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Gabriela Samson P:1 Reproductive Cycle - Coggle Diagram
Gabriela Samson P:1 Reproductive Cycle
Anatomy of male reproductive structures
Site of sperm maturation
Sperm become motile and develop the ability to fertilize an egg
Epididymis:Tightly coiled tube connected to the testis, leading from the testis to the ductus (vas) deferens
Ductus Deferens: Muscular tube, leading from epididymis into body cavity
Epididymis and Ductus Deferens
Unites with the seminal vesical duct, and empties into the
ejaculatory duct
Other accessory organs: Prostate gland. Bulbourethral glands.
Ejaculatory duct travels through prostate gland, and empties its contents into the urethra
Each testis is associated with: An epididymis. A ductus deferens.A seminal vesicle.
Seminal Vesicles and Prostate Gland
Male internal accessory organs -Nurture and transport the sperm cells
Seminal Vesicles: Saclike structure attached to the vas deferens near the base of the urinary bladder
Male Internal Accessory Reproductive Organs
During emission, seminal vesicles secrete a fluid that makes up a large portion of the semen:
Interstitial cells (cells of Leydig) lie between the
seminiferous tubules and produce the male sex hormones
Contains fructose to nourish sperm
Channels leading from the seminiferous tubules carry sperm
to the epididymis, which continues into the ductus deferens (Vas deferens)
Has an alkaline pH, to help regulate pH in vagina
Seminiferous tubules are lined with stratified epithelium
that contain spermatogenic cells that give rise to sperm cells
Prostate Gland: Chestnut-shaped structure surrounding the urethra at the base of the urinary bladder
Each lobule holds 1 to 4 coiled seminiferous tubules
Secretes a thin, milky fluid that contains citrate, a nutrient for sperm, and prostate-specific antigen (PSA), an enzyme which helps to liquefy semen.
Structure of the Testes: Each testis consists of 250 lobules separated by connective tissue septa
Testes: ovoid structures suspended by spermatic cord outside trunk in a sac, the scrotum
Accessory (secondary) sex organs of the male: Internal and external reproductive organs
Primary sex organs (gonads) of the male: Testes: produce sperm and hormones
Organs of the Male Reproductive System
Events of the female hormonal cycles (be sure to include all categories)
Follicle Maturation-At puberty, FSH secretion from anterior pituitary increases, and causes ovaries to enlarge
During reproductive years, primordial follicles develop into
primary follicles
At end of meiosis II, the chromosomes of the sperm and ovum combine, resulting in formation of the zygote
Early follicle maturation involves enlargement of the follicle,
proliferation of the follicular cells, and formation of a fluid-filled cavity (antrum)
Polar bodies contain unnecessary genetic material, and have no further function, so they degenerate
Then the cell grows to about 10 mm, and the primary oocyte is now surrounded by a clear layer, the zona pellucida, and several layers of follicular cells, the corona radiata
If fertilization occurs, a second, unequal cytoplasmic division (meiosis II) gives rise to a large egg cell (ovum) and a tiny second polar body
Follicle Maturation-Primary oocyte + surrounding layers is the egg
When a primary oocyte undergoes meiosis I, it divides unequally, giving rise to a large, haploid secondary oocyte and a tiny first polar body
Follicle development takes about 300 days
Meiosis results in oocytes having half the number of chromosomes (23) as other body cells (haploid)
Each month, up to 20 primary follicles start maturation, but only one dominant follicle completes maturation, while the others degenerate; the dominant one is called the mature follicle
Starting at puberty, some oocytes are stimulated to continue meiosis
Usually only 1 mature follicle is ready for ovulation every 28
days
Oogenesis: Process of oocyte production
Ovulation-Just before ovulation, primary oocyte in mature antral follicle finishes meiosis I, producing a secondary oocyte + first polar body
Oogenesis and the Ovarian Cycle
Ovulation: process of releasing the secondary oocyte and polar body from the mature antral follicle and the surface of the ovary
At time of ovulation, the oocyte is surrounded by 1 – 2 layers of follicular cells; it is propelled into a uterine tube
A burst of LH from the anterior pituitary triggers ovulation
If the oocyte is not fertilized within hours of its release, it will
degenerate
Hormones of the reproductive system (male)
Hormones control: Development and maintenance of secondary sexual characteristics.Sperm cell production
Hypothalamic and Pituitary Hormones
Male reproductive function is controlled by hormones secreted by the hypothalamus, anterior pituitary, and testes
At time of puberty, the hypothalamus controls many changes that lead to the development of a reproductively functional adult
Hormonal Control of Male Reproductive Functions
Gonadotropin-releasing hormone (GnRH): Secreted by the hypothalamus
A flagellum (tail):Provides lashing movements to propel the sperm through fluids, toward egg
Triggers the production of gonadotropins from anterior pituitary gland: Luteinizing hormone (LH): promotes development of interstitial cells of the testes, which then secrete male hormones (testosterone)
A midpiece (body) containing mitochondria
Follicle-stimulating hormone (FSH): stimulates sertoli cells of
seminiferous tubules to respond to testosterone
Acrosome contains digestive enzymes that erode tissues
surrounding female’s egg cell
FSH and testosterone stimulate spermatogenesis
Parts of a sperm: Head:Contains haploid nucleus and acrosome
Sertoli cells also secrete inhibin, which exerts negative feedback on the release of FSH; this prevents oversecretion
Male Sex Hormones
A mature sperm is shaped like a tadpole
Structure of a Sperm Cell
Androgens: Male sex hormones; testosterone is the most important one
Cells undergoes Meiosis I and II to form mature sperm cells starting at puberty
Actions of Testosterone: Stimulates development of male reproductive organs
Spermatogenesis (sperm production) is now arrested until puberty
Responsible for male secondary sexual characteristics (deep
voice, body hair, thickening of the skin, and increased muscular and skeletal growth)
In male embryo, spermatogenic cells are undifferentiated cells, each containing 46 chromosomes, number in normal human body cells
Sertoli cells support, nourish, and regulate the spermatogenic cells
Epithelium of the seminiferous tubules contains Sertoli cells and spermatogenic cells
Spermatogenesis
Anatomy of female reproductive structures
Vaginal orifice is partially covered by a membrane called the
hymen
Vaginal wall consists of three layers
Vagina: Fibromuscular tube that extends from uterus to the outside
Conveys uterine secretions, receives the penis during sexual
intercourse, and serves as birthing canal
Usually bends forward over the urinary bladder
Female External Accessory Reproductive Organs
Uterine wall has three layers: an inner, glandular endometrium, a muscular wall or myometrium, and an outer perimetrium
External accessory reproductive organs of the female: labia
majora, labia minora, clitoris, and vestibular glands
Lower one-third of the uterus is the cervix, which extends into the vagina
Structures surrounding openings of urethra and vagina make up the vulva
Upper two-thirds of the uterus, the body, has a dome-shaped
top, the fundus
Labia Majora: Enclose and protect other external reproductive organs; correspond to the scrotum of the male
Receives embryo from uterine tube, and maintains
development of the embryo and then fetus
Anterior ends meet to form the mons pubis, which covers
the pubic symphysis
Uterus: Hollow, muscular organ
The Labia Minora, Clitoris, and Vestibule
Normal site of fertilization
Labia Minora: Flattened, longitudinal folds between the labia majora
Cells lining the tubes have cilia, which beat in unison, drawing egg cell into the uterine tube
Form a hood around the clitoris
Near ovaries, they expand to form an infundibulum with
fingerlike fimbriae on its margins
Clitoris: Small projection at anterior end of vulva, between labia minora
Lead from the ovary to the uterus
Corresponds to the penis and has a similar structure
Uterine Tubes (oviducts or fallopian tubes):
Contains columns of erectile tissue
The female internal accessory organs consist of uterine tubes, uterus, and vagina
Vestibule: Space enclosed by the labia minora, into which the vagina and urethra open
Female Internal Accessory Reproductive Organs
Vestibular glands lie on either side of the vaginal opening;
correspond to bulbourethral glands and provide lubrication
Disorders associated with the reproductive system (including STI’s)
Acquired immune deficiency syndrome (AIDS), caused by HIV, can be transmitted by sexual intercourse; HIV is found in semen; this results in destruction of the body’s immune defenses, in which infections and cancers can be fatal
Some Diseases Associated with STIs
One possible complication of the STIs gonorrhea and chlamydia is pelvic inflammatory disease (PID), which may lead to infection and sterility in females; uterine tube scarring may cause infertility
Acquired immune deficiency syndrome (AIDS)-Human immunodeficiency virus (HIV)-Fever, weakness, infections, cancer-Drugs to treat or delay symptoms
Many STIs are silent or go unnoticed, especially in females
Chlamydia infection-Chlamydia trachomatis bacteria-Painful urination and intercourse, mucous discharge from penis or vagina -Antibiotics
Many STIs have similar symptoms, such as fever, sores, blisters or rashes, lower abdominal pain, discharge, painful intercourse
Genital herpes-Herpes simplex 2 virus (HSV2)- Genital sores, fever- Antiviral drug (acyclovir)
The term sexually transmitted infection (STI) is used now, instead of sexually transmitted disease (STD), since a person can have an infection and transmit it, but not develop symptoms
Genital warts- Human papilloma virus (HPV)- Warts on genitals- Chemical or surgical removal
Sexually Transmitted Infections
Gonorrhea- Neisseria gonorrhoeae bacteria- In women, usually none; in men, painful urination- Antibiotics.
Syphilis- Treponema pallidum bacteria- Initial chancre usually on genitals or mouth; rash six months later; several years with no symptoms as infection spreads; finally damage to heart, liver, nerves, brain- Antibiotics
Major functions of the Reproductive system (male and female)
Male system delivers sperm to female
Female system houses and nourishes developing embryo and fetus
Female sex cells: oocytes
Organs of the Female Reproductive System
Male sex cells: sperm
Female reproductive organs perform the following functions:
Gonads (testes and ovaries):Produce gametes (sex cells and hormones)
Develops and maintains organs for production of offspring
Produce and maintain sex cells (egg cells, oocytes)
Transport these cells to the site of fertilization
Reproductive system: Only body system a person does not need to survive
Provide environment for a developing fetus
Introduction to the Reproductive Systems
Deliver, feed and nurture offspringProduce female sex hormones
Primary sex organs (gonads) are the ovaries, which produce
the sex cells and hormones
Secondary (accessory) sex organs consist of the external and innternal reproductive organs
Methods and Classification of contraceptives
Combined Hormone Contraceptives: contain estrogen and
progestins to prevent pregnancy; disrupt normal hormonal patterns of female cycle, and prevent follicle maturation and
ovulation; examples: chemical ring, patch, oral contraceptives
Injectable Contraception: injection of a progesterone derivative prevents follicle maturation and ovulation; works for 3 months
Chemical Barriers: contain spermicides; are more effective
when used with a condom; examples: creams, foams, jellies
Contraceptive Implants: implantation of a rod containing
progestin under the skin in the arm; can prevent follicle maturation and ovulation for 3 years
Mechanical Barriers: prevent sperm from entering vagina
during sexual intercourse; examples: male or female condoms, diaphragm, cervical cap
Intrauterine Devices (IUDs): objects implanted in the uterus are either toxic to sperm and egg cells or prevent implantation of embryo by inhibiting growth of endometrium, thicken cervical mucus
Rhythm Method: abstinence from sexual intercourse around
time of ovulation; difficult to determine time of ovulation; not effective
Sterilization: surgical methods of permanently preventing
pregnancy; vasectomy in male (removal of a small portion of the vas deferens, preventing sperm from entering semen), tubal ligation in female (cutting of the uterine tubes, preventing sperm from reaching egg)
Coitus Interruptus: withdrawal of penis from vagina before
ejaculation; not very effective; some sperm may reach vagina before ejaculation
Hormones of the reproductive system (female)
Labia Minora:Flattened, longitudinal folds between the labia majora
Form a hood around the clitoris
The Labia Minora, Clitoris, and Vestibule
Clitoris:Small projection at anterior end of vulva, between labia minora
Anterior ends meet to form the mons pubis, which covers
the pubic symphysis
Corresponds to the penis and has a similar structure
Labia Majora: Enclose and protect other external reproductive organs; correspond to the scrotum of the male
Contains columns of erectile tissue
Structures surrounding openings of urethra and vagina make up the vulva
Vestibule:Space enclosed by the labia minora, into which the vagina and urethra open
External accessory reproductive organs of the female: labia
majora, labia minora, clitoris, and vestibular glands
Vestibular glands lie on either side of the vaginal opening;
correspond to bulbourethral glands and provide lubrication
Female External Accessory Reproductive Organs