Reproduction System Flashcards
What are the reproductive systems
Produce new individuals through germ cells and fertilization
Scrotum
- contains the testes
- Sac of loose skin divided into two pouches.
- Contains dartos muscle, causing wrinkling
Testes Temperature
Sperm survives in 3 degrees lower than body core temp.
95 degrees, anything warmer than that can cause infertility
Cremaster muscle
Elevates testes on exposure to cold and during arousal
Warmth reverses the process
Testes
Paired oval glands, about 2 in. by 1 in.
- Endocrine and Exocrine
- Has several butter layers ( tunica vaginalis and tunica albuginea being the prominent )
- Divided in two lobules, Each filled with seminiferous tubules where sperm is formed
Descent of Testes
- Develop in pelvic cavity near the kidney
- Descend into the scrotum by passing through the inguinal cavity during 7 months of development
Tunica Vaginalis
Piece of peritoneum that descends with the testes
It allows for easier movement of testes within the scrotum bc of fluid in air.
Location of Sperm formation
Seminiferous tubule
Leydig cells secrete testosterone
What are the supporting cells of sperm formation
Sertoli cells: Extend from basement membrane to lumen
- form blood
- support, nourish and protect developing sperm
- produce fluid and control the release of sperm into the lumen
What is Spermatogenesis
process by which the seminiferous tubules of the testes produce haploid sperm
Take about 70 days
100 million sperm in 1 ml
ejaculate about 3-5 ml
Less than 20 million sperm in an ml of someone infertile
Starts at Spermatogonia
Spermiogenesis
The maturation of spermatids into sperm cells
Spermiation
The release of sperm cells from a steroli celll
Sperm and its parts
Are adapted to reaching and penetrating a secondary oocyte to achieve fertilization and create a zygote
Head, Neck, Midpiece, Tail
Hormonal controls of spermatogenesis
at Puberty
LH stimulates Leydig cells to secrete testosterone
FSH stimulates spermatogenesis
Inhibin is released if too much sperm as a negative feedback
Testosterone hormonal effects
At puberty, the final development of secondary sexual characteristics
- sexual behavior
- male metabolism ( bone and muscle mass heavier)
- deepening of voice
Pathway of Sperm Flow
Seminiferous tubules Straight tubules Rete Testes Efferent Ducts Ductus Epididymis Vas deferens SPERMATIC CORD Pubic synthesis SEMINAL VESSICLES EJACULATORY DUCTS URETHRA OUT THROUGH SPONGE URETHRA
Epididymis
Comma shaped organ
The tail region continues to duct deferens
Sperm is transported out of the testes through the efferent ducts in the epididymis which empty into a single tube called the ductus epididymis
Histology of epididymis
Lined with pseudostratified columnar epithelium
-a layer of smooth muscle
Site of sperm maturation
Storages sperm for 1-2 months
Propels sperm onwardsDuctus (Vas) Deferens Pathway
The 18-inch muscular tube ascends along the epididymis and up through the spermatic cord reaching the posterior surface of the urinary bladder and empties into the prostatic urethra with seminal vesicle
Vas Deferens
Lined with pseudostratified columnar epithelium and covered with a heavy coating of muscle
The dilated portion is called the ampulla
Stores sperm and propels them towards the urethra during ejaculation
Vasectomy
Male sterilization -Vas deferens is cut and tied off -Sperm production continues -Sperm degenerate 100% effective and 40% reversible
Ejaculatory ducts
Formed from the duct of seminal vesicle and ampulla of vas deferens About 1 inch long function is to eject spermatozoa into the prostatic urethra and eject seminal vesicle secretion just before the release of seman from the urethra
Urethra
Pathway for urine and semen Are 3 regions -Prostatic urethra -Membranous urethra -Penile urethra
Accessory sex glands
Seminal Vesicles
Prostate gland
Cowpers gland
Seminal vesicle
Found posterior to the bladder
Secretes sugar, gives sugar to semen, for ATP
Prostate gland
Size of chestnut found inferior to the bladder
-Secretes milky fluid that increases sperm mobility and viability
Cowpers gland
Pea-sized
Secretes alkaline mucus, gives semen stickiness
semen
A mixture of sperm and seminal fluid
Milky appearance and sticky
Ph is 7.2-7.7
Penis
The passageway for semen and urine
Composed of 3 erectile tissues
Composed of bulb, crura, body and glans penis
Erection
- Parasympathetic
- Sexual stimulation dilates the arteries supplying the penis
- Blood enters the penis compressing the veins so that the blood is trapped
- Parasympathetic reflex causes ejaculation
Ejaculation
- Sympathetic
- Muscle contractions close at the base of the bladder and move fluids through the vas deferens, small seminal vesicles, and ejaculatory ducts
- ischiocavernosus and bulbospongiosus complete the job
Glans penis
The enlarged distal end of corpus cavernosum
Covered by loosely fitting foreskin
Circumcision
The removal of the foreskin
3-4 days after birth
Possible lowers UTI’s, cancer and sexually transmitted disease
Female reproduction system
Involves Ovaries: produce secondary oocyte and hormones Uterine tubes: aka fallopian tubes Transport fertilized ova Uterus: Where fetal development occurs Vulva: Vagina and external genitalia Mammary Glands: Produce milk
Ovary
2 Almond shapes
Supported by ligaments
The main function is to produce Oocytes within the folicles
Histology of ovaries
Germinal epithelium: Simple epithelial covering over the ovary
Tunica albuginea: Capsule of dense connective tissue
Cortex: Region just deep to tunica and contains follicles, follicular cells, and granulosa cells
Medulla: Deeper region that is composed of connective tissue, blood vessels, and lymphatics
Histology of Graafin Follicle
Zona Pellucida: Clear area between the secondary oocyte and granulosa cells
Corona Radiata: Granulosa cells attached to zone pellucid, still attached to oocyte at ovulation
Antrum: Follicular fluid formed by granulosa cells
Oogonia
Germ cells from yolk sac that migrate to the ovary during fetal development
Divide into germ cells, some becoming primary oocytes.
Review of Oogenesis
- Fetal Development, germ cells in the yolk cell begin to develop
- Germ cells move to the ovary and are diploid un chromosome number
- They begin to divide through mitosis to produce many diploid cells to produce cogonian cells
- Most of them will die and reabsorbed
- The ones that don’t die and survive will begin miosis 1
- Stops at metaphase 2 of miosis 2 and will ovulate
- Moves into the fallopian tube and waits there to be fertilized by sperm
- Once fertilized, Oocyte will continue to meiosis 2 and complete it, becoming a zygote once uniting with the sperm
8b. IF not fertilized then it will never complete miosis 2 and it will be removed from the body , causing menstruation
Histology of Fallopian tubes
3 layers
Mucosa
Muscularis: Circular and longitude smooth muscle that helps move mature oocyte down the fallopian tube to the uterus
Serosa:
Lining of Uterine tubes
Cilia: acts as bristles to help sweep oocyte down the fallopian tube
Atopic Pregnancy
Pregnancy outside of the uterus
Higher risk for smokers
Smoking paralyzes the cilia in the uterine tubes.
Causing fertilized egg to get stuck in the fallopian tube bc the cilia cannot respond to moving oocyte
Anatomy of the Uterus
Site of menstruation, endometrium lining, and development of the fetus
Organ holds zygote if it does not implant
Subdivided into the fundus(top), body(central), isthmus(between body and cervix) and the cervix(inferior )
Histology of the uterus
Endometrium(inner): Simple columnar epithelium, its stratum functionalists is the layer that sheds each month
Myometrium(middle) : 3 layers of smooth muscle; straumn funcionalis & stratumn basalis
Perimetrium(outter)
Hysterectomy
Surgical removal of the uterus
A complete one removes the cervix
A radical one removes the uterus, tubes, ovaries, part of the vagina, pelvic lymph nodes and the supporting ligaments
The Vagina
The passageway for birth, menstrual flow and intercourse
Lies between the urinary bladder and rectum
Partially closed with hymen
Layers of Vagina
Mucosal layer: Produces acidic PH
Muscularis layer:
Adventita: Loose connective tissue that binds it to other organs
Vulva
Contains
Mons Pubis: fatty pad
Labia majora and minora: folds of skin at the vaginal opening
Clit: a small mass of erectile tissue
Mammary glands
Modified sweat glands that produce milk
contain 15-30
Mainly of adipose tissue
milk secreting cells are clustered in small lobules on breasts
my-epithelial cells surround dfethe glands & promote milk expression
Lactation site of PRL,RIEP, OT
Female reproductive system
- Controlled by a monthly hormone cycle of anterior pituitary, hypothalamus, and ovary
- Monthly coordinated events in ovary and uterus
- 2 types: Ovarian cycle and Uterine cycle
Ovarian cycle
Occurs in the ovaries
Changes in the ovary during and after maturation of the oocyte
Uterine cycle
Occurs in the uterus
Preparation of uterus to receive fertilization
If implantation does not occur then the stratum functionalis is shed during menstruation
Hormonal regulation of reproductive system
Cycles are controlled byGnRH from the hypothAlamus.
Stimulates the release of FSH & LH by the anterior pituitary
Phases of Female Repro, Cycle
Hypothalamus releases gonadotropin
Travels to the anterior pituitary
Produces follicle-stimulating hormone and luteinizing hormone
The production of follicles increase due to the FSH (maturing is occurring)
This creates the lining of the uterus to thicken
If fertilization doesn’t occur then all the blood vessels, thick lining, etc. is removed at menstruation
Menstrual phase
28 days long
Bleeding lasts first 5 day of cycle
-Day 1- 5 bleeding occurs, all depends on the person
-Proliferate phase Day 6-13: New. blood vessels are being formed, linning is thickening
-Day 14 is the ovulation day
- Day 15-menstrual phase is post-ovulatory phase: Secretary phase where you wait for fertilization
Closer to day 28: either menstruate or fertilization occurred
Cycle starts over
Menstrual phase in the ovaries and uterus
In ovary: 20 follicles that begin to develop 6 days before, are now beginning to secrete estrogen
In uterus: declining levels of progesterone caused spiral arteries to constrict, glandular tissues die
Stratum functionalis layer is sloughed off along with 50- 150 ml of blood
Ovulation Phase
The repture of follicle and release of second oocyte on day 14
Caused bc increasing levels of estrogen stimulate the release of GnRH and releases LH
Signs of ovulation
An increase in body temp. ( by 1 degree or so )
Changes in cervical mucus
Mittelschmerz pain
Post ovulatory phase
Lasts 14 days ( Day 15-28 )
Post ovulatory phase in the ovary and uterus
In the ovary: Luteal phase
If fertilized: developing embryo secretes hCG, which maintains the health of the corpus luteum and its hormonal secretions
In not fertilized, corpus Albicans is formed
In the uterus: Secretory phase
Hormones from corpus luteum promote the thickening of the endometrium to 12-18mm
If no fertilization occurs, menstrual phase will begin.
Tunica Albuginea
Prominent outter layer in Testes
Produces the Septum, which divides testes into the lobules
Sperm Head
Contains DNA and acrosome; contains enzymes to help penetration
Sperm Neck
contains centrioles that from microtubules to make up tail
Sperm Mid Piece
Contains mitochondria to form ATP for locomotion of sperm
Sperm tail
Used for locomotion
Spermatogenic Cells
1-4
1. Primary spermocyte: Diploid Develop into sperm 46 chromosomes 2.Secondary spermocyte: haploid 23 chromosomes 3. Become spermatids 4.Sperm cells
2n
46 chromosomes
n
23 chromosomes
Primary Spermocyte undergoing
- Meiosis I: to becomes secondary supermocyte
Diploid to Haploid
2.Meisos II takes place and secondary sperm divides chromatids into separate cell, becoming 4 speratids
Haploid to Haploid
Sustentacular cells
Very important for sperm production
Produces an androgen binding hormone that allows testosterone level to stay very high.
Facilitating development of the sperm
Hormones related to Male Reproductive system
GnRH: stimulates cells in the anterior pituitary gland to produce LH and FSH
LH: luteinizing hormone, stimulates c ells in the testes to produce testosterone
FSH: follicle stimulating hormone, stimulates spermatogenesis, causes elevating levels of androgen binding hormone.
Testosterone & dihydrotestosterone effects
Prenatal development
Development of male sexual characteristics
Development of sexual function
Stimulation of anabolism
Ovarian follicles
Contain:
Oocytes, follicular cells and granulose cells
Ovaries consist of
Germinal epithelium: Covers surface
Tunica albuginea: capsule of dense connective tissue
Ovarian cortex: consist of ovarian follicles and stormal cells
Ovarian medulla: connective tissue, blood vessels, lymphatic vessels and nerves
Primary follicles
Primordial follicles stimulated by FSH and LH.
Only one reaches maturity
A few start to grow, turning into primary follicles
Fallopian tubes
Pathway for the sperm to reach the ovum.
End of it is called the infundibulum
Widest portion is the ampulla
Fimbriae project from it
Birth control methods
designed to limit number of children produced Methods include: complete abstinence, 100% reliable Surgical sterilization Hormonal methods Periodic abstinence
Vasectomy
Used in males by removing portion of the vas defers
Tubal ligation
Used in females to tie closed and then cut the Fallopian tubes
Non-incisional sterilization
Insertion into each uterine tube, scar tissue grows and blocks the tubes
What develops into the male reproductive system
Mesonephric ( Wolffian ) ducts
What develops into the female reproductive system
Paramesonephric ( Mullerian ) ducts
Beginning of Puberty for girls called
Menarche, the beginning of menstration
What are the accessory reproductive organs
Ducts, glands and external genitalia
Sex hormones secreted in sex organs
Androgens(males)
Estrogen
Progesterone(females)
What membrane covers the testes
Tunica vaginalis
Tunica Albuguinea
Male reproductive system
structures of reproduction include the testes, a system of ducts (ductus epididymis, ductus deferens, ejaculatory duct, urethra), accessory sex glands (seminal vesicles, prostate gland, bulbourethral glands), and several supporting structures, including the penis
Semenifrious tubules
Where sperm is made
Contain two types of cells: Spermatogenic cells and Sustentacular cells
Spermatogenisis steps
begins in the stem cells
They undergo mitosis to reserve future stem cells and to develop cells (2n primary spermatocytes) for sperm production
The diploid primary spermatocytes undergo meiosis I forming haploid secondary spermatocytes.
Meiosis II results in the formation of the haploid spermatids. The spermatids are connected by cytoplasmic bridges.
The final stage of spermatogenesis is spermiogenesis which is the maturation of the spermatids into sperm.
The release of a sperm from its connection to a Sertoli cell is known as spermiation.
Reproductive ducts
the seminiferous tubules, straight tubules, and rete testis
Spermatic cord
supporting structure of the male reproductive system, consisting of the ductus deferens, the testicular artery, autonomic nerves, veins that drain the testes, lymphatic vessels, and the cremaster muscle
Uterine prolapse
downward displacement of the uterus. It has many causes and may be characterized as first degree (mild), second degree (marked), or third degree (complete)
cervical mucus
supplements the energy needs of the sperm
protect sperm from the hostile environment of the vagina, and protect sperm from phagocytes
perineum
diamond-shaped area between the thighs and buttocks of both males and females that contains the external genitals and anus
May stretch during childbirth
Estrogen important functions
Promotes development and maintenance of female reproductive structures, Increases protein anabolism and building strong bones, lower blood cholesterol
What happens if fertilization does occur
The corpus luteum is maintained until the placenta takes over its hormone producing function
Once the placenta begins its secretion, the role of the corpus luteumn becomes minor
