Transcript human reproduction

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The process of meiotic cell division in a
human male usually forms
one diploid cell, only
four diploid cells
one monoploid cell, only
four monoploid cells
Castle learning “Reproduction”
Structure that is responsible for
storing sperm before leaving the
organism
•A.K.A. sperm ducts
•Tube used for sperm transport
•Merges with the urethra
A tube that is responsible for two functions:
1.Elimination of urine
2.Elimination of semen
Leads to the outside of the body
Located in the center of the penis
Male sex organ
Extends off of the lower abdominal cavity
Consists of erectile tissue
Function – deposition of the semen
inside the female reproductive
tract
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Produce and secrete a nutrient
rich fluid called seminal fluid
When the sperm and the seminal fluid
combine it forms a fluid known as semen
Which process is represented by the diagram?
1. fertilization
2. production of gametes
3. cloning
4. evolution
A male sex hormone is produced within
1. structure A
2. structure B
3. structure E
4. structure F
When asked to relate the terms
sperm, scrotum, testes, and
zygote, a student wrote the
statements below.
(A) They all contain homologous pairs of chromosomes.
(B) The location of the testes within the scrotum aids in the
production of sperm needed for zygote formation.
(C) Mitotic cell division in involved in the formation of the
testes and scrotum, and meiosis is involved in the production
of sperm, which is involved in the formation of a zygote.
(D) Formation of the testes, scrotum, and sperm occurs in
human males; zygote formation occurs in females.
Which statements are correct?
1. A, B, and D, only
2. B, C, and D, only
3. B and D, only
4. A, B, C, and D
Castle learning “Reproduction”
Reproductive systems
Two versions:
•Male reproductive system
•Female reproductive system
The term gonads
refers to the ovaries in females
and testes in males
Do Now: Label the diagrams below
•Are egg-producing reproductive organs
• often found in pairs
•Ovaries in females are homologous to
testes in males
Ovaries are oval shaped and, in the
human, measure approximately 3 cm
•Contain approximately 250,000 immature
eggs, called follicles, at birth
•Once follicles mature and are released
they are called ova/ovum.
A.K.A. oviducts and uterine tubes
two very fine tubes leading from the ovaries
of female mammals into the uterus
In humans, the Fallopian tubes are about 7–
14 cm long and
as “thick” as three strands of hair
Function: Transport egg to the uterus
•A.K.A. the womb
•Muscular organ
•Connected to the
fallopian tubes and the
vagina
• Outside of pregnancy, its size in humans
is several centimeters in diameter
•The main function of the uterus is to
accept a fertilized ovum which becomes
implanted into the uterine wall
•derives nourishment from blood vessels
for the developing embryo
The cervix is the lower, narrow
portion of the uterus where it
joins with the top end of the
vagina
During menstruation the cervix stretches
open slightly to allow
the uterine wall to be shed
During childbirth, contractions of the uterus
will dilate the cervix up to 10 cm in diameter
to allow the fetus to pass through.
A.K.A. Birth Canal
is a fibromuscular tubular tract leading
from the uterus to the exterior of the body
in female mammals
Functions: acts as a
canal for fetus to
exit the mother and
location for semen
to be deposited
Summary
• Which two glands in the diagram produce
gametes?
• glands A and B
• glands B and E
• glands C and F
• glands E and F
This structure releases estrogen
into the circulatory system.
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structure 1
structure 2
structure 3
structure 4
structure 5
Menstruation involves the periodic
shedding of the lining of
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Structure 1
Structure 2
Structure 3
Structure 4
DID YOU KNOW>>>the ovum is the
largest cell of the body (with a
diameter of about 0.5 mm)
Reviewbook pg. 66 #11-21
is a recurring cycle of physiologic
changes that occurs in reproductive
age females of several mammals
28 days
Frequency – approximately ___________
Named is derived from the latin word
menses which means month
The menstrual cycle is under the control
of the hormone system and is necessary
for reproduction
The Endocrine system
The menstrual cycle may be divided
into several phases. The length of each
phase varies from woman to woman
and cycle to cycle.
Phases of the menstrual cycle
• Menstruation
• Follicular phase
• Ovulation
• Luteal phase
•Menstruation is also called
menstrual bleeding, a period
•regular menstruation that lasts
for a few days usually 3 to 5 days
•the average blood loss during
menstruation is 35 milliliters
1. the lining of the uterus thickens
2. stimulated by gradually increasing
amounts of estrogen
3. Follicles in the ovary begin developing
4. after several days one or occasionally two
follicles become dominant (non-dominant
follicles atrophy and die)
5. The dominant follicle releases an ovum or
egg in an event called ovulation
1. When the egg has matured, it triggers
the release of luteinizing hormone (LH).
2. In the average cycle this LH surge starts
around cycle day 12 and may last 48
hours.
3. The release of LH matures the egg and
weakens the wall of the follicle in the
ovary. This process leads to ovulation:
the release of the now mature ovum
4. The egg is swept into the fallopian tube
After ovulation, the residual follicle
transforms into the corpus luteum
The corpus luteum is the solid body
formed in the ovaries
This corpus luteum will produce
progesterone in addition to estrogens
for approximately the next 2 weeks
Progesterone plays a vital role in preparing
the uterine wall to wither support a
pregnancy or to be secreted
In the absence of a pregnancy,
progesterone levels fall. This will set the
stage for the next cycle…..
Progesterone withdrawal leads to
menstrual shedding
If fertilization of an egg has occurred, it will
travel to the uterine cavity and implant itself
6 to 12 days after ovulation.