Gametogenesis Flashcards

1
Q
The development of a human from a zygote to birth is divided into two main periods. Which of the following periods are correct?
A. Embryonic and Postnatal
B. Embryonic and Feotal
C. Postnatal and Prenatal
D. Before life and After life
A

B

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2
Q

Zygote undergoes cell division, migration, growth, differentiation, Reproduction and responsiveness.

Is this True or False?

A

False, because the zygote only undergoes cell division, migration, growth, and differentiation.

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3
Q

The difference between Spermatogenesis and Oogenesis

A

Spermatogenesis – maturation of male gametes.

Oogenesis – maturation of female gametes

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4
Q

What regulates the maturation of sperms and at what stage of life does it begin?

A

The maturation process begins at puberty – regulated by testosterone.

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5
Q

List 3 things you know about spermatogonia

A
  1. lie dormant in seminiferous tubules.
  2. Increase in number during puberty.
  3. Transformed into primary spermatocytes.
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6
Q

Spermatogonia undergo mitosis to form primary spermatocytes. Primary spermatocytes undergo meiotic division to form secondary spermatocytes.
These then go through a second meiotic division to form four haploid spermatids. The 2 haploid spermatids undergo spermiogenesis which transforms them into mature sperms.

is this true or false?

A

Spermatogonia undergo mitosis to form Primary spermatocytes and undergoes meiotic division to form two haploid secondary spermatocytes.
These then go through second meiotic division to form four haploid spermatids. The four haploid spermatids undergo spermiogenesis which transforms them into mature sperms.

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7
Q

Mature sperm cells are active and motile consisting of:

A. Head: contains a nucleus, and has an acrosome which assists in penetration of zona pellucida in fertilization. Neck. Tail: provides motility of sperm.

B. Head: contains a nucleus, Neck, Tail.

C. Head: contains a nucleus, and has an acrosome which assists in penetration of Primordial follicle in fertilization. Neck. Tail: provides motility of sperm.

A

A

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8
Q

Characteristics of Oogonia

A

Oogonia are the primordial germ cells.

Oogonia develop into primary oocytes – no oogonia develop after birth.

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9
Q

DESCRIBE PRENATAL OOCYTES FORMATION.

A

As oocytes form – connective tissue cells surround them forming a layer of follicular cells.
Primary oocyte + Follicular cell layer = Primordial follicle
As primary oocyte enlarges during puberty, primordial follicle becomes primary follicle.
Primary oocyte surrounded by glycoproteinaceous material – zona pellucida
Follicular cells secrete oocyte maturation inhibitor which pauses meiotic process of oocyte

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10
Q

Primary oocytes were suspended in which stage of cell division and that stage if prolonged what gonna happen?

A

prophase – long duration of this phase can lead to meiotic errors

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11
Q

What are Polar bodies ?

A

cells that form based on meiotic divisions, and then degenerate.

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12
Q

Are the following statements about the uterus true or false?

  1. Thick-walled, pear shaped, skeletal organ.
  2. Two major parts: body and cervix.
  3. Body of uterus narrows from the fundus to ilium.
  4. Cervix is the end of the vaginal end of the uterus.
A
  1. FALSE
  2. TRUE
  3. FALSE
  4. TRUE
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13
Q

EXPLAIN WHAT YOU KNOW ABOUT THE Lumen of cervix – cervical canal.

A

Has an opening at each end.
Internal os – communicates with cavity of uterine body.
External os – communicates with the vagina.

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14
Q

Name and explain the three layers of uterus, after that Name and explain the three layers of the thin, internal layer of Uterus.

A

Body of uterus has three layers:
Perimetrium - Thin external layer, firmly attached to:
Myometrium – Thick, smooth muscle layer.
Endometrium – Thin, internal layer.
Three layer of endometrium:
Compact layer – around neck of uterine glands.
Spongy layer – contains bodies of uterine glands.
Basal layer – blind ends of uterine glands.

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15
Q

THE COLLECTIVE NAME FOR SPONGY AND COMPACT LAYERS.

A

compact and spongy layers collectively known as functional layer

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16
Q

Name the layer of endometrium that is not removed during menstruation.

A

Basal layer

17
Q

Uterine tube is divided into:

A

Infundibulum
Ampulla
Isthmus
Uterine part

18
Q

Almond-shaped reproductive glands. Located close to lateral pelvic walls on each side of the uterus. Produce oocytes, oestrogen, and progesterone.

Name the reproductive female organ that matches the following characteristics.

A

Ovary

19
Q

Describe oocyte transport.

A

Fimbriated end of uterine tube comes in close proximity to the ovary.
Finger-like processes of the tube – fimbriae move over the ovary.
Movements of fimbriae “sweeps” secondary oocyte into infundibulum.
The oocyte then passes into ampulla – as a result of peristalsis – causing the oocyte to pass toward uterus.

20
Q

Describe Sperm Transport.

A

Sperm rapidly transported from epididymis to urethra by peristaltic contractions of ductus deferens.
Accessory sex glands – seminal glands, prostate and bulbourethral glands produce secretions added to the semen.
Transport occurs in two phases:
Emission: semen passes to prostatic part of urethra through ejaculatory ducts after peristalsis of the ductus deferens.
Ejaculation: semen is expelled from urethra through external urethral orifice.

21
Q

A. Human oocytes are usually fertilized within——— of ovulation.
B. An oocyte cannot be fertilized after——- it begins degeneration.
C. Most human sperm cells do not survive for more than ——– in the female genital tract.

A

A. 12 hours
B. 24 hours
C. 48 hours

22
Q

Termination of pregnancy – ovarian and menstrual cycle will resume after about 2-3 weeks.

True or False? explain.

A

False, because resume after 6-10 weeks

23
Q

Hormones that produce changes in the ovaries and corpus luteum formation.

A

Follicle-stimulating Hormone & Luteinising Hormone

24
Q
  1. Primary follicle increases in size – adjacent connective tissue forms a capsule. Name that capsule.
  2. Name and explain the 2 layers this above capsule forms.
A
  1. theca folliculi
  2. This capsule forms two layers:
    Theca interna – vascular and glandular layer
    Theca externa – capsule like layer
25
Q

Fill in the missing words.

  1. Follicular cells divide and stratify.
  2. Follicle becomes oval with the ——- in the centre.
  3. Fluid-filled spaces form between cells, fuse to form —— containing ———.
  4. Once antrum forms it is now termed ———.
  5. Primary oocyte pushed to one side of follicle and surrounded by clump of cells called ———-.
  6. Follicle continues to grow until it produces a swelling on ovarian surface – growing follicles produce ———.
A
  1. Oocyte
  2. Antrum, Follicular fluid
  3. Secondary oocyte
  4. Cumulus oophorus
  5. Oestrogen
26
Q
  1. What hormone triggers Ovulation.

2. Expelled secondary oocytes surrounded by what? and together they form what?

A
  1. Triggered by surge in luteinizing hormone (LH).
  2. Expelled secondary oocyte surrounded by zona pellucida and layer of follicular cells – together forming corona radiata.
27
Q

Fill in the missing information about Corpus leutum.
After ovulation.
Walls of —A—– and —B—– are thrown into folds.
Under —-C— influence these develop into corpus luteum – glandular structure secreting –D—— and —–E—-.
Prepares endometrium for implantation of —-F—–.

A
A. Ovarian follicle
B. Theca folliculi
C. LH
D. progesterone
E. Oestrogen
F. Blastocyst
28
Q

What is menstrual phase?

A

Functional layer of uterine wall passes out with menstrual flow. Usually lasts 4-5 days. Blood discharged from vagina is combined with small pieces of endometrial tissue. After menstruation the eroded endometrium is thin.

29
Q

What is proliferative phase?

A

Lasts approximately 9 days – controlled by oestrogen.
Increase in thickness of endometrium and water content.
Repair and proliferation occur in this phase. Early in this phase the surface epithelium reforms and covers endometrium. Glands increase in size and spiral arteries elongate.

30
Q

What is Luteal phase

A

Lasts approximately 13 days – influenced by LH, progesterone and oestrogen.
Progesterone stimulates glandular epithelium to secrete a glycogen-rich material.
Glands become wide, tortuous and saccular – Endometrium thickens.
Spiral arteries grow into superficial layer and become coiled – Lacunae develop.
If fertilization does not occur:
Oestrogen and progesterone levels fall – secretory endometrium enters ischaemic phase.
Menstruation occurs.

31
Q

What is Ischemic phase

A

Occurs when oocyte not fertilized.
Spiral arteries constrict – endometrium has pale appearance.
Constriction occurs due to decrease in hormone production
Resulting in stoppage of glandular secretion and shrinking of endometrium.
Towards end of this phase the spiral arteries constrict for longer periods – resulting in ischemic necrosis in superficial tissues.
This is followed by rupture of blood vessels – high blood flow also causes pieces of endometrium to detach and this flows into uterine cavity and through vagina