Human Reproductive System A comparison of the male and female anatomy

Review: sexual reproduction Mammalian life begins as a single celled organism called a zygote The union of gametes (sperm and egg) is called fertilization. Zygote undergoes rapid, mitotic cell divisions: forms the embryo to fetus (12 weeks)

Sexual Reproduction Sexual reproduction is known as meiosis 2 types of meiosis: oogenesis and spermatogenesis Oogenesis: Occurs in ovaries makes female gametes/eggs form haploid cells 2 cell divisions (meiosis I/II) 1 functional ovum (egg) Completes the cell cycle at fertilization Spermatogenesis: Occurs in testes makes male gametes/sperm 4 functional sperm Completes cell cycle at production of sperm Sexual Reproduction

A comparison of sperm and ovum

How life begins for humans Genetics control gender Hormones control development of sex organs After 6th week of gestation hormones released for sex organ development Males: androgen Androgen : released by gonad Effect: Female oviduct disintegrate Females: estrogen Estrogen: released by gonad Effect: Male vas deferens disintegrate

oviduct Sperm duct

Warm-up: control of reproduction and STI’s Which type of “controlling reproduction” method were you least familiar with? What did you learn about it? Which STI were you least familiar with?

Male Reproductive System: Tracing the development of sperm Reproductive system is a system that creates, stores, and nourishes gametes that will be used to produce offspring Males anatomical structures are designed to make sperm to create offspring Male gonad: testis/ testes- right and left function: make sperm and release hormones Testicular cancer (see model) Scrotum: external sac that protects testes on the outside of body Testes drop through abdominal cavity during last trimester (think about the pigs)-in humans usually drop the last 2 months of gestation Sperm production 1-3 degrees lower than internal body temperature

Sperm Development Puberty: 14-16 Hormones released to cause male changes: GnRH- produced in hypothalamus stimulates pituitary gland LH: luteinizing hormone- produced in the pituitary gland causes testes to make and release testosterone FSH: follicle stimulating hormone- produced in the pituitary gland causes sperm producing cells to take in testosterone Testosterone: produced in the testes 1. Stimulates sperm development-(sperm production until death) 2. primary and secondary sex characteristics Primary: pubic hair and finishing touches on male reproductive tract Secondary: muscle development, deepened voice, body hair, and chest broadens

and testosterone

Sperm Development and transport Testes made-up of seed bearing tubules: seminiferous tubules- produce sperm Mature in tubules for 2-3 months Spermatogenesis occurs here Sperm travel through vas efferentia from the seminiferous tubules to the epididymis Sperm stored in the epididymis Stored 18-48 hours- mature and become motile Transported from the vas deferens to the urethra Vas deferens is contained in a protective structure called spermatic cord Sperm will enter ejaculatory duct prior to the urethra Vas deferens Vas efferentia

Sperm

The journey of the sperm Urethra: passageway for semen and urine through abdominal cavity 3 major male glands responsible for contributions to semen: sperm + seminal fluids 1. seminal vesicle Produces a seminal fluid with nutrients 2. bulbourethral gland (Cowper's gland) Produces alkaline seminal fluid to neutralize urethral lining 3. prostate gland: Produces alkaline seminal fluid to neutralize vagina Enlarged prostate: cancer Symptoms: frequent urination See models

The journey of the sperm Penis: made-up of spongy tissue, blood vessels, smooth muscle Function: transport seminal fluids to vagina Erection increases sperm delivery Blood fills spongy tissue Muscles around urethra contract Ejaculation controlled by autonomic nervous system 1 drop of semen: 5 million 1 mm of semen: 100-200 million sperm 1 ejaculation of semen: 600 million How many sperm does it take to fertilize an egg?

Penis constrict dilate Physiology behind the erection: the nerves release nitric oxide that stimulates the production of a protein that causes the arteries to relax and erectile tissue fill with blood and the veins contract to prevent blood loss.

Cross Section

Vasectomy and other conditions Sterile: 20 million sperm or less in ejaculation of semen- only 3.3 sperm would make it to the fallopian tubes Causes: chemicals, smoking, alcohol, drug abuse, obesity, over heating Erectile dysfunction: unable to obtain an erection Erectile tissue doesn’t expand enough to compress veins Hernia: opening or separation of some part of the abdominal wall in which a portion of the internal organs will protrude.

List the 4 phases of the female menstrual cycle. Anatomy: warm-up List the 4 phases of the female menstrual cycle. How are hormones related to the major events of the female menstrual cycle?

Female Anatomy: trace the path of an egg (ovum) Females anatomy is designed to produce eggs and store, nourish, and protect a growing embryo Female gonads: ovaries (2)- produce eggs and hormones Born with 2 million immature egg follicles Reduced to approximately 350,000 by puberty New studies are showing the female ovary may have stem cells to regenerate new eggs?????? Will complete oogenesis at fertilization Releases 1 egg/month (average) until menopause Releases approximately _______ in lifetime ARTICLE

Puberty- hormones (released through menopause) Age 11-13 Hypothalamus: produces and releases GnRH activates pituitary Pituitary: releases FSH- stimulates egg follicles to take in estrogen Pituitary: releases LH- activates ovaries to produce and release estrogen Activates corpus luteum to release estrogen and progesterone Stimulates ovaries to release ovum Ovaries: release estrogen: Thickens uterine lining Primary and secondary sex characteristics Primary: Secondary: Corpus Luteum: release progesterone- thickens uterine lining

Warm-up Write 3 female hormones and tell me either where they are produced or what their role are in terms of the female reproductive system.

Ovum Development http://highered.mheducation.com/sites/0072495855/student_view0/chapter28/animation__maturation_of_the_follicle_and_oocyte.html

Trace the path of the ovum Fimbrae: fingerlike projections that “sweep” a released ovum into the fallopian tubes (oviduct) Fallopian tubes: an 11 cm lubricated and ciliated tube that transports egg/zygote to the uterus Location of fertilization 2-3 days in FT

fimbrae

Female Uterus: muscular womb- location of embryonic and fetal development. Endometrium: lining of uterine wall Location of implantation of blastocyst- growing embryo Endometriosis: lining spreads throughout abdomen Cervix: round and hard; made of connective tissue area between the uterus and the vagina Opening for sperm entry Dilates during contractions (10 cm)

Biobag Artificial womb Gives infants that are born too early (premature) to have a more natural, uterus-like environment to continue developing

fimbrae

Female Anatomy Vagina: muscular tube/ birth canal/ receives penis Vulva: folds of epidermal tissue Major and minor labia Protects vagina (birth canal) Glans clitoris: erectile organ- anatomically comparative to the glans penis

fimbrae

fimbrae

Female Topics Menopause Hysterectomy Tubal birth Tubal ligation Infertility Causes: PID, obesity, endometrioses

See pig ovary , uterus, and fallopian tubes