Transcript Major Organs of Female Reproductive System

6.6 Hormones, homeostasis and reproduction
Essential idea: Hormones are used when
signals need to be widely distributed.
Thyroxin is a hormone produced by the thyroid gland. It's
key role is in controlling the metabolism of cells. If affects
almost every physiological process in the body including
growth and development. Most hormones affect more
than one target tissue in more than one way.
https://commons.wikimedia.org/wiki/File:Thyroid_system.svg
https://commons.wikimedia.org/wiki/File:%28S%29-Triiodthyronine_Structural_Formulae_V2.svg
6.6 – Understandings
• Insulin and glucagon are secreted by β and α cells of the pancreas
respectively to control blood glucose concentration.
• Thyroxin is secreted by the thyroid gland to regulate the metabolic
rate and help control body temperature.
• Leptin is secreted by cells in adipose tissue and acts on the
hypothalamus of the brain to inhibit appetite.
• Melatonin is secreted by the pineal gland to control circadian
rhythms.
Testosterone causes pre-natal development of male genitalia and
both sperm production and development of male secondary sexual
characteristics during puberty.
• Estrogen and progesterone cause pre-natal development of female
reproductive organs and female secondary sexual characteristics
during puberty.
• The menstrual cycle is controlled by negative and positive feedback
mechanisms involving ovarian and pituitary hormones.
Applications:
• Causes and treatment of Type I and Type II diabetes.
• Testing of leptin on patients with clinical obesity and
reasons for the failure to control the disease.
• Causes of jet lag and use of melatonin to alleviate it.
• The use in IVF of drugs to suspend the normal secretion
of hormones, followed by the use of artificial doses of
hormones to induce superovulation and establish a
pregnancy.
• William Harvey’s investigation of sexual reproduction in
deer.
Intro to Hormones – crash course
Ms. K checks hw (from last week) during the video.
Think big picture  not all of this is part of our material.
The Endocrine System
A stimulus is received and processed.
Hormones are secreted directly into the blood.
 carried to the target tissues (the place of intended action).
The action of the hormone changes the condition of the tissue.
This change in monitored through feedback.
Most hormonal change results in negative feedback.
Key endocrine glands:
1.
2.
3.
4.
5.
6.
7.
8.
Endocrine glands from: http://en.wikipedia.org/wiki/Endocrine_gland
The Endocrine System
A stimulus is received and processed.
Hormones are secreted directly into the blood.
 carried to the target tissues (the place of intended action).
The action of the hormone changes the condition of the tissue.
This change in monitored through feedback.
Most hormonal change results in negative feedback.
Key endocrine glands:
1.
2.
3.
4.
5.
6.
7.
8.
Pineal gland
Pituitary gland
Thyroid gland
Thymus
Adrenal gland
Pancreas
Ovary (female)
Testes (male)
Endocrine glands from: http://en.wikipedia.org/wiki/Endocrine_gland
Explain the control of blood glucose (8).
Thyroxin:
• Secreted by the thyroid gland .
• Regulates metabolic rate
• Helps control body temperature.
Correct functioning of the thyroid
requires IODINE in the diet.
Lack of dietary iodine causes GOITRE
Lack of thyroxin causes:
• lack of energy
• Depression
• Weight gain despite appetite
loss
• Feeling cold
Click for animation
Leptin:
• Secreted by adipose tissue cells.
• Acts on the hypothalamus
• Inhibits appetite
Leptin is a protein hormone that targets the appetite center of the
hypothalamus.
Food intake triggers Leptin secretion
which in turn inhibits appetite which
reduces food intake.
This is an example of negative
feedback.
Spot the mouse treated
with Leptin blockers.
Leptin and Obesity:
should GM Leptin be
made available as a
treatment for obesity?
6.6.A2 Testing of leptin on patients with clinical obesity and reasons for the failure to control the disease.
Leptin treatment for obesity
1949 Scientists discovered the ob/ob or
obese mouse. It is a mutant mouse that eats
excessively and becomes profoundly obese.
It was found that obese mice possess two
recessive alleles and consequently do not
produce any leptin.
Obese mice treated with
leptin saw large losses
of weight
Clinical trials were carried out to see if the effect was similar, but trials failed:
• Most people have naturally high levels of leptin
• If linked to leptin, obesity in people is due to resistance, of the appetite control
center, to leptin
• Very few patients in the clinical trial experienced significant weight loss
• Many patients experienced side-effects such as skin irritations
https://commons.wikimedia.org/wiki/File:Fatmouse.jpg
Melatonin:
• Secreted by the pineal gland .
• Helps control circadian rhythms
(including sleep timing and blood
pressure).
High levels of MELATONIN cause feeling of
drowsiness and promote sleep.
Falling melatonin levels encourage waking
at the end of the night.
Melatonin is
Melatonin also promotes a drop in core
sometimes
temperature and probably causes the night
advertised as a
time body temperature drop.
treatment for jet lag
why do you think it
might work?
6.6 Reproduction
6.6 U.1 A gene on the Y chromosome causes embryonic gonads to
develop as testes and secrete testosterone.
• Initially the development of the embryo is
the same in all embryos and embryonic
gonads could develop into testis or
ovaries.
• The developmental pathway for the
gonads depends on presence or absence
of one gene
• When SRY is present the gonads develop
into testes.
• SRY codes for a DNA binding protein
called TDF (testis determining factor).
• TDF stimulates the expression of other
genes that cause the development of the
testis
6.6.S1 Annotate diagrams of the male and female reproductive system to show names of structures and their
functions.
Can you label and annotate the diagram of the male reproductive system?
a. Vas deferens (sperm duct)
b. Prostate gland
c. urethra
d. Penis/erectile muscle
e. Seminal vesicle
f. epididymis
g. testis (pl. testes)
h. scrotum
6.6 S.1 Annotate diagrams of the male and female reproductive system
to show names of structures and their functions
Male Reproductive System:
1. Epididymus:
•Large coiled tube (23 ft. long) that surrounds testes.
•Stores sperm (about 20 days).
•During ejaculation, about 400 million sperm cells are propelled from epididymis.
2. Vas Deferens:
• Long muscular ducts from scrotum to
back of bladder.
• During ejaculation, the sperm pass
from epididymis into these two ducts.
*Vasectomy: Each vas deferens is cut to
prevent sperm from entering urethra.
3. Ejaculatory Duct:
• Short duct after two vas deferens
ducts unite.
4. Urethra:
• Deliver sperm to the exterior.
• In males, urine and sperm pass
through the urethra.
5. Scrotum
• maintains temperature (lower than body)
that sperm require for normal
development
6.6 S.1 Annotate diagrams of the male and female reproductive system
to show names of structures and their functions
Accessory Glands: Produce semen.
Functions of semen:
• Activate sperm cells
• Provide nutrients for motility
• Counteract acidity of vagina and male urethra
A. Seminal vesicles (2): Secrete fluid that nourishes sperm. Contribute
about 60% of semen volume.
B. Prostate gland: Produces a thin milky secretion.
• Largest of semen secreting glands.
• Contributes 30% of semen volume.
C. Bulbourethral glands
• Secrete a clear mucus that neutralizes acid from urine in
urethra.
Front View of Male Reproductive System
6.6 U.3 Estrogen and progesterone cause pre-natal development of
female reproductive organs and female secondary sexual characteristics
during puberty
Side View of Female Reproductive System
6.6.S1 Annotate diagrams of the male and female reproductive system to show names of structures and their
functions.
Can you label and annotate the diagram of the female reproductive system?
a. uterus
b. fallopian tube (oviduct)
c. ovary
d. endometrium (lining of the
uterus)
e. cervix
f. vagina
g. kidney
i. bladder
h. ureter
j. urethra
Major Organs of Female
Reproductive System:
1. Ovaries: Produce ova (egg)
and sex hormones.
»Size and shape of large
almond.
*Follicles: A single egg with
surrounding cells that
nourish and protect it.
Women are born with all of their
follicles (40,000 to 400,000).
Major Organs of Female
Reproductive System:
2. Oviducts (Fallopian Tubes):
Transport the egg from the ovary to the
uterus. Fertilization occurs here.
3. Uterus
• Has thick walls of smooth muscle
responsible for uterine contractions
and cramps.
• Inner mucous lining, which thickens
each month in preparation for
pregnancy. If fertilization does not
occur, breaks down and is
discharged during menstruation.
• If fertilization occurs, the egg
implants here and helps support
growth until the placenta develops.
4. Cervix: Lower portion of the uterus, which
projects into the vagina.
*Pap smear: Examination of cervical tissue to
detect abnormalities. Recommended yearly.
*Cervical cancer: Most cases caused by a viral
infection.
5. Vagina: Thin walled, muscular chamber.
• Receives the sperm and penis
• Acid pH kills bacteria and sperm cells
• Part of birth canal
6.6 S.1 Annotate diagrams of the male and female reproductive system
to show names of structures and their functions
Frontal View of Female Reproductive System
Hormones of the reproductive system!
Functions of Estrogen
Estrogen and progesterone
cause pre-natal development of female
reproductive organs and female
secondary sexual characteristics during
puberty.
The menstrual cycle is controlled
by negative and positive feedback
mechanisms involving ovarian and
pituitary hormones.
01.20.17 Menstrual Cycles
What is the function of the fallopian tubes?
6.6 A.1 The use in IVF of drugs to suspend the normal secretion of
hormones, followed by the use of artificial doses of hormones to induce
superovulation and establish a pregnancy.
6.6 A.2 William Harvey’s investigation of sexual reproduction in deer
• Embryogenesis an early theory of
egg development proposed by
Aristotle. His idea called the Seed
and soil theory, believed that males
produce seed, females form an egg
which mixes with menstrual blood
to develop into a fetus inside the
mother
• William Harvey tested this idea by
shooting deer during mating season
• He discovered that it took months
for the fertilized egg to develop in
the uterus.
• This help debunk the idea of
spontaneous generation and lead to
a better understanding of
embryology.
(1578-1657)
6.6 U.4 The menstrual cycle is controlled by negative and positive
feedback mechanisms involving ovarian and pituitary hormones.
Two Parts to Female Reproduction
1. Uterine Cycle
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•
•
•
Days 1-5 – Menstruation (“no” steroids)
Days 6-13 - Proliferative phase (Estrogen effect)
Day 14 – Ovulation (LH effect)
Days 15-28 - Secretory phase (Progesterone effect)
2. Ovarian Cycle
•Follicular Phase - FSH promotes development of an ovarian follicle containing
an egg ready to be ovulated
secretes increasing levels of estrogen
•Luteal Phase –LH promotes ovulation and development of corpus luteum
that secretes progesterone
Female Menstrual Cycle /Uterine Cycle : Approximately
28 days.
• Menstruation: Days 1-5 of cycle.
– Walls of endometrium break down.
– Caused by falling levels of progesterone and estrogen.
– Can last 3 to 7 days.
• Pre-Ovulatory /Proliferative phase (Estrogen effect):
Starts around day 6 of cycle.
– Rising estrogen levels cause the endometrium to start
thickening.
• Ovulation (LH effect) : Occurs around day 14 of cycle.
– FSH stimulates growth of ovarian follicle.
– LH causes follicle to finish meiosis I (secondary oocyte) and
to be released by ovary.
– Corpus luteum: Starts to secrete estrogen and
progesterone.
• Post-ovulatory Secretory phase (Progesterone effect):
Starts around day 15.
– Endometrium continues to grow in response to rising
estrogen and progesterone.
– If no fertilization occurs, corpus luteum degenerates and
menstruation occurs.
– If fertilization occurs, embryo maintains corpus luteum.
Female Cycle
01.23.17 Today!
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•
•
•
CC Review of Female anatomy/cycles
Diagram menstrual cycle hormones
Complete HW (due at end of period).
Practice short answer questions
– Keys tomorrow.
6.6.U8 The menstrual cycle is controlled by negative and positive feedback mechanisms involving ovarian and
pituitary hormones.
6.6.U8 The menstrual cycle is controlled by negative and positive feedback mechanisms involving ovarian and
pituitary hormones.
01.23.17 Today!
•
•
•
•
CC Review of Female anatomy/cycles
Diagram menstrual cycle hormones
Complete HW (due at end of period).
Practice short answer questions
– Keys tomorrow.