Human Reproductive Systems

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Human Reproductive Systems
Human Reproduction Part II

• Our species lives on.

http//www.youtube.com/watch?vhAgOk3-loUYfeatu
rerelated
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MALE REPRODUCTIVE SYSTEM
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Male Sexual Development

• Testosterone is the male reproductive hormone
• Secreted in small amounts until puberty
• Puberty begins when
• Hypothalamus ? Pituitary ? increased FSH and LH?
  GONADS (TESTES)
• GONADS ? TESTOSTERONE
• Testosterone produces male 2ndary sex
  characteristics (such as body hair, muscle
  development, deep voice)

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Male Reproductive Parts

• Testes
• Male reproductive gland
• Sperm and testosterone produced
• Scrotum
• Protective sac around testes
• Keeps testes cool (this keeps the sperm at an
  optimum temperature for development 
• Epididymus
• Stores sperm while they mature
• Vas Deferens
• Tube that carries sperm from epididymis to
  urethra

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Diagram of Testicle
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Male Reproductive Parts

• Prostate gland -- the largest of several glands
  which add lubricating and other fluids to the
  sperm 
• Urethra
• tube through the penis carrying sperm to the
  outside of the body
• Other glands work together to produce seminal
  fluid.
• Combination of sperm and seminal fluid semen

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• 6. penis -- adaptation for internal fertilization
  of the
• female
• Semen travels from testes ?vas deferens? urethra?
  penis ? outside of the body through ejaculation
  (uncontrolled muscle contractions)

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Female Reproductive System
Side view
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Female Sexual Development

• Estrogen and progesterone are the female
  reproductive hormones
• Puberty begins when
• Hypothalamus ? Pituitary ? increased FSH AND LH
  ? GONADS (OVARIES)
• GONADS ? Estrogen and progesterone
• Estrogen produces female 2ndary sex
  characteristics (broadening of pelvis, breast
  development, and are involved in the menstrual
  cycle and pregnancy).

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Female Reproductive Parts

• Ovaries
• Female Reproductive Gland (females have two of
  these)
• Eggs (ova) produced here
• Also contain follicles
• Place where eggs mature
• Fallopian tubes (Oviduct)
• Tubes that carry an egg from ovary to uterus
• Place of fertilization
• Egg Travel From the ovaries ? fallopian
  tubes/oviducts ? uterus

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• Uterus
• Mostly muscle
• implantation and development of the embryo and
  fetus before birth occurs here
• Vagina (or birth canal)
• entry point for sperm from the male and exit tube
  for the baby when it is born

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HUMAN REPRODUCTIVE SYSTEMS Diagrams.
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Fertilization Development
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Types of Fertilization

• External gametes fuse outside the body of the
  female
• Occurs in animals that breed in the water (most
  invertebrates- Fish/amphibian)
• The two parents release their eggs into the
  water, and the sperm fertilizes the eggs.

• Internal gametes fuse inside the body of a
  female
• Fertilization occurs inside the female body where
  it is moist
• Occurs mostly in animals that reproduce on land
  and some aquatic animals like sharks, reptiles,
  and mammals

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COMPARISON
PROS CONS
EXTERNAL Large numbers of eggs and sperm are released to increase chances of survival. Gametes released at the same time Sperm may not find the eggs. Predators may find and eat eggs or small offspring. Changes in temperature or oxygen content of the water may cause death.
INTERNAL Fewer eggs need to be released. Hormones and mating signals trigger the release of the eggs and sperm. Ex. Singing, special feathers, and pheromones. Mating must take place within 24 hours for fertilization to occur
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FERTILIZATION

• DAY 0
• When sperm penetrates egg
• Sperm releases special enzymes to do this
• Forms a ZYGOTE
• Recombination occurs
• Combining of genetic info from both parents
• (n23) (n23) (2n46)
• Sperm egg zygote
• Occurs in the oviduct

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Multiple births

• fraternal twins- 2 eggs
• identical twins- one egg that splits in two,
  always the same
• http//www.brainpop.com/health/geneticsgrowthandde
  velopment/twins/

- Conjoined twins (aka Siamese twins) are
identical twins whose bodies are joined in utero.
Abby Brittany Hensel
Abby Brittany turn 16 http//www.bing.com/videos
/search?qabbyandbrittanyhenselmid78A3B27DF1E
F569A364278A3B27DF1EF569A3642viewdetailFORMVIR
E2adltstrict
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Fertilization
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Early Development- The First Week

• Occurs in the oviduct
• Zygote begins a series of mitotic divisions
  (cleavage) to undergo differentiation
• Division process is rapid - no increase in size,
  just the number of cells
• 1 cell? 2 cells? 4? 8? 16?32?64? 128 etc
• Implantation of zygote in uterus
• occurs around day 7

2010 Reproduction -SMB
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EMBRYONIC DEVELOPMENT
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Embryonic Layers and Functions

• GASTRULATION
• Cells in zygote form into
• 3 distinct layers
• The cells within each layer DIFFERENTIATE to
  form specialized cells (muscle, liver, heart,
  etc) then tissue and organs.
• This is caused by gene activation which can be
  influenced by the environment.

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Ectoderm Mesoderm Endoderm
skin and nervous system Muscular, circulatory skeletal, excretory and reproduction systems lining of digestive and respiratory tract (body organs)
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• These developing cells are now called an
  embryonic stems cells and can be used as for
  medical research and application
• http//www.brainpop.com/science/cellularlifeandgen
  etics/stemcells/
• http//www.pbs.org/wgbh/nova/body/stem-cells-break
  through.html

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HUMAN FETAL DEVELOPMENT

• Placenta
• Develops at 3 weeks
• Placenta is a fetal organ
• Connects mother and fetus
• Food, gases and wastes DIFFUSE across blood
  vessels

2010 Reproduction -SMB
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• 2. Umbilical cord- rope-like structure that
  connects the fetus to the placenta
• 3. Amnion- membrane surrounding the fetus
• 4. Amniotic fluid fills the amnion, protects
  the fetus, and absorbs shock

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First and Second Trimester Dangers!!!!

• Most critical time of development
• is the 1st trimester when organs are
  developing
• Harmful environmental risk factors include
• drugs,
• alcohol
• tobacco
• medicines
• poor diet,
• toxic substances
• infections
• This can halt development or cause major
  developmental issues
• Not taking care can result in miscarriage or can
  severely damage embryo/fetus

2010 Reproduction -SMB
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Later Development

• 8 weeks FETUS
• Umbilical cord forms at 3 months
• Body systems become more specialized
• Fetus becomes bigger
• Birth (36 weeks)

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Human fetal development
7 weeks
4 weeks
2010 Reproduction -SMB
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Human fetal development
10 weeks
2010 Reproduction -SMB
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Human fetal development
2010 Reproduction -SMB
12 weeks
20 weeks
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Human fetal development

• The fetus just spends much of the 2nd 3rd
  trimesters just growing
• and doing various flip-turns kicks inside
  amniotic fluid

Week 20
2010 Reproduction -SMB
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Human fetal development

• 24 weeks (6 months 2nd trimester)

fetus is covered with fine, downy hair called
lanugo. Its skin is protected by a waxy material
called vernix
2010 Reproduction -SMB
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Getting crowded in there!!

• 32 weeks (8 months)

The fetus sleeps 90-95 of the day sometimes
experiences REM sleep, an indication of dreaming
2010 Reproduction -SMB
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Human fetal development

• 30 weeks (7.5 months)

umbilical cord
2010 Reproduction -SMB
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The end of the journey!
And you think 9 months of Biology is hard!
2010 Reproduction -SMB
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The Menstrual and Ovarian Cycles

• The Truth behind PMS!!

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Menstrual Cycle

• Begins at puberty and ends at menopause
• Takes about 28 days
• Regulated by four hormones estrogen,
  progesterone, FSH and LH
• Menopause
• The menstrual cycle stops permanently usually
  between the ages of 45 and 50 although it may
  occur sooner. The permanent cessation of the
  cycle is called Menopause.

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Vocabulary- THE HORMONES

• A. Secreted by the Pituitary gland
• FSH (Follicle Stimulating Hormone)
• Stimulates follicle to cause egg to mature
• LH (Luteinizing Hormone)
• Causes release of mature ovum (ovulation)
• Prepares uterus for implantation of fertilized
  egg
• B. Secreted by Ovaries
• Estrogen
• Causes uterine lining to thicken
• Progesterone
• Works with estrogen to finish uterine lining
  thickening

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The Cycles

• A. Ovarian Cycle
• Occurs over 28 days in the ovaries
• Process during which an ovum matures in a
  follicle and is released during ovulation
• After ovulation, a corpus luteum (yellow body) is
  left behind
• B. Menstrual (Uterine) Cycle
• Occurs over 28 days
• Process during which uterine lining is preparing
  for fertilized ovum
• If fertilization occurs, this cycle stops until
  after birth
• If not fertilized, lining sheds (menstruation!)
  and cycle begins again

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Menstrual Cycle Flow Chart

• Menstruation (3-5 days)
• Uterine lining sheds and FSH increases
• This causes drop in estrogen and progesterone
• Occurs if egg is not fertilized

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Menstrual Cycle Flow Chart

• Follicle Stage (10-14 days)
• Low estrogen FSH to be released (negative
  feedback)
• This stimulates growth of follicle
• Follicle (egg) matures causing estrogen levels
  to go up
• Uterine lining begins to thicken again

• Menstruation (3-5 days)
• Uterine lining sheds and FSH increases
• This causes drop in estrogen and progesterone
• Occurs if egg is not fertilized

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Menstrual Cycle Flow Chart

• Follicle Stage (10-14 days)
• Low estrogen FSH to be released (negative
  feedback)
• This stimulates growth of follicle
• Follicle (egg) matures causing estrogen levels
  to go up
• Uterine lining begins to thicken again

• Menstruation (3-5 days)
• Uterine lining sheds and FSH increases
• This causes drop in estrogen and progesterone
• Occurs if egg is not fertilized

• Ovulation (1 day)
• Major SPIKE of LH
• This causes follicle to break and release egg
  into oviduct

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Menstrual Cycle Flow Chart

• Follicle Stage (10-14 days)
• Low estrogen FSH to be released (negative
  feedback)
• This stimulates growth of follicle
• Follicle (egg) matures causing estrogen levels
  to go up
• Uterine lining begins to thicken again

• Menstruation (3-5 days)
• Uterine lining sheds and FSH increases
• This causes drop in estrogen and progesterone
• Occurs if egg is not fertilized

• Ovulation (1 day)
• Major SPIKE of LH
• This causes follicle to break and release egg
  into oviduct

• Corpus Luteum Phase (10-14 days)
• LH and FSH levels crash
• Corpus luteum forms from broken follicle
• Corpus luteum secretes estrogen and progesterone
• This thickens uterine lining to prepare for egg

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What is going on all at once?

• Negative Feedback
• When one hormone is increased it shuts off
  another hormone
• Ex. Glucagon is high, Insulin is Low

Ovary response
Uterus response
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REPRODUCTIVE TECHNOLOGY

• In vitro Fertilization Process
• http//www.youtube.com/watch?vGeigYib39Rs
• http//www.sumanasinc.com/webcontent/animations/co
  ntent/invitrofertilization.html

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Directions READ your review book pageS 71-72.
Fill out the blank columns for each of the 4
technologies listed.
Technology Purpose
Agriculture 1. 2.
Ecology 1. 2.
Health Care 1. 2. 3.
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Directions READ your review book pageS 71-72.
Fill out the blank columns for each of the 4
technologies listed.
Technology Purpose
Agriculture 1. Alter plants so they are resistant to insects, frost etc. 2. Artificial insemination of farm animals allows desired traits
Ecology 1. Build up of endangered populations 2. Use of hormones to regulate pest popns instead of harmful chemicals
Health Care 1. Hormone therapy 2. In Vitro Fertilization 3. Ultrasounds
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Menstrual Cycle Flow Chart

• Follicle Stage (10-14 days)
• Low ______________________ _________to be
  _____________________ (negative feedback)
• This stimulates _____________________________
• Follicle (egg) matures causing
  _____________________________ to go up
• Uterine lining begins to thicken again

• Menstruation (3-5 days)
• Uterine lining ___________and FSH
  ___________________
• This causes ____________ in ________________and
  ___________________
• Occurs if egg is _________________

• Ovulation (1 day)
• Major __________________of _______
• This causes _____________to _______________and
  ______________________ into ________________

• Corpus Luteum Phase (10-14 days)
• LH and FSH levels _______________
• _______________________________ forms from
  _____________ _____________
• Corpus luteum ____________________________________
  and __________________
• This _________________________________________ to
  prepare for ______