducts, accessory
reproductive glands and penis
Testis​- subdivided by a connective tissue septa into
lobules containing ​seminiferous tubules
Seminiferous tubule​- lined by the ​stratified germinal
epithelium​, consisting of two major cell types;
spermatogenic cells ​& ​non proliferating supporting
cells (sertoli cells)
Spermatogenic cells- ​divide, differentiate and produce
spermatozoa by a process called spermatogenesis.
Interstitial cells of Leydig- ​epithelial connective
tissue
Germinal epithelium-​ specialized stratified epithelium
that lines the seminiferous tubules
SPERMATOGENESIS
(1) Mitotic divisions of spermatogonia to from
spermatocytes
(2) Two meiotic divisions in which the number of
chromosomes is reduced by half; spermatids
(3) Spermiogenesis- morphological transformation
into spermatozoa
Blood-testis barrier​- prevents the entrance of harmful
substances from blood into the germinal epithelium
SERTOLI CELLS
(1) Support, protect and nutrition of the developing
sperm cells
(2) Phagocytosis of the excess cytoplasm of the
developing spermatids
(3) Release of spermatozoa into seminiferous
tubules
(4) Secretion of testicular fluid as transport
medium
(5) Production of androgen-binding protein and
inhibin
Follicle stimulating hormone-​ controls the androgen
binding production of sertoli cells
Androgen-binding protein​- increases the concentration
of testosterone in the seminiferous tubules for proper
spermatogenesis
Inhibin-​ hormone that suppresses/inhibits the
production of FSH
Interstitial cells of Leydig​- clusters of ​epithelioid cells
between the seminiferous tubules; produces
testosterone
Testosterone- ​hormone necessary for
spermatogenesis; depends primarily on Luteinizing
hormone
Luteinizing hormone-​stimulates the production of
testosterone by interstitial cells
*Testosterone- need to be high levels for
spermatogenesis
TESTIS VIEW (ORDER)
Tunica albuginea​-thick connective tissue
Tunica vasculosa​- vascular layer of loose connective
tissue
Interstitial connective tissue​- connective tissue;
surrounds, binds and supports the: ​seminiferous
tubules
Septa- ​thin and fibrous; divides the testis into
compartments called ​lobules
FEMALE REPRODUCTIVE SYSTEM
-consists of the ovaries, uterine tubes, uterus, vagina,
mammary glands and the external genitalia.
Follicle stimulating hormone-​ influences the growth
and maturation of ovarian follicles and stimulates the
granulosa and thecal cells of the maturing follicles to
produce ​estrogen.
Luteinizing hormone-​stimulates the lutein cells to
secrete estrogen and large amounts of progesterone;
induces rapid transformation of the granulosa and
theca interna cells
OVARY VIEW (ORDER)
Germinal epithelium- ​low cuboidal or squamous cell
that covered the ovarian surface
Tunica albuginea- ​connective tissue layer
Cortex- ​occupied greater part of the ovary
Medulla-​ dense, irregular connective tissue
SCHOENWOLF LAB GUIDE
Oogenesis and Fertilization
Oogenesis- begins in the paired ovaries
Follicles​ contain a large central cell containing yolk in
its cytoplasm - PRIMARY OOCYTE
Follicle cells-​surrounds the primary oocyte
Germinal vesicle-​ large nucleus in the primary oocyte
Vitelline membrane-​ lies between the follicle cells
and the plasmalemma
Theca folliculi externa-​ forms the surface layer of the
ovary
Theca folliculi interna-​ partially surrounds each
follicle
*Each ovary contains cells called ​oogonia
Oogonia- undergo rapid mitotic divisions
*Primary oocytes enter the ​prophase​ of the first
meiotic division forming the ​first polar body ​and
secondary oocyte.
*secondary meiotic division is initiated by the
secondary oocyte
*Fertilization occurs externally (frogs)
*second meiotic division is completed only when a
sperm contacts and penetrates the secondary oocyte,
resulting into a ​second polar body ​and a ​mature
ovum
Gastrulation
Involution- ​cells located on the surface turn inward
● Germ layers
ENDODERMMESODERM
ECTODERM
Blastopore+dorsal blastoporal lip= gastrula
Yolk plug- yolk filled endodermal cells
Exogastrulation-​ process which surface cells move
but fail to involute over the blastoporal lips
Cleavage and Blastulation
Cleavage- consists of series of rapid mitotic divisions
that result in ​blastulation (​formation of​ blastula)
Blastomeres- ​group of cells surrounding a cavity
(blastocoel)
Cleavage is total (holoblastic)
*​furrows that are pass through the vegetal hemisphere
is slow than the animal hemisphere (more yolk in the
animal hemisphere)
Micromeres- ​4 small animal hemisphere cells
Macromeres- ​4 larger vegetal hemisphere cells
Animal hemisphere-​ heavily pigmented cortex; 4 or 5
cells thick; blastomeres contain very little yolk
Vegetal hemisphere-​ a pigmented cortex;
blastomeres are very large in few numbers;
blastomeres are packed w yolk
Neurulation
Neural Ectoderm- induced to thicken as the neural
plate
*from gastrula to neurula