Transcript CH.12 Power Point

12-2 Objectives
• * What is a system? (See slide 2)
• * What are the individual functions of each
structure within the male reproductive
system?
• * Where are each of the structures located
within the male reproductive system?
sys·tem
noun \ˈsis-təm\ : a group of related parts that
move or work together
: a body of a person or animal thought of as an
entire group of parts that work together
: a group of organs that work together to
perform an important function of the body
Male Reproductive System
12-2
• Puberty-period of sexual development during which
males and females become capable of reproducing.
• Changes at Puberty
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• Fertilization-Joining of an egg cell with a sperm cell.
Structures & Functions of the
MRS
• Testes-Have two major functions
– Produce testosterone
– Produce sperm cells
• Scrotum- Hold the testes outside the body and
regulates the temperature of the sperm cells.
They can’t survive at 98.6 Needs to be slightly
lower!
• Epididymis-”J” shaped tube on the back of each
teste used to store sperm for 2-4 days until they
3 Glands along the MRS which
add fluids to sperm cells to create
the fluid
known
as
semen.
• Seminal Vesicle
• Cowper’s Gland
• Prostate Gland
• Vas Deferens-An 18 inch tube that receives sperm
from the epididymis and runs to the urethra.
• Urethra-Tube which passes through the penis to
the outside of the body. Both urine and sperm
cells pass through the urethra to the outside of the
body but cannot do so at the same time. A valve
closes off the bladder during sexual arousal.
Spermatogenesis
• The process by which sperm are produced.
• FSH, LH, & Testosterone are the 3
hormones responsible for spermatogenesis.
• Approximately 400 million sperm cells are
released during a normal ejaculation. Why?
Disorders of the MRS
• Undescended Testes-when one of the testes
does not drop into the scrotum during the
development process.
• Inguinal Hernia-when part of the intestines
breaks through into the scrotum.
• Prostate & Testicular Cancer-p.281
Female Reproductive System
(12-3)
• Changes at Puberty•
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Structures and Functions of the
FRS
• Similarities between the MRS & FRS?
• Ovaries-Have 2 functions
• Release of female hormones estrogen and
progesterone.
• Produce and release mature egg cells.
Each ovary contains 200,000 egg cells, present from
birth.
Ovulation-Release of an egg cell every 28 days.
More Structures & Functions of
FRS
• Fallopian Tubes-oviducts, carry the released egg
from the ovary to the uterus. Small hairs (cilia)
sweep the egg through the tube. Inside diameter is
no larger than a strand of hair! Where fertilization
takes place.
• Uterus-The womb. The inside lining is called the
endometrium. This is where the fertilized egg
implants.
• Cervix-base of the uterus that leads to vagina.
Disorders of the FRS
• Pre-Menstrual Syndrome-Severe discomfort
before menstruation. Marked by nervous tension,
mood swings, headaches, bloating, irritability,
Believed to be caused by dramatic changes in
hormone levels. Equivalent to?
• Ovarian, Cervical & Breast Cancer-p.288
• Pap Test-Recommended for women over 20
The Menstrual Cycle
• The process by which women produce and
release egg cells.
• 0-14
Endometrium rebuilds
• 14-21 Egg released from ovary &
travel fallopian tube
• 21-28 Endometrium breaks down and
is discharged from body.
12-3 continued…
• Menopause-ovaries slow down hormone
production & no longer release mature egg
cells. Approximately between the ages of
45-55.
• Endometriosis-when the endometrium
grows somewhere other than the uterus.
p.285
Heredity
(12-4)
• The passing on or transmission of biological traits
from parent to child.
• Chromosomes-tiny structures in every cell that
carry info. about the characteristics.
• Each cell in our body contains 23 pairs of
chromosomes. 23 from each sex cell, or parent.
• DNA-Deoxyribonucleic Acid=chemical substance
that makes up chromosomes.
12-4 cont.
• Genes-a section of chromosome that determines a
specific trait. ie) eye color, hair color, straight
hair, curly hair
• Genes are either Dominant or Recessive
• Recessive-are only expressed when another
recessive gene is present
• Dominant-Are always expressed when present
Dominant & Recessive Traits
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• Dominant
Brown Eyes
Curly Hair
Freckles
Dimples
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• Recessive
Blue Eyes
Straight Hair
Blond Hair
Pug nose
Sex Determination
• Among the 23 pairs of chromosomes, 1 pair is the
sex chromosomes.
• All egg cells contain X chromosomes
• 1/2 of the 400 million sperm cells are X, the other
1/2 are Y.
• X,X=Females
• X,Y=Males
• Figure 12-14
Genetic Disorders
• Any abnormal condition that a person inherits
through genes. Defective genes are usually what
cause genetic disorders.
• There are recessive and dominant genetic
disorders. However, most are recessive! What
must happen then for someone to actually have a
genetic disorder? What is a carrier?
Disorders
• Sickle Cell Anemia-Recessive blood disorder.
Abnormally shaped RBC. Frequent among
African Americans. Usually fatal.
• Tay-Sachs-Recessive disorder characterized by
the lack of an important chemical in the brain.
Frequent among Eastern Europeans. Usually fatal
by age 5.
• Cystic Fibrosis-Recessive disorder of the lungs.
Glands produce too much mucus for the lungs to
Sex Linked Disorders
• Recessive disorder that affects the X
chromosomes only of sex chromosome pair.
• Which sex do you think sex linked disorders
are more common in?
• Color blindness and hemophilia are
examples of sex linked disorders.
Down Syndrome
•
Caused by receiving an extra chromosome at the
21st pair.
•
Distinct physical appearance:
– Shortened height and limbs
– Almond shaped eyes
– Rounded face
•
Mental retardation ranging from mild to severe.
Can lead a normal life within reason.