Reproductive System Quiz

Reproduction in Humans

• Blue text in the original material indicates content for interest only and is not for study
• The study notes cover textbook pages 63-89 and will include topics such as sexually transmitted infections (STIs), surrogacy, and circumcision

Reproduction

• Asexual reproduction involves no fusion of gametes, requires only one parent, and results in genetically identical offspring
• Sexual reproduction involves the fusion of two gametes to form a zygote, generally requires two parents, and results in offspring with genetic variation

Natural Vegetative Reproduction

• Relies on the separation of a plant part, which then develops into a new plant
• Examples include rhizomes, bulbs, corms and tubers

Artificial Methods of Vegetative Propagation

• Examples include cutting, layering, marcotting, grafting, and tissue culture

Parts of a Flower

• include the pedicel(stalk), receptacle, sepals, and petals
• Stamens consist of the filament and anther
• The pistil consists of the stigma, style, ovary, and ovule

Male Sex Organs

• Testes produce male gametes (sperm) and male sex hormones (testosterone)

Fertilization

• The process where pollen grains from an anther fuse with an ovum (egg) from ovules

Zygote

• Fertilization results in a zygote

Female Sex Organs

• Ovaries produce the female gamete (egg) and female sex hormones (progesterone, estrogen)

Asexual vs Sexual Reproduction Comparison

• Asexual reproduction has one parent whilst sexual reproduction has two parents
• Asexual offspring are genetically identical (clones), whereas sexual offspring are genetically different
• Asexual reproduction uses mitosis only; sexual reproduction uses both mitosis and meiosis

Subtopics to be covered include:

• The structure of both the male and female reproductive systems and secondary sexual characteristics
• Sperm, ova (egg cells), semen
• Menstrual and ovarian cycles
• Fertilization, embryo development, and implantation
• Pregnancy (gestation) and the stages of pregnancy
• The placenta structure and function, labor and birth
• Contraception methods, STIs, surrogacy, circumcision, and Foetal Alcohol Syndrome (FAS)

Male Reproductive System: Testes

• The testes are the glandular gonads in males
• They are oval-shaped structures that hang outside the abdominal cavity in a double-layered pouch called the scrotum

Male Reproductive System: Seminiferous Tubules

• Each testis contains ~1000 tubules lined with germ cells that divide (mitosis then meiosis) to form haploid spermatozoa
• The total length of these is over 500 m within each testes
• The seminiferous tubules produce 200-500 million sperm for each ejaculation
• Men can produce sperm for their entire adult lives

Male Reproductive System: Leydig Cells

• Masses of interstitial cells/Leydig cells lie between the seminiferous tubules
• These cells produce testosterone, which is responsible for:
  • The growth of the penis and testes
  • Secondary sexual characteristics such as body hair growth and voice deepening
  • Stimulation of sperm production

Male Reproductive System: FSH and ICSH

• As testosterone concentration increases in the bloodstream, it inhibits FSH and ICSH secretion by the pituitary gland
• A decrease in testosterone concentration then stimulates the pituitary gland to produce more FSH and ICSH
• This self-regulating mechanism is called negative feedback

Male Reproductive System: The Scrotum

• The scrotum is a pouch-like structure that holds the testes outside the body
• The temperature in the scrotum is slightly lower than body temperature, favoring sperm production
• Sperm develop most effectively at 34°C
• In the male fetus, testes develop inside the abdominal cavity and descend into the scrotum by birth time

Male Reproductive System: Epididymis

• Seminiferous tubules open into the epididymis, which is a coiled tube lying outside the testis but within the scrotum
• The epididymis curves upwards and forms the vas deferens (sperm duct), which enters the abdominal cavity
• Sperm mature and are stored in the epididymis until ejaculation, when they pass along the vas deferens (sperm duct)
• Vas deferens is Latin for "carrying-away vessel"

Male Reproductive System: Vas Deferens and Urethra

• The vas deferens (sperm duct) begins at the end of the epididymis, runs up into the spermatic cord into the abdominal cavity, curves over and behind the bladder, and enters the urethra just after it leaves the bladder
• The urethra acts as the exit route for both sperm and urine

Accessory Glands

• Accessory glands add secretions as the sperm travels from each testis to the urethra
• These secretions form the semen, and they are secreted by the seminal vesicles, the prostate gland and Cowper's gland

Seminal Vesicles

• These glands add secretions before each vas deferens enters the urethra, which is a thick, clear fluid that contains fructose that provides the sperm with fuel, which stimulates spermatozoa movement and contains mucus to assist with lubrication

Prostate Gland

• This gland is a large, chestnut-shaped gland at the bladder's neck that secretes a milky white, alkaline fluid into the semen
• The fluid corrects the pH for the sperm

Cowper's glands

• (or bulbourethral glands) are two small round glands open into the urethra at the base of the penis which secretes mucous substance that protects the sperm from chemical damage and adds lubrication

The Penis

• Spongy connective tissue makes up the penis, along with small, numerous blood sinuses, thus erection enables insertion of the penis and the urethra terminates there
• The tip is known as the glans penis and covered by the foreskin

Circumcision

• (as specified in SAGS Aim 3) is the surgical removal of the foreskin to expose the glans penis common to newborn boys among certain cultural groups or religious in certain regions or family traditions for personal hygiene

Erection vs Ejaculation

• Learn the difference, during erection there are two chambers filled with spongy erectile tissue, and small muscles dilate it for blood to flow in which swells the penis
• During ejaculation sperm passes the ducts from seminal vesicles, the prostate and Cowper's glands, into the vaginal cavity to deliver the sperm

The Human Female Reproductive Organs

• 2 ovaries
• 2 fallopian tubes
• 1 uterus (with endometrium and cervix)
• 1 vagina

Ovaries

• The ovaries are the female glandular gonads, located in the lower abdominal region and held in place by ligaments
• Each ovary is almond-shaped and about 32mm long and 19mm wide
• Consist of connective tissue, blood vessels, follicles, and oogonia
• Partly covered by an expanded, cilia-lined, funnel-shaped extension of the oviduct or Fallopian tube

Fallopian tubes (oviducts)

• The Fallopian tubes begin as expanded, cilia-lined funnels partly enclosing the ovaries and continue as extremely narrow tubes
• Walls are composed of smooth muscle, lined with ciliated columnar epithelium to convey egg cells which is where fertilization and implantation occur in the upper section of the endometrium

The Uterus

• Fallopian tubes open into the uterus, a pear-shaped, hollow organ with thick muscular walls
• Lies in the pelvic cavity behind the bladder and is about 7.5cm long
• The broad ligament from the lateral walls of the pelvis keeps it in position
• Neck of the uterus extends into the vagina called the cervix where mucus prevents sperm from blocking the monthly cycle, ovulation occurs here with changes and expansion during childbirth

Vagina

• Muscular walls that open too the exterior called the vaginal orifice posterior to the urethral and surrounded by labia tissues called a clitoris

Oogenesis

• The germinal epithelium (layer of diploid cells near the surface of each ovary) divides by mitosis
• Some cells transform into mature follicle cells, for every three polar bodies during meiosis at the end to protect
• The mature follicle becomes a Graafian follicle

Ovulation

• Occurs when a Graafian follicle bursts and releases by cell that must be fertilized to complete to meiosis so follicle has layers for protection

Ovarian cycle

• Describes the monthly 28-day cycle of when to release an egg that is developed between puberty and menopause

Menstrual cycle

• Thickens to endometrium 28 cycle when possible implantation is possible

FSH

• Produced in the anterior pituitary and secretion starts on day 2 to stimulate a primary follicle into Graafian follicle

Oestrogen

• Secreted on day 6 by the lining causing the endometrium too thicken that inhibits FSH
• Functions to prepare endometrium
• Controls female characteristics

LH hormone

• secreted from the pituitary gland on day 12 through 13 with high estrogen for triggers on day 14 for control and follicle forming

Pregnancy

• Diploid results in division into an embryo as traveled before mitosis as cilia in the oviduct

Implantation

• In the uterus blastocyst with embryos with fertilzation within 6 to 7 day

Gestation

• 280 days until full development of the structure and protection such are umbilical cord to placenta and fluid for protection the extra layer is chorion and the inner amnion

Test your knowledge of the male and female reproductive systems. Questions cover structures, functions, and key concepts like gametogenesis and fertilization. Evaluate your understanding of reproductive health and related topics.