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):
1

The first 22 pairs of sex chromosomes are

Autosomes

2

Female sex chromosomes are truly what?

Homologous xx

3

What chromosomes do the males have?

X and a very short Y

4

What is Sry?

Sex-determining Region of the Y chromosome

5

One gene on the Y chromosome is called?

Sry

6

When does Sry become active?

When the embryo is about 6 weeks old

7

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

Anatomnically identical

8

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

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

9

If the Sry is absent then what?

Cells begin to develop into ovaries

10

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

Testosterone

11

What does the releasing of testosterone signal

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

12

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

Estrogen & eventually progesterone

13

What does the releasing of estrogen and progesterone signal

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

14

What are the 5 male reproductive organs

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

15

3 Male accessory glands

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

16

Function of testes

Seminiferous tubules: sperm production; Leydig cells: sex hormones

17

Function of Epididymis

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

18

Function of Vas deferens

Rapid transport of sperm

19

Function of Ejaculatory duct

After seminal vesicle, conduction of sperm to the penis

20

Function of the penis

Organ of sexual intercourse

21

Function of the seminal vesicle

Secretion of fructose & prostaglandins, a large part of semen

22

Function of Prostate gland

Secretion of buffers and other substances that become part of semen

23

Function of the bulbourethral gland

Secretion of lubricating mucus

24

Where can the Leydig cells be found

Found between seminiferous tubules of the testes

25

Fertile males operate w/in what

A narrow range of circulating male hormones







26

The meiosis is easily seen when

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

27

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

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

What is the meiotic stage for Spermatogonium

Mitosis

29

What is the meiotic stage for primary spermatocyte

Meiosis 1

30

What is the meiotic stage for Secondary spermatocyte

Meiosis 2

31

Location of Spermatogonium

Outermost cells within the tubule walls

32

Location of primary spermatocyte

Cells just inside the spermatogonia

33

Location of secondary spermatocyte

Numerous smaller cells in the mid-wall

34

Location of early spermatids

Yet smaller cells nearer to the cavity

35

Location of late spermatids

Inner cells still attached to the tubule wall

36

Location of immature sperm

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

37

Location of mature sperm

In the epididymis, furthest from the testes

38

Included structures of a sperm

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

39

Acrosome of a sperm is

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

40

Head of a spermis

Important, contains haploid DNA

41

Midpiece of a sperm is

Mitochondria supplying ATP's for microtubule movement

42

Tail of a sperm is

Microtubules propel sperm to egg

43

The 5 female reproductive organs are

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

44

Function of the ovaries

Oocyte production & maturation; estrogen & progesterone secretion

45

Function of the oviducts

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

46

Function of the uterus

Chamber of embryo & fetal development, myometrium & endometrium

47

Function of the cervix

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

48

Function of the vagina

Organ of sexual intercourse, birth canal

49

Estrogen is secreted by

The ovaries

50

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

Circulating blood levels of estrogen & progesterone

51

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

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

52

What are the 3 phases of menstrual cycle

1) Follicular phase
2) Ovulation
3) Luteal phase

53

Follicular phase is

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

Ovulation phase

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

55

The luteal phase is

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

56

If no pregnancy occurs during the phases what happens

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

57

In the female fetus several million primary oocytes will enter

Meiosis 1 but stop before meiosis 1 is complete

58

At birth, primary oocytes number is about what

2 million

59

At age 7, only how much oocytes remain

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

60

At puberty, meiosis will resume what at a time

One oocyte at a time starting with the first menstrual cycle

61

How many oocytes will develop and be released until menopause

About 400-500

62

What is the order for the cell (genome)

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

Meiotic stage for Primary oocyte in primordial follicle

Arrested meiosis 1

64

Meiotic stage for Primary oocyte in maturing follicle

Arrested meiosis 1

65

Meiotic stage for Secondary oocyte in mature follicle

Only meiosis 1 completed

66

Meiotic stage for secondary oocyte

Only meiosis 1 completed

67

Characteristic of primary oocyte in primordial follicle

Very few follicular cells surround oocyte

68

Characteristic of primary oocyte in maturing follicle

Zona pellucida then antrum develops

69

Characterisic of secondary oocyte in mature follicle

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

70

Characteristic of secondary oocyte

Ovulates when LH triggers follicle ruptures

71

When are the 2nd & 3rd polar bodies formed

When the sperm penetrates into the cytoplasm

72

What is required for male fertilization

High count of motile/functional sperm

73

What is required for female fertilization

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

74

What are the 3 birth control aspects

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

The hypothalamus senses what?

blood vessels of testosterone & inhibin

76

If blood levels are LOW what happens

If blood levels low, hypothalamus will secrete GnRH

77

The anterior pituitary secretes what into the blood stream

Anterior pituitary secretes FSH & LH into blood stream

78

Which of the male organs are set in motion

Testes "set in motion"

79

If testes or overstimulated what happens

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

80

One the hypothalamus senses the low blood levels what happens next

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