Flashcards in Lab 4: Reproductive System Deck (73)
In humans, spermatogenesis takes ...
Spermatogonia are types of ...
Describe the two fates of the spermatogonia after mitosis.
1) Some remain near the basement membrane in an undifferentiated state to serve as a reservoir of cells for future cell division.
2) Rest lose contact with basement membrane, squeeze through tight junctions of the blood-testis barrier, undergo developmental changes, and differentiate into primary spermatocytes.
Does replication of DNA occur to primary spermatocytes or secondary spermatocytes?
What unique process occurs during spermatogenesis?
As spermatogenic cells proliferate, they fail to complete cytoplasmic separation (cytokinesis). The cells remain in contact via cytoplasmic bridges through their entire development.
What is the purpose of the unique process of spermatogenesis?
This pattern of development most likely accounts for the synchronised production of sperm in any given area of the seminiferous tubule. The larger x chromosome may carry genes needed for spermatogenesis that are lacking on the smaller Y chromosome.
What occurs during spermiation?
Sperm are released from their connections to sustentacular cells.
What two systems are the mammary glands a part of?
Integumentary and female reproductive system
What hormones do ovaries secrete?
Progesterone, estrogens, inhibin and relaxin
What holds ovaries in position?
A series of ligaments.
What is the broad ligament?
A fold of the parietal peritoneum.
How does he broad ligament attach to the ovaries?
By a double-layered fold of peritoneum called the mesovarium.
What does the ovarian ligament anchor?
Anchors the ovaries to the uterus
What anchors the ovaries to the pelvic wall?
What is the purpose of the hilum of an ovary?
Point of entrance and exit for blood vessels and nerves along which the mesovarium is attached.
List the layers of the ovary
Describe the germinal epithelium.
Layer of simple epithelium that covers the surface of the ovary.
Describe the tunica albuginea.
A whitish capsule of dense irregular connective tissue located immediately deep to the germinal epithelium.
Describe the ovarian cortex.
A region just deep to the tunica albuginea. It consists of ovarian follicles surrounded by dense irregular connective tissue that contains collagen fibres and fibroblast-like cells called stromal cells.
Describe the ovarian medulla.
Deep to the ovarian cortex. The border between the cortex and medulla is indistinct, but the medulla consists of more loosely arranged connective tissue and contains blood vessels, lymphatic vessels, and nerves.
Where are ovarian follicles found? What do they consist of?
In the cortex. They consist of oocytes in various stages of development, plus the cells surrounding them.
When the surrounding cells of an oocyte form a single layer, they are called ...
Later in development, when they form several layers, they are referred to as ...
What do the surroundings cells of an oocyte do?
Nourish the developing oocyte and begin to secrete oestrogen as the follicle grows larger.
What is a mature follicle?
A large, fluid-filled follicle that is ready to rupture and expel its secondary oocyte.
What does the corpus luteum contain? What does it produce? What does it then form?
The remnants of a mature follicle after ovulation.
Produces progesterone, estrogens, relaxin and inhibin until it degenerates into fibrous scar tissue called the corpus albicans.
What happens to the primordial (primitive) germ cells during early fetal development?
Migrate from yolk sac to the ovaries.
What happens to germ cells after they have migrated to the ovaries?
Differentiate into oogonia
What are oogonia?
Diploid stem cells that divide mitotically to produce millions of germ cells.
Before birth. most germ cells degenerate in a process known as ...
However, what happens to a few?
A few develop into larger cells called primary oocytes that enter prophase of meiosis I during fetal development, but do not complete this phase until after puberty.