Reproductive system flashcards

Primary sex organs

The gonads, which are the ovaries in females and testes in males.

Secondary sex organs in males

Includes paired ductus deferens, single prostate gland, paired seminal vesicles, scrotum and penis, and paired bulbourethral glands.

Functions of primary sex organs

Produce gametes (sex cells) and secrete hormones.

Epididymis

Site of maturation and storage of sperm, the fluid is acidic due to waste products from sperm.

Seminiferous tubule

The site of sperm production.

Vas deferens

Conducts the fluid containing sperm from the epididymis to the urethra.

Seminal vesicles

Located behind the bladder. Secretes alkaline fluid rich in fructose and prostaglandins, forming 60% of semen volume.

Prostate gland

Secretes thin milky alkaline fluid that forms about 30% of semen volume.

Sperm concentration in semen

Contains about 120 million sperm cells per milliliter.

Pathway of sperm

1. Rete testis 2. Vasa Efferentia 3. Epididymidis 4. Vas deferens 5. Ejaculatory duct 6. Prostatic urethra 7. Urethra.

Erectile tissues of penis

Includes double corpora cavernosa and single corpus spongiosum.

Descent of testes

Influenced by hormones (testosterone) and the gubernaculum; occurs about 1-2 months before birth.

Why does the scrotum need to descend?

It needs to be outside the body to keep the temperature of the testis cooler for sperm production.

Cryptorchidism

Condition where testes do not descend, leading to potential infertility or testicular cancer.

Erection

Caused by parasympathetic nerve signals.

Ejaculation

Caused by sympathetic nerve signals; emission is the movement of semen into urethra.

Leydig cells

Secrete hormones, specifically testosterone.

Spermatogonia (what are they? How many chromosomes?)

Germ cells or stem cells that divide to form sperm cells. They are diploid, so 23 pairs

Sertoli cells

Provide nutrients and support to sperm cells, forming a blood-testis barrier.

Acrosome

Located at the tip of the sperm, contains enzymes to digest the egg's wall during fertilization.

Nucleus of sperm cell (how many chromosomes?)

Contains 23 chromosomes (haploid).

Mitochondrial spiral

Synthesize ATP needed for sperm movement.

Microtubules in sperm

Facilitate lashing movements of the tail for propulsion.

Spermatogenesis, describe the process

Beginning from spermatogonia, divide into 2 primary spermatoocytes through mitosis, then divide into 4 secondary spermatoocytes (2 per primary spermatoocyte) which give rise to 4 spermatids.

Primary spermatocyte (how many chromosomes?)

Diploid, 23 pairs

Secondary spermatocytes

Haploid cells that form from primary spermatocytes via meiosis I.

Spermatids

Four haploid cells formed from secondary spermatocytes after meiosis II.

Stem cells in seminiferous tubules

Spermatogonia, which are diploid (46 chromosomes).

Meiosis

Two cell divisions resulting in four haploid daughter cells.

DNA replication in meiosis

Produces two identical copies of chromosomes called sister chromatids.

Female meiosis difference

Only one primary oocyte receives good nutrients, while the other becomes a polar body and dies.

Polar body

The cell that receives poor nutrients & cytoplasm during meiosis in females and ultimately dies.

Function of seminal vesicles

Secretes fructose which provides nutrition for sperm and prostaglandins which cause contractions in females and facilitate sperm movement.

Hormonal influence in testis descent

Testosterone plays a key role in guiding the descent of the testes.

Functions of sertoli cells

Tight junctions form a blood-testis barrier to protect developing sperm. Provide nutrients and support developing sperm cells

Result of meiosis I

Production of haploid cells from a diploid primary spermatocyte.

Enzymes in acrosome

Aid in digesting the eggs' protective layers during fertilization.

Sperm cell structure

Includes nucleus, mitochondria, acrosome, and microtubules.

Meiosis II results

Sister chromatids are separated to produce distinct haploid cells.

Fertilization process

Acrosome enzymes digest the egg wall, allowing sperm entry.

Crytorchidism treatment

May involve surgical removal or hormonal injections.

Semen components

Semen consists of sperm cells and secretions from seminal vesicles, prostate gland, and bulbourethral glands.

Acid-neutralizing secretions (where do they come from?)

Prostate gland secretes alkaline fluid to counteract acidity, and seminal vesicles

Meiosis compared in males and females

Females produce one viable oocyte and polar bodies; males produce four functional sperm cells.

Testes internal structure

Includes cells of Leydig and Sertoli cells supporting spermatogenesis.

Secondary sex organs function

Support process and transportation of sperm.

Temperature control of testes

Essential for successful spermatogenesis.

Fluid composition in epididymis

Fluid is acidic due to sperm waste products.

Ejaculatory duct function

Transports sperm from vas deferens to urethra.

Sperm maturation location

Epididymis.

How much do seminal vesicles contribute to semen volume?

60% of semen volume

Erection mechanism

Parasympathetic signals lead to increased blood flow to erectile tissues.

Propulsion of sperm

Microtubules allow tail movement for sperm motility.

Mitosis vs Meiosis

Mitosis produces identical cells; meiosis produces genetically unique haploid cells.

What is the ventral erectile tissue?

Corpus sponginosum

What is the dorsal erectile tissue?

Corpus cavernosum

Scrotum temp.

34-35 C

When does spermatogenesis begin?

Begins at pubery

When does oogenesis begin?

Begins at fetal development

Describe the structure of a normal sperm

Head, midpiece, microtubules (motions for tail), mitochondrial spirals

Inner folds of the vagina

Labium minora

Outer folds of the vagina

Labium majora

Clitoris

Formed by left and right labia minora

What layer of endometrium is shed during menstraution?

Stratum functionalis

Normal menstrual cycle

28 to 30 days

Name the stem cells in the ovary

Oogonia

What is the difference between stem cells in females and males?

Females have a limited amount of stem cells, while male stem cells continuously divide throughout their entire lifetime

Days of follicular phase

1-14 days

Day of ovulation

Day 14

Days of luteal phase

15-28 days

Define ovulation and name the anterior pituitary hormone that is essential for bringing about ovulation

Ovulation is the release of the secondary oocyte from the ovary, triggered by surge in lutenizing hormone

How many secondary oocytes are formed from a single oogonium?

1

Name the hormones secreted by the corpus luteum

It secretes estrogen, but the primary hormone is progestrone

What is the corpus luteum?

Empty follicle left behind after secondary oocyte is ovulated

What are polar bodies and when are they formed? What is the fate of polar bodies?

They are formed during meiosis of oogensis, they degnerate and die, they get an uneven distribution of cytoplasm.

Describe the process of follicle maturation

Starts with primodial follicle → Primary follicle, follicular cells begin to develop → Secondary follicle, antrum fluid spaces begin to appear → Graafian follicle, corona radiata begins to appear, large antrum, zona pellicuda → Ovulation, secondary oocyte released

Name the hormone secreted by the follicular or granulosa cells

estrogen

Name the cell that is released from the mature follicle during ovulation

Secondary oocyte

Bulboetheral gland secretion

Purely mucus, which allows for lubrication

How does the spike in LH form?

A surge in estrogen levels causes a positive feedback loop signal to anterior pituitary to secrete LH which triggers ovulation.

List two conditions/diseases that are woman is susceptible to after menopause

Osteoporosis, heart disease

Describe the changes occurring at menopause

Decline in estrogen and progestrone

Name the phases of the uterine cycle

Menstrual, proliferative, secretory

Name the phases of the ovarian cycle

Follicular, ovulation, luteal

What is the fertile window?

the five days leading up to ovulation, the day of ovulation and the day after ovulation

State which phase of the ovarian cycle is variable in women with longer or shorter cycles

Follicular

State the average normal duration of the menstrual cycle, and the average blood loss during each cycle

70 ml, about 28 days

Proliferative phase

Endometrium thickens due to increase in estrogen

Secretory phase

Occurs after ovulation where endometrium continues to thicken due to progestrone. After corpus luteum dies, the endometrium starts to weaken.

State the impact of progesterone and estrogen on mammary glands

Progestrone stimulates development of alveolar glands
Estrogen stimulates depostion of fat in the development

Actions of inhibin

Secreted by gonads in response to rising levels of estrogen or testerone, causing fsh and lh lev

How is testorone regulated?

Hypothalamus secretes GnRH → Anterior pitutiary secretes LH and FSH → FSH creates sperm, LH stimulates testeorone production, testeorone creates a negative feedback loop

rhythm method

Tracking ovulation to see when you are most likely to conceive, or avoiding conception

coitus interruptus

The male withdraws his penis before ejaculating into the vagina

Pathway of sperm from seminiferous tubules into the urethra

Epdidiymis, ejaculatory duct, then urethra