Reproductive System

Describe the structure and function of the Vagina

Structure: passageway from cervix to outside Function: birth canal houses erect penis during intercourse

Describe the structure and function of the Scrotum

Structure: pouch of skin and fat that holds testes Function: hold testes at cooler temperature to insure optimum sperm production

Describe the structure and function of the Seminal Vesicles

Structure: sac-like structure attached to vas deferens Function: addition of fructose (energy source) to sperm/semen

Describe the structure and function of the Clitoris

Structure: small projection at anterior end of labia two columns of vascular tissue Function: female excitatory organ

Briefly explain why human reproduction is significant, and how sexual reproduction always results in a unique zygote.

Human reproduction is significant because all living organisms must reproduce in order to continue their species. In sexual reproduction,always results in a unique zygote because the genetic information is contributed by both parents, and therefore a unique combination of genetic information results in each zygote.

Define Gametes

Human sex cells

Discuss the structure (3 layers) of the uterus, and provide the name for the lower one-third where the uterus narrows

Endometrium = inner lining. Site of implantation of blastocyst. Myometrium = bundles of smooth muscle bulk of uterus Perimetrium = visceral covering. Lower one-third of uterus narrows to form cervix

Name the location where sperm is stored

Epididymides is tightly coiled tube leading to vas deferens and the site of storage of sperm cells.

Distinguish between erection, emission, ejaculation and orgasm in males

Erection is when vascular spaces within erectile tissue become engorged with blood when male becomes sexually stimulated. Emission is movement of semen from epididymis into urethra. Ejaculation is forceful movement of semen from urethra to outside. Orgasm is culmination of sexual stimulation accompanied by involuntary rhythmic contractions of the epididymis causing emission and ejaculation of semen, resulting in a sense of psychological and physiological release.

Describe the structure and function of the Cervix

Structure: lower one-third of uterus Function: Pap smear location

Describe the structure and function of the Penis

Structure: male excitatory organ vascular columns fill with blood causing erection Function: is held in female vagina during intercourse for transfer of sperm

Describe the structure and function of the Uterus

Structure: muscular (smooth) organ that houses developing embryo, fetus 3 layers Function: houses developing embryo/fetus

Describe the structure and function of the Vasa Deferentia

Structure: muscular tube leading from epididymis into abdominal cavity Function: movement of sperm

Describe the events involved in maturation of an ovarian follicle each month.

1. FSH stimulates one primordial follicle to mature 2. Primary oocyte enlarges and undergoes meiosis I 3. The follicular cells multiply and give rise to stratified epithelium composed of granulosa cells 4. A layer called the zona pellucida appears and separates the oocyte from the granulosa cells. The follicle is now called a primary follicle. 5. A fluid-filled cavity, called the antrum appears. A crown of granulosa cells surrounds the oocyte (corona radiata). The follicle is now called a secondary follicle.

Discuss the sequence of events involved in oogenesis.

1. Mitosis of primordial germ cells within female embryos produces diploid oogonia (23 pairs of chromosomes), which duplicate their DNA and give rise to Primary oocytes (23 pairs of duplicated chromosomes) 2. Note that human females are born with all their potential ova as primary oocytes. 3.At puberty, once each month, FSH stimulates one primary oocyte to undergo Meiosis I, which gives rise to one Secondary oocyte (23 duplicated chromosomes) and a polar body due to unequal cytokinesis. 4. The secondary oocyte is then ovulated from the ovary (LH) 5. If the secondary oocyte is penetrated by a sperm cell, Meiosis II initiated. 6. When and if Meiosis II is complete, a second polar body is separated from the large ovum (23 chromosomes) 7.The haploid nuclei of the sperm and the nowmatured ovum fuse.

List and describe the sequence of events involved in spermatogenesis, beginning with a spermatogonium and ending with mature sperm cells.

1. One spermatogonium (23 pairs of chromosomes) duplicates its DNA. 2. This gives rise to One primary spermatocyte (23 duplicated pairs of chromosomes) which undergoes meiosis I. 3. This gives rise to Two secondary spermatocytes (each with 23 duplicated chromosomes), which undergo meiosis II. 4. This gives rise to Four spermatids (each with 23 chromosomes). These cells mature into Four sperm cells (each with 23 chromosomes). 5. The sperm cells collect in the lumen of the seminiferous tubule.

What are the Five Functions of the Reproductive Systems?

1. Produce Gametes 2. Transport Gametes 3. Maintain Gametes 4. Maintain the developing fetus/zygote 5. Produce sex hormones: male = testosterone & female = estrogen and progesterone.

Define Zygote

A flagellated sperm (from the male father) fertilizes an ovum (from the female mother) producing a zygote.

Explain what portion of the penis is surgically removed during a circumcision

A loose fold of skin called the prepuce covers the glans as a sheath and is sometimes removed by a surgical procedure called a circumcision.

Define Diploid

Diploid means the cell contains 46 chromosomes or 23 pairs.

Describe the microscopic structure of the testes

Each testis is divided into lobules. Each lobule contains: seminiferous tubules (production of sperm cells under the influence of what hormone?), which are separated by interstitial cells (of Leydig) (production of male sex hormones under the influence of what hormone?) The seminiferous tubules unite and give rise to the epididymis on the outer surface of the testis.

Name the common term for both the male and female gamete.

Haploid

Define Haploid

Haploid means the cell contains only 23 chromosomes.

Explain why a secondary oocyte does not always undergo Meiosis II.

If the secondary oocyte is penetrated by a sperm cell, Meiosis II initiated.

Explain how DNA Replication differs during Mitosis Vs Meiosis

In Mitosis - Occurs during interphase before nuclear division occurs. In Meiosis - Occurs during interphase before nuclear division occurs.

Explain the difference between the Number of Divisions in Mitosis Vs Meiosis

In Mitosis - One (PMAT) In Meiosis - Two (2xPMAT) no replication between divisions synapsis occurs during Prophase I.

Explain the difference between the Number of daughter cells & genetic composition in Mitosis Vs Meiosis

In Mitosis - Two, each diploid (2n) and genetically identical to parent cell. In Meiosis - Four, haploid cells (1n), genetically non-identical to parent cell.

Define Somatic Cells

In humans, each somatic (body) cell is diploid, which means the cell contains 46 chromosomes or 23 pairs.

Name the specific step of meiosis where homologous chromosomes are arranged together in tetrads (this is also called synapsis) where crossing over occurs.

Prophase I

Describe the structure of the mammary glands

MAMMARY GLANDS (within breast tissue) are modified sudoriferous (apocrine) glands that produce milk and consist of 15-20 lobes separated by adipose tissue. Each lobe is composed of lobules composed of CT and milk-secreting glands called alveoli.

Explain why a sperm cell contains so many mitochondria and name the portion of the spermatocyte that houses these mitochondria.

Many mitochondria needed to produce ATP for energy for the sperm cell to complete its long journey. & The body (mid-piece) houses the most mitochondria

Describe the internal structure of an ovary and locate where oogenesis occurs

Medulla = CT, blood & lymph vessels and nerves nourishment and support. Cortex = ovarian follicles covered by germinal epithelium.

Distinguish between spermatogenesis and oogenesis.

Meiosis is called spermatogenesis in the male (testes). Meiosis is called oogenesis in the female (ovaries).

Define Meiosis

Meiosis is the type of cell division that results in gametes that possess half the chromosome number of the parent cell

Explain the difference between the Importance of Mitosis Vs Meiosis

Mitosis is vital to Growth, repair, development of multi-cellular organism from zygote. Mieosis is vital to the Production of gametes reduces chromosome # by ½ variation.

List the 1o Female Reproductive Organs

Ovaries, Fallopian Tubes, Uterus, Cervix, Vagina, Vestibule, Vestibular Glands, Labia Major, Labia Minor, Clitoris

Define the term ovulation and name the gonadotropin responsible for its occurrence.

Ovulation: Oogenesis (meiosis I) is complete as the follicle matures (approximately 14 days) Upon maturation, luteinizing hormone (LH) causes the follicle to burst, releasing a secondary oocyte.

Distinguish between a pap smear and colposcopy.

Pap smears are taken from cervical tissue. Colposcopy is used to follow-up to an abnormal pap smear.

Track the flow of milk from the alveoli to the nipple.

Production/Flow of milk: 1. Milk is produced by alveoli & passes into 2. secondary tubules then into 3. mammary ducts then into 4. lactiferous sinuses (near nipple) then into 5. lactiferous ducts and exits through the 6. nipple.

Describe the structure and function of the Labia

Structure: external reproductive organs Function: protect underlying organs

Illustrate the steps involved in gamete formation (meiosis), explain the highlight(s) of each step, and explain any differences between male and female end-products.

STARTING PRODUCT: One Parent Cell (Two sets of duplicated chromosomes) [23 pairs duplicated chromosomes] INTERMEDIATE PRODUCTS: Two Daughter Cells (one set of duplicated chromosomes) [23 duplicated chromosomes] END-PRODUCTS Four Gametes (one set of chromosomes) [23 chromosomes]

Describe the structure and function of the Testes

Structure: solid ovoid structure held in scrotum lobules of seminiferous tubules separated by interstitial cells Fucntion: production of sperm (seminiferous tubules/FSH) secretion of testosterone (interstitial cells, LH)

Describe the structure and function of the Ovaries

Structure: solid, ovoid structures on posterior pelvic cavity cortex of ovarian follicles Function: production of secondary oocytes for fertilization production of estrogen for development of 2o sex organs production of progesterone to prepare endometrium for implantation

Describe the structure and function of the Prostate Gland

Structure: sponge-like structure below bladder and surrounding urethra Function: addition of milky alkaline fluid to semen for sperm motility

Describe the structure and function of the Epididymides

Structure: tightly coiled tubule superior to testes leads to vas deferens Function: storage of sperm

Describe the structure and function of the Urethra

Structure: tube leading from bladder/prostate to outside held within penis Function: transport of sperm and urine to outside

Describe the structure and function of the Uterine Tubes

Structure: tubes that pass medially from ovaries to uterus lined with cilia, expanded ends (fimbriae) over ovary Function: site of fertilization transportation of fertilized egg to uterus

Describe the structure and function of the Bulbourethral Glands

Structure: two pea-shaped structures below prostate Function: addition of penis lubricant to sperm/semen

List the 1o Male Reproductive Organs

Testes, Scrotum, Epipidymis, Vas Deferens, Seminal Vesical, Ejaculatory Duct, Prostate, Urethra, Bulbourethral Glands, Penis

Fully describe the structure of a mature sperm cell

The Head - The head contains 23 chromosomes and is covered by a helmet like structure called an acrosome. Contains enzymes to help penetrate the oocyte. The Body - The body (mid-piece) contains many mitochondria needed to produce ATP for energy for the sperm cell to complete its long journey Tail - The tail is a flagellum provides locomotion for the sperm cell.

Which organ secretes lubricant?

The bulbourethral gland

Name the components of the spermatic cord and name the "canal" that houses these organs and passes them into the abdominopelvic cavity.

The components of the spermatic cord are the vas deferens, a testicular artery, autonomic nerves, testicular veins, lymphatic vessels The canal that houses these organs is the cremaster muscle pass upward within the inguinal canal

Explain the function of the cremaster muscle

The cremaster muscle is an extension of the internal oblique muscle that elevates the scrotum during sexual arousal and on exposure to cold.

Define DNA

The genetic information of living organisms is DNA (deoxyribonucleic acid) that is carried on the genes of chromosomes.

Which organ secretes alkaline fluids?

The prostate gland

Which organ secretes fructose?

The seminal vesicle

Explain where spermatogenesis and androgen production occurs.

The seminiferous tubules are lined by stratified epithelium. This germinal epithelium consists of two types of cells: Spermatogenic cells which give rise to sperm cells. Sustentacular cells (Sertoli cells), which support and nourish the spermatogenic cells.

Name the site where the seminal vesicle and vas deferens unite within the prostate gland

The spermatic cord fuses with duct from seminal vesicle to form ejaculatory duct (within prostate gland).

Which organ secretes sperm cells?

The testes

Distinguish between a primary and secondary follicle.

The zona pellucida appears and separates the oocyte from the granulosa cells is now called a primary follicle. A fluid-filled cavity, called the antrum appears. A crown of granulosa cells surrounds the oocyte (corona radiata). The is now called a secondary follicle.

Name the female reproductive organ containing fimbriae and cilia

Uterine Tubes (Fallopian Tubes, Oviducts)

Name the female reproductive organ that houses the erect penis during intercourse, the organ(s) that protect the internal organs, and the organ that corresponds to the male penis.

Vagina is the passageway from cervix to outside that serves to receive erect penis. Labia encloses and protects underlying organs and tissues. Clitoris is a small projection at the anterior end of the labia, which corresponds to the male penis.