Transcript Ch 18x - Fort Bend ISD

Chapter 18
Reproduction and Heredity
The Endocrine System
• Endocrine glandsglands that produce
and release chemicals
• Hormones- chemical
substances produced
by endocrine glands.
The Pituitary Gland
small gland at the base
of the brain
Controls growth rate,
metabolism, and
reproduction
Called the “master
gland” because it
regulates many other
endocrine glands
Hypothalamus
Controls the pituitary
gland
Regulates body
temperature, use of
water, and blood
pressure
Oversees many of the
hormone levels in the
body
Adrenal Glands
Produce hormones that
affect the functioning
of your kidneys, your
metabolism, and your
response to stressful
situations
Adrenaline – hormone
important in the fight
or flight response
Thyroid Gland
Releases a hormone that
regulates metabolism
Releases a hormone that
regulates the amount
of calcium in the
blood
Parathyroid Gland
4 tiny glands attached to
the back of the
thyroid that regulates
levels of calcium and
phosphorus.
Pancreas
Located behind the stomach
Part of two systems –
digestive and endocrine
In the endocrine it controls
the level of sugar in the
blood.
Improper function can cause:
Diabetes—level of sugar
too high or
Hypoglycemia—level of
sugar too low.
Thymus
Function not thoroughly
understood.
Plays a role in
developing some of
the body’s defenses
against infection.
Reproduction and the Endocrine System
• Ovaries – reproductive glands in females
• Testes – reproductive glands in males
• Follicle-stimulating hormone (FSH)
• Luteinizing hormone
– Two hormones produced by the pituitary gland
that begin that process of sexual maturation in
adolescents
Reproduction and the Endocrine System
• In males, testosterone and FSH control production of sperm,
the male sex cells.
• Testosterone is also responsible for developing and
maintaining other male traits such as deepening voice and
body hair
• In females, two female sex hormones, progesterone and
estrogen are produced by the ovaries.
• They are responsible for developing other female traits such
as breast development and widening of the hips
• In addition, progesterone and estrogen work with FSH and LH
to produce ova or eggs.
Reproductive System terms
•Puberty – is the period of sexual development
during which males and females become
sexually mature and able to produce children.
•Fertilization – the joining of a sperm cell with
an egg cell
The Male Reproductive System
Testes- produce
testosterone and sperm
The testes hang outside the
body within sac of skin
called the scrotum
Epididymis- a J-shaped tube
located on the back of each
testis
Sperm mature and gain the
ability to move while in the
epididiymis. They are stored
there for several weeks.
The Male Reproductive System
Penis – external sex
organ through which
sperm leave the body.
Glans – tip of the penis
Circumcision – surgical
procedure that
removes the foreskin
after birth
The Male Reproductive System
Vas deferens- tube that
receives sperm from
the epididymis
Urethra- tube that
passes through the
penis to the outside of
the body
The Male Reproductive System
Seminal Vesicle – a pair of
glands located near the
bladder
Cowper’s glands – a pair of
glands located at the base
of the penis
Prostate gland – near the
bladder at the midline of
the body
Sperm mixes with fluids from
these glands to form
Semen
Sperm Production
For most men sperm
production continues
throughout adult life
unless the
reproductive system is
altered in some way
About 400 million sperm
are released during
one ejaculation
Sperm Production
Semen contains nutrients
that enable the sperm to
survive for several days
inside the female body.
Ejaculation- ejection of
sperm from the penis
Nocturnal emission –
erection and ejaculation
during sleep
“Flow Chart” of the male
reproductive system
Hypothalamus signals pituitary to release FSH&
LH > stimulate cells of testes> produce
testosterone> produce sperm in testes> moves
them to epididymis> through Vas Deferens>
through Seminal Vesicles, Prostate Gland, and
Cowper’s Gland where other fluids are added to
form semen> out through Urethra/Penis> out of
body through process called ejaculation.
Disorders of the Male Reproductive
System
• Sterility- condition in which a person is unable to
reproduce
• Environmental factors, mumps, cancer, injury
• Undescended Testes- results when one testes does
not descend into the scrotum at birth. Corrected
with surgery or hormone treatment
• Inguinal hernia-occurs when part of the intestine
pushes into the scrotum through a weak spot in the
wall near the scrotum. Corrected with surgery
Disorders of the Male Reproductive
System
Enlarged Prostate- causes pain and discomfort
Cancer of the Prostate or Testicle
Cancer is an area of uncontrolled cell growth
that invades the surrounding tissue and
destroys it. Most effective when treated
during the early stages.
Keeping the Reproductive System
Healthy
•
•
•
•
Cleanliness
Protective equipment
Avoid heavy lifting
Any signs of pain during urination, unusual
discharge, swelling in the genitals or sores on
the genitals should require a medical
examination
• Testicular self-examination
Female Reproductive System
Ovaries
• Small organ about the size
of an almond
• They release estrogen and
progesterone and they
release mature egg cells
• Ovulation- the monthly
process where the ovaries
release one ripened egg
Fallopian Tubes
• Also called oviducts, are
small tubes that carry the
released egg from the
ovaries.
• The fingerlike ends of the
fallopian tube draw the
egg into the opening.
• Tiny hairs in the oviducts
sweep the egg through
the sperm.
• The fallopian tubes are
where eggs are usually
fertilized.
Uterus
• A hollow pear-shaped
organ located
between the two
ovaries and behind
the bladder.
• This is where the
fertilized egg develops
and grow into a baby
• Cervix-the narrow
base of the uterus
Vagina
• Or birth canal, is a
hollow muscular
passage leading from
the uterus to the
outside of the body.
The Menstrual Cycle
• The process during
which an egg matures
and is released and
the uterus prepares to
receive it.
The Menstrual Cycle
• Endometrium- lining of
the uterus
• The endometrium
thickens to prepare for a
fertilized egg. When the
egg is not fertilized the
endometrium breaks
down and is discharged
from the body. This
discharge of blood and
tissue is know as
menstruation
Stages of the Menstrual Cycle
• Every woman’s menstrual cycle is different.
• Premenstrual Syndrome (PMS)-discomfort
experienced before the menstrual period.
• Menopause-hormone production slows and
eggs are no longer released. Gradually
menstruation stops, and the women is no
longer fertile.
Disorders of the Female
Reproductive System
• Endometriosis- condition where tissue from the
lining of the uterus grows outside the uterus causing
pain in the pelvic area.
– Can lead to sterility
– Can be corrected through hormone treatment or surgery
• Toxic Shock Syndrome- a rare disease caused by a
bacterial infection
– It is important to change tampons regularly to avoid
infection
– Symptoms include: sudden high fever, a rash, vomiting,
diarrhea, and dizziness
Disorders of the Female
Reproductive System
• Sterility- blocked fallopian tubes, failure of the
ovaries to release eggs, and endometriosis
• Cysts and Cancer• Pap Test-medical procedure in which a sample of cells
is taken from the cervix and examined under a
microscope for signs of cancer.
Keeping the Reproductive System
Healthy
• Cleanliness
– Feminine Hygiene products are not necessary and
in fact can sometimes be harmful
• Monthly breast self-examination
• Yearly gynecological exam for women who
have reached puberty
• Mammogram- an x-ray of the breast that can
detect cancer.
Heredity
• Heredity- the passing on, or transmission, of
biological characteristics from parents to child.
• Chromosomes- tiny structures found within every
cell that carry the information about the
characteristics you will inherit.
• Deoxyribonucleic acid or DNA is the chemical
substances that make up chromosomes
• Gene- a section of a chromosome that determines a
single trait.
Heredity
• Dominant and Recessive Genes
– Dominant genes are expressed whenever they are present
– Recessive genes are expressed only when the dominant
gene is not present
• Sex Determination
– XX= female
XY= male
– All eggs have one X chromosome
– Sperm cells have either an X or Y chromosome so the
sperm cell determines the sex of the child
Genetic Disorders
• Genetic Disorder-an abnormal condition that a
person inherits through genes or chromosomes
• Recessive Disorders
– Sickle Cell disease
• A genetic blood disorder that occurs most often among african
americans.
• The abnormal sickle shape of the red blood cells caused clumping
and blocking of small blood vessels
Genetic Disorders
• Tay-Sachs Disease- characterized by the lack of an
important chemical in the brain
– Found primarily among people of Eastern Jewish descent.
– No treatment
• Phenylketonuria or PKU- a rare metabolic disorder
that can cause severe mental retardation in infants
– Can be treated successfully if the infant follows a special
diet
Genetic Disorders
• Cystic Fibrosis- a recessive disorder that occurs
mainly among white people.
– Mucus that lines the lungs becomes thick and
sticky
– Causes bacteria to stay in the lungs leading to
infection and eventually lung damage
Sex-linked Disorders
• Sex-linked disorders- the gene for the disorder
is found on a sex chromosome, usually the X
chromosome
• Duchenne muscular dystrophy- a condition in
which the person lacks a protein needed for
muscle function
– A person with the disease eventually loses muscle
control
Sex-Linked Disorders
• Hemophilia- a person’s blood does not clot
properly
– Physical activity can lead to internal bleeding
– Medications can help control hemophilia
Down Syndrome
• A disorder that is the result of an extra
chromosome
– The have a distinctive physical appearance and
have mental impairments that can range from
mild to severe