Human Reproduction Flashcards
Where is the male reproductive system located?
In the pelvis region
What are the main components of the male reproductive system?
A pair of testes, accessory ducts, glands, and external genitalia
What is the function of the scrotum?
Helps maintain a low temperature for the testes necessary for spermatogenesis
What is the temperature range that the scrotum helps maintain for the testes?
2-2.5° C lower than the normal internal body temperature
What is the average length and width of an adult testis?
Length: 4 to 5 cm, Width: 2 to 3 cm
What are the compartments within each testis called?
Testicular lobules
What do the seminiferous tubules in the testicular lobules produce?
Sperms
What types of cells line the inside of the seminiferous tubules?
- Male germ cells (spermatogonia)
- Sertoli cells
What role do Sertoli cells play in the seminiferous tubules?
Provide nutrition to the germ cells
What type of cells are found in the interstitial spaces of the testes?
Leydig cells
What do Leydig cells synthesize and secrete?
Testicular hormones (androgens)
List the male sex accessory ducts.
- Rete testis
- Vasa efferentia
- Epididymis
- Vas deferens
What connects the seminiferous tubules to the vasa efferentia?
Rete testis
Where is the epididymis located in relation to the testis?
Along the posterior surface of each testis
What does the vas deferens do?
Ascends to the abdomen, loops over the urinary bladder, and leads to urethra
What is the external opening of the urethra called?
Urethral meatus
Fill in the blank: The urethra originates from the _______.
Urinary bladder
What is the male external genitalia?
The penis is the male external genitalia. It is made up of special tissue that helps in erection to facilitate insemination.
What is the glans penis?
The enlarged end of the penis is called the glans penis, which is covered by a loose fold of skin called foreskin.
What are the male accessory glands?
The male accessory glands include paired seminal vesicles, a prostate, and paired bulbourethral glands.
What do the secretions of male accessory glands constitute?
The secretions of these glands constitute the seminal plasma, which is rich in fructose, calcium, and certain enzymes.
What is the function of the bulbourethral glands?
The secretions of bulbourethral glands help in the lubrication of the penis.
What does the female reproductive system consist of?
The female reproductive system consists of a pair of ovaries, oviducts, uterus, cervix, vagina, and external genitalia.
What are the primary female sex organs?
The ovaries are the primary female sex organs that produce the female gamete (ovum) and several steroid hormones.
Where are the ovaries located?
The ovaries are located one on each side of the lower abdomen.
What is the structure of the ovaries?
Each ovary is about 2 to 4 cm in length and is covered by a thin epithelium enclosing the ovarian stroma.
What are the two zones of the ovarian stroma?
The stroma is divided into two zones: a peripheral cortex and an inner medulla.
What are the female accessory ducts?
The oviducts (fallopian tubes), uterus, and vagina.
How long are the fallopian tubes?
Each fallopian tube is about 10-12 cm long.
What is the infundibulum?
The funnel-shaped part of the fallopian tube that is closer to the ovary.
What are fimbriae?
Finger-like projections on the edges of the infundibulum that help collect the ovum after ovulation.
What does the infundibulum lead to?
A wider part of the fallopian tube.
What are the layers of the uterus?
Endometrium, Myometrium, and Perimetrium.
What is the function of the cervix?
It connects the uterus to the vagina.
What is the role of the vagina?
It serves as the canal for childbirth and menstrual flow.
What is the ampulla in human reproduction?
The ampulla is part of the oviduct where fertilization typically occurs.
What is the isthmus in human reproduction?
The isthmus is the last part of the oviduct with a narrow lumen that joins the uterus.
What is the uterus also known as?
The uterus is also called the womb.
What is the shape of the uterus?
The uterus is shaped like an inverted pear.
How is the uterus supported?
The uterus is supported by ligaments attached to the pelvic wall.
How does the uterus connect to the vagina?
The uterus opens into the vagina through a narrow cervix.
What is the cervical canal?
The cervical canal is the cavity of the cervix.
What are the three layers of the uterus?
The three layers are the myometrium, endometrium, and the outer layer.
What is the function of the myometrium?
The myometrium exhibits strong contractions during the delivery of the baby.
What is the function of the endometrium?
The endometrium undergoes cyclical changes during the menstrual cycle.
What are the components of the female external genitalia?
The components include mons pubis, labia majora, labia minora, hymen, and clitoris.
What is the mons pubis?
The mons pubis is a cushion of fatty tissue covered by skin and pubic hair.
What are the labia majora?
The labia majora are fleshy folds of tissue that surround the vaginal opening.
What are the labia minora?
The labia minora are paired folds of tissue under the labia majora.
What is the hymen?
The hymen is a membrane that partially covers the vaginal opening.
What is the clitoris?
The clitoris is a tiny finger-like structure located at the upper junction of the labia minora.
How can the hymen be broken?
The hymen can be torn during coitus, by a sudden fall, or by the insertion of a tampon.
Is the presence of hymen a reliable indicator of virginity?
No, the presence or absence of hymen is not a reliable indicator of virginity or sexual experience.
What is characteristic of all female mammals?
A functional mammary gland.
What do mammary glands contain?
Glandular tissue and variable amounts of fat.
How many mammary lobes does each breast contain?
15-20 mammary lobes.
What do the cells of alveoli secrete?
Milk.
Where is milk stored in the mammary glands?
In the cavities (lumens) of alveoli.
What do the alveoli open into?
Mammary tubules.
What do several mammary ducts join to form?
A wider mammary ampulla.
What connects the mammary ampulla to the outside?
Lactiferous duct.
What are the primary sex organs in males and females?
Testis in males and ovaries in females.
What process produces gametes?
Gametogenesis.
What do spermatogonia produce?
Sperms by spermatogenesis.
When does spermatogenesis begin?
At puberty.
What type of division do spermatogonia undergo?
Mitotic division.
What is the chromosome number in spermatogonia?
46 chromosomes.
What do primary spermatocytes undergo?
Meiosis.
What do primary spermatocytes form after the first meiotic division?
Two equal, haploid cells called secondary spermatocytes.
How many chromosomes do secondary spermatocytes have?
23 chromosomes each.
What do secondary spermatocytes produce after the second meiotic division?
Four equal, haploid spermatids.
What process transforms spermatids into spermatozoa?
Spermiogenesis.
What happens to sperm heads after spermiogenesis?
They become embedded in Sertoli cells.
What is the process called when sperm are released from seminiferous tubules?
Spermiation.
What hormone triggers spermatogenesis at puberty?
Gonadotropin releasing hormone (GnRH).
What two gonadotropins are stimulated by GnRH?
Luteinising hormone (LH) and follicle stimulating hormone (FSH).
What do androgens stimulate?
The process of spermatogenesis.
What do Sertoli cells secrete to aid spermiogenesis?
Factors that help in the process.
What is the structure of a sperm composed of?
A head.
What are the main components of a sperm?
A sperm is composed of a head, neck, middle piece, and tail.
What does the sperm head contain?
The sperm head contains an elongated haploid nucleus and is covered by a cap-like structure called the acrosome.
What is the function of the acrosome?
The acrosome is filled with enzymes that help in the fertilization of the ovum.
What is the role of the middle piece of a sperm?
The middle piece possesses numerous mitochondria, which produce energy for the movement of the tail.
How many sperms are typically ejaculated during coitus?
The human male ejaculates about 200 to 300 million sperms.
What percentage of sperms must have normal shape and size for normal fertility?
At least 60 percent of sperms must have normal shape and size.
What is the process of formation of a mature female gamete called?
The process is called oogenesis.
When does oogenesis begin?
Oogenesis is initiated during the embryonic development stage.
What are oogonia?
Oogonia are gamete mother cells formed within each fetal ovary.
What happens to primary oocytes during development?
Primary oocytes enter prophase-I of meiotic division and get temporarily arrested.
What are primary follicles?
Primary follicles are formed when primary oocytes are surrounded by a layer of granulosa cells.
How many primary follicles remain at puberty?
At puberty, only 60,000-80,000 primary follicles are left in each ovary.
What characterizes a tertiary follicle?
A tertiary follicle is characterized by a fluid-filled cavity called antrum.
What happens during the first meiotic division of the primary oocyte?
It results in the formation of a large haploid secondary oocyte and a tiny first polar body.
What is the zona pellucida?
The zona pellucida is a new membrane formed around the secondary oocyte.
What is ovulation?
Ovulation is the process by which the Graafian follicle ruptures to release the secondary oocyte from the ovary.
