Chapter 16 and 17 course packet Flashcards Preview

Human Biology > Chapter 16 and 17 course packet > Flashcards

Flashcards in Chapter 16 and 17 course packet Deck (80)
Loading flashcards...
1
Q

The first 22 pairs of sex chromosomes are

A

Autosomes

2
Q

Female sex chromosomes are truly what?

A

Homologous xx

3
Q

What chromosomes do the males have?

A

X and a very short Y

4
Q

What is Sry?

A

Sex-determining Region of the Y chromosome

5
Q

One gene on the Y chromosome is called?

A

Sry

6
Q

When does Sry become active?

A

When the embryo is about 6 weeks old

7
Q

Up to about 6 weeks, both male and female embryos are what?

A

Anatomnically identical

8
Q

If the Sry is present in only XY chromosomes what happens?

A

Germ cells and the cells immediately around them begin to develop into testes at about 7 weeks

9
Q

If the Sry is absent then what?

A

Cells begin to develop into ovaries

10
Q

The cells that become the male gonad (testes), begin to secrete and release what

A

Testosterone

11
Q

What does the releasing of testosterone signal

A

The further developlment of the male sexual organs in the embryo & the male secondary sexual traits at puberty

12
Q

The cells that become the female gonad (ovary), begin to secrete and release what

A

Estrogen & eventually progesterone

13
Q

What does the releasing of estrogen and progesterone signal

A

The further development of the female sexual organs in the embryo & the female secondary sexual traits as puberty

14
Q

What are the 5 male reproductive organs

A

1) 2 testes
2) 2 epididymis
3) 2 Vas deferens
4) 2 Ejaculatory ducts
5) Penis

15
Q

3 Male accessory glands

A

1) 2 Seminal vesicle
2) Prostate gland
3) 2 Bulbourethral gland

16
Q

Function of testes

A

Seminiferous tubules: sperm production; Leydig cells: sex hormones

17
Q

Function of Epididymis

A

Sperm maturation site; & further from the testis, sperm storage

18
Q

Function of Vas deferens

A

Rapid transport of sperm

19
Q

Function of Ejaculatory duct

A

After seminal vesicle, conduction of sperm to the penis

20
Q

Function of the penis

A

Organ of sexual intercourse

21
Q

Function of the seminal vesicle

A

Secretion of fructose & prostaglandins, a large part of semen

22
Q

Function of Prostate gland

A

Secretion of buffers and other substances that become part of semen

23
Q

Function of the bulbourethral gland

A

Secretion of lubricating mucus

24
Q

Where can the Leydig cells be found

A

Found between seminiferous tubules of the testes

25
Q

Fertile males operate w/in what

A

A narrow range of circulating male hormones

26
Q

The meiosis is easily seen when

A

Looking at a cross-section of a seminiferous tubule & moving from the outside in

27
Q

What is the order of the cell (genome) for meiosis

A

1) Spermatogonium (2n)
2) Primary spermatocyte (2n)
3) Secondary spermatocyte (n, but still replicated DNA)
4) Early spermatids (n)
5) Late spermatids (n)
6) Immature sperm (n)
7) Mature sperm (n)

28
Q

What is the meiotic stage for Spermatogonium

A

Mitosis

29
Q

What is the meiotic stage for primary spermatocyte

A

Meiosis 1

30
Q

What is the meiotic stage for Secondary spermatocyte

A

Meiosis 2

31
Q

Location of Spermatogonium

A

Outermost cells within the tubule walls

32
Q

Location of primary spermatocyte

A

Cells just inside the spermatogonia

33
Q

Location of secondary spermatocyte

A

Numerous smaller cells in the mid-wall

34
Q

Location of early spermatids

A

Yet smaller cells nearer to the cavity

35
Q

Location of late spermatids

A

Inner cells still attached to the tubule wall

36
Q

Location of immature sperm

A

Sperm cells now released into the cavity start to head to the epididymis

37
Q

Location of mature sperm

A

In the epididymis, furthest from the testes

38
Q

Included structures of a sperm

A

1) Acrosome
2) Head
3) Midpiece
4) Tail

39
Q

Acrosome of a sperm is

A

Enzyme-rich cap enables sperm to penetrate all the “stuff” around ovum

40
Q

Head of a spermis

A

Important, contains haploid DNA

41
Q

Midpiece of a sperm is

A

Mitochondria supplying ATP’s for microtubule movement

42
Q

Tail of a sperm is

A

Microtubules propel sperm to egg

43
Q

The 5 female reproductive organs are

A

1) 2 Ovaries
2) 2 Oviducts
3) Uterus
4) Cervix
5) Vagina

44
Q

Function of the ovaries

A

Oocyte production & maturation; estrogen & progesterone secretion

45
Q

Function of the oviducts

A

Conduction of oocyte from ovary to uterus, usual site of fertilization

46
Q

Function of the uterus

A

Chamber of embryo & fetal development, myometrium & endometrium

47
Q

Function of the cervix

A

Narrowed entry in uterus, secretes mucus which enhances sperm movement into uterus & forms a bacterial barrier after fertilization

48
Q

Function of the vagina

A

Organ of sexual intercourse, birth canal

49
Q

Estrogen is secreted by

A

The ovaries

50
Q

Both FSH & LH are involved in negative feedback loops just like in the male, except the females hypothalamus is sensing

A

Circulating blood levels of estrogen & progesterone

51
Q

During the menstrual cycle while the GnRH from the hypothalamus stimulates the anterior pituitary to secrete FSH & LH, there is a specific

A

Mid-cycle surge of LH that triggers ovulation at about day 14 of the cycle

52
Q

What are the 3 phases of menstrual cycle

A

1) Follicular phase
2) Ovulation
3) Luteal phase

53
Q

Follicular phase is

A

Days 1-5 Endometrium breaks down, menstruation; low estrogen, progesterone, FSH LH
Days 6-13 Hypothalamus: increase GnRH, anterior pituitary: increase FSH & LH, to maturation of one follicle to estrogen increase to gradual thickening of endometrium
Day 13 & midcycle surge of LH

54
Q

Ovulation phase

A

Day 14 Secondary oocyte relseased from ovary; FSH & LH decrease; estrogen stabilizes, progesterone begins to increase

55
Q

The luteal phase is

A

Day 15-28 Corpus luteum established, estrogen secretion is maintained & progesterone increases, Endometrium thickens & ripens for implantation of fertilized egg

56
Q

If no pregnancy occurs during the phases what happens

A

Back to day 1 as corpus luteum degenerates, decrease of estrogen & progesterone levels

57
Q

In the female fetus several million primary oocytes will enter

A

Meiosis 1 but stop before meiosis 1 is complete

58
Q

At birth, primary oocytes number is about what

A

2 million

59
Q

At age 7, only how much oocytes remain

A

About 300,000 remain still in a state of arrested meiosis 1 (prophase 1)

60
Q

At puberty, meiosis will resume what at a time

A

One oocyte at a time starting with the first menstrual cycle

61
Q

How many oocytes will develop and be released until menopause

A

About 400-500

62
Q

What is the order for the cell (genome)

A

1) Primary oocyte in primordial follicle
2) Primary oocyte in maturing follicle
3) Secondary oocyte in mature follicle
4) Secondary oocyte
5) Secondary oocyte will actually not undergo meiosis 2 until sperm penetrates into cytoplasm

63
Q

Meiotic stage for Primary oocyte in primordial follicle

A

Arrested meiosis 1

64
Q

Meiotic stage for Primary oocyte in maturing follicle

A

Arrested meiosis 1

65
Q

Meiotic stage for Secondary oocyte in mature follicle

A

Only meiosis 1 completed

66
Q

Meiotic stage for secondary oocyte

A

Only meiosis 1 completed

67
Q

Characteristic of primary oocyte in primordial follicle

A

Very few follicular cells surround oocyte

68
Q

Characteristic of primary oocyte in maturing follicle

A

Zona pellucida then antrum develops

69
Q

Characterisic of secondary oocyte in mature follicle

A

1st polar body formed, follicle protrudes slightly from ovarian surface

70
Q

Characteristic of secondary oocyte

A

Ovulates when LH triggers follicle ruptures

71
Q

When are the 2nd & 3rd polar bodies formed

A

When the sperm penetrates into the cytoplasm

72
Q

What is required for male fertilization

A

High count of motile/functional sperm

73
Q

What is required for female fertilization

A

Functional menstrual cycles w/ regular ovulation, open oviducts for conductiong both egg and sperm, and ovulations timed with monthly endometrial thickening

74
Q

What are the 3 birth control aspects

A

1) Correct & consistent use of most contraceptive methods results in a low risk of pregnancy
2) Contraceptives pose little risk to a user’s health, although personal risk factors should influence personal choice
3) Half of all pregnancies are unintended (~3 million each year)

75
Q

The hypothalamus senses what?

A

blood vessels of testosterone & inhibin

76
Q

If blood levels are LOW what happens

A

If blood levels low, hypothalamus will secrete GnRH

77
Q

The anterior pituitary secretes what into the blood stream

A

Anterior pituitary secretes FSH & LH into blood stream

78
Q

Which of the male organs are set in motion

A

Testes “set in motion”

79
Q

If testes or overstimulated what happens

A

If testes are overstimulated, sertoli cells will secrete inhibin for HIGH sperm counts

80
Q

One the hypothalamus senses the low blood levels what happens next

A

Then turn GnRH down decreasing FSH & LH secretion which then decreases testosterone secretion & sperm production by the testes