B STR 301 Study Guide - Final Guide: Membranous Urethra, Ejaculation, Spongy Urethra
27 Jun 2018
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WEEK 10 OBJECTIVES
1. Explain the functions of the reproductive systems
- Production of offspring
oFertilization of egg & sperm
- Basic reproduction
oMale and female both produce HORMONES and GAMETES
Eggs (females)
Largest cells in the body
Non-motile
oDependent on fluid currents
Sperm (males)
Small with flagella
Swim and search for the egg
oGametogenesis: gamete production
Very different in females and males
Women are born with all the eggs (oocytes)
oThese are released from the ovaries for about 40 years
oMenopause: end of reproductive cycle
Men manufacture sperm continuously from puberty
oSperm and testosterone diminish with age
2. Explain how meiosis is used to create sperm and eggs (ova)
-Meiosis:
oReduces the number of chromosomes in gametes to half (23)
-Spermatogenesis (production of sperm):
oType A spermatogonium undergoes mitosis forming
One type A spermatogonium
One type B spermatogonium
oThe type B spermatogonium becomes primary
spermatocyte
oPrimary spermatocyte undergoes meiosis I
Forms two haploid secondary spermatocytes
oThe secondary spermatocytes undergo meiosis II
Forms four haploid spermatids
oThe spermatids differentiate into sperm
(spermiogenesis)
find more resources at oneclass.com
find more resources at oneclass.com
WEEK 10 OBJECTIVES
-Oogenesis (oocyte/egg production):
oResults in a SINGLE egg
oStages occur at different times
Birth = about half a million of PRIMARY OOCYTES
Have gone through meiosis I but is “arrested” (stopped) in
that process
Female begins ovulation (puberty)
Meiosis I RESUMES
Produce two cells that have 23 chromosomes
oSecondary oocyte will go on further in the meiosis
process
oOther cell (POLAR BODY) will disintegrate
Donates cytoplasmic material to potential egg
Can also further divide into more polar bodies
Ultimately disintegrate
Secondary oocyte will go through meiosis II once FERTILIZATION
EVENT has occurred
Produce more cells with 23 chromosomes (haploid)
oPolar body discarded
oSUMMARY:
Primary oocyte (diploid) completes meiosis I forming
One SECONDARY OOCYTE (haploid)
One POLAR BODY (haploid)
Secondary oocyte is ovulated and will complete meiosis II if fertilized
Produces and discards a SECOND POLAR BODY
Ovulation of secondary oocyte from mature follicle occurs around day
14 of menstrual cycle
Collapsed follicle becomes corpus luteum
find more resources at oneclass.com
find more resources at oneclass.com
WEEK 10 OBJECTIVES
If there is no pregnancy, it involutes and becomes corpus
albicans (white body)
-Folliculogenesis:
oFollicles enclose the egg (these go through changes as well)
oPrimordial follicles
One layer of cells
oPrimary follicles
Larger eggs
Cells become bigger
oSecondary follicles
Larger eggs
More layers of follicle wall
oTertiary follicle
Pockets of fluid develop inside of follicle
oMature follicle
Large
Filled with fluid
Will erupt and release egg at ovulation
oCorpus luteum
Hormone produce body
Releases estrogen
oSUMMARY:
Primordial follicle: egg and one layer of follicular cells
Primary follicle: larger egg
one layer of cuboidal follicular cells
Secondary follicle: larger egg
Two or more layers of granulosa cells
Tertiary follicle: contains fluid-filled pockets or a single fluid-filled
antrum among granulosa cells
Mature (Graafian) follicle: larger blister bulging from ovary
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Week 10 objectives: explain the functions of the reproductive systems. Production of offspring: fertilization of egg & sperm. Basic reproduction: male and female both produce hormones and gametes. Swim and search for the egg: gametogenesis: gamete production. Women are born with all the eggs (oocytes: these are released from the ovaries for about 40 years, menopause: end of reproductive cycle. Men manufacture sperm continuously from puberty: sperm and testosterone diminish with age, explain how meiosis is used to create sperm and eggs (ova) Meiosis: reduces the number of chromosomes in gametes to half (23) Spermatogenesis (production of sperm): type a spermatogonium undergoes mitosis forming. One type b spermatogonium: the type b spermatogonium becomes primary spermatocyte, primary spermatocyte undergoes meiosis i. Forms two haploid secondary spermatocytes: the secondary spermatocytes undergo meiosis ii. Forms four haploid spermatids: the spermatids differentiate into sperm (spermiogenesis) Oogenesis (oocyte/egg production): results in a single egg, stages occur at different times.
