Lecture #11 Flashcards Preview

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Flashcards in Lecture #11 Deck (46):
1

Define biparental and Gametes

Biparental- means offspring receive genes from two parents

Gametes - sex cell produced by each parent

2

Gametes are combined to form a?

zygote (or a fertilized egg)

3

Sperm

- has motility
- parent with Y chromosome is male
- produced in testes

4

Egg (ovum)

- female parent, lacking Y chromosomes

5

Male reproductive system's Purpose

produce sperm and introduce them into the female body

6

Female reproductive system's purpose

produce eggs, receive sperms, provide gametes' union, carries fetus, and nourishes offspring

7

Puberty

-occurs during the first few years of adolescence
maked by periods in girls at age 12
and ejectulation in boys age 14

8

Physical Characteristics of Puberty

1. Growth of sex organs
2. Testosterone stimulates generalized body growth
3. Erythropoiesis, basal metabolic rate, and increase in appetite
4. Pubic hair, axillary hair, and facial hair develop in response to
dihydrotestosterone (DHT)
5. Stimulates sperm production and libido (sex drive)

9

What is GnRH

as hypothalamus matures it produces GnRH, which stimulates the anterior pituitary cells to secrete
1) FSH
2) LH

10

FSH

Follicle-stimulating hormone responsible for stimulating sustentacular cells that secrete androgen-binding protiens that bind to testosterone (stimulates spermatogenesis)

11

LH

Luteinizing Hormone (LH:)
stimulates interstitial cells in testes to produce testosterone

12

Spermatogenesis

process of sperm production in seminiferous tubules of testes

13

If a male animal is castrated would you expect the FSH and LH levels to rise, fall, or be unaffected

levels to rise because the testes are removed because testosterone is none longer there so the negative feedback loop isn't there

14

What does Testosterone do?

- sustains the male reproductive tract
- sperm production
- sex drive (libido)
- testosterone secretion decline with age

15

What is male andropause (climacteric)

- declining reproduction
- drop in testosterone and inhibin triggers rise in FSH and LH
mood changes and hot flash

16

Mitosis

one parent cell produce 2 daughter cells that are genetically the same

17

Meiosis

duplication and crossing over of genetic information

18

Spermatogenesis

spermatogonia lie along periphery of seminiferous tubules and is divided by mitosis

19

Type A spermatogonium

one daughter cell of each division remains in the tubule as stem cell

20

Type B Spermatogonium

other daughter cell migrate away from wall and is on its way to producing sperm

- becomes a primary spermatocyte, undergoes mitosis which gives rise to two secondary spermatocytes, then undergoes meiosis II dividing into two spermatids

21

Sperm Head Contains

A head:
- nucleus (haploid set of chromosomes)
- Acrosomes - enzyme cap that contains enzymes that penetrates the egg

22

Sperm Tail contains

- Mitochondria (in mid piece)
- Axoneme (flagella)

23

Seminal Fluid

90% of fluid expelled during orgasm
- water
- lubricant: mucus
- Buffers: neutralizers and nutrients
-Prostaglandin: smooth muscle contraction

24

Puberty in Females

- triggered by an increase of GnRH, which stimulates anterior pituitary FSH and LH

25

Eggs are stored in

the follicles within the ovary

26

FSH stimulation in Females

FSH stimulates ovarian follicles and they secrete estrogen, progesterone, inhibin, and androgen

27

Stages of Puberty

1. Thelarche - breast development, earliest signs of puberty

2. Pubarche - apperance of pubic and axillary hair, sebaceous glands, and axillary g;ands

3. Menarche - first menstrual period, dependent on body fat

28

Climacteric

- midlife change in hormone secretion
- begins when 1000 follicles left
- cholesterol levels increase
- skin becomes thinner
- bone mass decreases

29

Menopause

cessation of menstrual cycles
- 45-55
- Menopause is considered complete once there is no menstruation for 1 year

30

Hormone Replacement Therapy (HRT)

low doses of estrogen and progesterone to relieve some of these symptoms
- risks and benefits still being debated

31

What is Oogenesis

is egg production
- produces haploid gametes by meiosis
- release 1 egg each month

32

Ovarian Cycle

three principals steps
- follicular phase, ovulation, and luteal (after ovulation) phase

whats left over is corpus luteum is progesterone and estrogen

33

Control of Ovulation by pituitary and ovarian hormones

POSITIVE FEEDBACK LOOP

1) maturing follicle secretes estradiol

2)Estradiol stimulates hypothalamus and anterior pituitary

3)Hypothalamus secretes GnRH

4) GnRH and estradiol stimulate pititary to secrete LH and FSH

5) Occytes completes meiosis I: follicel rapidly enlarges and then ovulates

34

What is Endometriosis

Growth of endometrial tissue outside of the uterus
- growth peritoneum of pelvic cavity or on surface of ovary
- occurs in 6-10% of women
-causes pain, sometimes infertility
- result from retrograde menstruation (backward flow of menstrual fluid that exits uterine tube)

35

Contraception

Birth Control Pills:
- Maintain high blood levels of estrogen/progesterone which inhibits release of FSH

- most popular among women

- also indicated for amenorrhea (no menstruation) and dysmenorrhea (painful menstruation)

36

Fertility Drugs

1) Clomiphere
- Estrogen Receptor Antagonist
- Stimulates release of FSH, LH and ovulation

2)Gonadotropin (FSH)
- extracted from postmenopausal urine
-stimulates follicles to mature and rupture

37

Define Conceptus:

all products of conception: the embryo or fetus, the placenta, and associated membranes

38

Prenatal Development

Blastocyst: the developing individual is a hollow ball for the first 2 weeks

Embryo: day 16 - week 8

Fetus: week 9-birth

Neonate: newborn -6weeks

39

What are the hormones with the strongest influence on pregnancy?

- Human Chorionic Gonadotropin (hCG)
- Estrogens
- Progesterone
- Human chorionic somatomammotropin

These hormones are secreted by the placenta

40

Terminated Pregnancy

Corpus luteum is important source for first several weeks, if its removed before week 7 the pregnancy terminates

7-17 week the corpus luetum degenerates and the placenta takes over endocrine function

41

Human Chorionic Gonadotropin (hCG)

- secreted by blastocysts and placenta
- in urine 8-9 days after conception
- stimulates growth of the corpus luteum

42

Estrogen

increase 30X by end of gestration
- from corpus luteum for first 12 wks then placenta
- causes tissue growth in fetus and mother (mother's uterus enlarges, mammary ducts, breath growth, widen pelvis)

43

Progesterone

- from placenta and corpus luteum
- prevents follicular development b/c it stops FSH and LH
- stops uterine contractions
- promotes endometrial cells
- stimulates development of acini in breasts

44

Childbirth

7th months, the fetus rotates so its head is down

-fetus is a passive player in its own birth
- explusion achieved by contaction of mother's uterine and abdominal muscles
- fetus chemically by stimulates labor contraction
- sends chemicals when the baby is develop and ready to be born

45

Define Parturation

the process of giving birth marked by the start of true labour contractions

46

Factors that Regulate Uterine Contractility

1. Progesterone and estradiol balance
2. Oxytocin
3. Conceptus may produce chemical stimuli promoting its own birth
4.Uterine Stretching